England and Wales High Court (Patents Court) Decisions

(BIRMINGHAM DISTRICT REGISTRY)

CHANCERY DIVISION

BEFORE:

BETWEEN:

Mr Henry Carr QC and Mr Giles Fernando (instructed by Messrs. Wragge & Co., Birmingham) appeared on behalf of the Plaintiff.

Miss Denise McFarland (instructed by Messrs. Eversheds, Nottingham) appeared on behalf of the Defendants.

The Hon Mr Justice Neuberger

Dated: 13th November 1998

2. This action concerns UK Patent number 2,095,595 ("the Patent in suit") of which the plaintiff, Hadley Industries PLC ("Hadley"), is the proprietor. The defendants are Metalsections Limited ("Metalsections") and Metsec (UK) Limited ("Metsec UK"); these two companies are within the same group, and I shall refer to them together as "Metsec". Hadley contends that Metsec have infringed the Patent in suit; Hadley also seeks to amend the Patent in suit. Metsec not only deny infringement; they also apply to revoke the Patent in suit alleging insufficiency, anticipation and obviousness. In the event that the Patent in suit is held to be valid and would otherwise be held to be infringed, Metsec raises defences based on Section 64 of the Patents Act 1977 ("Section 64") and estoppel.

4. The Patent in suit claims a priority date of 26th March 1981. It is concerned with the production of metal or plastic sheet, which is stronger than the plain sheet material from which it is made and which can be formed into other shapes. It contains a product claim to sheet material, and also a process claim to a method of producing formations in such material. The description begins by stating that "the present invention relates to continuous processing of metallic and plastics materials". The description makes it clear that the expression "sheet material" refers to a large number of different configurations of material (albeit that nothing in the present case hangs on the meaning of that expression). The description goes on to acknowledge that it is known that the strength of sheet material (by which is meant resistance to bending) can be increased by corrugating (which only increases strength in the direction of the corrugations) and by providing discontinuous formations both in longitudinal and in transverse directions through a pressing operation.

5. Claim 1 is a product claim. Although it is set out as a single continuous paragraph, it was divided into features both in evidence and in argument, and it will assist in understanding the nature of the Claim and, indeed, in analysing the arguments, if I set it out in that way. It is in these terms:

6. I shall refer to Claim 1 of the Patent in suit as "Claim 1".

7. Claims 2 to 5 add nothing to Claim 1 for the purpose of these proceedings. In summary form, it is Hadley's case that the projections described in Claim 1 essentially increase the strength of the plain sheet material by local stretching, and do so without significant reduction in the length of such sheet material, and in such a way that it can still be roll-formed into a section. The advantage of this is that a lower gauge (sc. thickness) of material can be used to achieve a particular standard of strength; this, contends Hadley, is to be contrasted with corrugation, whereby, in economic terms, the gained strength from corrugating is, completely or to a substantial extent, offset by the need for an increase in the quantum of material due to the corrugating.

9. I have added the dimensions "a" and "b" to the figure: feature (e) of Claim 1 requires the height of dimension a to be twice that of dimension b.

10. Feature (g) of Claim 1 is best understood by referring to Fig. 5 of the Patent in suit:

11. The pitch along rows is the distance between e.g. points 26 and 28, and the pitch across rows is the distance between e.g. points 28 and 29.

12. I turn to Claim 6 which is a process claim. Claim 6 was also separated into features for the purpose of argument and evidence; I shall take the same course here. However, unlike Claim 1, Claim 6 is the subject of applications to amend. As there are two applications to make amendments (to which I shall respectively refer as the proposed "amendments" and "re-amendments") it is sensible to set out Claim 6 in its final proposed form, with Hadley's proposed amendments set out in italics; the proposed re-amendments, are the deletions. Subject to those qualifications, Claim 6 is in the following terms:

13. Save where the contrary is stated I shall refer to Claim 6 of the Patent in suit as proposed to be amended as "Claim 6" and in its current form as "the present Claim 6".

14. Claims 7 to 13, like Claim 6, are process claims, but, again, it does not seem to me that they take matters further in relation to the points at issue in the present case.

15. The process described in Claim 6 contemplates a series of sequential steps, the last of which is the formation of the material (already bearing the strengthening formations as a result of the initial steps) into the required shape, such as a channelled section, by a further device or further devices which acts or act at substantially the same speeds as the rollers. In this connection, it is perhaps helpful to illustrate this by reference to Fig. 2 of the Patent; in which 17 and 19 are the "mating components":

Fig. 1 is, as it were, a "close-up" of the rolls shown as 17 and 19 on Fig. 2, at the point where the metal or plastic sheet is going through the rolls.

16. As I have already mentioned, Hadley emphasises the concept of local stretching, referred to in feature (b) of Claim 1 and feature (c) of Claim 6 as being of considerable significance in relation to these proceedings. It is explained in the description of the Patent in suit in the following way:

17. The description then goes on to explain how the tooth which projects from the forming roll into the sheet material "is engaged to the maximum displacement of that part of the sheet material relative to adjacent parts of the sheet material", and how the formations of the teeth on the forming rolls are such to enable the projections to be of the necessary depth. In other words, the concept of "local stretching" involves stretching that part of the material in which the projection is formed, rather than stretching the whole of the material, and that this is achieved by having an appropriate separation, or clearance, between the two forming rolls (including any teeth or grooves). This clearance is said to allow, indeed to enable, the projections to be formed by local stretching; the clearance is such that the material being formed can effectively flow into the gap when the projection is made by the tooth from one roll into the equivalent groove of the mating roll. The stretching is local because the portion of the sheet material to be formed into the projection is effectively isolated as a result of appropriate gripping between the two rolls.

19. As in any case such as the present, where obviousness is in issue, it is necessary to ascertain the nature and extent of the common general knowledge as at the priority date, in this case 26th March 1981.

20. Miss Denise McFarland, who appears on behalf of Metsec, says that she does not disagree with the law as summarised by Mr Henry Carr QC (who appears on behalf of Hadley with Mr Giles Fernando) as to what constitutes common general knowledge, as a matter of principle. However, I think that there may be a difference, at any rate of emphasis, between the parties on this issue. I therefore briefly deal with the principles, before turning to their application to the facts of the case.

23. The alleged invention in the Patent in suit involves producing formations in metal, by a technique known as cold roll forming. This technique, which has been well known since the 1930's, involves forming the metal, while cold, by passing it in sheet form (usually in long strips fed from a coil) through a number of rollers, which are usually paired and designed so that, as the strip passes from one set of rollers to another, it is gradually formed into a profile shape (normally a box or "C" shape), after which it is cut to length.

24. As at the priority date, there were three types of formation which it was well known could be produced in sheet metal, namely corrugating (also known as ribbing), knurling and embossing. Corrugating involves rolling a number of ribs into the surface of the metal, primarily to strengthen it. The process by which this is achieved is normally cold roll forming. The best known example is metal corrugated sheet, which has been manufactured since the mid-1930's.

25. Knurling involves creating indentations in the surface of material in a lathe. Thus, if it is desired to make a gripping or non-slip surface on a metal bar, the bar is passed between a pair of rollers, made of harder metal and bearing projections, which press in to the surface of the bar causing indentations by displacing the metal. The projections displace metal sideways, rather than pushing projections through to the other side of the sheet. The technique has been known about since the mid-1960s, but was further developed in the late 1970's, so that one knurling roller had teeth and the other had corresponding depressions: the purpose of this was to reduce wear on the teeth. Knurling was not generally known, or undertaken, to give increased strength to the metal itself; indeed it was normally only applied to those areas of sections where fixings would be used (because the purpose of the knurling was to avoid slippage in relation to such fixings). It is right to add that the evidence in this case (which I discuss more fully below) appears to confirm that knurling does not significantly increase the structural strength of the metal compared with its strength before it is knurled.

26. Embossing involves compressing the metal between two rollers in order to reduce its thickness beyond its ultimate tensile strength into the purely plastic range; it is a compression process which uses significant force to squeeze the material between two rollers (one of which has some sort of projection) whereby the pattern on the roller is transferred on to the surface of the material. Normally, embossing produces a comparatively shallow pattern, around 0.25mm deep. Embossing, which has been known since the early 1950s, was known to result in increased stiffness, but it was not generally known or thought to result in significantly increased strength although there was some published material suggesting it could, in some circumstances, do so. Again, the fact that embossing does not normally result in significantly increased strength is supported by the evidence to which I refer below. Embossing normally results in the cross sectional area of the metal being reduced.

27. Not only was cold rolled forming of metals well established as common general knowledge as at the priority date, but so was the method of doing so by using "male" and "female" mating rolls (i.e. mating rolls with respectively projections and corresponding indentations) to deform plain sheet metal passing between them. Additionally, there was a general appreciation that the formation of sheet metal created a hardening effect. Corrugating, knurling and embossing were, as I have mentioned, clearly within common general knowledge, but only corrugating was generally understood to have the effect of significantly strengthening metal. As stated in the description in the Patent in suit, the increased strengthening effected by corrugating was substantially set off in financial terms by the fact that an increased amount of metal was involved. Additionally, corrugating has, and was perceived to have, the disadvantage of only increasing strength in one direction.

28. The essential objective of the Patent in suit is to effect strengthening in two dimensions in such a way as to enable a lower gauge of metal to be used, so that one avoids the attendant cost-saving of the strengthening being set off by a reduction in the length of the material. I am satisfied that, as at the priority date, it was not part of the common general knowledge that any the three processes to which I have referred, namely corrugating, knurling or embossing, could be used to achieve that composite objective. The only one of those three processes which, at least so far as common general knowledge was concerned, was used for strengthening metals was (as I have mentioned) corrugating, and that process strengthens metal in one dimension, and does not have the economic benefit which is the aim of the Patent in suit. Although knurling was certainly generally known, and has similar features to the teaching of the Patent in suit, as they both involve introducing projections into sheet metal, there are important distinctions. First, it was, in my judgment, not part of common general knowledge that knurling would significantly strengthen sheet metal; in addition, the idea of knurling with a view to minimising the reduction in the length of the metal, or by means of specifically localised stretching, was no part of common general knowledge. Additionally, knurling as generally understood and undertaken as at the priority date, did not involve making projections which were as deep as described in feature (e) of Claim 1.

29. So far as embossing is concerned, Mr Deeley, who was closely involved with the invention (if such it be) taught by the Patent in suit, and who was put forward by Hadley both as a witness of fact and an expert witness, suggested that it would have been common general knowledge, as at the priority date, that embossing could be used to increase the strength of metals. However, Mr Andrews, (called as an expert witness by Metsec) who was in the business of manufacturing and repairing rolls and pressed tools between 1968 and 1977, and who has, since then, been closely involved in cold roll forming, said that, at any rate in 1981, by which time he had been involved in the relevant art for some 12 years, he did not appreciate that embossing metals could be used to increase their strength. Mr Andrews was undoubtedly a man skilled in the relevant art, and the fact that Mr Deeley apparently believed that embossing could strengthen metal does not persuade me that this information was common general knowledge in 1981. Quite apart from this, there is no evidence to suggest that it was common general knowledge that embossing could be used to reduce the quantity of metal needed for a particular task by increasing the strength without a concomitant decrease in length.

