Case No: CHPCF/2001/2175/A3	
Neutral citation no. [2002] EWCA Civ 976 
IN THE SUPREME COURT OF JUDICATURE
COURT OF APPEAL (CIVIL DIVISION)
ON APPEAL FROM THE HIGH COURT OF JUSTICE
CHANCERY DIVISION PATENTS COURT
Laddie J.
Royal Courts of Justice
Strand, 
London, WC2A 2LL

Thursday 11 July 2002
Before :

LORD JUSTICE PETER GIBSON

LORD JUSTICE JONATHAN PARKER

and 

LORD JUSTICE LONGMORE

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Between :

	SABAF SPA	Appellant	
	
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MFI FURNITURE CENTRES AND ANOTHER	
Respondents	

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(Transcript of the Handed Down Judgment of
Smith Bernal Reporting Limited, 190 Fleet Street
London EC4A 2AG
Tel No: 020 7421 4040,  Fax No:  020 7831 8838
Official Shorthand Writers to the Court)
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Mr. Simon Thorley Q.C. and Mr. Mark Vanhegan (instructed by Messrs Field Fisher Waterhouse of London) for the Appellant
Mr. Alastair Wilson Q.C. and Mr. Peter Colley (instructed by Messrs Middleton Potts of London) for the Respondents

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Judgment
As Approved by the Court
Crown Copyright ©

