Case No: OCL 701145
Neutral Citation Number: [2012] EWPCC 38
IN THE PATENTS COUNTY COURT
The Rolls Building
7 Rolls Buildings
London EC4A 1NL

Date: 27/07/2012

Before:

HIS HONOUR JUDGE BIRSS QC
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Between:

	BOS GMBH & CO KG
(formerly BAUMEISTER & OSTLER GmbH)	
Claimant	
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	COBRA UK AUTOMATIVE PRODUCTS DIVISION LIMITED	Defendant	

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(Computer‑aided transcript of the Stenograph Notes of Marten Walsh Cherer Ltd., 
1st Floor, Quality House, 6‑9 Quality Court, Chancery Lane, London WC2A 1HP.
Telephone No:  020 7067 2900.  Fax No:  020 7831 6864
e‑mail: info@martenwalshcherer.com)
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PETER COLLEY (instructed by Withers & Rogers LLP) appeared for the Claimant.
GEOFFREY PRITCHARD and STUART BARAN (instructed by 
Wragge & Co) appeared for the Defendant.

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Judgment
HIS HONOUR JUDGE BIRSS QC : 
1.	This is an action for infringement of European Patent (UK) 0 649 778 entitled "Security net installation".  Security nets are used in cars, especially estate cars, between the row of back seats and the luggage area.  In a crash the luggage flies forward.  The point of the security net is to protect the passengers by catching the flying luggage.  
2.	The patent belongs to the claimant, BOS GmbH.  BOS contends that the defendant Cobra has infringed the patent.  The product alleged to infringe is a luggage net for Volvo XC60 cars.  BOS contends that the product infringes claims 1, 7, 9 and 14.  Cobra denies infringement and also contends the patent is invalid.  The claims said to be independently valid are claims 1, 7, 9 and 14.  Claim 15 is also said to be independently valid.  Cobra are not alleged to infringe claim 15 and does not advance a case of invalidity against claim 15.
3.	Cobra is also being sued by BOS in Germany.  On 13th July 2010 the Düsseldorf District Court decided that Cobra's Volvo net product infringed the German designation of the same patent.  The decision in Germany is not concerned with validity.  The infringement decision is under appeal.
4.	In order to give itself a degree of commercial certainty, Cobra redesigned its net.  In May 2011 BOS's German patent attorneys confirmed that the new Volvo net design did not infringe.  Cobra has undertaken not to sell the old design until judgment in this action.  Cobra argues that that means this case is purely historic and concerned with damages only.  That is not right since, as I understand it, if Cobra win the action, they will be free to sell the old net in future.
5.	Before me Peter Colley appears for BOS instructed by the patent attorneys, Wither & Rogers, while Geoffrey Pritchard and Stuart Baran appear for Cobra instructed by Wragge & Co..
The Issues
6.	The issues relate to infringement and obviousness.  On infringement Cobra denies that its product infringes claim 1.  If claim 1 is infringed then Cobra accepts that the Volvo net is within the relevant dependent claims.  On validity Cobra contends that the patent is obvious.  Five items of prior art are relied on.  Two are prior uses ‑ a security net sold with a Mercedes Car ("the Mercedes net") and a security net sold with an Opel car ("the Opel net").  Two are prior publications known as Ament and Butz and one allegation is obviousness over common general knowledge alone.
7.	In summary, the issues are:
(i) Does the Cobra Volvo net infringe the claims?
(ii) Is claim 1 obvious over any of the cited starting points?  
(iii) If so, are the relevant dependent claims also obvious?  They are claims 7, 9 and 14.  One point is that it is accepted that if claim 1 is obvious over Butz then so too is claim 7.
The Witnesses
8.	The claimant relied on two witnesses:  Mr. Marcus Keefer and Dr. Timothy Goodhead.  
9.	Mr. Keefer is an engineer.  He joined BOS in 1992.  Since then he has worked on security nets and electric sunshades.  He gave evidence on the common general knowledge.  He is a native German speaker and while he felt his English was sufficient to give evidence about factual matters, such as what was common general knowledge, he did not feel able to give evidence on obviousness in another language.  I entirely sympathize with Mr. Keefer.  He was a good witness and he gave his evidence fairly.  