30. The above discussion as to common general knowledge is limited to metals, and does not extend to plastics, which are also within the ambit of the Patent in suit. During the course of the hearing, much less evidence and argument was given over to plastics, and, indeed, the only substantial issue between the parties with regard to the inclusion of plastics in the Patent in suit arises from the first of Metsec's two arguments on sufficiency. Accordingly, I propose to deal with plastics when discussing the arguments on insufficiency.

32. Metsec advance two arguments on insufficiency. The first applies both to Claim 1 and to Claim 6, and relies on the fact that both those claims refer to plastics as well as metal. The second insufficiency argument relates only to Claim 6, and in particular to the aspect of the Claim contained in the proposed amendment to feature (f).

34. Plastics

35. As to the insufficiency argument which is based on the inclusion of plastics in the Patent in suit, Miss McFarland argues that the Patent in suit makes no distinction so far as the claimed properties of the product, or the claimed nature of the process, are concerned, between plastics and metal. There is simply no teaching, she contends, as to plastics.

36. On this issue, Hadley called a plastics expert, Mr Harris, and Metsec did not call an expert, although one of its witnesses had had experience of plastics in the past. Mr Harris has had some fifty years experience of plastics, and stated in his evidence in chief that he considered that there was "sufficient teaching in the ... patent to apply the invention to plastics and materials". He also indicated that the only further information necessary would be the identity of the plastic materials and the conditioning of the plastic before it is to be put through the rollers. He said that the process claim would have to be used on a plastic in a certain state, namely viscous and extruded, rather than rigid and brittle, and that this would have been "obvious to anyone with any experience of plastics". He also stated in chief that he considered that, if an appropriate plastic in an appropriate state were stretched according to the process claim, "the resulting plastic would have a strength, as measured by its subjecting the material to an increased bending load until permanent deformation occurs, which would be at least 10% greater than the strength of the plain sheet plastic material from which it was formed." He also said that he believed that "the length of sheet material issuing from the rollers would not be less than 90% of the length of the initial piece of plain material."

37. In cross examination, Mr Harris expressed the view that it would be easier to work the process taught by the Patent in suit with plastics than with metal, because plastics are generally more easily distorted than metal. Although it was established by Miss McFarland that Mr Harris had never come across the deforming or working of plastics through meshing rollers, although he accepted that it was clear from the patent that the inventors "are obviously not specialists in plastic materials", and although he was not able to give any specific figures or examples, Mr Harris's views as expressed in his witness statement did not seem to me to be significantly shaken as a result of cross examination. Furthermore, although certain of Metsec's witnesses criticised the reference to plastics in the Patent in suit, none of them seemed to have had any significant relevant experience of plastics. Even so, some of them appreciated that it would be necessary to heat most, if not all, plastics before they were subjected to the processes described in Claim 6.

38. Accepting the evidence of Mr Harris, as I do, it appears to me that there is nothing in Metsec's first argument on insufficiency.

39. Increased strength

40. I turn to the other aspect of alleged insufficiency, namely the assessment of increased strength as contained at the end of feature (f) of Claim 6. Metsec contends that the concept of the "point of permanent deformation" of a material is very specific. It is the minimum load which it will take to deform that material in such a way that, upon removal of the load, the material does not revert to its original shape. According to Mr Deeley, this involves subjecting the material in question to a bending load which increased until permanent deformation occurs, and is a standard beam test.

41. However, Professor Rhodes, Professor of Mechanical Engineering at the University of Strathclyde, who gave evidence on behalf of Metsec, stated that the point of permanent deformation of a substance is a precise concept, which is time consuming and difficult to assess. In cross examination, he agreed, indeed emphasised, that the assessment of the point of permanent deformation, in the technical sense as he understood the expression, would be pointless having regard to the objectives of the Patent in suit, and, indeed it would not even be of any interest to a structural engineer.

42. It is common ground that the precise assessment of the point of permanent deformation (in the sense used by Professor Rhodes) of material before and after it has been subjected to the process described in Claim 6 would be of no concern to anyone, not even a structural engineer, who would be interested in the product or process claims in the Patent in suit. It is also clear that the point of permanent deformation, if it is to be precisely assessed in accordance with its strict technical definition, is an expensive and difficult exercise. Given that, when considering and construing a patent, one is not indulging in an academic exercise, it seems to me that one should lean against construing the closing part of feature (f) of Claim 6 in the way for which Metsec contend, namely by reference to the strict, technical meaning of "point of permanent deformation" as identified by Professor Rhodes.

43. In my judgment, in light of evidence of Professor Rhodes and of Mr Walker, also called on behalf of Metsec, such an arid construction of feature (f) of Claim 6 can properly be rejected, given that one should construe the claim, like all parts of the patent, through the eyes of the notional addressee, that is, a person reasonably skilled in the relevant art. Mr Walker worked from 1975 to 1985 for companies in the BPB Industries Ltd group ("BPB"), a very large group of companies, and during that time he worked on rigidising of metal frame posts made of steel - i.e. stud partitions. He explained how, at BPB, they tested the strength of such stud partitions. An hydraulic ram was put up at approximately the middle of the partition, and the load was gradually increased, until the point at which, when the load is removed, the stud partition was permanently deformed, or, to put it another way, the stud had buckled. Mr Walker agreed in terms that the minimum load which resulted in such buckling represented what he, as a practical person, would regard as "the point of permanent deformation". He also stated that the test, as he described it, was easy to carry out, and that, both at BPB and with his current employers he "do[es] [such testing] all the time, every day, even now".

44. To an academic, the tests described by Mr Walker are rather gross and imprecise. Those tests were not dissimilar from the tests carried out on behalf of Hadley in connection with the current proceedings by Mr Castellucci. Professor Rhodes nonetheless castigated Mr Castellucci for, among other things, measuring the yield point rather than the point of permanent deformation. In my judgment, the sort of tests carried out by Mr Walker and by Mr Castellucci are the type of tests which a practical person skilled in the art could expect to carry out, when reading the Patent in suit, and would in due course carry out if he wanted to test the product he had made, or test the result of the process he had assembled, when applying the teaching of the Patent in suit. Indeed, in cross examination, I understood Professor Rhodes, albeit somewhat reluctantly, to concede that this was indeed the case. He emphasised that even such practical and (in academic terms) crude tests had to be "carried out carefully and correctly": although that was intended as a criticism of Mr Castellucci, it suggested to me that the tests he carried out had a sensible purpose. Indeed, it seemed to me that Professor Rhodes accepted that there was a correlation (which I understood to be a mathematical correlation) between the load which (albeit assessed in slightly imprecise terms) would achieve the buckling effect described by Mr Andrews and was assessed by Mr Castellucci in his experiments, and the load which would achieve the point of permanent deformation.

45. In any event, it is to be noted that feature (f) of Claim 6 does not necessarily envisage the point of permanent deformation being precisely identified either in relation to the untreated material or in relation to the treated material. What it requires is a sufficient test to show that the processed material has a point of permanent deformation which is 10% greater than that of the unprocessed material - i.e. a comparative test. Given that Professor Rhodes has indicated that there is a correlation between the load which achieves the buckling effect i.e. the yield point and the load which achieves the point of permanent deformation in the academic sense, it appears to me that, if one subjects both the unprocessed material and the processed material to the same tests, namely that described by Mr Andrews (and indeed that carried out by Mr Castellucci in the present case), there is no reason to think that the increased strength of the processed material, as demonstrated by such tests, would not mirror the increased strength if assessed by reference to the point of permanent deformation, as that term is used by academics.

46. In these circumstances, I reject the contention on behalf of Metsec that, where feature (f) of Claim 6 refers to "permanent deformation" it means a point which is difficult and expensive to identify, and of no practical value or interest. It is right to add this. Even if I had concluded that the reference in that feature was to the point of permanent deformation in the strict technical sense, the mere fact that it is said to be difficult and expensive to identify this point would not have persuaded me that, in all the circumstances, Claim 6 would thereby be rendered insufficient. Professor Rhodes did not condescend to details and particulars as to the nature of the difficulties, or to the extent of the expense; I would have required much more in the way of such particulars before being persuaded that there was anything in this point anyway.

48. Metsec rely upon two prior published patents as constituting anticipation of the Patent in suit. These are UK patent application 2,063, 735 ("the 735 Application") and US patent specification 2,986, 193 ("The Howell Specification").

51. The 735 Application

52. The 735 Application was filed on 7th September 1979, before the priority date of the Patent in suit, but was only published (in substantially the terms of the Application) on 10th June 1981, after the priority date. Accordingly, the 735 Application cannot be relied on by Metsec in connection with their case on obviousness (which I deal with below) but it can be relied on in support of their attack based on novelty, albeit subject to Section 2(3) of the 1977 Act.

53. The 735 Application undoubtedly has similarities with the Patent in suit, and, indeed, some of those similarities are, at first sight, very striking. It is concerned with the creation of projections on one face of a sheet metal surface, and it includes two figures, one of which (figure 2) is effectively identical to figure 1 of the Patent in suit, and the other of which appears, at least on the face of it, to be a representation of the first, and most significant, stage of the process claim in the Patent in suit, as it shows sheet metal being passed between the toothed upper roller and a grooved lower roller, thereby causing projections throughout the surface of the metal.

54. In summary terms, the 735 Application teaches the creation of projections on one face of sheet metal, commonly used for flooring and generally for the purpose of being walked on: the purpose of the projections is to reduce the risk of slippage. What the 735 Application discloses, and indeed claims, is an improved method of forming such projections. As I have already briefly described, the forming rolls in the 735 Application have a profile which, viewed along the axis of the roll, includes two involute curves which are arranged symmetrically about a diametrical plane of the corresponding roll, with projections having such involute curves.

55. In relation to Claim 1, it seems to me that there are aspects of the 735 Application which rule it out as constituting anticipation. The 735 Application does not specify any overall thickness of the material, which is scarcely surprising bearing in mind its purpose. However, this means that it contains neither a description of, nor a direction to make, material whose overall thickness is at least twice (or bears any other specific relationship to) the thickness of the material at the point between adjacent projections. Metsec seek to answer this point by referring to the two figures of the 735 Application, which, they suggest, do show that the depth of the projections is twice the overall thickness of the materials. In my judgment, this argument involves an impermissible approach to the proper construction of the 735 Application. On the face of it, the figures on the 735 Application do not appear to be drawn to scale; and nothing in the specification or the claims of the 735 Application suggests that they are drawn to scale. In this connection, I should perhaps refer to Section 125(1) of the 1977 Act which provides, so far as relevant, that:

57. Furthermore, it is to be noted that Claim 1 teaches a minimum extent for the projections, in that they must be at least as thick again as the non-projecting parts of the metal sheet; given that the 735 Application is concerned with metal which is to be walked on, one would have thought that, if the extent of the projections was to be defined at all, it would be subject to a maximum, rather than a minimum. Quite apart from this, there is no reference to "local stretching" or the like in the 735 Application.

58. In my judgment, since there is no teaching of such minimum depth of projection or, indeed, as to local stretching, either in the description or in the Claims, of the 735 Application, and I consider that it is impossible to say (and indeed Miss McFarland does not suggest, as I understand it, that it is possible to say) that a skilled man would so understand in the 735 Application to teach either of the features, I do not consider that it can be said that the 735 Application anticipated Claim 1.

