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Cite as: [2006] EWPCC 49

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		Neutral Citation Number: [2006] EWPCC 49
		Claim No: PAT 04 054

IN THE PATENTS COUNTY COURT

20 February 2005

B e f o r e :

HIS HONOUR JUDGE FYSH QC
____________________

	(1) WEATHERFORD UK LIMITED (2) WEATHERFORD/LAMB INC	Claimants
	And
	(1) BJ TUBULAR SERVICES LTD (2) BJ SERVICES COMPANY (UK) LTD	Defendants

____________________

Colin Birss and Miles Copeland, instructed by Simmons & Simmons, appeared for the Claimants.
Daniel Alexander QC and Richard Meade, instructed by Bristows, appeared for the Defendants.
Dates of hearing: 13-16 December 2005
____________________

HTML VERSION OF JUDGMENT
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Introduction^[1]

This is a patent infringement action with a counterclaim for revocation of the patent in suit. The patent, no. 0 958 447 (EP) ('the Patent') stands in the name of a Delaware corporation, Weatherford/Lamb Inc, the second claimant in the action. The first claimant, Weatherford UK Limited, is the exclusive licencee in this country under the Patent. The technical field with which the Patent is concerned is the oil drilling industry and more particularly, it is concerned with equipment used on the drilling floor of rigs for positioning what is called a 'tong'. The Patent which has a priority date of 29 January 1997, is entitled 'Apparatus for positioning a tong and drilling rig provided with such an apparatus.' The claims of the Patent are product claims, all but one being directed to apparatus for positioning the tong. The final claim, claim 6, is to a drilling rig with the claimed apparatus mounted on it. The claimants, whom I shall refer to collectively as 'Weatherford', were represented by Mr Colin Birss and Mr Miles Copeland.

No distinction was drawn between the defendants whom I shall simply call 'BJ'. They provide offshore services to the oil industry in this country (and in UK territorial waters) and as part of this, they offer for sale apparatus for positioning a tong called a Leadhand Mk II ^[2]. This apparatus is what Weatherford say infringes claims 1,4 and 6 of the Patent. BJ were represented by Mr Daniel Alexander QC and Mr Richard Meade.

Infringement has been denied and in their counterclaim for revocation of the Patent, BJ have raised issues of anticipation and obviousness. In this connection, four items of prior art were relied upon as follows:

(a). The Ferrari 535 series crane (brochure, specification sheet and the crane itself called collectively 'the Ferrari Crane'),

(b) The General Catalogue of Maritime Hydraulics for 1990-91, p 17 ('MH arm'),

(c) US patent No 4,843,945 ('Dinsdale') and a late entrant,

(d) BJ's own Leadhand Mk I tong positioning device.

BJ also allege that the Patent is invalid on the ground of obviousness in the light of the common general knowledge.

The principal issues in the case are the proper construction of the Patent, infringement and validity. As far as I am aware, no novel or unusual questions of law are involved.

Introductory Technical Background

I have taken what follows from the general background information provided by the parties' experts in their reports. One of the tasks undertaken on the drilling floor is passing down the drill hole what is known as a string of 'tubulars'. Tubulars are used at two stages of the process for the production of oil. 'Drill pipe' is used in connection with the actual drilling operation. The drill bit is run down on the tubulars and drilling is carried out with 'mud' being pumped down which lubricates the operation and carries away the debris. Once the hole is drilled, the casing is used to line the hole for oil production. The operation of joining lengths of tubular together to form the 'string' is carried out by a 'tong' which is in effect a motorised wrench which screws the lengths of pipe together. It operates with an integral 'back up' which holds the lower tubular whilst torque is applied to an upper tubular so as to screw the tubulars together. Tongs, which come in various sizes, some of them weighing well over a ton, were well known at the priority date. By its nature, the tong is used intermittently on the drill floor but it must remain available even when it is not in use. The invention is not concerned with the tong as such but with how it is positioned for use and more significantly, with how it and its associated positioning equipment is stowed on the drilling floor when it is not in use.

For some years before the priority date of the Patent, the method of fixing a tong to a tubular was undertaken by a combination of brute force on the part of operatives and a 'tugger line'. A tugger line is a stout metallic cable which runs from a winch to a block at the top of the derrick and then through another block and down so as to hang (and usually at an angle) over the drilling floor. The tugger line is a general purpose lifting device (the 'workhorse of the drilling rig floor'^[3]) which is used for a number of operations on the drilling floor including bearing the weight of the tong so that the latter can be raised or lowered for positioning adjacent the tubulars for screwing. When used for this purpose it was usual to have a compensator attached to it before attachment of the tong. The compensator accommodates vertical movement by the tong as the latter threads (or disengages) tubulars, moving up and down the length of the tubular. As I understand it, tugger lines had been in use for years before the priority date – and indeed they are still in use.

In such an arrangement, with the tong suspended at the end of the tugger line just above the drilling floor, its positioning onto the tubulars had traditionally to be carried out manually by men called appropriately, 'roughnecks' who manhandled the tong into grasping position. Later, devices called 'iron roughnecks' were introduced. These were trolleys on rails which carried the tong into its operative position. When in position, the tong jaws were latched shut around the tubulars and the screwing (or unscrewing) began. But tugger lines did not always have to be used to carry the weight of the tong. Fixed cranes of various kinds (including folding and telescopic cranes) were also used on the drilling floor to move all sorts of bits of heavy drilling equipment about – including tongs. This freed up the tugger line for other uses. All the foregoing was in my judgment, well known in the drilling industry at the priority date (see below: 'Common General Knowledge').

Behind the proposal of the Patent is a safety consideration which should be borne in mind in approaching the solution to the particular problem described in the Patent - which I shall consider in a moment. Roughnecks suffered accidents in the positioning of tongs (for example through the loss of fingers) and pressure grew in the industry for the positioning operation to be mechanised. I think that the first proposals for mechanical tong positioning were suggested in the Norwegian fields before the priority date ^[4]. At any rate, by the priority date of the Patent, mechanical means had already been devised for achieving this^[5]:

"The combination of an existing tugger line to support the power tong and a light weight hydraulic arm to position the tong horizontally appears to be a natural evolution. Both devices were available before 1997 and each has been in use for many years in the very same application of handling power tongs."

In spite of this, I understand that the day of the human roughneck has not drawn to a close even now. As we shall see, the Patent opens with such a mechanical proposal for tong positioning. In my judgment, the mechanical positioning of tongs was certainly known and used before the priority date but there is some dispute as to whether it actually formed part of the common general knowledge.

The presence of both equipment and active personnel make the drilling floor a crowded and busy place ('pressure on space' as it was referred to). It is common ground that at all times, space has been at a premium on the drilling floor and any equipment which takes up unnecessary space at or near the wellhead when not in use is for that reason, undesirable. While the use of a tugger line to assist the manual or semi-manual positioning of tongs generated safety problems, it was at least not wasteful of space. Thus, any mechanical replacement for the roughneck (of whatever kind) had to be designed with space in mind if it was to be commercially attractive.