10.	Dr. Goodhead is a retired engineering lecturer having taught in the field of manufacturing systems in the Department of Engineering at Warwick University for 23 years.  He is an academic engineer.  One part of his relevant experience involved teaching high‑flying graduates in UK manufacturing companies like the Rover Group, Rolls Royce, British Aerospace and Lucas.  As a teacher of engineering students for many years, he has taught automotive engineers and production engineers.  He did not profess to explain anything from the specific perspective of a skilled person in this case, but he could give opinions about obviousness to engineers generally.  He was a good witness.  However, I must make allowance for his perspective.  He was to some extent looking at this particular art from the outside.
11.	The defendant relied on the evidence of Mr. Steven Van Lieshout.  
12.	Mr. Van Lieshout worked in safety nets and luggage covers at the relevant time.  He was also an engineer.  He was well placed to give evidence of what a skilled person would think.  
13.	Mr. Colley submitted that given the number of patents to his name, Mr. Van Lieshout was too inventive to assist the court on obviousness.  I do not accept that.  As a matter of principle, the fact that a witness has patents to their name does not disqualify them from giving such evidence.  I listened carefully to what Mr. Van Lieshout said.  In my judgment, he was seeking to assist the court in appreciating what an uninventive skilled person would do and would think.
14.	Mr. Colley also submitted that Mr. Van Lieshout had set out producing his report after reading the patent, the statement of case and the prior art and so his opinions were tainted as a result.  Mr. Colley is right that that is indeed how Mr. Van Lieshout's reports were prepared and I will bear this in mind, but I do not accept that this submission is a strong point.  No doubt the opinion about obviousness of a witness who has formed his view without having read the patent and so on may well be one on which more weight can be placed.  But, as I have said in other cases, the point of calling an expert witness is not to conduct an experiment to find out the views of a sample of one of uninventive skilled people untainted with hindsight.  What is important in the evidence of an expert are the reasons they give for their opinion and not merely their opinion itself.
15.	Mr. Colley also submitted that Mr. Van Lieshout had a tendency to argue the case.  I do not accept that.  In my judgment, he was understandably nervous in the witness‑box.  It was understandable because he was giving evidence in a foreign language.  His mother tongue is Dutch.  What Mr. Colley detected as argument I detected as nothing more than a consequence of Mr. Van Lieshout's understandable nerves.  I thought he was a good witness and again gave his evidence fairly.
16.	Both Mr. Keefer and Mr. Van Lieshout deserve my thanks for giving evidence in a foreign language.
The Skilled Person
17.	There is no dispute in this case that the skilled person would be an automotive engineer with experience of designing interior accessories and in particular security nets.  Engineers of the training and background of Mr. Van Lieshout and Mr. Keefer are exactly the sort of people to whom the patent is addressed.  
18.	There was a debate about whether the skilled person was a team or an individual.  It was irrelevant.  There was a question about Dr. Goodhead's ability to speak about such a person and I have dealt with that already.
Common General Knowledge
19.	There was no disagreement on the law applicable to common general knowledge.  The defendant referred me to the statement made by Kitchin J (as he then was) in Select Healthcare v Cromptons Healthcare as follows:
"The common general knowledge is all the knowledge which is generally known and generally regarded as a good basis for further action by the bulk of those engaged in the art to which the invention relates.  It also includes all that material in the field in which the skilled person is working which he knows exists,  which he would refer to as a matter of course if he cannot remember it and which he understands is generally regarded as sufficiently reliable to use as a foundation for further work or to help understand the pleaded prior art."
20.	There were three topics arising in relation to common general knowledge.  First, rattle and squeak.  Rattling and squeaking are often caused by metal to metal contact.  Obviously rattling generally has a lower frequency, whereas squeaking generally has a higher frequency.  
21.	An issue in the case was how important the rattling and squeaking of objects was at the priority date from the point of view of an automotive engineer considering accessories in a car.  Mr. Van Lieshout thought it was very important.  Mr. Keefer did not say it was trivial but thought it was less important than Mr. Van Lieshout did.