Peter Gibson L.J. (giving the judgment of the court):
1.	This is an appeal in a patent infringement case.  Laddie J. on 25 September 2001 dismissed the action brought by the Claimant, SABAF SpA (“SABAF”), the registered proprietor of a patent, against the Second Defendant, Meneghetti SpA (“Meneghetti”).
2.	The patent in suit, GB 2,100,411C, is in respect of burners for gas hobs.  It was applied for on 12 June 1981 and it expired 20 years later.  SABAF is an Italian company, as is Meneghetti.  Meneghetti in Italy manufactured burners which it sold to the First Defendant, MFI Furniture Centres Ltd. (“MFI”).  Meneghetti’s burners were imported into this country for sale by MFI in its retail stores.  On 15 February 2000  SABAF commenced this action, alleging infringement of its patent by MFI and Meneghetti, who, SABAF said, committed infringing acts within the jurisdiction by importing its burners and by being a joint tortfeasor with MFI.  SABAF settled its claim against MFI, which took no part in the proceedings.  At the trial before the judge Meneghetti contended that the patent was invalid, that its burners do not fall within the scope of the patent, and that it had not infringed the patent, whilst in force, by doing any infringing act within the jurisdiction.  It denied being the importer of the burners and being a joint tortfeasor with MFI.  The judge held that Meneghetti’s burners did fall within the scope of the patent, and that Meneghetti did infringing acts within the jurisdiction by importing its burners from November 1998 onwards; but he dismissed SABAF’s claim that Meneghetti was a joint tortfeasor with MFI, and he held that the patent was invalid for obviousness, there being at the heart of the alleged invention the mere collocation of two well-known concepts.
3.	SABAF now appeals with the permission of the judge on the two points on which it failed.  In this court it argues that the patent was not invalid, and also it repeats its claim that Meneghetti was a joint tortfeasor with MFI.  Meneghetti, with the judge’s permission, cross-appeals on two points on which it was not successful before the judge:  it contends that its burners did not infringe the patent because one feature of the claims in the patent is not to be found in its burners, and that it was not the importer of the burners and so did no infringing act within the UK.
The facts
4.	The facts were set out comprehensively and lucidly by the judge and we need only refer to the salient facts to make this judgment comprehensible.
5.	 As the judge explained, the burning of gas on a kitchen hob involves the reaction of the gas with oxygen from the air.  Some air (“secondary air”) will come from the atmosphere surrounding the jet of gas leaving the burner, but that may not be capable of supplying sufficient oxygen to the gas.  Consequently it has for a long time been normal to pre-mix the gas with air (“primary air”) prior to it leaving the burner, so that what comes out of the burner is a mixture which contains sufficient oxygen to ensure that, when ignited in the presence of secondary air surrounding the burner, it burns completely.
6.	Gas can be mixed with primary air in a number of ways of which two are relevant.  One is by the use of a simple cylindrical tube such as is found in a Bunsen burner, the gas being mixed inside the tube with primary air drawn in around the gas injector.  Provided the tube is sufficiently long, there will be sufficient mixing within it to enable complete combustion.  The other way is by use of a Venturi tube.  Such a tube typically has a narrowing or throat such that on either side of the throat the walls of the tube widen.  Figure A annexed to this judgment illustrates such a tube as used for a gas burner.  In the centre of the mouth of the tube is the gas injector.  The gas injection causes primary air to be drawn into the mouth of the tube through the opening around the gas injector.  At the throat of the tube the gas and air are moving comparatively fast and have high kinetic energy.  As the walls of the tube widen out beyond the throat the flow of air and gas slows down, losing kinetic energy.  That loss of kinetic energy changes into potential energy, increasing the pressure of the gas and air.  That pressure recovery enables the mixed gas to be available at the holes in the burner at a sufficient pressure to force the mixture through the holes to the outside where it can be ignited.  As the judge stated, what happens in a Venturi tube is but one example of a general effect:  the increase in potential energy, generated by a decrease in kinetic energy, of a gas stream is a general phenomenon.  The same effect can occur otherwise than in a Venturi tube, for example when a gas stream leaves a tube and enters a fan-shaped space; the reduction in speed as the gas spreads out is accompanied by an increase in pressure, and the same effect occurs.
7.	With that background we turn to the amended patent.  The specification explains the invention in the following terms:
“BURNER FOR GAS COOKERS AND HOBS
This invention relates to a burner for gas cookers and hobs in general.
Various types of gas burners for cookers and hobs are known, but these have the disadvantage, among others, that they are relatively tall, for which reason they are not suitable or cannot be used for hobs which must have the most compact and flat structure possible.
Furthermore in burners of the known type the channels for the primary air intake always lead downwards, more specifically below the hob, or towards the oven, in the case of cookers provided with an oven, or towards the chamber or in any event towards the intakes provided for the purpose below the hob.
In addition to this the fitting and centering of burners of the known type is rather laborious and difficult, and once fitted the burners have little stability and are therefore susceptible to undue movement.
Thus they are fitted in such a way that access to and dismantling of the needle and gas injector, when necessary, requires the removal or lifting of the top plate of the appliance or the removal of the front, with the result that the operation is never easy and convenient.
These known burners are also rather rigid in their operating capabilities, in that they only ensure correct combustion for given pressure and gas flow conditions, a factor which means that such burners are not suited to every appliance and therefore makes it necessary to have a range of different burners to suit all requirements.
The object of this invention is to produce a gas burner for cookers and hobs which comprises units which can be combined with ease, are conveniently accessible and are easily separable so as to eliminate the inconveniences and disadvantages of existing burners.
Another object of the invention is to seek to provide a burner including units shaped so as to produce the so-called venturi effect in mixing and distribution of the gas, the said effect being obtained substantially between the support of the flame spreader and the flame spreader itself, in a radial direction and over a circular course from the centre towards the holes of the said flame spreader unit.  This provides the burner with considerable versatility and flexibility in use in that correct and complete combustion is maintained at all times even in the case of extensive gas pressure variations and with all types of gas.  The burner is therefore suitable for all operating requirements and can be fitted to any cooker or hob.
A further object of the invention is to seek to provide a gas burner of very low height which can therefore be used with advantage in hobs which must be flat or, in any event, as low as possible compatible with the installation requirements of the hob itself.
Yet another object of the invention is to seek to provide a burner in which the primary air for mixing is drawn from the exterior directly above the cooker top or hob, eliminating the provision of a closed and isolated box or air intakes below the said level as happens when traditional gas burners are used.
Yet another object of the invention is to seek to provide a gas burner which is easier to locate and centre and is stable when placed directly on the top of a cooker or hob, the said burner also being capable of being fitted with a flame spreader of the conventional type, which is therefore easily available.”