The Patent

The Patent has been drafted in 'problem and solution' form and the preamble at once opens by identifying the problem to which it is addressed. This is done by reference to an earlier Weatherford proposal for the mechanical positioning of a tong: PCT application ? WO95/10686 which was published before the priority date (but was not cited by BJ)^[6]. This apparatus was I believe made and sold as the Weatherford 'Pushmaster'. Since there was a threshold dispute as to inventive concept, I must consider this proposal more closely. The PCT application envisages making use of two rigid arms extending from a mounting on a beam of the drilling tower and meeting at a point where the tugger line and the suspended tong could also meet. The operative, working now from a console (thus perhaps, no longer being a roughneck), can fully position the tong (whose weight was largely being taken by a tugger line) by using the mechanical means described in the PCT application proposal. According to this proposal, the presence of a rig hand is no longer needed in the vicinity of the tong. The set-up is well illustrated in Fig 3 of the PCT application (the tugger line being shown as 'cable 109'). What is presently relevant however is the alternative mechanical means described in the PCT application whereby provision is made for the arms to be retractable piston and cylinder assemblies by which the tong can be brought up to (and away from) the tubular being manipulated as a result of the simultaneous movement of the pistons. The alternative is illustrated in Figure 4 of the PCT application. The Patent suggests however that this embodiment 'has not been adopted commercially' because of the following problem [§3]: 'the hydraulic pistons and cylinders and associated tong could not readily be moved out of the way to facilitate other operations on the rig floor.' This is the problem which the Patent seeks to solve. The narrative flows immediately to the consistory clause [§4] with the following words: 'With a view to reducing this problem…'. When I first read all this I was in no doubt that the Patent was in essence concerned only with solving this stowage problem. But this is not the way Weatherford see it and under 'Construction' (below) I shall have to return to the matter.

The Patent continues by again proposing the use of a conventional piston and cylinder assembly (101) in a retractable arm (a single one this time) to 'position' the tong. This is fixed in a 'mounting assembly' (102) for mounting on a 'convenient' support beam of the drilling tower, with the tong suspended at the far end of the retractable positioning arm. In its 'operative position', the tong can be moved towards and away from the tubulars by the human operative as required – rather as before in the PCT application. The Patent then describes an 'inoperative position' where the piston and cylinder assembly is fully retracted with the piston and cylinder assembly disposed to either side of the mounting assembly and the retracted arm being tilted upwardly at an angle so as to provide yet more space on the drilling floor. The proposal is easy to understand and the Patent is short. With this in mind, Figures 1, 2 and 3 of the Patent have been annexed to this judgment.

The positioning arm is telescopic, having three 'barrels' (104,105 and 106) with a piston and cylinder within them (103) for this purpose. At full extension, the arm can be deflected 'by a small amount'. It is fitted in a 'mounting assembly' which is mounted via a 'bearer' on a support beam 2 to 3 metres above the drilling floor. The mounting assembly includes bilateral ears which are drilled with holes to accommodate trunnions which project either side of a 'carriage' (111) for the telescopic barrels to move in and out of when in a fully retracted state. A clamp assembly (112) is bolted to the top of the carriage which maintains the piston and cylinder assembly in fixed position with respect to the mounting assembly.

The Patent next invites the reader to consider the fully retracted position of the arm when its free end 113 (and presumably, the tong) will lie adjacent the extremity (114) of the outer barrel (104). This much retraction, one is told, is 'for many purposes …deemed untenable' since this degree of retraction is insufficient. The Patent continues: 'The present invention provides a simple and elegant solution to the problem…' - by which I understand the patentee to be again referring to the 'pressure on space'.

The narrative now describes the invention in use [§20]: the bolts of the clamp assembly on top of the carriage are slackened and the entire piston and cylinder assembly slides backwards (and thus out of the way) within the carriage till the free end of the outer barrel (ie 114) is adjacent the mounting assembly 102. This leaves the major portion of the piston and cylinder assembly to the rear of the mounting assembly. The clamp on the carriage (112) is then tightened up again to prevent further sliding movement of the piston and cylinder assembly (101) and the ensemble is pivoted at an angle to the horizontal (in 'an upwardly extending axis') using the carriage trunnions as the pivot. If the tilt is downwards the tong rests on the drilling floor [§20], this being the first inoperative position. This may be seen in Fig 4 which I have reproduced below. If the tilt is upwards, a tugger line (called 'an overhead cable') is used in the conventional manner to suspend the tong (presumably from the fixing point at 113) whilst it is not in use [§21]^[7]. I note:

(i) that this is the only occasion in the Patent in which use of the tugger line is invoked, and

(ii) that the Patent gives no indication of the amount that the piston and cylinder assembly (101) has to be withdrawn in the inoperative position nor the degree that the assembly has to be pivoted to an 'upwardly extending axis'.

The 'upwardly extending axis' as shown in Fig 4 was about 55° whereas in Fig 5 it was only about 26° to the horizontal.

The Claims

The claims are product claims - and not method claims. Claims 1,2,4,5 and 6 are contended to be independently valid. Of these claims it is alleged that BJ's Leadhand Mk II infringes claims 1 and 4 and that BJ has infringed claim 6 by providing the Leadhand Mk II for installation on a rig. Whether or not there is infringement of claim 6 will depend primarily on whether the alleged infringement falls within claims 1 or 4. I have set out the integers of claims 1 and 4 in tabular form and will again use this breakdown when I consider infringement.

Claim 1 may be broken down as follows:

(i) An apparatus for positioning a tong

(ii) comprising a piston and cylinder assembly (101) and

(iii)a mounting assembly (102) therefore characterised in that:

(iv) the said piston and cylinder assembly can be pivoted between an operative position in which it can be extended and retracted to move a tong towards and away from a string of tubulars, and

(v) an inoperative position in which the said piston and cylinder assembly extends along an upwardly extending axis, and

(vi) with part of said piston and cylinder assembly disposed either side of said mounting assembly.

Claim 4 This claim, which is dependent in claim 1, may be broken down as follows:

(i) an apparatus as claimed in any of the previous claims wherein the said mounting assembly (102)

(ii) comprises a bearer (107) which can be clamped to a structural member in a drilling tower

(iii) a carriage (111) pivotally mounted on said bearer, and

(iv) a clamp assembly (112) for securing said piston and cylinder assembly (101) to said mounting assembly (102).

The Inventive Concept

It is usual to consider this topic as the first ingredient of the structured approach to assessing obviousness proposed by Oliver LJ in Windsurfing International (see below). However I must address the question now because the parties put forward significantly divergent views about the purpose and teaching of the Patent. In my view, the outcome of this threshold enquiry permeates the remainder of this judgment and so I must deal with it at once.