22.	Part of this debate raised an issue about the sort of sophisticated test equipment which might be used to look at vibrations in objects in 1993.  There was a document from the Rover Group presented in evidence which related to rear‑view mirrors which were subjected to a severe vibration test.  However, while a rear‑view mirror is an inevitable part of a car, a security net is an accessory.  It may or may not be branded by the car maker.  Mr. Keefer explained that BOS did not have the sophisticated vibration testing equipment in 1993 which would have been used to conduct the tests in the Rover document.  I accept that evidence.  No doubt it was a reflection of the fact that BOS were only making accessory products.
23.	In my judgment, rattle and squeak were important at the priority date.  I have accepted the evidence that companies like BOS did not use severe vibration testing equipment, but that does not mean that rattle and squeak were unimportant.  I also believe that by 1993 rattle and squeak were becoming more significant than they had been in the 1980s.  
24.	I accept the evidence that metal on metal contacts were undesirable in 1993.  Rattle and squeak generally and metal to metal contact in particular was something that a person skilled in the art in 1993 would watch for, be concerned about and would seek to eliminate by design.
25.	The second topic is design techniques.  Various engineering design techniques were discussed in evidence.  Two worth mentioning are DFM and FMEA:
(a) DFM stands for Design for Manufacturing.  Essentially, it means thinking about how a product could best be made, never mind how you have designed it.  
(b) FMEA stands for Failure Mode Effect Analysis.  FMEA involves exploring how a product fails in the real world and using that information to improve the design.
26.	It is clear that techniques of that kind, and some others which were also mentioned, would be taught to the person skilled in the art.  They were matters of common general knowledge but they are generalised approaches and the devil is in the detail.  I also bear in mind that, as a general proposition, these techniques are all refinements to the basic design process.  In the basic design process, function comes first and the need for a product to be economical comes second and to be easy to manufacture comes after that. 
27.	The third topic of common general knowledge which falls to be considered is the Opel and Mercedes nets themselves.  It was common ground that their existence was common general knowledge.  The issue is the state of the knowledge of a skilled person of the internal workings of the fixing bar arrangements of these two nets.  
28.	The claimant submitted that knowledge of the internals of these nets was not common general knowledge.  The defendant said that it was.  
29.	I find on the evidence that the person skilled in the art did not know what the internal details were.  They did know how to find out.  You would have to get a net and disassemble it.  That is a process that was described as benchmarking.  Benchmarking was a perfectly well known technique in the common general knowledge, but that is different from saying that the skilled person actually carried the information in their heads.  However, of course just because they did not carry the information in their heads is not the end of the matter.
30.	The defendant referred me to paragraph 25 of the judgment of Jacob LJ in the Court of Appeal in Generics v Daiichi [2009] RPC 23.  It is as follows.
“Of course material readily and widely to hand can be and may be part of the common general knowledge of the skilled person - stuff he is taken to know in his head and which he will bring to bear on reading or learning of a particular piece of prior art.  But there will be other material readily to hand which he will not carry in his head but which he will know he can find if he needs to do so (my emphasis).  The whole passage is about material which the skilled man would refer to 'as a matter of course.'  It by no means follows that the material should be taken to be known to the skilled man if he had no particular reason for referring to it."  
31.	Mr. Pritchard submitted that the sentence about "knowing that he can find it if he needs it" means that the fact that the existence of the Opel and Mercedes nets themselves was common general knowledge has the result that their internal workings are to be treated as part of the common general knowledge as well since the skilled person obviously would know where to find the internal workings if he needed to.  He would go and take either one apart and have a look.  Thus Mr. Pritchard submitted it would be legitimate to combine elements from the internal workings of the Mercedes net with elements from other prior art and for that matter elements from Opel as well; in other words, to combine a cited prior art document, say, Butz with elements from Opel and from Mercedes.
32.	In my judgment the passage I have quoted is not talking about that sort of case.  In paragraphs 26 and 27 of Generics v Daiichi, Jacob LJ continued:
“26.	Kitchin J having reviewed Raychem and other authorities, said this: 
‘[40] It seems to me that a subtle but potentially significant point of principle emerges from these passages. I can readily accept that, faced with a disclosure which forms part of the state of the art, it may be obvious for the skilled person to seek to acquire further information before he embarks on the problem to which the patent provides a solution. But that does not make all such information part of the common general knowledge. The distinction is a fine one but it may be important. If information is part of the common general knowledge then it forms part of the stock of knowledge which will inform and guide the skilled person's approach to the problem from the outset. It may, for example, affect the steps it will be obvious for him to take, including the nature and extent of any literature search.’