8.	There are 7 claims, but it is common ground that it is sufficient to look at the first claim.  The amended claim 1 is in the following form (as divided by the judge into numbered paragraphs):
“A  burner for gas cookers and hobs, comprising
(i) a support bearing a gas supply injector or needle,
(ii) a body associated with this support defining a chamber in which the gas is mixed with primary air drawn from the outside, and
(iii) a flame spreader unit mounted on the said body defining therewith a passage for promoting complete mixing of the gas and primary air and for the supply of the gas-air mixture for burning through the holes of the said flame spreader,
(iv) wherein the said support has a sleeve portion having a vertical axis and defining a chamber which is open at the top and closed at the bottom and contains the said injector or needle, the said sleeve portion having a peripheral flange by which it is securable to the plate of a cooker or hob, and the said sleeve portion being associated with
(v) a body having a tubular central portion defining a through opening which is concentric with the said chamber, and a peripheral portion with an edge which extends downwards to lie proximate to the said plate, in use, defining therewith a circumferential passage for the intake of primary air above the said plate, the said body having radial passages for passing the primary air into the said chamber in order to form the gas-air mixture,
(vi) and the flame spreader unit being supported on the said body overlying the hole in the tubular portion of the body itself, 
(vii) the upper surface of the said body and the internal surfaces of the said flame spreader unit, which are opposite to each other, define a radial passage of circular shape through which the gas-air mixture passes from the said through hole to the holes in the flame spreader with a suitable reduction in velocity and a recovery of pressure, the radial mixing passage being shaped to produce a venturi effect to promote complete mixing and distribution of the gas and the primary air.”
9.	The claimed invention was described by reference to a number of drawings of which Figures B and C annexed to this judgment are the most important.  There are three components:  a flame spreader unit (13), a removable body (12) and a support unit (2).
10.	The support unit has a “sleeve portion” which faces vertically upwards and has a bottom wall where the injector is located.  The bottom wall and sleeve portion create a chamber (5).  On the outside of the sleeve portion there are radial ribs (19) which define the radial passages for the entry of primary air.
11.	The removable body is mounted over and centred on the support unit.  The body has an outer skirt ending in an edge (17) which is located a short distance above the hob plate, thereby creating a circumferential passage (18) through which primary air can be drawn.  The body contains a central tubular portion (14), incorporating an internal circular sleeve which can be adjusted to ensure that the burner will work with different types of gas.  In the central tubular portion the flue includes a through opening (15) leading to the underside of the flame spreader unit.  The body also has radial centring fins (16) to ensure that the body fits into the open mouth of the chamber in the support unit.  Finally the flame spreader unit is mounted over the other components.  It has a row of holes (21) through which the gas/air mixture can leave the burner.
12.	The way the invention works is as follows.  Gas leaves the injector under pressure at the bottom of the chamber in the support unit and moves upwards.  As it does so, it draws in primary air which is sucked in from just above the hob plate, passes into the burner by way of the circumferential passage, up through the radial passages defined by the radial ribs on the outside of the sleeve portion of the support unit.  It then descends in the vertical passages (16') between the sleeve and the central tubular portion of the removable body.  At the bottom of the chamber it becomes entrained with the gas and begins to mix there.  The gas/air mixture passes up through the lumen in the central tubular portion and goes via the through opening into the disc-shaped space between the top surface  (12') of the removable body and the undersurface (13') of the flame spreader unit.  It passes laterally and leaves the burner through the holes, where it burns in the secondary air surrounding the burner.
13.	At this point we must quote a further passage from the specification relating to the effect of the disc-shaped space under the flame spreader unit:
“The upper surface 12' of the body 12 and the internal surface 13' of the flame spreader 13 which are opposite each other may, depending on requirements, e.g. the pressure of the gas which is to be burnt, the type of gas, etc., be divergent, parallel, or convergent, from the centre towards the periphery or towards the series of holes 21 in the flame spreader 13.  In any case, the said opposing surfaces 12' and 13' define a radial passage of circular extent 22 through which the gas-air mixture, which is produced in the central opening 15, is passed to the holes 21 of the flame spreader 13, where combustion occurs.  In accordance with the Venturi effect, the velocity decreases and the pressure recovers, either as the result of the shape of passage 22 when this is given a particular divergent shape, or because the cross-section of the passage increases as a function of radius from the centre of the periphery.  In this way the mixture is supplied and its combustion is correct and complete even in the case of major variations in the pressure and type of gas used.”
14.	The Meneghetti burners said to infringe bear a similarity in overall appearance and principles of construction to the burners illustrated in the patent.  They too are made up essentially of three parts: a flame spreader, a removable body and a support unit housing a gas injector.  There is also a central space in the removable body the top of which is roughly saucer-shaped, allowing a mixture of gas and primary air to rise and pass into the gap between the underside of the flame spreader and the top of the removable body and to move laterally so as to exit from holes in the periphery of the top of the burner just below the flame spreader.  Primary air is drawn in under the skirt of the removable body and passes towards the centre of the burner where it becomes entrained with the gas rising upwards out of the gas injector and the mixture then proceeds as we have indicated.  The judge found that there were insignificant differences between the Meneghetti burners and the burners as claimed in the patent.
The judgment
15.	The judge in his judgment dealt with a number of issues of construction in a way which is not challenged in this court.  He then turned to infringement and considered four points which Meneghetti took on why its burners did not infringe the patent.  We need only mention one.  Meneghetti contended that its burners did not possess a "sleeve portion .... defining a chamber" as taught in para (iv) of claim 1.  The judge (in para. 36) noted that the Meneghetti support unit, as seen in Figure D annexed to this judgment (being the exploded version of the crosssection of the Meneghetti burner), had a much more splayed out appearance, so that the depression surrounding the gas injector is more in the shape of a shallow bowl rather than a cup with vertical sides as depicted in the patent.  He rejected the argument that the patent required a sleeve with essentially vertical walls for reasons which he gave in paras. 21 and 22 and which it is unnecessary to rehearse.  He said (in para. 36) that even with its splayed-out design the Meneghetti product incorporated a sleeve portion having a vertical axis defining a chamber.  Accordingly he held that that feature of the Meneghetti burner did not avoid infringement.