First, so Mr Birss says, rig hands/roughnecks are not these days much involved in tong positioning. I agree; that is indeed supported by the evidence. He submits that dispensing with such operatives altogether in the tong positioning process is the problem to be solved by the apparatus claimed in the Patent- just as it was in Weatherford's PCT application. This is thus an improvement on the proposal of the PCT application. This is also a patent for a product and it is quite wrong to view it as a proposal for (in effect) a method of stowage. The problem is overcome by the apparatus (which is clearly described) together he added, with the tugger line ('or some such' as he put it) – ie the two in combination.

Moreover, since the skilled reader would understand that the apparatus proposed by the Patent always requires a tugger line to be present ^[8], he would appreciate that this therefore is no mere lifting device; it is a 'tong positioning apparatus', which in use does not demand the presence of roughnecks. A saving of space on the drilling deck may indeed result from the installation of the apparatus but this as it were, logically flows from the inventive concept. In effect, space saving is merely a bonus. I have found considerable difficulty with that submission for a number of reasons – even without taking into account the possible impact of expert evidence on the point.

First, a fair reading of the Patent as a matter of ordinary English, tells me from start to finish, that this is a proposal for apparatus which results in the more efficient stowage of a basically known type of hydraulically retractable arm for positioning a tong. As a matter of language, the contrast is between an operative and an inoperative position of that arm and the apparatus claimed is said to achieve this. Furthermore, I have already drawn attention to the only instance in the narrative where mention is actually made of a tugger line (Col 3, ll 27-30). This mention is in relation to the storage of the tong in the alternative inoperative position and even then, it is unclear whether the tong is suspended from the tugger line or from a further line attached from the hydraulic assembly. Moreover, this 'omnipresent' tugger line is not an integer in any of the claims. The fact is that the Patent does not explain and its claims do not specify how the weight of the tong is to be supported: that is left to the reader. No doubt, if necessary, this could be done with a tugger line. But it could also be done by a crane (see above and below).

I found that Mr Alexander's submission on this point well accorded with my own first impression: that the inventive concept lies rather in 'maximising the compactness' of the apparatus when it is not in use by arranging for three things to be done:

(a) First, the free end of the extendible arm is hydraulically retracted from its work point into the arm in a well-known manner.

(b) Next, the arm with the free end thus retracted, is caused to be tilted 'upwards' about a pivot thus moving it more out of the way.

(c) Finally (and additionally), the arm is located yet further away from the drilling area by arranging for it to lie in repose 'to either side of the mounting assembly'.

Mr Alexander submitted that the means of supporting the tong weight is not nor is it claimed to be, part of the invention. That seems to me to be supported by a layman's reading of the Patent. However, the layman is not of course the proper addressee of the Patent and I can come to an informed conclusion on the inventive concept only after assessing the likely impact of the teaching of the Patent on the skilled reader. I shall therefore next focus on that notional person.

The Skilled Addressee

The addressee of the Patent, also known as the 'person skilled in the art', is a notional construct who is used by the court for a number of purposes in patent matters. I was not addressed on the law relating either to the skilled addressee or to the common general knowledge which he is deemed to possess. For the record however the principles are set out in Terrell on the Law of Patents 15^th edn §§ 6.25-6.28.

The description of the skilled addressee which I think both sides were content with, was approximately the following ^[9]: 'A qualified engineer working in the oil drilling industry (inland or offshore) involved in particular in the design, development, installation and maintenance of inter alia tong positioning devices.' In other words, one will have in mind a qualified working engineer having the basic specialist 'engineering toolbox'.

The Expert Witnesses

Only two witnesses gave evidence at trial, both being the parties' experts. Before considering their evidence however, I must just deal with a matter which much exercised Mr Birss. BJ had intended to call their Technical Services Manager, a Mr Barker, but did not do so. He served three witness statements and was in Court for most of the trial. He was the designer of both the BJ Leadhand Mk I (the late citation in the pleaded prior art) and of the Leadhand Mk II, now said to infringe. In one of his witness statements he admitted measuring Weatherford's mounting assembly for its Powerscope arm. Whilst accepting the irrelevance of copying to any pleaded issue, Mr Birss invited me nevertheless to draw a strong inference against BJ when it came to obviousness: it apparently required a close examination of Weatherford's Powerscope to enable Mr Barker to design the Leadhand Mk II. "How was the infringing device arrived at?" asked Mr Birss. "The Court should be told where Mr Barker got his ideas from."

Though I have not yet considered the obviousness attack, I can say now that I am drawing no adverse inference from the incident for the following reasons. First, though this is a specialist field, it is hardly one of high technology. As I have already said, the Patent is essentially concerned with solving a storage problem. This is not for example a situation in which the manner of working of the invention can only properly be understood by an exercise in reverse engineering of an example of it. The essentials of the claimed apparatus can be gleaned by any competent engineer from an example of it at a glance. More importantly, obviousness falls to be assessed objectively. Like 'long felt want' (which is not an issue in this case), such an 'antidote to obviousness' is at best only a matter of secondary evidence. Finally, it is my experience that particularly in specialist fields, competitors keep a keen eye on what each other is doing. There is nothing sinister or wrong with that as such.

Weatherford's expert: Mr George Sangster. Mr Sangster began his professional career as an agricultural engineer in Scotland but by 1970 he was working in the North Sea oil drilling industry and has in fact never left that industry. Mr Sangster has worked over 30 years for specialist drilling equipment and drilling instrumentation manufacturers and has visited numerous rigs all over the world in connection with the commissioning and repair of such equipment. By far the longest of his time was spent with a company called Varco - from 1974-2004 in fact. Varco is a major player in the industry; it makes drilling and pipe handling equipment. But it is by no means the only such manufacturer and Mr Alexander criticised his evidence as being 'Varco-centric' and thus lacking a more generous perspective. I have borne this in mind.

BJ's expert: Mr John Gammage. Mr Gammage has a degree from the University of Bristol (1970) and has attended several specialist petroleum industry courses. He has worked for a number of leading companies in the field – also for about 30 years – starting as a rig operative. He began his career as a 'roustabout'^[10] in 1975 on onshore rigs and thereafter worked his way up the rig hierarchy in a 'hands on' way. He became a 'toolpusher' (ie rig foreman) in 1984 and later rig manager (1990). He has also worked as a rig constructor and in the latter capacity he was involved in design and fabrication. He has worked on rigs all over the world. Significantly for present purposes, he worked for 10 years at BP's Wytch Farm field in Dorset, the largest oilfield in Western Europe. He was an ExxonMobil consultant till 2004 and now works as an independent consultant to the industry. During his career he has worked with both litigants in this action on various projects.

Both experts were of assistance to the Court; both fulfilled their duties very well. However, in issues involving practice on the drilling floor I prefer the evidence of Mr Gammage when it conflicts with that of Mr Sangster. I felt that his practical experience in such matters made his evidence more realistic and valuable.