27.	I agree with that although I personally do not find the point of principle "subtle". It would be wholly subversive of patents and quite unfair to inventors if one could simply say "piece of information A is in the standard literature, so is B (albeit in a different place or context), so an invention consisting of putting A and B together cannot be inventive." The skilled man reads each specific piece of prior art with his common general knowledge. If that makes the invention obvious, then it does. But he does not read a specific citation with another specific citation in mind, unless the first causes him to do so or both are part of the matter taken to be in his head.
33.	This shows that proving that the person skilled in the art knew as a matter of common general knowledge that these products existed does not carry with it a result that their internal workings are to be regarded as part of the common general knowledge as a matter of principle.  It is all a question of fact.  A different thing would be a case in which it was found to be obvious, say, starting from one piece of prior art, for a skilled person to go away and find out how a particular other thing worked, but there was no evidence for that in this case.  The benchmarking point shows that skilled persons could find out how other things work, but it does not mean that a skilled person would do so in any given situation and in my judgment it does not make the internals common general knowledge.  
34.	It is not legitimate to combine details of the manner in which the Opel and Mercedes nets work with other prior art, say Ament and Butz, without a proper motivation to do so. A different issue would be whether in a given case a person skilled in the art might start from a product and then have a specific reason to disassemble Opel and Mercedes.  However, as I think I have said already, no such case was made on the facts.  I reject the submission that the internal mechanisms inside the Opel and Mercedes nets were common general knowledge.
The Patent  
35.	The patent is about luggage security nets.  Such nets are secured to the body of the car with a lower fixed mounting and a removable up bar which can be attached to the car by hooks by hooking it to fixings on the car body.  Figure 1 is as follows:

36.	The general idea of such nets was known at the priority date.  The patent refers to a number of problems relating to these nets and in particular with a net of the prior Ament patent.  Problems include manufacturing the bar of the safety nets, dealing with rattling and the use of an energy absorbing means in the bar.  
37.	The solutions taught by the patent fall into two categories: (a) improvements in the upper bar fixings and (b) the provision of energy absorbing means.  Much of the disclosure is concerned with energy absorption means but these two aspects (energy absorption and upper bar fixings) are separately claimed and it is only the improvements to the upper bar fixings which relate to this action.
38.	The upper bar fixing mechanism taught by the patent is exemplified by the specific embodiment shown in figure 3:

39.	This has a mushroom headed fitting (21) which hooks into a fixing on the car body.  The retaining element (19), on which a mushroom head is fitted, is spring loaded and fits within an insert which can be pre‑assembled and then inserted into a bar which supports the upper edge of the luggage net.  The patent teaches that there are specific advantages to a solution of this nature.  These are best seen in the passage bridging page 2 to 3 of the published form of the translation, which is as follows:  
"The use of the tubular insert permits the retaining element and the insert first of all to be simply fabricated and after the preassembly thus achieved to be inserted into the corresponding cavity in the fixing arrangement and secured there.  The separate production of the insert permits a close tolerance of the opening relative to the shank of the retaining element, so that rattling noises are precluded.  Moreover, the new design readily permits combination with energy-absorbing means which on impact convert the kinetic energy of the parts caught into the net into resilience.  These energy-absorbing means can act between the insert and the retaining element or can be located as an extension of the insert in the direction of the centre of the bar-shaped fixing arrangement."
40.	The next two paragraphs in the patent highlight the simple construction and economical manufacture which can be achieved using the invention and how a spring can be used to help avoid rattling.
41.	There are further clauses which relate to other matters and then the description deals with the specific embodiments shown in the figures.  I have shown in one of those in figures 1 and 3.  