16.	The judge then considered Meneghetti's argument that even if its product fell within the scope of claim 1, Meneghetti did not infringe the patent because it carried out no relevant act within the jurisdiction.  He found the relevant facts to be as follows (in para. 41):
“Meneghetti has a British sales agent who participated in discussions with MFI which led to them buying Meneghetti burners for their hobs. It is not suggested that the activities of the agent, per se, renders Meneghetti liable for infringement. The burners bought by MFI were from Meneghetti’s standard range but they were installed in hob units to which an MFI trade mark was applied. The hobs were clearly destined for MFI’s British market. The hob units were supplied with English language instruction booklets. These were drafted by MFI, but Meneghetti arranged for them to be printed. The hobs were also supplied with English style electric wiring instructions. There is no dispute that title to the hobs, including the burners, passed to MFI in Italy. Originally, MFI arranged for the hobs to be collected by its lorries from Meneghetti’s plant in Italy. From November 1998 onwards, delivery of the goods was by independent haulier. The haulier was chosen, paid and instructed by Meneghetti. The costs of doing this were subsequently recovered from MFI. SABAF did not plead, and did not ask leave to amend to plead, that Meneghetti or its agent offered to supply the burners in England.”
17.	The judge then considered the contention of Mr. Wilson Q.C. for SABAF that Meneghetti carried out infringing acts in the jurisdiction in two ways.  One was by being an importer of its burners from November 1998 (s.60(1)(a) of the Patents Act 1977 ("the Act")).  The judge said (in para. 42):
“The independent haulier was instructed by and carried out the transportation on behalf of Meneghetti. If there was a breakdown in delivery, Meneghetti would be responsible for taking the matter up with the haulier. Similarly, if, for example, a cheque paid to the haulier was not honoured by the bank, it was to Meneghetti that the haulier would look. MFI was isolated from this part of the logistics. I think it would be fair to say that Meneghetti was arranging importation into England as part of its service to its customer. The fact that it was subsequently reimbursed for this service, does not alter the fact that it was Meneghetti which was importing the goods for commercial purposes.”
18.	The judge then dealt with the argument of Mr. Vanhegan for SABAF that Meneghetti was a joint tortfeasor with MFI because the facts demonstrated a common design to sell burners in England.  The judge disagreed, saying (at para. 43):
“It is apparent that Meneghetti was content that its burners were used and sold by MFI in England, just as, no doubt, it was content that its products were sold in a very large number of other countries in the world. It is also apparent that it was prepared to help its customers, for example by supplying them with instruction booklets in the language of the market in which the customer traded. But this does not demonstrate a common design. Meneghetti assisted its customer and facilitated the latter’s business, but at all times the sale and use of the burners in the English market was solely the commercial venture of MFI. I think Mr Wilson is right to say that Meneghetti had no interest in whether MFI actually sold the hobs with burners in England. As far as it was concerned, MFI could have decided to store or destroy the complete stock, or send them to a market where there were no SABAF patents. Meneghetti’s actions were those of a company making its standard products available to customers, like MFI, from all over the world. It did not have a common design with MFI to market in England.”
19.	The major issue between the parties before the judge, as it is before us, was Meneghetti's claim that the patent was invalid for obviousness.  Before we set out the judge's treatment of this issue, it is convenient to refer to the statutory background as interpreted by the authorities.  The statutory provisions relevant to this issue are the following sections of the Act (so far as material):
“1 (1)  A patent may be granted only for an invention in respect of which the following conditions are satisfied, that is to say –
(a) the invention is new;
(b) it involves an inventive step ....
2 (1)  An invention shall be taken to be new if it does not form part of the state of the art.
(2) The state of the art in the case of an invention shall be taken to comprise all matter (whether a product, a process, information about either, or anything else) which has at any time before the priority date of that invention been made available to the public (whether in the United Kingdom or elsewhere) by written or oral description, by use or in any other way.
....
3  An invention shall be taken to involve an inventive step if it is not obvious to a person skilled in the art, having regard to any matter which forms part of the state of the art by virtue only of section 2(2) above ....”
20.	The question therefore posed by s. 3 is whether the claimed inventive step involved in the invention is obvious to a person skilled in the art having regard to what was at the priority date included in the state of the art. Sir Donald Nicholls V.-C. in Mölnlycke AB v Proctor & Gamble Ltd. [1994] RPC 49 at p. 112 said that the statutory test requires the court to make two findings of fact: what was included in the state of the art, and whether the claimed inventive step would be obvious to a person skilled in the art.  The Vice-Chancellor further said that in applying the statutory criterion and making its findings the court would almost invariably require the assistance of expert evidence, and that the evidence of properly qualified expert witnesses on whether the relevant step would have been obvious to a skilled man having regard to the state of the art would be the primary evidence for the court, all other evidence being secondary.  Thus the court will look to the experts to give evidence of what the skilled man would know, that knowledge being common general knowledge.  In the light of that evidence the court decides what Jenkins L.J. in Allmanna Svenska Elektriska AB v The Burntisland Shipping Co. Ltd. (1952) 69 RPC 63 at p. 70 called "a kind of jury question", the question of obviousness posed by s. 3.
21.	The structured approach to answering that question was expounded by Oliver L.J. (giving the judgment of the court consisting of himself, O’Connor and Slade L.JJ.) in Windsurfing International Inc. v Tabur Marine (Great Britain) Ltd. [1985] RPC 59 at pp. 73,4:
“There are, we think, four steps which require to be taken in answering the jury question.  The first is to identify the inventive concept embodied in the patent in suit.  Thereafter, the court has to assume the mantle of the normally skilled but unimaginative addressee in the art at the priority date and to impute to him what was, at that date, common general knowledge in the art in question.  The third step is to identify what, if any, differences exist between the matter cited as being “known or used” and the alleged invention.  Finally, the court has to ask itself whether, viewed without any knowledge of the alleged invention, those differences constitute steps which would have been obvious to the skilled man or whether they require any degree of invention.”
22.	In Terrell on Patents 15th ed. (2000) in para. 7.26 the editors point out what is entailed by each of those steps:
“The answer to the first question requires a purposive construction of the claim in issue in order to determine its ambit and thus to determine the characteristics of all items falling within that ambit so as to define the inventive concept possessed by all.
The second question requires the court to identify the skilled man (or men) and the common general knowledge.
The third question requires the court to have regard to the nearest piece of prior art, to identify what that prior art is teaching that skilled man and then to identify the lacuna between that teaching and the inventive concept. ....
It is, of course, the fourth question which requires the court to answer the question, formerly left to a jury:  is the invention obvious?  It is in answering this that the court must take care not to allow hindsight to colour its judgment ....”