59. In my judgment, it is equally difficult to contend that Claim 6 of the Patent in suit, the process claim, was anticipated by the 735 Application. That application does not purport to disclose projections which are strengthenings: indeed, that is not the purpose of the projections in that Application. When compared to Claim 6, the 735 Application does not refer to any increase in strength, whether by more than 10% or otherwise: again, that is not surprising as it is not the object of the teaching or disclosure of the 735 Application. The same point may be made about the absence of any disclosure in the 735 Application as to the maximum reduction of the length of the material following its treatment in accordance with the process described in the 735 Application.

60. It is right to say that Mr Carr raised another reason, which I do not accept, as to why the 735 Application did not anticipate Claim 6, namely that in the 735 Application the sheet is bent before the projections are rolled onto it. First, I am far from persuaded that that difference is of any significance as a matter of fact; secondly, the contention relies on what is shown in one of the Figures of the 735 Application. It does not seem to me that it is permissible to read the 735 Application, which refers neither in the description nor in the claims to the sheet having to be bent before the projections are rolled onto it, as being thus limited, merely because that is how it is shown in one of the two Figures of the application.

61. The Howell Patent

62. The Howell Patent was published in 1961, which was 20 years before the priority date of the Patent in suit. It describes a method for manufacturing curved metal channels, which bear projections over their surface, by passing sheet metal between two rollers. The main purpose of the process is to gather the metal so as to make the channel form an arc; the purpose of the projections is primarily to prevent buckling and wrinkling of the inner surface. In the Howell Patent, the projections are more concentrated in the central section than in the outer sections.

63. Once again, the problem for Metsec's argument, that the Howell Patent anticipated Claim 1, is that the former includes no disclosure that the overall thickness of the material should be at least twice the thickness of the material at the point between adjacent projections. Additionally, there is no disclosure in the Howell Patent of the formation of the projections by local stretching. Indeed, as Mr Carr pointed out, since the purpose of the Howell Patent is to gather the metal in order to curve the sheet into an arc, it must envisage projections which reduce the metal thickness as little as possible. As if that were not enough to defeat the argument that the Howell Patent anticipates Claim 1, there is the teaching in the Howell Patent that the projections are more numerous on the central section than on the other sections: this is quite different from the Patent in suit where it is an integral part of the teaching that the projections are consistently applied throughout the material.

64. When one comes to consider the Howell Patent in relation to the present Claim 6, however, it seems to me that Metsec's argument on anticipation is much stronger. Indeed, I am inclined to the view that it succeeds. The only basis for defeating this aspect of the argument on anticipation which Mr Carr could raise was that the Howell Patent did not disclose the relationship between the pitch of the projections along, and across, the rows. The point was not pursued in any detail at all by either party, either in evidence or in argument. Accordingly, any view I have is somewhat tentative. Nonetheless, at least as at present advised, having heard a comparatively large amount of evidence and argument in relation to the relative importance or otherwise of the various features of the present Claim 6, it does not appear to me that feature (e) was of any particular significance. I am inclined to think, therefore, that the present Claim 6 was indeed anticipated by the Howell Patent.

65. However, once one turns to the proposed amendments to Claim 6, and in particular feature (f), Metsec's case on anticipation appears to me to fall away. While it is right to say that there is reference in one of the claims (namely Claim 4) of the Howell Patent to the stiffening effect of the projections, there is no quantification of any increase in strength. Indeed, strength and stiffness are rather different concepts. Furthermore, if an increase in strength is desired, it would seem to be a positive disadvantage for the metal sheet to be curved, as in the Howell Patent. Additionally, the projections in the Howell Patent do not cover the total surface of the material: in those circumstances, I do not see how it could be said that metal treated in accordance with the Howell Patent could produce an increase in "the strength of the plain sheet material from which it is formed", given that the strength of material will effectively be governed by its strength at its weakest point. Quite apart from feature (f), there is feature (g) of Claim 6: in relation to that, there is nothing in the Howell Patent which suggests, let alone claims, that the metal, as formed in accordance with its teaching, should be no less than 90% of the initial length of the untreated material.

70. Obviousness over common general knowledge

71. So far as the expert evidence on this aspect is concerned, it appears to me that the views of Mr Deeley, on behalf of Hadley, and of Mr Andrews, on behalf of Metsec, support the conclusion that the Patent in suit was not obvious over common general knowledge as at the priority date.

73. So far as embossing is concerned, even if it strengthens metal, it does so by subjecting the metal to much greater pressure than cold rolling and that, as a result the metal becomes plastic: accordingly, projections which are inserted into the metal by embossing would not involve local stretching so much as the plastic mass flowing to make up for increase in surface area. Embossing thus thins the whole sheet, whereas the subject process is largely restricted to localised thinning in the sides of the projections. Further, embossing rolls will not normally involve teeth (because sharp projections are difficult to etch a process which normally follows embossing) which would also substantially inhibit local stretching: contrast the teeth in the Patent in suit.

74. Accordingly, quite apart from the fact that the strengthening effect of embossing (if and when it exists) was no part of common general knowledge, it appears to me that it would work by a different process from that allegedly disclosed by the Patent in suit. Not only was it different, embossing was more expensive, requiring much heavier rolls, and, as I understood it, other specialised and expensive machinery and tooling. Cold rolling did not.

75. As for knurling, although it bears strong superficial physical similarities to the process in the Patent in suit, namely the making of projections in metal (which is then reformed) by cold rolling, the treatment involved, the purpose of the treatment and the knowledge of the effect of the treatment were all quite different. Knurling was only applied to part of the surface; the projections were an anti-slipping device; the projections were much shallower than those taught by the Patent in suit; the strengthening effect of knurling (if it existed) was unknown; local stretching was no part of the process, nor any sort of essential ingredient, of knurling.

76. Mr Deeley further explained that Hadley had not in fact commercially exploited the process claimed in the Hadley Patent, because a subsequent process was developed by Hadley which, according to Mr Deeley, involved using an improved method of projection rolling, and this effectively superseded the process claimed in the Patent in suit. That new process has also been patented, and, according to Mr Deeley, has been widely exploited by Hadley in this country, and indeed throughout the world. The product of this later process is known as "Ultrasteel". Apparently many companies, including Metsec, have taken a licence to use the Ultrasteel process.

77. Mr Andrews also struck me as an honest witness and, like Mr Deeley, he was very experienced in the relevant art by the date of the hearing, and fairly experienced as at the priority date. His evidence in chief was directed primarily to the issue of obviousness over prior art and prior use, and his view on obviousness over common general knowledge was little more than a throw away line. Quite apart from that, it seems to me that, at least on the question of obviousness over common general knowledge, he was effectively "turned" during the course of Mr Carr's cross-examination. Mr Andrews was asked what he would have done if he had been asked in 1981 to devise a process for the production of strengthened metal sections which avoided shrinkage. His answer was that he would have carried out a search of the literature, spoken with others in the industry, and then considered the ideas that his investigative exercise would have thrown up. To my mind, that would have involved going quite a lot further than common general knowledge.

78. The conclusion that the disclosure of the Patent in suit was not obvious over common general knowledge in 1981 derives support from three aspects of the factual evidence which was called.

79. First, around the time that Hadley launched Ultrasteel, March 1993, it appears that Mr James, the General Manager of H E P Cold Rolled Sections Limited (known as "Hepsec"), a subsidiary of Metsec UK, received enquiries for products requiring a heavier knurl. Around the end of 1993 or the beginning of 1994, Mr James sent a pair of knurling rolls ("the Hepsec knurling rolls") to Mr Salt, the Operations Director at the Technology Centre of Metsec UK. Approximately two years before this, Mr Salt had (apparently unknown to his colleagues) been investigating rigidising and he had the idea of strengthening material through the use of ribbing. Although I am not entirely clear on the point, it seems that his interest did not produce anything particularly worthwhile, and his enthusiasm may have flagged. However, it was rekindled by the launching of Ultrasteel and Mr Salt's desire to find a process similar to Hadley's process without infringing their Patent.

80. The first relevant drawing produced by Metsec is dated April 1995. Although there was some evidence from Mr Salt which suggested that there were drawings which had been destroyed, or which only existed upon the computer screen, I am not convinced that that is so. The April 1995 drawing disclosed by Metsec was described by Mr Salt (and indeed by another witness called on behalf of Metsec) as a prototype. The earliest date when any drawing was produced showing rolls to form "Supasteel" as Metsec's allegedly infringing product is called, was March 1996. Thus, both before and for sometime after, Ultrasteel was launched, Metsec personnel were searching for a similar product.

81. Secondly, there was evidence given by Mr Walker, who was employed by BPB as Project Manager (Construction & Insulation) Development of British Gypsum Limited ("British Gypsum") a company in the BPB Group. He confirmed the evidence given by another witness that, from about 1978, British Gypsum had also been searching for a method of reducing gauge without reducing metal length, and that British Gypsum had tried all their suppliers, who, with the exception of Hadley, had failed to come up with a solution.

82. Thirdly, according to Mr James, as at 1981 there had been a desire in the art to reduce the material gauge without a consequent reduction in metal length for many years, a point supported by Mr Deeley.

83. In my judgment, these three aspects of the factual evidence are significant, because, viewed as a whole, they strongly suggest that Metsec, BPB, and, indeed, those in the relevant industry generally, were interested in finding a method of strengthening material, and in particular metal which was to be formed into sections, in such a way as would not involve a substantial increase in the total amount of material needed (as would occur, for instance, with corrugation). The factual evidence also suggests that, until Hadley came up with the alleged invention the subject of the Patent in suit, nobody, at least so far as general common knowledge was concerned, had come up with a solution to the problem. In other words, these three aspects of the factual evidence appear to me to be consistent with the effect of the expert evidence as I understand it, namely that the alleged invention the subject of the Patent in suit is not obvious over common general knowledge.

85. There is, however, force in Miss McFarland's contention that the differences between common general knowledge as to what was "known or used" as at 1981 and that the alleged invention embodied in Claims 1 and 6 of the Patent in suit consist more of the aggregation of various aspects of what was then common general knowledge than of an entirely new concept. Even local stretching must be involved to some extent in most cases where projections are formed in sheet material. However, I do not consider that that means that Hadley fails on the third of Oliver LJ's steps. As I have mentioned, one must be careful if employing wisdom of hindsight, and the thrust of the expert evidence and of the factual evidence relating to Metsec's and British Gypsum's attempts to find a way of avoiding the concomitant loss of length of material resulting from the strengthening process, was telling. These considerations also go to the fourth step identified by Oliver LJ, and, to my mind, make it difficult for Metsec to justify the argument that, given the state of common general knowledge as at 1981, the alleged invention embodied in Claim 1 or Claim 6 was "obvious to the skilled man". In my judgment, in light of the expert and factual evidence, Hadley has established that it was not obvious.

86. Nonetheless I have to confess to some hesitation before reaching this conclusion. The idea of passing sheet metal through a pair of rolls, at least one of which has teeth and the other corresponding teeth or grooves, with a view to making projections into the metal, following which the metal is passed through other pairs of rolls which reshape it, was plainly common practice by 1981. Although it was not expressed precisely in these terms by Miss McFarland, one way of putting Metsec's case might be that the Patent in suit suffers from what is sometimes called parameteritis - i.e. taking a product or process which is common general knowledge and then imposing specific and possibly somewhat artificial requirements (e.g. as in features (e), (f) and (g) of Claim 1 and of Claim 6) or introducing an apparently new concept (e.g. local stretching) to make it appear that an inventive step is involved.