I shall also say at this juncture that nothing either expert told me has made me revise my prima facie view as to the thrust of this Patent; it is a proposal for an apparatus for the better stowage of certain drilling equipment, the apparatus enabling the three stage 'putting away' process which I have already described, to be carried out.

The Common General Knowledge

In the 'Introductory Technical Background' section of this judgment, I have set out some relevant general knowledge with regard to drilling floor practice at the priority date and in particular, the practice with regard to the positioning of tongs: see §§ 5-8 above. I have also stated my prima facie view (confirmed by the experts) as to the gist of the teaching of the Patent. I incorporate this into this section by reference.

There are several matters to be investigated under this head: first, knowledge of the need to maintain clear working space on the drilling floor and thus the concomitant need to eliminate 'protruding objects'. I have already dealt sufficiently with this; the need was well known and proposals had been made to deal with it. I gained the impression that general engineering techniques would automatically be invoked by the skilled man to cope with the matter. Flowing from that, there is the further question which pertains to this field: knowledge of how telescopic arms might be stowed out of the way when they are not required since the universal use of such arms on rigs seems to be accepted. Mr Gammage deals with this in [61] of his Report.

Telescopic retraction into a sleeve. "Any telescopic structure will normally be collapsed for storage": Gammage Report §61 I. It was in fact common ground that the use of telescopically retractable structures to minimise the size of an enormous number of items while not in use was well known at the priority date (and, I suspect, for years before it) not only to the skilled addressee but probably to a broad section of the public as well. In relation to heavier apparatus, telescopic collapse was assisted by the use of hydraulic piston and cylinder mechanisms. One only has to think of such items as crane arms, collapsible aerials, mechanically retractable aerials for use in motor cars, masts on small boats and a legion of other items as well. Moreover, in the case of e.g. aerials, the majority of the telescopically collapsed aerial will slide into and project behind a sleeve so as to be stowed out of the way - yet still be retrievable as required. See Mr Gammage, in his Report §61 K : "It is common to slide long objects back through a sleeve to protect them and/or to make them more compact or less intrusive." None of this was challenged.

Storing upright or at an angle by pivoting. I am also sure that at the priority date it was part of any design engineer's common general knowledge that if one wanted to get a working element out of the way when not in use, one common expedient was if possible, to stow it vertically – up or down. Again, one's experience of say, ironing boards, couchettes and bunk beds etc confirm the self-evident commonsense of all this. Mr Gammage included in this proposition hydraulic arms and regarded it as being particularly relevant when space is at a premium ^[11] : "If one wants to store something out of the way, it is often convenient to store it vertically or near vertically. This is particularly relevant to offshore drilling rigs where space is at a premium." I am not surprised that this was not the subject of cross-examination. Moreover, Mr Sangster, agreed in cross-examination that on an oil rig, if one wanted to get say, an arm out of the way one could "Stick it up in the air safely." : see D2/222.

Mounting an elongate device at or near its mid-point. In his Report, Mr Gammage says this ^[12]: "It is often desirable to support long structures at or near their mid-point so as to minimise stresses and strains in the item." Again, this was not challenged.

Finally I note and accept the following observation of Mr Gammage ^[13] :

" Storing something in a vertical or near vertical position, reducing a telescopic structure to its shortest possible length and sliding the structure back through a sleeve [were] well known ideas which form part of the skilled addressee's common general knowledge."

Again, I am not surprised that this statement went unchallenged in cross-examination.

Construction

I was not addressed at any length on the law to be applied. I need therefore only record that the two recent authorities to which my attention was drawn (and which I have of course followed) were: Kirin-Amgen Inc v Transkaryotic Therapies Ltd [2005] RPC 9 (HL) and Mayne Pharma Pty Ltd v Pharmacia Italia SPA [2005] EWCA Civ 137 §5 (CA). Both sides emphasised the need for 'purposive construction' on a number of occasions.

The proper construction of many phrases in the claims was in contest.

Claim 1 integers

'An apparatus for positioning a tong'. First, 'for' in that phrase is I believe, to be construed in the sense of 'suitable (without alteration) for': Bühler AG v Satake Ltd [1997] RPC 232 at 239. It does not necessarily require the apparatus of the prior art to be designed with the very purpose of the claim in mind. I shall come back to this matter later in this judgment under 'Validity'. But there is a more important point. Weatherford consider that there should be read into this integer a requirement for the apparatus to position the tong with a fair degree of both vertical and horizontal accuracy. Mr Sangster goes so far as to say that the vertical accuracy required is plus or minus two inches ^[14]. I can find no support in the Patent for such a reading. The claim does not even require that the device actually positions the tong around the tubulars; it merely requires that in the operative position, the apparatus moves the tong 'towards and away from a string of tubulars'. In evidence, Mr Gammage observed that in use, a power tong is to some extent self-positioning in that once the tong is approximately positioned, closing the doors of the tong and rotating the dies, will self-centre the tong around the casing^[15]. This is the area of evidence where I feel more confident in the hands of Mr Gammage than Mr Sangster.

Which apparatus comprises a piston and cylinder assembly' 'Comprises' means 'includes'. Thus the phrase does not exclude a device which may include other things (such as other hydraulic assemblies doing other things) which are not mentioned in the claim. The claim will identify what the patentee regards as being the essential features of the invention.

'Mounting assembly'. Weatherford invite the implication that the phrase requires rapid or easy disassembly ie a degree of versatility in installation and removal –even portability. In my view this submission is wrong as a matter of English and may I believe, have been generated with an eye to the prior art. This is not the right approach to the construction of the claims of a patent. Mr Alexander said that if the Patent is indeed directed to storage of the tong positioning arm (as I believe it is), then there would be no point in a reading of this phrase which suggested a benefit of actual 'dismountability' between periods of use. I agree. Following the Weatherford argument, he also said that if a person were to make a device identical to that proposed in the Patent except with a larger or permanent mount, on that argument, it would not infringe. I also agree. In fact, under cross-examination in relation to the prior art, the importance of this construction point shrank considerably. Weatherford also submit that the mounting assembly may be regarded as the pivot point alone that is, simply the trunnions (111) in fig 2 of the Patent. I think that that is an unsupported and strained meaning, probably fashioned for the purposes of infringement. In any event, in my view, it is wrong (see below).

'Move a tong towards and away from a string of tubulars.' There was a suggestion by Mr Birss that there was an implied limitation in this phrase that restricted the movement of the arm to extension in a straight line ie no 'slewing' to either side during positioning. In my view, there is no warrant in the Patent for such a limitation.

'can be pivoted between an operative position…and an inoperative position.' In my judgment, this means 'is physically capable of being pivoted between such positions' even if it may not always have to be stored in the inoperative position. Capacity for such storage is what counts. Again, this point seems to have arisen with an eye to the prior art.