23.	The judge did not take the four steps indicated by Windsurfing nor did he specifically state or seek to identify the inventive concept of the patent, save for identifying two features which the judge said were put forward as its inventive heart:  (i) drawing primary air in from above the hob unit and (ii) a radial mixing passage shaped to produce a Venturi effect to promote complete mixing and distribution of the gas and the primary air.  The judge neither made findings as to the attributes of the person skilled in the art, nor did he make findings as to the common general knowledge which the skilled man would have. 
24.	What the judge did was to look at the major disadvantages in the prior art which, he said in para. 12 of the judgment, were identified in the patent:  (i) existing burner units are tall and so do not fit into slim hob units; (ii) the primary air which is entrained with the combustible gas comes from underneath the hob unit; and (iii) existing burner units are difficult to disassemble.  The judge said that the third disadvantage could be left to one side as save in one very limited respect it had not been suggested that there was anything inventive in the specific arrangement or design of parts required for the burners the subject of the patent other than those arrangements or designs which were included to overcome the first two disadvantages.  The judge said that therefore it was the first two disadvantages and the way in which they could be overcome which was significant to the issues in the case, and he added that there was no interrelationship between the height of the existing burners and the bringing of air from above the hob surface.
25.	When the judge turned specifically to the question of obviousness, he drew attention to "the two important features of the SABAF burners which are said to constitute an invention" and the absence of any interaction of those features.  He referred to the argument of  Mr. Wilson on what the judge termed "the law of collocation", viz. that there is no invention in putting together two known and obvious integers; that, Mr. Wilson had said, was well-accepted under pre-1977 law and still applied.  Certain of the European Patent Office ("EPO") decisions were referred to, as was the following statement in the EPO's Guidelines for Substantive Examination:
“(B1)  Obvious and consequently non-inventive combination of features:
The invention consists merely in the juxtaposition or association of known devices or processes functioning in their normal way and not producing any non-obvious working inter-relationship.
Example: Machine for producing sausages consists of a known mincing machine and a known filling machine disposed side by side.”
26.	The judge said (in para. 47):
“Mr Vanhegan concedes that the law of collocation applies under the 1977 Act just as it did before. He accepts that the extract from the Guidelines for Substantive Examination set out above is a fair statement of that principle, although he also concedes that it may be expressed a bit narrowly, because the objection of mere collocation would apply as much to the putting together of obvious, but non-interrelating, devices and process as to the putting together of  known such devices and processes. However he says that it is not enough to ask whether the two (or more) devices or processes are individually known and obvious and do not interact. He says that Meneghetti must also show that there is a reason why the devices should be put together. In other words before a collocation of known or obvious parts can be invalid it must be obvious to put them together.  In my view this would turn the law of collocation on its head. Since, by definition, the devices or processes do not relate to each other and do not affect each other’s function or performance, there is little technical incentive for the worker in the field to put them together. Thus the lack of interrelationship would render the collocation non-obvious. As a result, virtually all collocations would become patentable.”
27.	The judge accepted Mr. Wilson's argument saying (in para. 48):
“The law of patents is set on a public policy foundation that a man in the art cannot be stopped by a subsequent patent from using one or more known or obvious devices. He is not to be regarded as having been issued with a ration card allowing him to use only one such device. If there is no inventive step in using one and there is no inventive step in using another, there is no inventive step in using the two together. Where the devices or features interact, different considerations may apply.”
28.	The judge then considered the two features in turn.  He said that taking primary air from above the hob surface was well known and practised before the priority date and that there was nothing in the patent which addressed the known problem of vitiation, caused by primary air being taken too close to the burning flame so that products of combustion become entrained  in the primary air, thereby interfering with performance of the burner.  The judge considered one of the two pieces of prior art relied on by Meneghetti in relation to the first feature, the Alpes-Inox SpA hob.  This was a commercially available hob unit (though at the Rolls Royce end of the market) which was sold before the primary date.  The illustration of its design, which was annexed as Figure 15 to the judge's judgment, showed primary air being taken in above the hob surface.  The judge said that the flow path in the burner was similar to that of the SABAF burner, but he rejected an argument by Meneghetti that there was some Venturi effect.
29.	The judge described the second feature as "a radial mixing passage being shaped to produce a Venturi effect to promote complete mixing and distribution of the gas and the primary air".  He referred to two pieces of prior art relied on by Meneghetti to demonstrate that having a Venturi in a radial passage was known.
30.	One was a patent in the name of Zanussi.  The judge recited the explanation of this invention in the Zanussi patent as being "a horizontal or vertical gas burner whose mixing or Venturi-tube divergence, in addition to developing along a linear axis .... also continues radially in the circular space comprised between the pan and an appropriately shaped surface of the flame distributor; the invention achieves the aim of substantially reducing the length of the Venturi tube in the initial section, whether it is vertical or fairly horizontal".  The judge said that the Venturi arrangements in the Zanussi patent indicated that the injector put the Venturi in the radial section under the flame spreader for the same reason as SABAF, viz. to reduce the overall height of the burner.
31.	The other piece of prior art relied on by Meneghetti was a French patent in the name of Hourdry.  This was directed to the manufacture of gas burners for more compact hobs and the object of the invention was described as being "a gas burner of the type entraining primary air in a Venturi tube through a gas injection nozzle characterised in that the Venturi effect is produced perpendicularly to the axis of the injection nozzle and circularly to the upper portion of a burner which is low in terms of height between the corner plate of the burner and an adjacent inner tray with a central opening of suitable profile above the gas injection nozzle".  The judge said that the inventive step, if any, was having the Venturi arrangement in the radial passage under the flame spreader.
32.	The judge considered that both features of the SABAF burner were "known" and that their use together was a mere collocation.  Accordingly he held the patent invalid for obviousness.
The issues
33.	There are 4 issues before this court:
(A)  Is the patent invalid for obviousness?
(B)  If not, do Meneghetti's burners escape infringement of the patent by reason that they do not possess a "sleeve portion .... defining a chamber" of the kind required by claim 1?
(C)  If its burners do infringe, did Meneghetti do infringing acts within the jurisdiction by being a joint tortfeasor with MFI?
(D)  If not, did Meneghetti do infringing acts within the jurisdiction by importing the burners?