87. In the end, however, bearing in mind the various matters I have mentioned in this section, as well as in the section concerned with common general knowledge, in this judgment, I have reached the conclusion that the alleged invention was not obvious.

88. In these circumstances, Metsec's argument on obviousness over common general knowledge fails, save to the extent that it would succeed, in light of the Howell Patent, in relation to the present Claim 6.

89. Obviousness over prior art

90. As I have already briefly mentioned, Metsec relies on eleven items of prior art; six are patents (and include the Howell Patent) registered before the priority date in the instant case; the remaining five consist of published articles which also all appeared before the priority date. There is force in Mr Carr's submission that reliance on so many separate items of prior art is, at least in general, inappropriate: it can considerably increase the cost and time taken up in preparing for the hearing, and also will add to the length, and therefore to the cost, of the hearing. Of course, in some cases it is appropriate or even necessary for a party to rely upon a large number of instances of alleged prior art, but in the great majority of cases it seems to me that to rely upon as many as ten or eleven is undesirable. During closing speeches (and it may be that it should have been done earlier) I invited Miss McFarland to identify which three citations were, on Metsec's case, the strongest, and she was good enough to identify them. I propose first to deal with those three citations, and then turn to the other eight citations, of prior art.

91. However, before turning to the prior art relied on by Metsec, I should mention the general approach of the expert witness on whose evidence Metsec relied on this aspect, namely Mr Andrews. He prepared a "tick chart" which identified his case as to which of the features of Claim 1 or Claim 6 was already disclosed in each of the alleged items of prior art. As a result of cross examination, two things became tolerably clear. The first was that he treated as disclosed by an item of prior art not only that which was expressly disclosed, but also that which he considered that any person reasonably skilled in the relevant art would have appreciated could be included in, or might be implied into, the relevant item of prior art. Secondly, it would appear that Mr Andrews' conclusion that the alleged invention the subject of the Patent in suit was obvious over the prior art was based on mosaicing two or more of the items of prior art. That is most clear from the following exchange in cross-examination:

92. It would be wrong to go so far as to say that a claim for obviousness over more than one item of alleged prior art is doomed to fail if it depends on mosaicing two or more items of prior art. However, it is fair to say that it is difficult for such an argument to succeed. I turn now to consider each item relied on by Metsec as prior art, turning first to the three which are in the forefront of Miss McFarland's argument.

93. The Howell Patent. While, in his witness statement, Mr Andrews stated that all aspects of Claim 1 were "clearly disclosed in Howell", it seemed to me that he clearly resiled from this at least so far as feature (e) is concerned. He suggested that one of the figures in the Howell Patent, namely Fig. 10, could be treated as a scale drawing, but, as with the 735 Application, that appears to me to be quite inappropriate. In my judgment, and, indeed as it seemed to me, in Mr Andrews's revised opinion, there is no reason to treat the Howell Patent as claiming, or even suggesting, feature (e) of Claim 1 of the Patent in suit.

94. More broadly, and in agreement with the evidence of Mr Deeley, I consider that the step from what is involved in the Howell Patent, namely the selective creation of dimples on an already formed channel for the purpose of making the channel curve, to the concept of covering a flat sheet with strengthening projections which will not bend the sheet and will allow it to be subsequently formed is not obvious, and I reach that conclusion without even going to the specific concept of localised stretching which is involved in Claim 1.

95. The Wogerbauer Patent. This is US Patent Specification No. 3,273,976 granted on 20th September 1966, which describes a process of corrugating metal sheet on a continuous basis, and involves strengthening the sheet partly by use of corrugations and partly by working the metal to increase its yield point. It does describe local stretching (as "stretched zones") and some of the tables included in the description appear to show the depth of the ridges is equal to the thickness of the metal. Furthermore, the process claim in the Wogerbauer Patent produces strengthening formations by a pair of mating components on sheet material which is continuously processed. However, neither of the rolls in the Wogerbauer Patent have teeth: they have longitudinal ridges, and there is therefore no teaching in the Wogerbauer Patent the pitch across and the along rows.

96. Although Mr Andrews said that Claim 1 of the Patent in suit was obvious over the Wogerbauer Patent, he accepted that the latter did not disclose features (d), (f) and (g) of Claim 1, and the effect of his cross-examination was that it did not disclose feature (e) either. He also said in his witness statement that Claim 6 was obvious over the Wogerbauer Patent, but he accepted that features (e), (f) and (g) were not disclosed in it.

97. In my judgment, neither the product claim nor the process claim of the Patent in suit was obvious over the Wogerbauer Patent; they are different ways of hardening metal sheet to increase its yield point. The alleged invention in the Patent in suit involves projections with local stretching; the Wogerbauer Patent involves corrugation. Indeed, the evidence suggests that the projections in the Patent in suit enable the metal to be more versatile, in terms of how it can subsequently be formed, than the process taught by the Wogerbauer Patent. Although the Patent in suit and the Wogerbauer Patent are each concerned to increase strength in both directions, the Wogerbauer Patent does so in a way which would greatly increase both the cost and the complexity of the process, when compared with the Patent in suit.

98. The textured metal articles. These items of prior art consist of two articles, one titled "Textured metal: Bad news for graffiti vandals" the other titled "Texturing UPS strength to lower metal weight". They were both published in a magazine called "Iron Age" on 23rd August 1976. They can conveniently be considered together with another item of alleged prior art, namely an article titled "Texturised metals find wide application" published in a magazine called "Steel" on 24th May 1948. These articles appear to have been published for the purpose of advertising products of certain US companies. The general thrust of each of the articles could be said to suggest that the "texturing" of metals is a process which is, at least on the face of it, fairly similar in its mechanism and results as that described in Claim 6 of the Patent in suit.

99. Thus, the 1948 article refers to "strip metals" being subjected to "a new high-speed precision process which produces a three-dimensional pattern" and that the resultant "redistribution of the metal... has been found to result in a considerable gain in rigidity, buckling strength... and tensile strengths. The article goes on to mention that " in certain patterns, a 40% thicker plain sheet would have to be used to obtain the same transverse rigidity". The 1948 article also states that "what is involved is the careful tooling or engraving of the set of hardened match die-rolls which then must be synchronised and set up carefully for clearance to maintain a uniform impression across the surface of both sides of the sheet". As a result, there is "weight saving and payload improvement".

100. In the first 1976 article, one finds the following:

101. The article then goes on to refer to deep texturing as "a cold rolling process" whereby "the metal is rigidised or redistributed by passing a plain sheet... through a set of synchronised male and female rolls under accurately controlled pressure" resulting in redistribution of the metal. The article goes on to say that this results in "improved strength and rigidity and significantly increases the strength/weight ratio".

102. To much the same effect, the second 1976 article refers to "rigidised sheet" being "made with synchronised male and female engraved rolls" whereby the material is "redistributed above and below [its] original plane" and that this "strengthens the metal in all directions". The second 1976 article also emphasises the financial benefit of texturing, stating that it permits "a two-gauge reduction in metal thickness without sacrificing strength".

103. On the face of it, what these articles reveal might appear to be similar to the alleged invention embodied in the Patent in suit. However, Hadley advance a number of reasons for concluding that, whether one takes these articles together or separately, the alleged invention in Claims 1 and 6 of the Patent in suit was not obvious over them. First, the disclosures in the articles really relate to a form of embossing, which, it will be remembered, involves pressing metal sheet (whether with rollers or otherwise) under high pressure which causes the metal to thin and elongate: there is no question of local stretching. Secondly, and possibly another way of making the same point, while the purpose of what is revealed in the articles is the same as that of the Patent in suit, namely strengthening coupled with gauge reduction, the way in which it is achieved pursuant to the methods described in the articles is different from, and more expensive than, the process taught by the Patent in suit. Thirdly, as Mr Andrews accepted, one cannot work out from any of the articles the process by which the texturing is to be carried out, other than in the most general terms. Fourthly, there are good reasons for accepting Mr Deeley's evidence to the effect that the claims made in the articles as to the increased strength in metals following texturing are extravagant. It was striking how little Mr Deeley and Mr Andrews knew about textured metals, and yet one would have thought that if the result of texturing was anything like as effective as described in the articles, the treatment would be very well known. That is not the only reason for being sceptical about the claims in the articles: I found Mr Deeley's evidence that the indentations resulting from the texturing appear to be "so close together that the metal would shear rather than emboss".

104. In all these circumstances, I have reached the conclusion that the claims of the Patent in suit were not obvious over these articles or any of them.

105. The Schumacher Patent. This is US Patent Specification No. 3,137,922 granted on 23rd July 1964, whose object is "to provide a method of making rigid structural members, particular steel with decking, of substantially lighter weight than conventional decking, yet capable of carrying a greater load with less deflection on a longer span than conventional decking". So far as the product claim in the Schumacher Patent is concerned, it differs from Claim 1 of the Patent in suit in that it only involves a single row of projections: there is therefore no relationship between the separation of depressions across and along the rows, and the bottom of each depression does not have opposite margins parallel to the length of the rows. As the Schumacher describes a product with only one line of projections, which is along the bottom of the channel, it would not give added strength over the whole of the surface of the material, unlike the teaching of the Patent in suit: accordingly, the strengthening effect of the projections in the Schumacher Patent is in one direction only.

106. Although there are similarities in the process claims in the Schumacher Patent and Claim 6 of the Patent in suit, there are differences which are reflected in the differences between the product claims (e.g. the teeth on the Schumacher rolls are not arranged in a plurality of rows, the tips of the teeth do not have opposite margins parallel to the length of the rows, and there is no relationship between the pitch of the teeth along and across the rows). Furthermore, the section forming process is carried out in the process claim in the Schumacher Patent before the projections are formed on the metal. Further, the Schumacher Patent carries out the stretching and forming in separate operations, and does not appear to contain any teaching of "local stretching"; nor does the Schumacher Patent have similar teaching about the increase in strength.

107. Once again, it is fair to say that this item of alleged prior art has similarities with both the product claim and the process claim of the Patent in suit, but ultimately it seems to me that the Patent in suit contains sufficient differences which are inventive over the Schumacher Patent to defeat Metsec's argument of obviousness. Mr Deeley explained that the arrangement of the formations in the Schumacher Patent was "very different" from that in the Patent in suit and that it does not provide strengthening over the whole of the material, in that there is cross ribbing to strengthen a flat panel only. He further said that he was unaware of the Schumacher Patent until it was cited in these proceedings, and that he would not have derived assistance from it in his work leading up to the alleged invention embodied in the Patent in suit. While it is obviously right to be cautious before accepting Mr Deeley's evidence on this point, because he has an obvious interest, possibly financially, probably in terms of his job, and certainly as an inventor, he struck me as an honest witness in general, as I have already said, and I accept his evidence on this aspect.

108. The Reynolds Patent. This is US Patent No. 3,217,845 which was registered on 16th November 1965, and describes a rigidified corrugated structure with primary corrugations together with secondary corrugations which are shallower and spaced along the length of the primary corrugations; the corrugations are created by passing sheets through rollers with teeth. Mr Deeley and Mr Andrews agreed that, because the Reynolds Patent involved corrugations of a substantial size, they would result in a substantial decrease in the length of the material subject to the treatment described in the patent. Metal treated in accordance with the process described and claimed in the Reynolds Patent ends up looking a little like an egg box. The product described and claimed in the Reynolds Patent is essentially for the purpose of being sandwiched between two sheets of other material.