'An upwardly extending axis'. The experts differed as to what degree of upward extension would be regarded as sufficient to minimise unwanted intrusion into the drilling floor area. I am not sure that this is the right way to consider the matter. For a start, fulfilment of this integer for that reason will depend (for example) on the available floor space of the rig, the size and weight of the tong and its associated apparatus and perhaps other factors as well. I also felt that with regard to this integer, Mr Sangster may have had his eye on the prior art whilst Mr Gammage may have had his on non-infringement, thus heralding a 'squeeze' (see below). Mr Gammage for example, calculated a number of 'reductions in horizontal intrusion' towards the well centre (as a percentage) and came to the conclusion that an inclination of anything less than 45° to the horizontal yielded no or negligible benefit in this regard – thus in his view, taking a device of this character outside the claims. Mr Sangster disagreed: a modest degree of upward extension sufficed. For my part, I feel that 45° is an arbitrary figure. In my judgment, there is in fact no reliable 'magic' range of angles below which the benefit is absent and the integer may be said to be avoided; it is a question of fact and degree. I have noted that one figure in the Patent shows the stowed arm at 55° (fig 4) whereas another (fig 5) shows it at a mere 26°. I think that the way the integer would be understood by the skilled addressee is this: if there is some space saving benefit by stowage at an upward angle, that is enough. In each case one has to decide whether the apparatus under consideration contributes in some beneficial way to the 'pressure on space' problem with which the Patent is directed. It is a value judgment and not really a question of mathematics at all.

'With part of the said piston and cylinder assembly disposed to either side of the mounting assembly.' This is an important aspect of the proposal since the benefit claimed of the apparatus is not just telescopic collapse of the arm and its pivotal movement to an upwardly extending axial position. The inoperative position also requires a third locational limitation wherein part of the collapsed piston and cylinder assembly is disposed to either side of the mounting means^[16]. There are two aspects to this integer. First, the language of the claim does not require that this is achieved by further retractive movement of the arm through and somewhat to the rear of the mounting assembly as in the embodiments described. In the mechanism described in the Patent, this is done by a continued sliding movement after the normal telescopic retraction – but the claim is not so limited. Next, there was some difficulty over the word 'part' – which remains undefined. One has to apply some commonsense to this integer, I think. The narrative ([20] ll 22-24) refers to a 'major' portion of the piston and cylinder assembly lying to the rear of the mounting assembly. This also ties in with the drawings of the Patent. In my judgment, construing this part of the claim is likewise not a mathematical matter; in each case fulfilment of the integer falls to be assessed by whether a real degree of enhanced compactness in storage is achieved having regard to the differing 'operative and inoperative' positions of a device of a particular size.

Claim 4 integers

'Carriage (111)' and 'clamp assembly (112)'. The parties disagreed on the meaning of these words. Neither are words of art and both in my view look for context in the narrative. Col 3 lines 11-20 read as follows:

'The present invention provides a simple and elegant solution to the problem. In particular the clamp assembly (112) can simply be slackened, the piston and cylinder (101) can be slid on the carriage (111) until the extremity (114) lies adjacent to the mounting assembly (102) and the clamp assembly (112) re-tightened'.[Emphasis added]

Mr Birss submitted that in context the 'clamp assembly' was a temporary clamp. I agree. The next issue is whether claim 4 requires the retracted telescopic arm to be slidable between the two positions relative to the mounting assembly so as to achieve the benefit of the third stowage position of claim 1. 'Carriage' in context is any supporting structure which (on unclamping what is supported) may allow the assembly to move longitudinally relative to it - to a desired extent - before being re-clamped to maintain the arm in its inoperative position ready if desired, for use again.

Infringement

As noted, there is an agreed description of the Leadhand Mk II which is made in four 'Configurations'. The only integers of claim 1 which were in issue on the question of infringement were integers (v) and (vi): see §16 above. In their closing submissions, counsel for BJ helpfully epitomised their position on infringement by means of a table cross- referencing the various Configurations with the integers of the claim.

The Leadhand Mk II device may be connected to the drill rig by one of four variants or Configurations – all of which are described and drawn in annexes to the Product Description: see B/11. The arm is the same in each case but the mounting method and positioning varies somewhat between the Configurations. Rather than set out drawings of all four Configurations, I have reproduced below the general arrangement drawing of the second Configuration which is to be found as Drawing 1 on page 5 of the Product Description. For the purposes of the general description of the device and how it works it may I hope, prove to be sufficiently representative.

The Leadhand Mk II is described as a tong positioning device and an example of it was inspected by the experts for the purposes of compiling their reports ^[17]. It consists of a piston and cylinder assembly mounted on a rig by means of a mounting plate D on a beam or post. The piston and cylinder assembly actuates a three part telescopic arm A, section F of which is attached to 'saddle' G. Sections J and K slide inside section F. At the free end of the arm hangs a tong H supported at the same end (when in use) by a conventional tugger line I. The arm has no ability to slide through or in any other way pass saddle G. The telescopic arm is capable of extension to and retraction from the string of tubulars to enable the tong to be positioned to do its job (the operative position) and to be taken away again. When the job is done (the inoperative position), the arm may be stored in a telescopically collapsed position. The other end of the arm carries trunnions which engage with the mounting assembly enabling the arm to be raised up at a shallow angle for storage in an inoperative position.

Claim 1/Configurations 1 and 2

In Configurations 1 and 2 (ie. Drawings 4 and 1 of the Product Description), Mr Alexander relies on the fact that the positioning arm can only be raised or lowered through (so Mr Gammage says) 20° above/below vertical; these are the maximum angles of pivotal movement and correspond to a mere 6% reduction in horizontal intrusion towards the well centre. There was some numerical disagreement between the experts regarding the value of the angle of available movement between the operative and inoperative positions. The numerical difference is not great however and as a working compromise, I shall assume it to be about 25° - of the same order in other words as that shown in Fig 5 of the Patent. Basically, Mr Alexander said that there was no infringement of this integer (that is, integer (v) –see §16 above) in these two configurations because Leadhand Mk II did not afford the benefit promised by the Patent. It will be recalled that Mr Gammage's view was that this benefit would really be felt only when the angle was about 45° or more – and that I rejected that as an arbitrary figure. Mr Sangster maintained that the 20° movement did save some space: see D1/113-116. Space saving said Mr Birss, is not just about the 'shadow on the floor'.

At the angle of 25° there would thus appear to me to be some benefit-albeit small -in the saving of space on the drilling deck by virtue of the arm pointing in an upwardly extending axis in its inoperative position. I therefore hold integer (v) to be fulfilled in these two Configurations.