34.	In this court we have had the benefit of excellent argument from each of Mr. Thorley Q.C. (appearing with Mr. Vanhegan) for SABAF and Mr. Wilson (appearing with Mr. Colley) for Meneghetti.
(A)  Obviousness
35.	Mr. Thorley makes the following submissions on the issue of obviousness:
(1)  The patent claims are directed to a product, not to a process.  The judge erred in dissecting the invention and considering only a combination of two of its features, one being a method of operation (taking primary air from above the hob) and the other being an abstracted portion of one of the features of the claim (a radial mixing passage shaped to produce a Venturi effect).  He should have construed the claim as requiring a particular mechanical arrangement of discrete components shaped and arranged to form a burner which overcame the problems of the prior art burners set out in the specification.
(2)  There is no law of collocation.  It is not disputed that the "mere placing side by side of old integers so that each performed its own proper function independent of the others" (British Celanese v Courtaulds) (1935) 53 RPC 171 at p. 193 per Lord Tomlin) is not an inventive step; but to arrive at the conclusion that there is a "mere collocation" the court must determine the nature of the invention and the state of the art as viewed through the skilled person to determine what is known and whether it is obvious to put the integers together.
(3)  The judge erred in reaching his conclusion without first properly identifying (i) the invention the subject of the patent, (ii) the state of the art, (iii) the person skilled in the art, and thus (iv) (a) whether the invention comprised merely the juxtaposition of features known in the art, and (b) whether those features were merely performing their proper function, through the eyes of the skilled person.
(4)  Applying the structured approach in accordance with Windsurfing to the cited prior art, the judge would have found the patent not obvious but valid.
36.	Mr. Wilson submits as follows:
(1)  The judge was right to find that the patent was invalid for obviousness by reason of the mere collocation of two known features which have no interaction with each other.  Each feature contributes to the burner no more and no less than what the prior art would lead one to expect, still less is there any surprising or inventive consequence of the combination.  That is a different type of obviousness from that considered in Windsurfing, the first three steps of which do not apply.  This is a legitimate short cut to a finding of obviousness which is supported by the EPO and the European authorities, as well as by the pre-1977 law.
(2)  The Windsurfing analysis can apply in a collocation case such as this by treating the reference in the third step to "matter cited" as involving simultaneously both relevant citations of the prior art relating to the two features.
(3) Alternatively, taking primary air from above the hob was common general knowledge in Italy (Alpes-Inox).  To join to that knowledge published information on a radial Venturi (Zanussi, Hourdry) was obvious, and everything else in the patent was mere workshop detail.
37.	In our judgment, whilst there is no doubt but that the two features referred to by the judge are the most important features of the invention, there is some force in the criticism by SABAF that the judge concentrated too much on them and lost sight of the invention as being the overall combination of all its features.  Mr. Crowther, SABAF's expert, considered the essence of the patent to be:
“a combination of:
(a) an air supply from above the cooker plate, with
(b) the replacement of the traditional long mixing tube (either horizontal or vertical) with a very short vertical mixing tube followed by an elegantly designed horizontal mixing section shaped so as to produce a venturi effect within the area below the flame spreader so as to complete the mixing of the air and gas in that region and restore the presence of the mixed gas and air sufficient to permit complete combustion at the burner ports
all encompassed within an elegant mechanical arrangement to give a very compact burner, easily capable of being assembled and disassembled in situ and operating with all three gas families.”
38.	The judge's approach was very much coloured by his views on collocation and, not surprisingly, by the concessions which he understood were made by Mr. Vanhegan.  The sausage machine is the example usually cited in this area, not only in this country (see Terrell op. cit. para. 7.39), but also in Europe, as we have seen from para. (B1) of the EPO Guidelines.
39.	But the EPO Guidelines go on to make a contrast:
“(B2)  Not obvious and consequently inventive combination of features:
The combined features mutually support each other in their effects to such an extent that a new technical result is achieved.  It is irrelevant whether each individual feature is fully or partly known by itself.
Example:  A mixture of medicines consists of a pain-killer (analgesic) and a tranquillizer (sedative).  It was found that through the addition of the tranquillizer, which intrinsically appeared to have no pain-killing effect, the analgesic effect of the pain-killer was intensified in a way which could not have been predicted from the known properties of the active substances.”
40.	No doubt there will be cases which fall clearly one side or other of the line as illustrated by the examples in the Guidelines.  But it must never be forgotten that the very act of putting together two or more features may involve an inventive step, and great caution must be exercised in relation to an invention involving such a combination for the reasons given by Greene L.J. (giving the judgment of Slesser and Romer L.JJ. as well as himself) in Wood v Gowshall Ltd. (1936) 54 RPC 37 (the cat's eye case) at p. 40:
“The dissection of a combination into its constituent elements and the examination of each element in order to see whether its use was obvious or not is, in our view, a method which ought to be applied with great caution since it tends to obscure the fact that the invention claimed is the combination.  Moreover, this method also tends to obscure the fact that the conception of the combination is what normally governs and precedes the selection of the elements of which it is composed and that the obviousness or otherwise of each act of selection must in general be examined in the light of this consideration.  The real and ultimate question is: Is the combination obvious or not?”
41.	That real and ultimate question is the question posed by s. 3 in the present case, though the question is fleshed out further by the section by making the test one of obviousness to a person skilled in the art, having regard to anything which forms part of the state of the art.  It must always be remembered that it is through the eyes of that skilled person that the question falls to be decided.  The judge made no findings as to the attributes of that person.  Some attributes are well established by the authorities.  For example he is likely to have a practical interest in the subject matter of the invention but to lack inventive capacity (see Terrell op. cit. para. 6.25).  The experts called by the parties are often not persons skilled in the art, as being over-qualified, but their evidence on the attributes of the skilled man and in particular the common general knowledge which he is to be treated as possessing is often crucial.
42.	It is common ground that there is a difference between "common general knowledge" which is a characteristic of the person skilled in the art, and knowledge forming part of the state of the art.  Common general knowledge is "the information which, at the date of the Patent in question, is common knowledge in the art or science to which the alleged invention relates, so as to be known to duly qualified persons engaged in that art or science" (see British Thompson-Houston Co. Ltd. v Stonebridge Electrical Co. Ltd. (1916) 33 RPC 166 at p. 171 per Younger J.).  The classic statement of the distinction between common general knowledge and what is the state of the art through publication of patent specifications and scientific papers is to be found in General Tire and Rubber Co. v Firestone Tyre and Rubber Co. Ltd. [1972] RPC 457 at p. 482.  There it was said by Sachs L.J.(giving the judgment of himself, Buckley and Orr L.JJ.):
“it is clear that individual patent specifications and their contents do not normally form part of the relevant common general knowledge, though there may be specifications which are so well known amongst those versed in the art that upon evidence of that state of affairs they form part of such knowledge, and also there may occasionally be particular industries (such as that of colour photography) in which the evidence may show that all specifications form part of the relevant knowledge.”
The court will almost certainly need evidence from the experts to establish whether any published information has become common general knowledge.  As is stated in Terrell op. cit. para. 6.27, it is not enough to show that a matter was known to some but not to others.