109. So far as the process described and claimed in the Reynolds Patent is concerned, it results in very considerable increase in the overall depth of the sheet following treatment, and this could not be achieved by local stretching. Quite apart from these differences, the distances between pitches in the Reynolds Patent are very different from those taught in the Patent in suit. In my judgment, the teaching in the Reynolds Patent is a long way from that of the Patent in suit.

110. The Mannesmann Patent. This is a Swiss patent, No. 486,281, which is concerned with the production of rigidified corrugated sheets, made by passing a plain sheet of metal through two rollers with matching teeth, which are in alternate rows, displaced by the distance of half a tooth. It is basically directed to making a rigid flat surface for use as a road base, and Mr Deeley and Mr Andrews agreed that the strengthening effect provided by the process described and claim in the Mannesmann Patent appeared to relate to the shapes of the corrugations rather than any work hardening or increase in yield-point. Further, even on Mr Andrews's analysis, the Mannesmann Patent does not disclose features (d) and onwards of Claim 6.

111. I am satisfied that the Mannesmann Patent is not concerned with the same concept as the Patent in suit, and I was convinced by Mr Deeley's statement that, had he been aware of the Mannesmann Patent when he was developing the alleged invention the subject of the Patent in suit, it would not have been of any interest or assistance to him. I do not consider that the claims of the Patent in suit were obvious over this item of prior art.

112. The Salzer Patent. This a US Patent No. 2,378,661, and is concerned with a method of manufacturing profiled radiator elements by passing metal sheet through meshed rollers. The patent does not purport to disclose, or even suggest, that the projections are used for strengthening. Further, the product claim in the Salzer Patent does not refer to the extent of the depth of the projections, and the pitch of the projections is different. Quite apart from this, the product claim in the Salzer Patent forms the sheet into a zig zag, which is not a bend which extends without interruption, and there is no description of local stretching. As to Claim 6, it is also to be noted that there is no indication in the Salzer Patent that the process therein described reduces the material length by more or less than 10%, over and above the other factors to which I have referred.

113. In these circumstances, I have little hesitation in rejecting Metsec's contention that the Salzer Patent assists its case on obviousness.

114. The Cookson Article. In the October 1966 issue of "Sheet Metal Industries" there was published an article titled "The Cookson Method of Cold Roll-Forming". The article describes methods of forming ribs in sheet metal without stretching and at comparatively low pressure. The Cookson article does not describe a process involving mating rollers to produce sheet, and neither the process nor the product described in the Cookson article appear to be concerned with sheet material which has discontinuous projections on it; nor does the Cookson article refer to local stretching. I am somewhat at a loss as to why the Cookson article was included at all.

115. In the event, therefore, I have no hesitation in accepting Mr Deeley's evidence that, had he been aware of the Cookson roll-forming method in or before 1981, he would not have derived any assistance from it in relation to his work leading up to the alleged invention the subject matter of the Patent in suit.

116. Rotary Embossing article. In the December 1969 issue of "Metal Forming", there was an article titled "Rotary Embossing of Metals" and sub-titled "Engraved Fully Hardened Rolls". This article described a process employed by the Modern Engraving and Machine Corporation (known as "Memco") of the United States. The article describes a process involving "a matched pair of rolls having an interlocking male and female pattern on their surfaces and consequently the rolling of metal or other sheet or strip materials results in an embossed pattern", i.e. a method of embossing metal using rollers with matched patterns. Mr Andrews accepts that it does not contain feature (d) or (e) of Claim 1, nor features (f) or (g) of Claim 6 although Mr Andrews suggested in is cross-examination that feature (f), which teaches that the strength of the treated material is at least 10% greater than of the plain material, and feature (g), which teaches that the length of the material is reduced by less than 10% as a result of the treatment, are implicit in the Rotary Embossing article. I can see no warrant for that assertion.

117. Quite apart from this, I accept Mr Deeley's evidence that the Rotary Embossing article describes an embossing process which thins the whole of the sheet by compressing a pattern into the sheet, whereas the projections contemplated by the Patent in suit are formed by "local stretching" whereby the sides of the projections are stretched thinner than the rest of the sheet. Furthermore, it appears from the figures given in the Rotary Embossing article, that the maximum pattern depth is less than 50% of the maximum thickness of the material, which is a marked difference from the claims of the Patent in suit. In other words, as its name suggests, the Rotary Embossing article is concerned with a type of embossing, and it really takes the prior art relevant to the Patent in suit very little further forward over what was already known about embossing, namely that, as a result of embossing, material becomes plastic, and deformation of the sheet may increase its stiffness.

118. Once again, it does not seem to me that this item of alleged prior art assists Metsec's case on obviousness.

119. Cold Roll Forming article. In May 1958, an article, by William Kirkland of the American Iron and Steel Institute was published, entitled "Cold Roll Forming Practice in the United States". The article is a clear and useful explanation and description of cold roll forming processes, and forms the text of a lecture apparently given in 1958, albeit that the article was an 1966 revision. It is fairly general in its terms. Thus, it refers to "operations such as piercing, slotting, trimming, embossing, numbering and printing" and to the fact that this can be effected on "light gauge materials" with a "male roll". It also explains the embossing process, again in very general terms. Perhaps most relevantly, it refers to the fact that some designs of cold roll-formed sections can be given increased strength through cold roll-forming.

120. I am bound to say that this article does not seem to take matters any further at all in this case. It summarises what it is common ground was generally known in 1966, and, even if one is to assume that things have not moved on between then and 1981, I do not see how it helps. The fact that Mr Andrews, in his tick charts, considered that the Cold Roll Forming article disclosed all the features of Claim 1 and, indeed, all but two of the features of Claim 6, does not serve to assist his credibility.

121. Having considered all the patents and articles relied on by Metsec as constituting alleged prior art over which the claims of the Patent in suit are said to be obvious, I have come to the conclusion that they are all to be rejected.

122. Obviousness over prior use

123. As I have mentioned, Metsec allege two prior uses, namely the Hepsec prior use and the Firststeel prior use. In Mr Andrews tick chart, they are said to contain all the features of Claim 1, save feature (e), namely the teaching that the overall thickness of the material is to be twice the thickness at the point between adjacent depressions, and all the features of Claim 6, save (f) and (g), namely the increase in strength by at least 10% and the reduction in length than by no more than 10%.

124. The Hepsec prior use. This use involved rollers ("the Hepsec rollers") which knurl a pattern on the sides of a metal channel; the purpose of the pattern, as is normal in the case of knurling as I have mentioned, was to allow screws to bite into the metal rather than slipping sideways on a flat metal surface; in other words, the purpose of the process is to roughen the surface of the material rather than to strengthen it.

125. The process worked by passing the metal sheet through the two Hepsec rolls: the top roll had teeth which mated with the bottom roll, which has a series of ridges around its circumference. On the evidence I have heard and seen, the pattern applied by the Hepsec rolls was only applied to distinct areas of the plain sheet rather than over the whole of its surface, as is, of course, the case with the product and process claims in the instant case. Consequently, the Hepsec prior use did not actually involve strengthening a particular sheet of metal.

126. Furthermore, the depth of the pattern applied to the surface of the sheet metal by the Hepsec rolls was less than twice the thickness of the original metal. Experiments carried out by Mr Deeley showed that, if one applied the Hepsec rolls to the whole of the surface of a particular sheet of metal, it increased its strength by less than 5%. A further experiment carried out by a Mr Bushell of SGS UK Limited showed that the Hepsec prior use involved little or no local stretching of the material.

127. In my judgment, and assuming for the moment that the Hepsec prior use was indeed a prior use, neither the product claim nor the process claim of the Patent in suit was obvious over it. I cannot do better than quote Mr Deeley's evidence as to the three steps which a person of ordinary skill in the relevant art in 1981 would have had to take in order to arrive at the Patent in suit from the Hepsec use:

128. Once one remembers that the Hepsec prior use was for the purpose of knurling, and that this would involve applying a minimum, rather than a maximum, depth of projection, it seems to me that Mr Deeley's conclusion that these three steps were not such that an ordinary person skilled in the art would have taken them is made out.

129. I have reached the conclusion that the Hepsec use would not render the Patent in suit obvious, even if it was a prior use. However, although alleged to be a prior use in Metsec's pleading, Hadley has not admitted it as such, and no evidence has been called by Metsec which satisfies me that the Hepsec use was in fact a prior use.

130. The Firststeel prior use. Metsec have produced drawings of metal channels for supporting plasterboard, and these have been referred to as "the Firststeel drawings". They are substantially similar to the channels involved in the Hepsec prior use. Mr Deeley told me that such channels were widely used in the industry before the mid-1960's, and that, indeed, Hadley made such channels.

131. The Firststeel channels have knurling on parts of their exterior faces. The knurling does not appear to have been very deep. Its function was very similar, indeed probably identical, to the knurling in the Hepsec prior use.

132. It appears to be common ground between Mr Andrews and Mr Deeley that the Firststeel sections would not have been twice the thickness, and that they would not have achieved the strength increases, as claimed by the Patent in suit. There are no records of any testing for the depth of the knurl or for strength increases in the Firststeel sections, no doubt because this was irrelevant for the purpose for which the knurling was applied. Quite apart from this, Mr Andrews and Mr Deeley appeared to agree that it is most unlikely that a knurl of any significant depth could have been achieved in the Firststeel prior use, because the clearance between the teeth on the rolls was insufficient to enable this to occur. Further, there is nothing to suggest that the Firststeel prior use involved projections substantially achieved by local stretching.

133. My firm view that the Firststeel prior use does not assist Metsec is supported by evidence that, when asked by British Gypsum to provide material which was so strengthened as to enable gauge reduction to be achieved prior to 1981, Firststeel were unable to work out a way of doing this.

134. In these circumstances, it seems to me that the two prior uses upon which Metsec rely are of no assistance to them.

136. As I have mentioned, the product produced by Metsec which Hadley contends is infringing is called "Supasteel". This Supasteel is actually manufactured by Metsec UK. It is, or has been from time to time, marketed by Metalsections.

137. Supasteel has projections inserted in to it, and it is common ground that it has all the features of Claim 1, save that there is a dispute whether it has feature (e). In order to infringe Claim 1, it is not enough for Hadley to show that the Supasteel has features (a)-(d) and (f)-(g) of Claim 1. Feature (e) is an integral part of Claim 1, and, unless it can be shown that the Supasteel produced by Metsec has that feature as well as the other features of Claim 1, no infringement of Claim 1 will be established.

138. Hadley contends that Metsec's Supasteel process is designed to make deeper projections than the prior art, and that Metsec ought to ensure that the Supasteel thereby produced never infringes Claim 1, and in particular feature (e).

139. In connection with the infringement allegation, Metsec have not only made available to Hadley samples of Supasteel, but also have provided their in-process inspection sheets ("the inspection sheets"). On measurement, none of the samples of Supasteel produced by Metsec infringed feature (e). With one exception, Hadley accepts that the inspection sheets of Supasteel products disclosed by Metsec do not suggest that any of the Supasteel it has produced contains feature (e). The one exception is an inspection sheet recording Supasteel production at Metsec's factory on 15th June 1998, over a period of some three hours. Hadley contends that this inspection establishes that the initial gauge of the steel was 0.75mm and that the projection effected by the Supasteel process increased the gauge to up to 1.55mm, i.e. more than twice the thickness, which feature (e) of Claim 1 states is the minimum.