The Claims 
42.	The relevant claims are claims 1, 7 (and 6), 9 and 14.  They are as follows: 
1.	Security net installation for protecting the passenger compartment of estate cars relative to the luggage compartment 
with a security net (14) having two edges (16) which are substantially parallel to one another,
with a fixing arrangement (15) associated with one edge in order to connect the security net (14) to the estate car in the region of this edge.
with a bar-like fixing arrangement (18) which is fixed on  the other edge (16) and contains at least at one of its ends an elongated cavity which leads from the end in  question into the fixing arrangement (18) and of which the longitudinal axis is coaxial with the longitudinal axis of the fixing arrangement (18),
with a tubular insert (24) which goes into the cavity and is fixed in the cavity, and
with a retaining member (19) which has a shank (36) and which with its shank (36) fits displaceably into the interior of the insert (24), the end of the shank (36) which projects out of the fixing arrangement (18) bearing an anchoring member (21) which is to be inserted into a receptacle (23) fixed in the estate car,
with a spring member (41) which acts between the insert (24) and the retaining member (19) and by which the retaining member (19) is pretensioned in an end position with regard to the insert (24).
6.	Security net installation as claimed in claim 1, characterised in that the opening (27) in the insert (24) is substantially cylindrical. 
7.	Security net installation as claimed in claim 6, characterised in that the opening (27) in the insert (24) has a portion (29) which is widened in diameter in order to receive the spring member. 
9.	Security net installation as claimed in claim 1, characterised in that the retaining member (19) is secured against rotation in the insert (24). 
14.	Security net installation as claimed in claim 1, characterised in that the insert (24) has a radially projecting flange (26) on its end which lies outside in the inserted state. 
43.	It is notable that there is no energy absorbing feature referred to in these claims.  Claim 2 adds to claim 1 the feature of including energy absorb means, but claim 2 is not one of the claims in issue in these proceedings.
Interpretation
The Law
44.	The general approach to patent construction is well established and there was no dispute on it before me.  The leading authority is Kirin‑Amgen v TKT [2005] RPC 9 .  The key point is that construction is concerned with what a skilled person would understand the author to be using the words to mean.  Guidelines on the general approach were given by the Court of Appeal in Virgin Atlantic v Premium Aircraft [2010] FSR 10.  I remind myself that claims are not construed alone or in the abstract but in their context in the specification; that purposive construction is vital (and there may be several purposes and several embodiments) and that one is in the end concerned with the meaning of the language used.  Meticulous verbal analysis is eschewed.
45.	Another relevant point is the question of construing limitations out of existence.  This derives from what Hoffmann LJ (as he then was) said in STEP v Emson [1993] RPC 513 and in particular at 522:
"The well known principle that patent claims are given a purposive construction does not mean that an integer can be treated as struck out if it does not appear to make any difference to the inventive concept.  It may have some other purpose buried in the prior art and even if this is not discernible, the patentee may have had some reason of his own for introducing it."  
46.	I accept that.  It seems to me to arise from the application of the point that the wording of the claim is paramount.
47.	As it happens in this case, the issues of interpretation are best considered in the context of infringement, but before doing so I should mention a small point.  Claim 1 refers to the spring being pre‑tensioned.  Nothing turns on it, but it is common ground that the spring is not necessarily in tension at all.  The spring may be in compression.
Infringement
48.	The product alleged to infringe is Cobra's Volvo net.  
49.	It has a net.  The top edge has a hinged bar.  At each end of the top bar is a spring retainer part.  It was an angled rod with mushroom ends for slotting into the sides of the car.  The mushroom ended rod is attached to the top bar as follows.  The top bar is a steel tube and inside the end of the top bar is a plastic insert made in two halves.  The insert fits inside the steel tube.  The rod fits inside the insert and pushes on a spring.  The spring bears between the internal far end of the plastic insert and the end of the rod.  The insert has slots on either side and the steel tube also has slots which line up with the slots in the insert in use.  There was a steel pin which passes through a hole in the rod and travels in the slots.  
50.	The top bar is hinged.  It allows the whole thing to be folded in two.  
51.	The bottom edge of the net is attached to the car by a strap.  Starting from one corner, the strap is attached to the bottom edge by a buckle, then the strap comes down and there is a hook to hook on to the car, the strap then passes back up to a central fabric part and then goes back down to another hook to attach to the car at a second place.  Finally, the strap comes up again from the hook and attaches to the other bottom corner by another buckle.  In use the hooks are attached to the car and the buckles are tightened.  There was no convenient figure showing the Volvo net for me to insert into this judgment. 