43.	Given that s. 3 requires the test of obviousness to be performed through the eyes of the person skilled in the art having the relevant common general knowledge, it seems to us inevitable that in a case said to involve a mere collocation of two known concepts, the question is whether it will be obvious to the skilled man, using his common general knowledge, to combine those concepts.  If it is not obvious, for example if there is some interaction between features of an invention incorporating the two concepts and it would not have occurred to the unimaginative skilled man to put them together to produce that interaction, there may be an inventive step.  It appears to be accepted that it is impermissible to "mosaic" separate pieces of prior art by combining them together unless it is obvious to do so, such as where they cross-refer to each other.  That simply reflects the fact that the act of combining known concepts may itself involve an inventive step so that the person skilled in the art is, in the absence of evidence to the contrary, not to be taken to start from the position that the resulting combination is already known.  A mere collocation is no more than a species of obviousness judged by the statutory test.  In our judgment there is no separate law of collocation.
44.	It is not in dispute that there is no requirement that in every case the court should take the four Windsurfing steps to answer the question of obviousness.  But there are dangers in cutting the corner, which Mr. Wilson acknowledged the judge did in the present case, in that it is easy to assume from the fact that there have been disclosures in the prior art that which has to be established, that is to say that the skilled man using his common general knowledge would put together what had hitherto not been combined.  The dangers of hindsight are notorious.  We see no justification for treating a case of an alleged mere collocation as requiring some modification of the Windsurfing steps so that in the third step two pieces of prior art are treated as combined.  That again assumes what has to be proved, that it is obvious to combine the separate disclosures.
45.	We do not believe that anything that we have said is inconsistent with the EPO Guidelines or with the EPO cases to which we were referred.  In Kommerling [1992] EPOR 98 the EPO revoked a patent on the basis that the existence of the independent problems solved by the patent and the solution to each problem were obvious.  We doubt if it is truly a mere collocation case; it is one where the EPO viewed the matter through the eyes of the person skilled in the art with the requisite common general knowledge (see paras. 5.3 and 5.4).  Similar considerations applied to Sedlbauer [1993] EPOR 147 (see the last two sentences of para. 4.1) and Schindling [1997] EPOR 146 (see paras. 1.8 and 1.9).
46.	The judge may have read too much into Mr. Vanhegan's concessions and this may have led him to take as uncontroversial that which had to be established, viz. that the skilled man using his common general knowledge would accept that there was no interaction between the two concepts of taking air from above the hob and using the radial Venturi, and hence that the lack of interrelationship would render the combination obvious.  Mr. Vanhegan did not in fact concede before the judge that there was no interrelationship at all between the two features.  When asked by the judge about that, he replied (Transcript 18 July 2001 p.635):
“I do not say they are unrelated because they function to produce one end result, sufficiently complete.”
When the judge asked again at p. 636 whether Mr. Vanhegan was saying that there was a technical interrelationship between the mixing hardware inside the burner and bringing air in from above the hob Mr. Vanhegan replied:
“There always is to the extent that you have got to get sufficient primary air into that burner such that you can have it sufficiently mixed and presented to the burner ports .... [Y]ou are always concerned about the pathway of that primary air and the way in which it comes through the burners and .... that amount of flow of air will have an impact on the ability to use the Venturi effect to its maximum advantage.”
But Mr. Vanhegan said that he could not point to any other technical interaction between the two concepts.
47.	Mr. Thorley maintained before us that necessarily there was an interaction between the taking of air from above and the radial Venturi.  The burner works by primary air being taken from above in a manner which avoids vitiation but yet in sufficient quantity to enable the air and gas to mix in the Venturi radials and the mixture to come through the ports under sufficient pressure.  Further, as Mr. Thorley stressed,  the invention was not just the combination of all its features including the compactness of the burner and it being in three parts which are easy to assemble with accuracy.  Whether there was an interrelationship between the features of the invention and whether the combination was obvious were matters to be judged through the eyes of the skilled man with his common general knowledge.
48.	The judge did not address that question in that way at all.  In our judgment, therefore, he did not apply the test imposed by s. 3 correctly.
49.	We were urged by Mr. Thorley, in the event that we disagreed with the judge's approach, not to remit the case back to the High Court but to decide the point ourselves.  Mr. Wilson did not dispute that that was the appropriate course.  Accordingly, we would take up that invitation, applying the Windsurfing approach.
50.	We would accept that the inventive concept is as summarised by Mr. Thorley, viz. "a burner comprising 3 elements, namely a support, a body and a flame spreader, arranged and shaped so that
(1)  the air supply is drawn from above the cooker plate, radially into the burner;
(2)  the gas and air first begins to mix in a chamber defined by the support and thereafter continues to mix whilst passing through a short vertical tube, located concentrically above the gas injector;
(3)  thereafter the gas and air pass through a horizontal radial passage shaped so as to produce a venturi effect, created by the lower side of the flame spreader and the upper portion of a body which is associated with the support, in which further mixing occurs and in which the pressure of the mixture increases as its velocity decreases."
51.	In taking the second step we accept that on the evidence before the court the person skilled in the art was a person with basic experience and qualification in the production of gas equipment, who at the priority date
(i)  would only have been interested in natural gas burners,
(ii) would not have known of any of the prior art citations on which Meneghetti relied,
(iii) had a mindset against changing the then prevalent long horizontal Venturi tubes and had a fear about venturing into the unknown,
(iv) had a technical prejudice against drawing the primary air from above the hob and through the burner, and
(v) did not believe that the height of the vertical Venturi tube burners could be reduced.
Save for (ii), we did not understand Mr. Wilson to challenge these attributes.  On (ii) he suggested that taking air from above the hob would have been common general knowledge in Italy because of the Alpes-Inox burner.  But the judge did not think that it was common general knowledge even in Italy (Transcript 4 July 2001 p. 634) and the evidence does not support Mr. Wilson's submission.
52.	We also accept that in the light of the evidence and having regard to the attributes of the person skilled in the art neither the prior art citations on which Meneghetti relied nor drawing primary air from above the hob nor having a radial mixing passage to produce a Venturi effect formed part of the common general knowledge of the skilled person.
53.	In taking the third step, we would identify from the evidence before the court the main differences between the prior art cited by Meneghetti and the SABAF invention as follows:
(1)  Energietechnik
This 1958 East German burner took air from above the hob and was made of three components, like the SABAF burner, but those components had features differing from the SABAF burner's components.  It was a vertically arranged Bunsen burner containing no disclosure of a radial mixing zone shaped to produce the Venturi effect beneath the flame spreader.  It was intended for the use of town gas only.
(2)  Alpes-Inox
This 1963 burner also took air from above, but it was not a 3-component burner, and it was a structurally complex, vertically arranged burner not possessing any horizontal radial passages shaped to produce the Venturi effect.  Although the judge described the flow path in the Alpes-Inox burner as similar to that of the SABAF burner, we have to say that there are self-evident dissimilarities between them.
(3)  Zanussi
The 1963 patent for this burner disclosed the use of a Venturi arrangement in the radial section to reduce the overall height of the burner, but did not use air drawn radially from above the hob nor was it in 3 component parts nor did it use a support at all.  Mr. Sutton, the expert for Meneghetti, called it a different animal from the SABAF burner which he accepted was technically superior in respect of the radial passages.
(4)  Hourdry
The 1958 patent for this burner described the use of a radial passage to produce the Venturi effect.  But it was not in 3 component parts and the primary air was drawn from below.  It was concerned solely with town gas.