140. The evidence shows that Metsec required its operatives to check the Supasteel produced every hour (or when the roll of steel being processed had to be replaced) and to enter certain measurements on the relevant inspection sheet.

141. On the face of it, the 15th June 1998 inspection sheet does appear to record that the Supasteel, when measured on three occasions had a starting gauge of 0.75mm, and that the process increased it to over 1.5mm, thereby apparently bringing the Supasteel on that occasion within feature (e) of Claim 1; as there is no contest about Supasteel falling within the other sub-paragraphs of Claim 1, Hadley's contention is that it has thereby established infringement of Claim 1 by Metsec. Metsec raise a number of points in reply.

142. Metsec's first point is that the measurements on the inspection sheet do not in fact record what they purport to record. The only evidence called by Metsec to support this contention was that of Mr Derek Lum, a director of both the Metsec companies. He did not speak from his own knowledge, but from what he was told by the people who made the entries on the record sheets. Also he is not an expert in the relevant field nor was he tendered as such. No explanation was given as to why the person who made the relevant entries (who appears to have been a Mr Turley) or any other shop-floor operative was not called. Furthermore, I did not find Mr Lum a wholly convincing witness: he appeared to regard his role as that of an advocate rather than a witness, he not infrequently failed to answer a question which was put to him in cross examination, even though there is no reason to think he did not understand the question, and, for what it is worth, his general demeanour did not impress me favourably. Furthermore, Hadley called a witness, Mr Mayo, who is an employee of Hadley, but was formerly an employee of Metsec. In his cross examination, a few questions were put to him about the inspection sheets, but is was not suggested to him that they were intended to be, or actually were, completed inaccurately by the shop-floor staff.

144. Thirdly, Metsec contend that the Supasteel with the gauge which falls foul of feature (e) of Claim 1 would not have accorded with the specification of its relevant customer, and therefore would not have been sold. On this point, Metsec again rely on the evidence of Mr Lum. It did not appear to me that his evidence was based on first hand knowledge. Further, no specific evidence was given, for instance, to identify the customer concerned or the specification he had given, nor to call any evidence as to what actually happened to this infringing batch of Supasteel (or to explain why such evidence could not be called). As already mentioned, I did not find Mr Lum a convincing witness. In all the circumstances, I am not prepared to accept that the infringing Supasteel was destroyed.

145. Fourthly, Metsec contend that, although the Supasteel product in question may have had an infringing gauge after going through the Supasteel process, it would not have done so after being shaped - i.e. the final product, after the Supasteel process and after shaping was less than the minimum of twice the original gauge as taught in feature (e) of Claim 1. The only evidence for this case from Mr Lum, who neither inspected the Supasteel product in question nor had any expert knowledge; further, as I have said, he was not a reliable witness anyway. I therefore reject that point as well.

146. In these circumstances, I conclude that Hadley's case is made out so far as infringement of Claim 1 is concerned.

148. Hadley's case that the Supasteel process employed by Metsec infringes Claim 6 is primarily based on the evidence of Mr Deeley, acting as an expert. He said that all the features of Claim 6 which were not admitted on the pleadings to be features of the Metsec's Supasteel manufacturing process were in fact features of that process.

149. Metsec's argument that this method of manufacturing Supasteel does not infringe Claim 6 does not have a promising start so far as their evidence is concerned. In his witness statement, their relevant expert, Mr Andrews, did not challenge Mr Deeley's evidence on these matters. Indeed what he said about the matter was this:

150. Metsec argue that this is expressed in somewhat tentative terms, that Mr Andrews was not the only expert called on behalf of Metsec, that infringement of Claim 6 is and always has been clearly in issue, and that, in any event, infringement is ultimately a question for the court to be assessed on all the evidence, as well as being dependent upon any issue of construction. Some of these points have more force than others. So far as the evidence of the other expert called by Metsec, Professor Rhodes, is concerned, he did not really touch on this aspect. As to the reliance on the tentative way in which Mr Andrews has expressed himself is concerned, it seems to me to raise something of a trap. If a party, whose expert witness stated in his report and confirmed in chief that it did "seem likely" that his client was wrong on a certain point, the opposite party would (at least in the absence of any warning to the contrary) presumably not cross examine, on the basis that this really amounted to a concession. However, given that it has always been clear from the pleadings and has more recently become clear from the skeleton arguments that infringement of Claim 6 is in issue, I accept that it would be wrong to treat what Mr Andrews said in his witness statement, and confirmed in chief, as a formal concession of infringement of Claim 6 by Metsec.

151. I had the benefit of inspecting the manufacturing system of both Hadley and Metsec. Each involved processing a long strip of metal, which was first passed through rolls which inserted projections that strengthened the metal; the metal then passed through subsequent rolls which shaped it, so that the ultimate product was shaped with projections all over its surface. The basic processes were similar but, as Miss McFarland points out that does not take matters any further: processing metal strips or sheets through rollers to insert projections and/or to reshape is and has been for a long time a very familiar process. Accordingly, a closer analysis is required.

152. Hadley argue that the Metsec Supasteel process does, on the closer analysis which is obviously appropriate, infringe Claim 6 on each feature if it is present in the Supasteel process. Metsec contend that there is no infringement, relying essentially on the following points, namely:

153. So far as the first point is concerned, figs. 1 and 2 of the Patent in suit can be read as indicating that both rolls have "teeth", in the sense of quasi-pyramidal projections separated from similar projections along the wheel and across the wheel: that is, indeed, how the two rolls appeared on my inspection at Hadley's premises. Metsec's process, however, involves only the lower roll being in this form: the upper roll is rather simpler: it simply has grooves.

154. However, I do not consider that this distinction assists Metsec. So far as the figures in the Patent in suit are concerned, looked at on their own they are in fact perfectly consistent with either the lower roll or the upper roll, or (if one ignores the text of the Patent in suit) even both the lower and upper rolls, being grooved rather than toothed. However, if one looks at the text of the Patent in suit, it is clear that at least one of the rolls has to be toothed. However, there seems to be no reason why the other roll cannot be grooved. Indeed, that proposition derives strong support from feature (d) of Claim 6 that only "one" of the rolls need have "a plurality of teeth".

155. It is said by Miss McFarland that the reference to "mating components" in features (c), (f) and (g) of Claim 6 means that, if one roll is toothed, the other roll must be toothed. I do not consider that it is appropriate to give the concept of mating such a limited meaning in the context of Claim 6 as a whole. In my judgment, a toothed roll and a grooved roll can be said to be "mated", in the sense that the series of indented grooves along the grooved upper roll must coincide with the runs of teeth along and across the toothed lower roll, and the series of extruding grooves along the grooved upper roll must coincide with the line constituting the base between two lines of teeth along the toothed lower roll. Unless the concept of "mating" absolutely required both rolls to be toothed, it seems to me that it would be rather strange if features (c), (f) and (g) required both rolls to be toothed in circumstances where, in light of feature (e), it seems that the draftsman clearly intended that only one of the rolls had to be toothed.

157. As Mr Deeley showed, one can identify easily when the side of each tooth stops being straight and starts to be rounded. The notional horizontal line joining the upper point of the straight parts of each of the sides is the "tip" line which is "parallel".

159. As to Metsec's third argument, namely that Hadley has not established that Metsec's products have the necessary strength increase, this only relates to Claim 6 (as proposed to be amended), and in particular feature (f). As to this aspect, as I have already mentioned, experiments were carried out by Mr Michael Castellucci, a research and development engineer employed by Hadley, on steel which had been embossed, on steel which had been knurled, and on Supasteel. Those tests appeared to show that very little strengthening was achieved by the knurling or embossing processes, but that a substantial strengthening was achieved by Metsec's Supasteel process. In particular, according to the experiments carried out by Mr Castellucci, the load required to reach the point of permanent deformation in relation to Supasteel was significantly more than 10% greater than that required for steel which had not received the Supasteel treatment of Metsec.

160. It is fair to say that Mr Castellucci's experiments were open to criticism in one or two respects, and that there were one or two mistakes in his calculations. So far as the latter are concerned, they do not alter the fact that, at least on the face of it, his calculations established that knurling and embossing do not result in anything like a 10% increase in strength, whereas the Supasteel process results in substantially in excess of a 10%

161. increase in strength. As to the imperfections in the experiments, Professor Rhodes, in his evidence, made much of them. I agree with Mr Carr that Professor Rhodes came across as a partisan advocate putting the case of, and scoring points on behalf of, his clients, Metsec, rather than as a dispassionate expert doing his independent best to assist the court on the real issues. In making that observation, I am not resting my views so much on Professor Rhodes's manner, which was very combative (albeit in a rather engaging way) but more in light of the facts that he changed his answers on certain points, criticised Mr Castellucci for not using the relevant Eurocode, whilst having ultimately to admit that he did not use it himself (and in any event, it was only in draft form), and that he appeared to have attended Mr Castellucci's experiments and not criticised them at the time.

162. Further, it appeared that Professor Rhodes had carried out experiments himself, but he was not prepared to give any details of them. Accordingly, in order to decide whether the Supasteel process does indeed result in a strengthening which brings it within feature (e) of Claim 6, I have no direct evidence from Metsec, only Professor Rhodes's criticism of Mr Castellucci's experiments and conclusions. Even though Professor Rhodes was not the impartial witness that he should have been, there was some force in some of his criticisms. Thus, when assessing the increase in the load required to effect permanent damage (to use a neutral expression for the moment) before and after processing metal, it would appear that Mr Castellucci failed to take into account a constant weight. Although that required his calculations to be revisited, it was ultimately an arid criticism, as Professor Rhodes must have always appreciated, because it in no way altered the conclusion that, subject to any other criticism that might be made, Mr Castellucci's experiments showed significantly more than a 10% increase in the load necessary to effect permanent damage to steel after it had been subjected to Supasteel process.

163. Professor Rhodes also said, as I have mentioned, that the experiments conducted by Mr Castellucci, even if they established an apparent increase in strength of considerably more than 10%, did not, at least on the face of it, specifically establish this in relation to the point of permanent deformation (as that term is understood in academic circles). However, as I have already indicated, when dealing with sufficiency, I do not think that the reference to the point of permanent deformation in the Patent in suit is meant to be to the academic concept. It is meant to be to the practical feature which Mr Castellucci measured (and indeed which Mr Walker described), even if that is technically the yield point. In any event, for the reasons I have given when dealing with sufficiency, I do not think that there is anything in this criticism.

164. Quite apart from this, Professor Rhodes also stated that there was a relationship between the degree of strengthening established by Mr Castellucci's experiments and the change in the point of permanent deformation as a result of the relevant process (in this case the Supasteel process). However, for reasons best known to himself, Professor Rhodes did not condescend to carry out the appropriate calculations. In light of my view that he was a partisan witness, my clear belief is that he did not carry out these calculations because, had he done so, they would have shown that the Supasteel process did result in the point of permanent deformation being increased in accordance with the description in the teaching in feature (f) of Claim 6.