52.	Comparing the Volvo net with claim 1, what the claims call the 'retaining member' is the mushroom ended rod.  The defendant accepts that the Volvo net falls within claim 1, subject to three specific points.  They are: (i) bar-like; (ii) tubular insert; and (iii) fixing arrangement.
(i) Bar-like  
53.	The claim has the following feature:  
"with a bar-like fixing arrangement which is fixed on the other edge and contains at least at one of its ends an elongated cavity which leads from the end in question into the fixing arrangement end of which the longitudinal axis is coaxial with the longitudinal axis of the fixing arrangement."  
54.	Dr. Goodhead explained his view on this.  He said as follows:  
"If the fixing arrangement is 'bar-like' the bar must have a cross-section and a modulus of elasticity which enable it to withstand the maximum bending moment that could be encountered."
55.	Mr. Van Lieshout agreed with that.  
56.	The Volvo net had a hinge in the middle of the top bar.  The hinge is there to allow the product overall to be folded in two and carried in a bag.  The defendant's argument was that when in use in a crash the bar unhinges.  So it is not behaving like a bar.  By “unhinging” the defendant meant the normal hinging action of a hinge.  Dr. Goodhead said he did not accept that the bar would unhinge in that case.  He thought the forces in the crash would not tend to unhinge the bar.  In reply the defendant put in test results.  In a crash it showed that the net fails by the hinge section actually breaking, i.e. failing or cracking.  The movement is in the opposite sense from unhinging.  It is not unhinging.  I will assume that this test result means that the top bar is weaker as a result of the hinge than it would be if there was no hinge.  There was some suggestion in the evidence that it was 10 times weaker and I do not doubt that.  However, this evidence shows that however weak it is, in my judgment it is still behaving like a bar.  It is stiff until the hinge part fails.  Although it shows the top bar may be weaker, in my judgment it is still bar‑like.
57.	I would accept the defendant's point if the net was constructed so that the hinge part did simply unhinge in a crash, but it does not.  I think the argument for non‑infringement places too much emphasis on a gloss on the meaning of "bar‑like" in Dr. Goodhead's evidence.  Bar and bar‑like are not terms of art.  Bar‑like simply means the part must be stiff like a bar until it fails.  That is my interpretation of what Dr. Goodhead was getting at.  The reference to “withstanding the maximum bending moment that could be encountered” can be taken too far and in my judgment this feature is satisfied by the Cobra net.
(ii) Tubular insert
58.	The relevant part of the claim is as follows:
"with a tubular insert which goes into the cavity and is fixed in the cavity."
59.	The argument is that the word "tubular" in English is a mistranslation of the German word "rohrformigen".  Mr. Van Lieshout, who is Dutch, but is a fluent German speaker, said that the best translation of rohrformigen in his view was "pipe like".  Rohr is a pipe, a reed or a barrel.  The significance of this point is that whereas a tube may have an end, e.g. a test tube, a pipe does not.  Dr. Goodhead, who does not speak German, exhibited a dictionary showing that rohrformig rather that rohrformigen could be translated as tubular, as in the claim.  Mr. Pritchard pointed out that it was absurd to rely on Dr. Goodhead's evidence given that the claimants are German.  If they thought that Mr. Van Lieshout was incorrect, it would have been the simplest thing for them to say so.  So this argument appeared to be developing into a tricky area concerned with the authentic texts of patents, the relevant provisions of the Act and to some extent also the approach set out by Mann J by in Siemens Schweiz v Thorn [2008] RPC 4.  Of course, the authentic text of this patent is German.
60.	However, in my judgment this difficult issue does not arise on the facts of this case.  The insert in question is both pipe like and tubular.  It is not blocked at one end.  Mr. Pritchard submitted that it did not infringe because the retaining member, i.e. the rod, does not stick out beyond the end of the insert inside the tube, unlike for example the shank in figure 3 of the patent.  However, I reject the submission that this matters.  There is nothing in claim 1 which requires the shank of the retaining member to extend beyond the end of the insert.  If I put the words "pipe like" into this feature of the claim instead of "tubular", in my judgment Cobra's product would satisfy the claim.  Accordingly I do not need to decide this point.  There is infringement in relation to that integer either way.
(iii) Fixing arrangement  
61.	The relevant part of the claim reads:  
"with a fixing arrangement associated with one edge in order to connect the security net to the estate car in the region of this edge."  