In Configuration 1, fulfilment of integer (vi) is now admitted. Whether in its operative or inoperative position, the protrusion of the arm to the left of saddle G is plain to see: the arm rests in the middle of the saddle. If the claim is valid, it is thus infringed by Configuration 1. This is not however the case with Configuration 2 where, in relation to integer (vi) only a very small portion of the fixed end of the telescopic arm permanently extends beyond the mounting assembly, the remainder remaining obtrusively protuberant to the front of the machine. Furthermore, in reaching a view about this integer, one must look at both ends of the arm. I am not prepared to hold that this 'stub' N falls within integer (vi).

Claim 1/Configurations 3 and 4

Integer (v) of this claim is met in these Configurations (see Drawings 5 and 6 of the Product Description, respectively). However, with regard to integer (vi) of the claim, BJ's argument is similar to that raised for Configuration 2. No part of the piston and cylinder assembly is disposed behind or beyond the mounting assembly in the inoperative position (which note, is not where the trunnions are located– see above). Mr Gammage said this ^[18]:

"Utilising the end mounting plates D always leaves a very short length of the overall telescopic arm, half the length of the saddle, to one side of the pivot point at whatever angle the arm lies, operative or inoperative."

Weatherford's argument was based of course on the relevant 'point' being the pivot point; this is an argument which I have rejected^[19]. In summary, if claim 1 is valid, only Configuration 1 infringes it.

Claim 4: 'Carriage' and 'clamp assembly'

In this section, I can deal with all four embodiments together – as did Mr Gammage ^[20]. In my judgment, the carriage of claim 4 and the saddle of the Leadhand II are not the same in function: see above. Once installed, the arm of Leadhand II remains in a fixed relationship to its saddle; there is no translational sliding and there is no carriage. None of the Configurations therefore infringe this claim.

Validity

The Law

I was not addressed at any length on the relevant law. As to novelty I have followed the classic approach of Sachs LJ in General Tyre Co v Firestone Tire Co Ltd [1972] RPC 457 at 785. As for obviousness, I have been guided by the structured approach to the subject by Oliver LJ in Windsurfing International Inc v Tabur Marine (GB) Ltd [1985] RPC 59 at 73. As to the latter, I have identified the inventive concept and the common general knowledge earlier in this judgment.

General matters

All four citations (see §3 above) describe devices for handling objects by means of a telescopic arm which is extended and retracted by a piston and cylinder assembly to enable an object at its free end to be manipulated. Furthermore, all describe a device in an inoperative position when the machine is not in use. In this position, the telescopic arm is retracted and the device further compacted for storage in order to remove it from the working site. Two of the four citations are specifically for positioning tongs and the evidence shows that all the devices cited have been used on drilling rigs.

Before addressing BJ's citations seriatim, I may usefully revisit some observations which I have already touched upon under 'Construction'. First, it was accepted that in the case of two of the citations (the MH Arm and the Ferrari Crane), neither had been designed specifically to manipulate tongs. The MH arm had been primarily designed to manipulate and position tubulars whilst the Ferrari crane is a general purpose lifting device. The Bühler case (supra at 239-241) provides guidance as to how the court should approach product claims in novelty cases when it is faced with a citation for a product intended to be used for another purpose. This may often be an important threshold question. The first feature of claim 1 in Bühler was for a roller mill for the rolling of cereals. The prior art citation (Linden) concerned a roller mill for milling sticky substances such as chocolate or paint. The evidence was that to enable this to be adapted for milling cereals, the Linden mill required significant alteration viz the addition of 'a hopper in the right place'. It was not therefore a candidate for proper consideration on the issue of novelty. The question in general is no doubt one of degree; adaptation for a new purpose does not automatically amount to alteration.

In the present case, in relation to the telescopic arms described in these two citations, the threshold issue of their ability accurately to position a tong was questioned by Mr Birss. I have rejected the applicability of this issue for two reasons. First, accurate positioning of the tong (in both vertical and horizontal senses) does not feature in the teaching of the Patent (see above). The second issue is whether the lifting heads of these telescopic arms can be adapted without alteration for positioning tongs; see Bühler. The evidence shows that in both cases, they can easily be so adapted. If a citation is capable of positioning a tong it is 'an apparatus for positioning a tong'. All the citations fall within the opening words of the product claims of the Patent.

Another issue arose in that some of the prior art did not teach stowage of the arm in an upwardly extending position; stowage was proposed in other positions. This is also irrelevant to present issues- if the arm was capable of stowage in the upward position, that is enough.

I need only consider validity in relation to claim 1. Claim 4, which is alleged to be independently valid, is dependent on claim 1. The integers added by claim 4 (in particular the idea of a clamped fixing) are not disclosed or in my view, foreshadowed in any of the prior art citations. And the evidence in relation to the obviousness attack on claim 4 in the light of those citations is sparse. In my judgment, claim 4 is valid.

Finally, Mr Alexander accepts that telescopic retraction through the mounting assembly to achieve disposition to either side of the mounting assembly, the third stage of the stowage operation claimed, is not 'clearly and unmistakably' shown in any of the prior art citations. But neither, he submits, is it required by claim 1; what is called for is the physical disposition of part of the piston and cylinder assembly to either side of the mounting assembly regardless as to how this may be achieved. There is a consequence to this, he says: it puts a classic infringement/validity squeeze on Weatherford; the so-called 'sliding feature' is not relevant because it is not claimed.

The Prior Art Citations

The MH Manipulator Arm [C/5] This citation covers one page (in colour) of a 1990-1991 trade catalogue. It consists of a photograph of the MH arm mounted overhead on a rig, together with an explanatory diagram and some performance figures. Without expert assistance, the citation did not provide me with much technical information. It was however common ground that the arm of this general purpose rig tool is telescopic and may be retracted when not in use ^[21]. This is done by use of a piston and cylinder assembly, the hydraulic hosing for which is visible. The stroke length one is told, is in excess of 8 meters. The arm may also be tilted via a pivot from the horizontal in an 'upwardly extending axis', say at about 45° down and 10° up, as shown in the diagram which I have mentioned - when in an operative position. When fully stowed, being mounted overhead and not to the side, the MH arm would normally be in a horizontal position so as to get it completely out of the way, the telescopic arm then also being retracted. This is of course the opposite of what is called for in the claims; the 'nose up nose down' positions are different. I accept however that on stowage or on standby there could be an inoperative position with the telescopic arm at a slight angle yet being still clear of operations on the drill floor. However, this is not shown in the citation and there is I consider, no anticipation for that reason alone.

Mr Gammage explains that the MH arm is primarily a device for the wholly mechanical manipulation and positioning of tubulars and other heavy items on a rig -with a tugger line. He says that it would nevertheless be 'perfectly suitable' for positioning the power tong as well ^[22] - presumably also with a tugger line. He also says that it would in fact be 'a trivial engineering task to adapt the fitting at the end of the arm so as to handle a tong'. The end fitting as shown appears to be a claw of some sort. I do not believe that that was seriously challenged and following Bühler (above), I think that the threshold integer to the claims has been met: this is an apparatus for positioning a tong.