54.	We come to the fourth Windsurfing step.  We conclude, on balance, after taking account of the experts' written and oral evidence, that the differences between each matter cited as known and the SABAF invention would, in the light of the inventive concept of the SABAF patent, the attributes of the skilled man and the common general knowledge which he possessed, not have been steps obvious to the skilled man but required some degree of invention.
(1)  There was nothing in the very old (1958) Energietechnik disclosure which would have led the skilled person to incorporate a radial mixing zone shaped to produce the Venturi effect under the flame spreader nor to reduce the height and length of the vertically arranged Bunsen burner.  From the differences between the Energietechnik burner and the SABAF burner, the invention was not obvious to the skilled person in the light of the Energietechnik disclosure.
(2)  Similarly, the old (1963) Alpes-Inox disclosure would not have helped the skilled person to think of changing the design of that burner to incorporate any horizontal radial passages shaped to produce the Venturi effect nor to reduce the height or length of the vertically arranged burner, nor to make a 3-component burner.  Again because of the differences between the Alpes-Inox burner and the SABAF burner, the invention was not obvious to the skilled man in the light of the Alpes-Inox disclosure.
(3)  From the old (1963) Zanussi disclosure, the skilled man would not have been led to think of drawing in air other than from below nor to make up a burner with 3 components. Nor does Zanussi teach that sufficient pressure recovery could be achieved solely in the horizontal radial passages.  The differences between the "different animal" which was Zanussi and the SABAF burner lead to the conclusion that the invention was not obvious to the skilled person in the light of the Zanussi disclosure.
(4)  The very old (1958) Hourdry patent would not have led the skilled person to think of drawing air from above the hob radially into the burner:  it expressly taught that air should be drawn from below the cooker plate.  Nor would it have led the skilled person to think of a 3-component burner:  the upper part of the Hourdry burner is force-fitted so as not to allow the burner to be taken apart.  Because of the differences between the Hourdry patent and the SABAF patent, the invention was not obvious to the skilled person in the light of the Hourdry disclosure.
55.	Accordingly we would respectfully disagree with the judge on obviousness and we would hold that the patent was valid.
(B)  Non-infringement
56.	Mr. Wilson repeats his submission that the feature of SABAF's claim 1 consisting of a "sleeve portion .... defining a chamber" was not to be found in the Meneghetti burner.  There is no doubt but that the latter has a much shallower depression surrounding the gas injector that the chamber in the SABAF patent.  However, giving the patent a purposive construction and looking at the function performed by the equivalent part of the Meneghetti burner, we would agree with the judge that the Meneghetti burner can be said to incorporate a sleeve portion having a vertical axis defining a chamber.
(C)  Joint tortfeasor
57.	Mr. Thorley criticises the judge for failing to direct himself as to the correct legal test for joint tortfeasance.  He submits that the test is that set out by this court in Unilever Plc v Gillette (UK) Ltd. [1989] RPC 583 at pp. 608, 9, as recently approved in MCA Records Inc. v Charly Records Ltd. [2002] EMLR 1 at p. 28 para. 51.  He says that a party will be jointly liable with a primary infringer if it has participated in a "common design" or "concerted action" with the primary infringer.  He relies on the observations of Mustill L.J.in the Unilever case at p. 609 where he said of those terms:
“They all convey the same idea.  The idea does not .... call for any finding that the secondary party has explicitly mapped out a plan with the primary offender.  Their tacit agreement will be sufficient.  Nor .... is there any need for a common design to infringe.  It is enough if the parties combine to secure the doing of acts which in the event prove to be infringements.”
That was said in the context of a successful application to join the parent company of the primary infringer as a joint tortfeasor.
58.	Mr. Thorley accepts that the mere supply of infringing goods is not enough to make the supplier a joint tortfeasor.  Mr. Wilson accepts that Meneghetti knew that its burners were going to be imported into the U.K.  and may be said to have facilitated MFI's infringing acts.  But he submits that Meneghetti neither induced the infringing acts nor participated in any kind of common design that they should take place and that what Meneghetti did is not sufficient to make it a joint tortfeasor.  He suggests that the appropriate test for a joint tortfeasor is that each person has made the infringing act his own.
59.	We agree with Mr. Wilson.  The underlying concept for joint tortfeasance must be that the joint tortfeasor has been so involved in the commission of the tort as to make himself liable for the tort.  Unless he has made the infringing act his own, he has not himself committed the tort.  That notion seems to us what underlies all the decisions to which we were referred.  If there is a common design or concerted action or otherwise a combination to secure the doing of the infringing acts, then each of the combiners has made the act his own and will be liable.  Like the judge, we do not think that what was done by Meneghetti was sufficient.  It was merely acting as a supplier of goods to a purchaser which was free to do what it wanted with the goods.  Meneghetti did not thereby make MFI's infringing acts its own.
(D)  Importation
60.	The judge held on the facts set out in para. 41 of his judgment (cited in para. 16 above) that from November 1998 Meneghetti arranged importation into England as part of its service to its customer and he emphasised the undoubted fact that it was Meneghetti who made the contract of carriage;  it would thus be the right party to sue if there was a non-delivery and the party liable to the haulier if its cheque was not honoured by the bank.
61.	This conclusion that Meneghetti imported the goods sits unhappily with the fact that title to the burners and the hobs passed to MFI in Italy.  The reason for this was that the contract of sale was on ex works terms (see Antonio Brotto’s first witness statement, para. 9).  This meant that title (and risk) in the goods passed as soon as they left the factory gate.  In these circumstances it is an odd use of words to say that Meneghetti “imported” the goods.  Although it made the relevant contract of carriage, it itself had no ultimate interest in the goods.  It only arranged the transportation at MFI's request and it would be paid in any event.  It would be more usual to describe as importer the party who had the legal and beneficial interest in the goods, viz. MFI.  In any real sense, if property and risk pass to the buyer before or at the beginning of the carriage, the contract of carriage is made on behalf of the buyer even if it is the seller who agrees that he will make the contract (see Texas Instruments Ltd v. Nason (Europe) Ltd. [1991] 1 Lloyds Rep 146).
62.	The question remains whether a seller, who has no title but makes the contract of carriage, “imports the product” for the purposes of section 60(1)(a) of the Act.  We would not so construe the Act for three reasons.  First it is artificial to regard someone as an importer who has no legal or beneficial interest in the goods;  second, if as here, there is no joint infringement because the seller has not made the acts of the primary tortfeasor his own, there is no moral imperative to find an importation.  Thirdly, the statutory word is “imports” not “causes to import”.
63.	It is suggested that this conclusion is contrary to Waterford Wedgwood Plc v David Nagli Ltd [1998] FSR 92, a decision of Sir Richard Scott V.-C.  In that case it was held that a seller who had arranged the carriage of goods from Bilbao to New York was liable as an importer into the U.K. when, unknown to him, there was a transshipment in Felixstowe.  If, as appears to have been the case, the seller in fact had no interest in the goods, because title and risk had passed to the New York buyers, we would not ourselves agree with the decision.  But the court was considering the Trade Marks Act 1994, not the Patents Act 1977, and the facts were very unusual.  We are not persuaded by that authority that Meneghetti was an importer in this case.
Conclusion
64.	In the result because Meneghetti did no infringing acts within the jurisdiction, it is not liable for infringement of SABAF's patent.  For the reasons given we would allow SABAF's appeal on the validity of the patent but we would also allow Meneghetti's cross appeal on importation.  Accordingly, the judge's dismissal of the action will stand.
Order: Appeal allowed in part, cross-appeal allowed in part. The judge’s order will be set aside, the claim and the counterclaim dismissed, the patent suit be declared valid, and there is to be a certificate that the validity of the patent suit was contested and found valid.  Consequential orders will be dealt with at a further hearing on 24th July.
(Order does not form part of the approved judgment)
ANNEX

Figure A: Typical Venturi type arrangement in a gas burner –

Figure B: Illustration from the patent in suit – 

Figure C: Exploded version of the illustration in the patent in suit – 

                 

Figure D: Exploded version of cross section of Meneghetti product –