62.	The issue is what does "in the region of this edge" mean.  The defendant says that the straps arrangement in the Volvo net is not within the claim because the connection between the car and the net is made with the hooks on the end of the straps and that connection is not in the region of the lower edge of the net.  The connection is well away from the lower edge of the net.  It is at a distance comparable to about half or possibly more of the size of the net itself  away from the edge.  The defendant says that the feature in the claim is referring to an arrangement in which the connection to the car is itself in the region of the lower edge of the net.  So a roller blind‑type arrangement as shown in the figures of the patent would satisfy that feature.
63.	The defendant's case was that both arrangements were common general knowledge.  The Mercedes net uses one and the Opel net uses another, like the Cobra net.  These matters I should point out are nothing to do with the internal aspects of the fixing arrangement at the top of these nets.  The technical difference between the two arrangements is the rigidity of the connection and of the net overall.  A roller blind‑type of connection gives a more rigid arrangement than two straps or four straps.  So the defendant submitted the skilled reader would understand that the words have been used to draw this distinction.  
64.	The claimant submits that all the claim means is that the fixing arrangement is in the region of the lower edge of the net.  The straps are indeed in that place in the Volvo net and the buckles are right by the lower edge of the net.  The claimant also submits that this aspect should not be read too narrowly on the basis that the feature is "relatively unimportant to the inventive heart of the invention."
65.	In reply to that latter point, the defendant cited STEP v Emson, which I have cited above.  It is not legitimate, they say, to construe such a limitation out of existence.  
66.	In essence, the defendant's case is that the claimant's argument, while it gives a meaning to the first reference to the edge in the claim language I have quoted ("associated with one edge"), it ignores the second one (“in the region of this edge”).  The defendant says the claim has a double requirement - the fixing arrangement must be associated with the edge, as in the Volvo net, but it must also connect the net to the car in the region of that edge.  Clearly the use of a roller blind is not necessary.  One could simply fix the lower edge to the rear of the back seat by a series of pins.  That would have a similar effect and would clearly satisfy claim 1 on the defendant's construction, in that the connection is in the region of the lower edge of the net.  
67.	This point came before the Düsseldorf court.  They held there was infringement.  The key part of the court’s decision dated 13th July 2010 on this point is in section II 2.  In translation it is as follows: 
“The patent claim is silent as to what type of fixing arrangement is to be associated with the lower edge, i.e. the means and ways to connect the security net to the car at the lower edge.  A fixing arrangement according to the invention may as well be – like in the embodiment in question – a reinforcement engaging at the lower edge, where fixing belts for connection to the bottom of the car are disposed.  As the fixing belts engage at the lower edge almost immediately via the reinforcement, one might say without restraint that the connection to the car (bottom) is effected in the region of the lower edge.  That by means of fixing belts, the lower edge of the net is in a certain way spaced from the actual fixing point at the bottom of the car, is inoffensive.  Namely, it is a simple fact that the connection to the car is effected in the region of the lower edge. 
The contrary opinion of the defendant is not supported by the wording of the claim.  As far as the litigation patent demonstrates fixing of the net via a casing attached to the rear of the seat back, corresponding to the  state of the art, the illustration of a preferred embodiment of the invention is not adapted to limit the scope of patent claim 1 (see BGH GRUR 2004, 1023 – Bodenseitige Vereinzelungseinrichtung; BGH GRUR 2007, 309 – Schussfädentransport).  The basic stability of the lower edge of the net as addressed by the defendant, is not mentioned in the litigation patent, on the one hand, and may also be achieved by producing a corresponding tension of the net, on the other hand.” 
68.	I am very reluctant to disagree with the decision of an experienced court like the Düsseldorf court on this issue, especially when it turns on construction of a patent whose authentic text is German.  However, I am troubled that, as the defendant says, the claimant's interpretation in effect seems to strike through the words "in the region of this edge".  One way in which the difference between the two arrangements was characterised in the Düsseldorf court was by reference to stability of the lower edge.  A connection in the region of the lower edge makes the lower edge more stable than the looser lower edge that is found in the Opel net and in the Volvo net alleged to infringe.