The MH arm is undoubtedly a behemoth of a device, a 'big beast' as Mr Birss observed ^[23]. Mr Sangster suggested that it is far 'more muscular' than would normally be required merely to position a tong and suggested that it was entirely appropriate to regard it as a heavy lifting crane with no capacity at all accurately to 'position' an item dangling from its free end. I do not accept the relevance of that, having regard to the conclusion I have reached on the irrelevance in context of accurate positioning of the tong. There was a conflict of evidence about the ability of this arm to position items with accuracy. Mr Gammage was able to show I believe, that the machine had some ability to position tubulars with relative accuracy. There is also provision on the mounting assembly for slewing movement which would assist in this. I am satisfied however that this is not a crane; it is a large push/pull positioning device for use with suspended pieces of drilling equipment- with a tugger line. In this connection I note that the item is in fact referred to in the Catalogue as a 'Drill floor Manipulator Arm'.

The mounting assembly (see above under 'Construction') may be seen (but not in detail) in the photograph. It supports the piston and cylinder assembly from above at about the mid-point of the arm and when in the inoperative position, part of this may (I stress, may) lie collapsed to either side of the mounting assembly. Mr Sangster in fact accepted that the MH arm had a mounting assembly: D1/143-146 but did not I think accept that the last feature of claim 1 ('disposed on either side of the mounting assembly') was either shown (which I believe, is correct) or was necessary in the inoperative position of the arm.

What would the skilled worker seeking to implement the then current desideratum in the industry for mechanical tong positioning have made of the MH arm at the priority date? The fact that it is not described for use as a tong positioning apparatus would not have put him off (see above) and neither I believe, would the sheer size of the machine; tongs come in different sizes. Mr Alexander accepted that the MH arm might require some 'scaling down' but submitted that that to do so was not inventive. I agree.

In my judgment, the skilled worker would I believe be able to make the modifications suggested and come up with a workable machine for manipulating tongs - without the use of inventive capacity. But that would I think, still leave the MH arm so modified apparently outside the scope of claim 1 for lack of integers (v) and (vi) of claim 1. I can find no evidence as to why the skilled addressee need or should go further. The obviousness attack on the basis of the MH arm therefore fails.

The Ferrari 535 Crane [C/1-4] No one doubted that this was a general purpose crane with a telescopic arm powered by a piston and cylinder assembly. Use is also made of a second piston and cylinder to raise and lower the telescopic arm and there is capacity for swivel in a vertical plane – these being irrelevant for the purposes of this enquiry. It has found wide application. It has been fitted (for example) to the rear of builders' lorries, for over 30 years –but it seems never to have been fitted to drilling floors ^[24]. The telescopic arm is of course used to move objects to and away from a location.

Mr Gammage remembers using a Ferrari crane to handle oilfield equipment in Aberdeen in 1976 and BJ it seems, actually tried it out for mechanical tong handling on land before the priority date: see F/6 and D2/186-188. Mr Gammage suggests that it could be used to position a tong on a drilling floor even without a tugger line – though the use of the latter (as with the apparatus proposed in the Patent) would obviously depend upon the size of the chosen tong. Mr Sangster made much of the absence of the need for a tugger line in using the Ferrari crane to try to distance it from the disclosure of the Patent. For the reasons already given, I am not impressed with this argument, largely because a tugger line is not a featured integer of any of the claims in issue: see D2/187. Mr Birss also raised the issue of how accurately a tong might be positioned using a Ferrari crane. For the reasons already given, this argument is irrelevant, in my judgment. It also does not accord with my occasional observation of how accurately heavy pallets are offloaded from builders' lorries using cranes with telescopic arms. Moreover, nothing turns on the need (if necessary) to adapt the free end of the arm so as to suspend a tong ^[25]. In my view, the Ferrari crane is an apparatus having a telescopic arm powered by a cylinder and piston assembly 'for positioning a tong' which is capable of being manoeuvred between inoperative and operative positions.

With regard to the 'mounting assembly' this may be seen from the first drawing in C2; it is in a central symmetrical position. Weatherford say that in order to mount this crane on a rig, the rig floor would require substantial modification so as to bear the stress imposed by use. Again, having regard to my findings on the proper interpretation of 'mounting assembly', I can find no basis to justify this criticism even if it were technically correct. In fact, mounting the crane on a rig presented no real problem for the experts. Mr Sangster agreed that the device had an assembly which could be used for mounting and also accepted that such cranes were actually used on the pipe decks of drilling rigs ^[26] ie just below the drilling floor. Mr Gammage specifically addressed the method of mounting: four bolts would be inserted into the rig floor^[27] - as simple as that.

The drawing I have referred to shows how the Ferrari crane is self-stowed in its 'inoperative position'; it is hydraulically folded up on itself about three pivoting locations. In this position, the piston and cylinder assembly in the retracted outer arm can be seen in repose along an upwardly extending axis: see D2/195.

The last integer of claim 1 also appears to be met viz that in the inoperative position, the piston and cylinder assembly are either side of the mounting assembly. Again, this can be seen from the drawing. The 'sliding feature' it will be recalled, is not called for on a proper reading of the claim. In my judgment the Ferrari arm anticipates claim 1 of the Patent.

US patent No. 4,843,945 [Dinsdale] [C 6]. This a somewhat complicated Texan apparatus for 'making and breaking threaded well pipe connections' by means of a pair of telescopically extendable and retractable cantilevered arms for supporting and positioning a tong ^[28]. Dinsdale is a long and detailed narrative which is supported by no less than 22 drawings. Two basic embodiments are proposed the first of which (Figs 1-6) makes no use of a tugger line to support the tong – which as already noted, is irrelevant to this enquiry. BJ placed all its emphasis only on this first embodiment for which they helpfully provided reproductions of Fig 1 (inoperative position) and Fig 3 (operative position)^[29], with relevant parts shown in colour. In my view, this initial 'filtration' out of the second embodiment was conditioned by knowledge of the Patent and is not I think, objectively justified.

In view of the way Mr Alexander used this citation by the time of his closing address, I do not propose to go through its teaching. Suffice to say that all the integers of claim 1 is present in the first embodiment of Dinsdale except for the last integer viz the position of the retractable arm required in the third stage of stowage. In Fig 1, the piston and cylinder assembly (coloured blue in the drawings) is positioned vertically but entirely to one side of the mounting assembly (10), coloured red in the drawings. There is thus no question of anticipation. Compact stowage of the tong and its cradle and the two retractable arms can clearly be seen in Dinsdale's Fig 1. In my judgment, the evidence does not justify anything further being done to Dinsdale's proposal which might save more space on the drilling floor. Indeed, looking at fig 1, I find it hard to see how further space can be saved by adapting Dinsdale. Dinsdale is an engineered and complex proposal; if it delivers in terms of space saving, I see no reason to fiddle with it. I shall not therefore further consider this citation.