165. Indeed, in agreement with Mr Carr, I would go a little further with regard to Professor Rhodes. It appears from certain parts of Professor Rhodes's evidence in cross examination that, even before he wrote his report, he appreciated the basic truth of the facts that Mr Castellucci's experiments sought to establish (namely that knurling and embossing did not increase the strength of steel by more than 10%, and that the Supasteel process did so). In other words, Professor Rhodes's criticisms of Mr Castellucci's experiments, while not without foundation, were academic rather than practical, point scoring rather than significant, and went to detail rather than calling into question the basic conclusions which the experiments sought to establish, and indeed in my judgment did establish, and which I think Professor Rhodes knew they established, for the purpose of the issues in these proceedings.

166. In all these circumstances, it appears to me this third argument of Metsec, like the first two arguments, as to why the Supasteel process does not infringe Claim 6 fails.

168. Section 64(1) provides:

170. In this case, the defendants rely on the fact that Metsec UK, then called TI Metsec Limited, developed certain rolls before the priority date for the Patent in suit, i.e. before 1981. As I understood it, Metsec's case is that TI Metsec, as I shall call them for this purpose, sold the knurled product made from these rolls prior to 1981, but their activities are not relied on as a prior use at all.

171. In my judgment, Metsec falls a long way short of establishing its defence under Section 64. The process of knurling relied upon (which I shall call "the TI Metsec process") for this purpose does, on the face of it, have similarities with the Supasteel process currently undertaken by Metsec, and complained of by Hadley as constituting infringement. Thus, one could characterise the principal change between the TI Metsec process and the Supasteel process as merely increasing the depth of the depressions, or, to put it another way, the extent of the projections. However, it seems to me that this is not a "mere" change: in the context of the teaching of the Patent in suit, it is a substantial and significant change. The thrust of the teaching of the Patent in suit is to increase the extent of the projections, so as to accord with feature (e) of Claim 1 and to achieve the comparatively slight decrease in material length identified in feature (g) of Claim 6. This involves the local stretching identified in feature (b) of Claim 1 and feature (c) of Claim 6 and while it is to be found in the Supasteel process, it is wholly absent from the TI Metsec process.

172. Further, for Metsec to succeed in a defence under Section 64, they would have to show a clear link, or what Mr Carr called a "chain of causation" between the TI Metsec process and the Supasteel process. On my view of the evidence, Metsec have not established this. They have given no discovery of development documents, and while there has been some oral evidence which I understand to have been directed to the point, it has not satisfied me.

173. It is right to add that, even if Metsec UK could get over these two problems, I still do not understand how it could be said that Section 64 could assist Metalsections, whose alleged infringing acts constitute matters such as exhibiting a Supasteel metalsection at an exhibition in Birmingham.

174. In these circumstances, I am satisfied that Metsec's defence based on Section 64 must fail.

176. Metsec contended that, even if they fail on the issue of validity and would otherwise fail on the issue of infringement (as they do in my view), Hadley nonetheless should not succeed on the infringement issue on the grounds of estoppel and/or waiver (which I shall call "estoppel"). As pleaded, Metsec's case is that at a meeting "in about early 1996" attended by representatives of Hadley and of Metsec:

177. Metsec's pleading then goes on to allege that "in reliance upon such acknowledgement" Metsec has continued "to make and deal in such metal sections without any complaint being made by [Hadley] prior to the commencement of the present action."

178. In light of the oral and documentary evidence relating to this aspect of the case, I am satisfied that Metsec's case on estoppel and waiver fails. It is clear from the evidence that the meeting, at which the alleged statements relied on by Metsec were made, took place on 9th February 1996. That meeting was in the context of negotiations which were going on between Hadley and Metsec at the instigation of British Gypsum (who it will be recalled is a member of the substantial BPB group). British Gypsum is a large customer of both Hadley and Metsec, and required Hadley to grant a licence to Metsec in respect of a number of Hadley's patents, thereby enabling Metsec to manufacture and sell certain products to British Gypsum. Various meetings, which effectively culminated in that of February 1996, took place between personnel from Hadley and Metsec. I am satisfied that the main purpose of these meetings was to negotiate the terms of the licence to be granted by Hadley and Metsec in accordance with British Gypsum's requirements. Hadley and Metsec are and were competitors, and it is improbable that Hadley would have been prepared to grant the licence, which was in due course granted, to Metsec unless British Gypsum, a substantial client, had been very keen for it to do so.

179. In the context of those bare facts, it does not seem to me to be particularly likely that Hadley would have been prepared to give Metsec an unqualified acknowledgement as alleged in Metsec's pleadings, particularly bearing in mind that it is Metsec's case that Hadley was prepared to do this at a meeting at which a set of Metsec's rolls were produced to Hadley for the first time and apparently without warning, and were inspected only briefly by Hadley. Even if Hadley had been prepared to consider whether to accept that use of the rolls by Metsec would not infringe any of Hadley's legal rights, one would have expected Hadley to have wanted to think about the matter more carefully, in the sense of wanting more details of the rolls in question ("the Metsec rolls"), and in the sense of seeking advice from patent agents, particularly bearing in mind that it is Metsec's own case that Hadley is a litigious company.

180. Further, viewing matters from Metsec's viewpoint, it appears to me that, if the matter was sufficiently important to be raised at a meeting at which Metsec had actually brought along the Metsec rolls, and Hadley gave what amounted to a unqualified "go ahead", one would have expected to see some written record of it, or written reference to it. It is to be noted that there had been correspondence following at least some of the meetings between Hadley and Metsec in connection with the terms of the proposed licence, and I would have expected to have seen something either in correspondence, or even in the licence agreement which was ultimately signed by the parties, recording Hadley's acknowledgement as alleged in Metsec's pleading, or at least Metsec's contention, if such an assurance had been given.

181. It might, at first sight, be thought that the very facts that Metsec showed Hadley the Metsec rolls, and were prepared to describe to Hadley the process being carried on, represent a strong factor in favour of Metsec's case: as the two companies were commercial rivals, it may be thought hard to see why Metsec would have revealed the nature of their process to Hadley unless it was to get Hadley's clearance. However, in my judgment, the explanation for Metsec's conduct is to be found in the fact that the terms of the licence being negotiated between the parties required all improvements made by Metsec, which were not capable of being patented, during the subsistence of the licence, would be the property of Hadley, and all improvements which were capable of being patented would be licensed by Metsec to Hadley free of any royalty. Accordingly, it was in the interests of Metsec to disclose their existing developments to Hadley, who might otherwise allege that they represented improvements which fell within the provisions of the proposed licence.

182. That this was understood by Hadley (and, indeed, probably by Metsec) to be the purpose of Metsec's disclosures at the 9th February meeting appears to me to be supported by subsequent correspondence between their respective patent agents. Mr Shaw, Hadley's patent agent, wrote to Mr Carpenter, Metsec's patent agent, on 14th February 1996 referring to the "mutual confidential disclosure agreement" and stating that part of the arrangement between the parties "involved the release to [Hadley] of the text of two unpublished British patent applications [of Metsec]". His letter went on to request good copies of the patent application, which were then provided to him, following which he wrote on 22nd February stating that, having reviewed the patent applications, Mr Shaw considered that "they do not cover the subject matter which was independently patentable as at June 1995 and they do not present an obstacle to the request of [Metsec] for the grant of the licence from ... Hadley." Neither Mr Shaw nor Mr Clarke suggested that Metsec were revealing the patent application with a view to getting Hadley to agree that the use of the Metsec rolls did not infringe any of Hadley's Patents.

183. The aspects of the evidence I have so far been discussing in relation to the estoppel argument are essentially indirect. Of at least equal, and probably greater, weight is the direct evidence, that is, the oral evidence of the individuals who attended the 9th February 1996 meeting. In their statements, proffered as their evidence in chief, various witnesses called by Metsec, namely Mr Jeavons and Mr Tilsley (each directors of both the Metsec companies) and Mr Salt (Operations Director of Metsec UK) said that Mr Deeley stated, apparently in terms, that the Metsec Rolls did not infringe any of Hadley's intellectual property rights. However, during cross examination, Mr Jeavons said that, at that meeting, "the question of infringement... had not actually been raised" because "the purpose of the meeting... was... for [Metsec] to disclose information to [Hadley]", although it is fair to say that he also went on to say that "the indications that we had at that particular point in time was that we would not infringe their process". In their respective cross examinations, both Mr Tilsley and Mr Salt accepted that they could not recall anything being said in terms on behalf of Hadley about the Metsec Rolls not infringing any of Hadley's intellectual property rights. In agreement with Mr Carr, I do not think that this inconsistency between what these three witnesses said in their witness statements and what they said in cross examination casts any doubt on their honesty. I consider that there are two essential points which arise from these cross examinations. First, none of these Metsec witnesses has a particularly clear recollection as to precisely what was said or indicated by or on behalf of Hadley in relation to the Metsec Rolls. Secondly, none of them is able to say that any positive statement was made on behalf of Hadley to suggest that the Metsec Rolls infringed.

184. The furthest I consider that Metsec's case goes is that, although the Metsec Rolls were brought along to the meeting, and were shown to the representatives of Hadley, and in particular to Mr Deeley, no positive complaint or warning was given on behalf of Hadley to the Metsec representatives about the possibility of the use of the Metsec Rolls infringing any of Hadley's rights. It may well be that Mr Deeley, or someone else on behalf of Hadley, indicated that the Metsec Rolls appeared to be "old hat", but that was no more than a throw-away line. I accept the evidence of Mr Deeley, supported by Mr Hadley (Chairman and Managing Director of Hadley) and Mr Flynn (Group Sales and Marketing Director of Hadley) who attended the meeting with him. The meeting took place in order to seek to finalise the terms of the proposed licence agreement, and, although the Hadley representatives were concerned about the possibility of some of Metsec's machinery or products breaching Hadley's rights, that was not the primary purpose of the meeting. Mr Deeley did mention that Metsec's use of any equipment developed prior to the licence agreement would not of itself be a breach of the licence agreement, and it may be that it was that statement which persuaded those attending the meeting on behalf of Metsec into subsequently saying that they thought that Hadley did not object to the Metsec Rolls.

185. I accept the evidence of Mr Deeley to the effect that, after being shown (and very cursorily inspecting) the Metsec Rolls at the meeting, he and the other Hadley representatives were somewhat taken by surprise to be told that they were the subject of pending patent applications by Metsec; as a result, Mr Deeley decided to ask for the patent applications in order to form a view as to the position. The patent applications which were in due course received by Hadley's patent agent, Mr Shaw, did not in fact contain all the drawings which were ultimately included in the application, and, crucially, they did not contain drawings of the Supasteel process or Supasteel product, which are, of course, the very process and product, of which Hadley makes complaint. It is right to mention that there is no question of this omission having involved any dishonesty on the part of Metsec or its advisers, but the essential point is that when, after the meeting, information which Hadley clearly regarded as important was sent to Hadley, it did not contain the centrally relevant information, in the form of the relevant drawings, showing the very process and product of which Hadley makes complaint in these proceedings. Mr Deeley's recollection receives support from the fact that, very shortly after the meeting, the instructions he gave to Mr Shaw included the statement that he, Mr Deeley, had not had sufficient opportunity to inspect the Metsec Rolls, and that he was looking to the patent applications for the purpose of deciding the question of novelty.