Leadhand Mark I [See the photograph at G/9, the letter at J/21, the Ocean Alliance Report G/21 and E/30] Mr Birss sought to emphasise the poverty of BJ's case on invalidity by pointing to the fact that this citation was not only a BJ product but they considered it necessary to introduce it a mere week before trial. His insinuation was perhaps that it was the shortcomings of Leadhand Mk I that led to the allegedly infringing Mk II. Let us first see how Leadhand Mk I is made and how it works.

The Leadhand Mk I is a heavy duty jib-type crane with an extendible arm which could lift and position a tong (horizontally and vertically) by means of hydraulic lifting cylinders. It was intended to avoid the need of 'a couple of roughnecks to pull the tong on'. Mr Gammage had personal experience of this device as it had been installed at Wytch Farm in Dorset where he was working at one time [See Gammage 3]. It was apparently rugged enough to be used without a tugger line and was also capable of slewing ie rotating about a vertical axis, in order to position the tong ^[30]. It could nevertheless have been used with a tugger line to support the weight of the tong and thus to position the tong without lifting: Sangster D2/717-218. There is however little emphasis in the evidence on this item of prior art between its operative and inoperative positions. As I understand it, once its work was done, the horizontal arm of Leadhand Mk I was hydraulically retracted in the usual way – and that was it. There is a squeeze argument regarding the second stowage integer (v) (ie that which calls for an upwardly extending axis of the extensible arm in the inoperative position). One can see from G/9 that the arm could be raised vertically to some degree in the inoperative position though this facility was in fact there for use in the tong positioning mode. The squeeze centred on the modest angle this cylinder was capable of raising the arm in the inoperative position. Nonetheless, in the light of my conclusions on construction, I am satisfied that as with Dinsdale, all the features of claim 1 are present except the last viz the disposition of part of the piston and cylinder assembly to either side of the support means. There is thus no question of anticipation.

Again, I have difficulty in following why the skilled man should adapt or modify the Leadhand Mk I so as to achieve more compact stowage in its inoperative position beyond retraction and modest elevation. The evidence does not satisfy me that it would be obvious to adapt or modify Leadhand Mk I to bring it within claim 1.

Common General Knowledge. This pleading relates only to the obviousness case. I have already stated what I believe to be the common general knowledge in the field: see §32 et seq.

Tong positioning by means of apparatus making use of extensible hydraulic arms and a tugger line to take the weight of the tong was common general knowledge at the priority date. So was the desideratum to move towards wholly mechanical positioning of tongs. It was also common general knowledge that on the drilling deck space was at a premium and thus, when not in use, ancillary equipment had to be stowed as compactly as circumstances would permit. How could this be achieved at the time?

Any telescopic member is normally retracted (or collapsed) for storage purposes; that is in part at any rate, why it is so made. The hydraulic retraction of telescopic arms after use was common practice not only on a rig but in a very large number of engineering, mechanical and other operations. In a similar category was the stowing of things in a vertical or near vertical manner so as to save space or just to get them out of the way whilst not in use. One can think of anything from shelves and bunk beds to the upward tilting of an arm about a pivot. Moreover in my view combining the benefit of the two stowing operations which I have just mentioned, even if not precisely part of the common general knowledge in relation to telescopic arms, was I think, wholly uninventive at the priority date. In this respect there is no evidence to suggest that considerations on a drilling rig were any different to any other operation in which extendible arms were used at the priority date. To my mind, the only issue on obviousness arises in relation to the last of the three stowage elements, integer (vi).

In approaching this question, I was impressed with the compelling evidence concerning space being at a premium on the drilling deck. I therefore think that it is a wholly reasonable entrée to begin with the skilled man being asked further to 'compact' a retracted telescopic arm which had already been tilted upwards to provide more working space on the drilling deck. There are no doubt a number of ways of fulfilling such an order, any one of which may or may not be obvious. All would involve some mechanical modification to the initial stowed configuration, the simpler the result, no doubt the better. In my judgment, arranging for a retracted telescopic arm to be stowed with a part on either side of its mounting (whether or not in addition, its axis was upwardly extending) would involve no inventive capacity whatever. Furthermore, in the light of Mr Gammage's unchallenged evidence, even the sliding an object back through a sleeve for efficient storage (which as discussed, is not a requirement of claim 1), was also part of the common general knowledge.

For these reasons, I am of the view that claim 1 of the Patent is invalid on the ground of obviousness in the light of the common general knowledge.

Conclusion

Claims 1 and thus claim 6 of the Patent are invalid. Claim 4 is valid but is not infringed by the Leadhand Mk II. The action will therefore be dismissed and the counterclaim succeeds. I shall hear counsel on the appropriate form of final order to be made in due course.

Note 1   I have referred to papers in the Court bundle by volume, divider and (where necessary) by paragraph. Thus 4/1/§§2-6. Transcripts are identified by day and page thus: D3/396    [Back]

Note 2   BJ’s product description is to be found at B/10/4-6 and B/11    [Back]

Note 3   D2/217    [Back]

Note 4   Gammage Report §61 L    [Back]

Note 5   Gammage Report §63    [Back]

Note 6   See 1/2    [Back]

Note 7   This is illustrated in fig 5 of the Patent which I have not reproduced.    [Back]

Note 8   Thus incidentally, differentiating it from BJ’s prior art crane proposals.    [Back]

Note 9   D1/§9    [Back]

Note 10   See D2/377    [Back]

Note 11   Report §61 H    [Back]

Note 12   Report § 61 G    [Back]

Note 13   Report §143    [Back]

Note 14   Report §§112.1 and 118.1[D/1/30.33]    [Back]

Note 15   Supplemental Report §§12-13    [Back]

Note 16   But not just the pivot – see above. It is the mounting assembly as a whole which is in focus in this integer and not merely the pivot.    [Back]

Note 17   But not by the Court. Colour photographs were made available to assist my evaluation of the infringement issue.    [Back]

Note 18   Report §124    [Back]

Note 19   Elaborated in Exhibit X/6    [Back]

Note 20   Report §§108-109.    [Back]

Note 21   “Exactly like the Patent”: Sangster D1/143    [Back]

Note 22   Report §172    [Back]

Note 23   ‘Weight 8.1 tonnes including tracker head’    [Back]

Note 24   D2/191    [Back]

Note 25   Gammage First Report: F/1/§161    [Back]

Note 26   D2/190-191    [Back]

Note 27   D2/339-340    [Back]

Note 28   In the general description, Dinsdale nonetheless foresees the possibility of implementing his proposal with only one arm: Col 2, line 40    [Back]

Note 29   C/6/26    [Back]

Note 30   I mention the latter simply because time was taken at trial over the point. In the context of the teaching of the Patent (see[24]) and the claims, I consider the possibility of slewing to be irrelevant.    [Back]