186. In these circumstances, I am satisfied that nothing was said by or on behalf of Hadley at the meeting which even indicated that Hadley considered that the use of the Metsec rolls would not infringe, or result in infringement of any of Hadley's intellectual property, and, in particular, the Patent in suit.

187. Even if this were wrong, I should refer to the evidence of Mr Lum, a director of both the Metsec companies, to whom I have already referred. Although he did not attend the meeting, he appears to have been the Metsec employee most involved with considering the terms of the licence and writing the letters in connection with the negotiations. He met Mr Jeavons very shortly after the 9th February and, even though he said that he understood that Hadley had indicated that the Metsec Rolls would not infringe, he accepted that "the matter was not entirely resolved at that stage... because Hadley... asked us to supply copies of the patents to them". It appears that he never saw the correspondence between the parties' respective patent agents, and the overall effect of his evidence on this aspect, as I understood it, is that even he regarded Hadley as entitled to contend that the Metsec Rolls infringed Hadley's intellectual property rights once Hadley had seen Metsec's patent application. It seems to me that the right analysis, even if one accepts Mr Lum's second hand understanding (which I do not), is that Hadley was not committed to a position on the question of whether the Metsec Rolls infringed until after it had seen the relevant patent applications. First, there is no evidence that Hadley indicated either way once it was served with the patent applications. Secondly, it never received the patent application in full: vital drawings were omitted. Accordingly, even on their own evidence Metsec's case on estoppel would fail.

188. In these circumstances, it seems to me that the evidence falls a long way short of Metsec being able to establish a defence of estoppel to the infringement claims.

190. As I have mentioned, there are two sets of proposed amendments. The amendments primarily provide greater specificity to the process claim, namely Claim 6. Hadley says that they are proposed in light of one of the disclosures relied on by Metsec, namely the Howell Patent, over which is said by Metsec to anticipate the Patent in suit and in my view, probably does, so far as Claim 6 is concerned. I have no reason to doubt that, although it is true that there is no reference to that reason in the document. The nature and effect of the proposed amendments are clear, I think, from the way in which I have set out Claim 6, and there are corresponding proposed amendments to the description and elsewhere in the Patent in suit.

192. The reasons Miss McFarland advances for refusing leave to amend are:

193. So far as the first objection is concerned, I have already rejected it when dealing with the validity of the Patent: if I had accepted it then it would have been right to refuse leave to amend. So far as the second objection is concerned, I think it is somewhat fanciful to read the Claim as including the possibility of the material actually being lengthened as a result of the treatment described in Claim 6, bearing in mind common sense and also what the notional addressee of the Patent, namely a person reasonably skilled in the art, would have known and understood at the priority date. However, even if the point is a good one as a matter of construction, I do not see it as a reason for refusing leave to amend. As to the reference to plastics is concerned, I have already concluded that Claims 1 and 6 can properly extend to plastics. If I had reached a different conclusion, then it seems to me that, subject to further argument, the right course would have been to see whether Hadley would wish to delete the reference to plastics in the Patent, to learn whether that is opposed by Metsec, and whether after advertisement (if appropriate), it would be appropriate to make such a deletion. As to the fourth point, it does not seem to me to be a good argument for refusing leave to amend. I have held that Claim 6 as unamended was probably anticipated by the Howell Patent. However, to refuse leave to make an amendment merely because it would defeat an invalidity argument which would otherwise succeed seems to me quite impermissible, provided of course that there is no other reason for refusing leave.

194. Miss McFarland's fifth point is now proposed to be dealt with by the re-amendment, to which I now turn. The re-amendment proposes the deletion of the reference to piercing and punching in Claim 6, and, indeed, elsewhere in the Patent. In relation to the proposed re-amendment, there is again no question of prejudice. However, Miss McFarland contends that the circumstances in which the reference to piercings was included, and has been maintained, in the Patent in suit are such that it would be inappropriate to permit the re-amendments. In this connection, there are two points. The first is that, quite long ago, in April 1985, British Gypsum's Patent Agent and for Hadley's then Patent Agent, suggested to Hadley that the reference to piercing in the Patent in suit and the two figures concerned with piercing (Figs. 3 and 4, which the re-amendment would delete) should be deleted. Secondly, there is no explanation as to why it is only now, well after these proceedings were begun, that Hadley seeks to re-amend. Miss McFarland also points out that unlike in connection with the proposed amendments, Hadley has not produced evidence as to why the Patent contained the reference to piercings and punching in the first place.

195. Although these arguments are not without force, I do not consider that they justify my refusing leave to make the re-amendments, subject to the question of advertising. The discussions in April 1985 are, on their own, quite insufficient to persuade me that Hadley and its advisers were not acting in good faith when they included piercings in the Patent in suit, or that Hadley was intentionally seeking an unjustified and more extensive monopoly than that to which it believed it was properly entitled. It may well be right to refuse leave to amend a patent in circumstances where it was originally drafted in a way which was dishonestly or unfairly, or even unreasonably, wide. That is not this case. Even in such a case, it could be that, weighing up all relevant considerations, the court might think it right to grant leave to amend. However, that is not a point I need decide in the present case.

196. The explanation why the proposed re-amendment comes late is that it was only after reading the evidence of Professor Rhodes, that Hadley and its advisers appreciated that the references to piercing in the Patent in suit were inappropriate, and that is the reason that the instant re-amendments are sought. I am satisfied that I should give leave to make the re-amendments in principle.

197. Mr Carr contends that I should grant leave to make the re-amendments without requiring further advertising. I accept that it is unlikely that anybody could suffer as a result of the re-amendment. However, the terms and breadth of the Patent in suit are not merely matters between Hadley and Metsec: its terms apply to anyone seeking to manufacture steel (or indeed plastic) in the jurisdiction, and I would require to be quite satisfied that no prejudice could result to any third party as a result of granting the re-amendment before I was prepared to do so without the matter first being advertised. I have had no expert evidence that there could be no unfair repercussions on third parties, and while I have already expressed my views to the likelihood, I do not regard it as self-evident that third parties could not suffer.

198. In these circumstances, I propose to allow the amendments and, subject to advertising (and, of course, subject to there being no sustainable objections) the re-amendments.

200. Conclusions in principle

201. Neither Claim 1 nor Claim 6 as proposed to be amended have been anticipated, but Claim 6 in its present form was anticipated;

202. Neither Claim 1 nor Claim 6 was obvious, whether over common general knowledge, prior art, or prior use;

203. Metsec's Supasteel product and process respectively infringe Claim 1 and Claim 6;

204. Metsec's defences based on Section 64 and on estoppel fail;

205. Hadley's application to amend the Patent in suit is granted, and its application to re-amend is also granted, subject to advertising and any resulting objections failing.

206. Relief against Metsec

207. Apart from identifying them, and briefly describing their different roles in relation to Supasteel, I have not so far distinguished between the two Metsec companies. However, now that I turn to the question of Hadley's entitlement to relief, and the nature of the relief to be granted, it appears to me to be important to distinguish between them.

208. So far as Metsec UK is concerned, I have concluded that the Supasteel it manufactures has, on at least one occasion, infringed Claim 1. I have also concluded that the actual Supasteel manufacturing process, undertaken by Metsec UK, breaches Claim 6. I cannot see any basis for contending that Hadley should not be entitled to an injunction to restrain Metsec UK from carrying on a process which infringes Claim 6, or that Hadley should not be entitled to an inquiry as the damages to which it is entitled as a result of Metsec UK's infringement of Claim 6.

209. The question of relief against Metsec UK in relation to infringement of Claim 1 is not so clear, in light of the fact that the extent of infringement is on a much lower scale. However, I have reached the conclusion that, in light of all the evidence, Hadley should be granted an injunction and an inquiry as to damages so far as Metsec UK's infringement of Claim 1 is concerned. It is true that, at least in one sense, there has only been a single incident of Claim 1 infringement. However, that does not alter the fact that there has been an infringement. Furthermore, although, in one sense, an isolated event, the infringing material was manufactured over a period of what appears to have been some three hours. I also bear in mind that it is not as if the evidence has disclosed records in relation to anything like the totality of the Supasteel manufactured by Metsec UK, and accordingly it is at least possible that there have been other infringements of Claim 1. I bear in mind, too, that Metsec's position throughout these proceedings has been to deny that the Supasteel it has manufactured in the past has ever infringed Claim 1. It therefore appears to me appropriate in all the circumstances that Hadley should be granted relief in relation to Claim 1 similar to that which I grant it in relation to Claim 6, at least as against Metsec UK. However, Metsec UK is entitled to a qualification so far as the award of damages is concerned: the plaintiff became proprietor of the Patent in suit pursuant to a written assigment on 31st August 1984, and there was no reason why that assignment was not registered by 28th February 1985, and was only registered on 17th July 1997. In these circumstances, it is common ground that the combined effect of Sections 33 and 68 of the 1977 Act is that Hadley is not entitled to any damages in respect of any act complained of against Metsec UK before 17th July 1997.

210. I turn now to the question of whether Hadley is entitled to relief, and if so what relief, against Metalsections. So far as Claim 1, the product claim, is concerned, I accept that Metalsections has marketed and generally promoted Supasteel. However, the extent of such promotion and marketing is unclear. Given that none of the Supasteel inspected by Hadley and only one of the many inspection sheets made available to Hadley in these proceedings, have identified any infringing Supasteel, the mere fact that on one day for three hours Supasteel produced by Metsec UK infringed Claim 1 does not persuade me that at some time in the past Metalsections must have promoted or marketed Supasteel which infringed Claim 1. I accept that it is quite possible that Metalsections did this, but it is for Hadley to prove, and, even allowing for the fact that I accept that there may well have been other occasions when the Supasteel produced by Metsec UK infringed Claim 1, it would require something more than the current evidence to persuade me that Metalsections must also have been involved in such an infringement. For instance, if the evidence had shown that Metalsections marketed and promoted effectively all the Supasteel manufactured by Metsec UK, that might well have been enough for Hadley's purposes.

211. So far as Claim 6 is concerned, although Metalsections plainly did not manufacture Supasteel by the infringing, or indeed any, process, Hadley contends that, by virtue of Section 60(1)(c) Metalsections is liable for having advertised or promoted a product which has been made by Metsec's process which infringes Claim 6. The only ground upon which that contention is contested by Metalsections is that there is insufficient evidence to show that the product which Metalsections was promoting and advertising was in fact made by the infringing process. I do not accept that. Metalsections has been promoting Supasteel, and that product, on the evidence, is what has been manufactured by the infringing process employed by Metsec UK. The fact that the product is, immediately thereafter, subject to further workings for the purpose of reshaping the product does not alter this conclusion. Furthermore, it is not as if any evidence has been called on behalf of Metalsections to suggest that the Supasteel which it promoted and advertised for sale was manufactured in any relevantly different way from that which I saw on the inspection, and which was the subject matter of the evidence before me. Accordingly, it seems to me that Hadley is entitled to appropriate injunctive relief, and to damages (again only with effect from 17th July 1997) against Metalsections, on the basis of infringement of Claim 6 of the Patent in suit.

213. If for nothing else, this case has one claim to fame or, more accurately, to a footnote in legal history. It is the first case to have been heard by the Patents Court of the Chancery Division, sitting outside London, namely in Birmingham.