69.	As the Düsseldorf court said, the stability of the lower edge is not mentioned in the patent.  That is true, but it is undeniable that the patent expressly requires that the connection be "in the region of the lower edge".  Read with the common general knowledge, and in particular with the knowledge of both the Opel and the Mercedes nets, I think a person skilled in the art would understand that the patentee is indicating an arrangement with a connection at or near the lower edge which draws a distinction over the known Opel type.  The language is clearly not limited to a roller, all sorts of connections are possible.  However, it does require in my judgment that the connection between the net and the car should be at or close to the lower edge.  A net which went all the way to the floor and was strapped by very short straps would probably satisfy it.  But I am not satisfied that the skilled person would think that this feature could be disregarded.  I cannot help but wonder that if the alleged infringement was not like the prior art Opel arrangement in this respect but was connected close to the lower edge like a Mercedes net, then the patentee would be contending that this feature should be read narrowly in order to take the invention further from the prior art Opel net.  
70.	I respectfully disagree with the Düsseldorf court and I find there is no infringement.
Obviousness
71.	The correct approach is that set out in the Pozzoli case [2007] FSR 37 as follows:
(1)(a) Identify the notional “person skilled in the art”;
(b) Identify the relevant common general knowledge;
(2) Identify the inventive concept of the claim in question or if that cannot be readily done construe it;
(3) Identify what, if any, differences exist between the matter cited as forming part of the “state of the art” and the inventive concept of the claim or the claim as construed;
(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?
72.	I should also refer to what was said in Angiotech in the House of Lords ([2008] UKHL 49, [2008] RPC 28) and Lord Hoffmann's approval of the following passage from the judgment of Kitchin J (as he then was) in Lundbeck ([2007] RPC 32):
"'The question of obviousness must be considered on the facts of each case.  The court must consider the weight to be attached to any particular factor in the light of all the relevant circumstances.  These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success.'"
73.	In cross‑examination Mr. Pritchard put to Dr. Goodhead on a number of occasions that there was nothing technically difficult about various steps.  I accept that it is relevant in the sense that if a step was technically difficult then that would make it less obvious, but the converse is not true.  The fact that a step is not technically difficult is, in a case like this, almost entirely irrelevant.  This is a mechanical engineering case.  Most inventions in that field are not technically difficult.  It does not mean that they are obvious.
74.	Following the Pozzoli approach, I have dealt with the identification of the person skilled in the art and the common general knowledge above.  The next step is to consider the inventive concept.  I am dealing with claim 1.  Claim 1 is tolerably clear.  The key to the invention is the use of the particular combination of insert and spring, including the way in which the two interact that addresses rattling and allows pre‑assembly of the retaining members and the insert.
Butz
75.	That is German published application DE3314444, published in 1984.  This is a horizontal luggage cover.  The key is figure 3, as follows: 

76.	In figure 3 can be seen a mushroom headed part, a spring and a tube.  Cobra argue that it is obvious to take this bar fitting, modify it and make it into the top bar of a security net.  The argument was supported by Mr. Van Lieshout's opinion.  Dr. Goodhead in his report made a number of points, but one was that this was a completely different art, horizontal luggage covers being different from vertical security nets.  There was cross‑examination on these issues designed to show how obvious it would be to take the bar in Butz and turn it into a top bar in a security net.  
77.	I reject this obviousness case.  Not only is a luggage net not a security net, but the details of this bar are completely different from the claimed invention even if a person skilled in the art thought to learn anything from Butz in the context of security nets.  The bar in Butz has nothing but a superficial similarity to the patent.  The mushroom headed bar of Butz (item 24, the shank) does not move inside the insert or dowel (20).  To end up with a system in which the shank moves inside the dowel or insert is an exercise in pure hindsight in my judgment, knowing the invention as a target.  I do not propose to spend time on Butz.
The Mercedes Net  
78.	The Mercedes net has a roller blind arrangement as is shown in the figures in the patent in suit.  The top fixing arrangement is as follows.  The top bar is a steel tube.  At the end there is a metal retaining rod with a mushroom end.  It is sprung.  The rod goes inside the tube.  There is a pin through the tube about six inches from the end.  A spring bears between that pin and the end of the rod.  There are four slots, two on either opposite side in the tube.  At each slot there is a pin.  The pin goes right through the rod so that the pin can move inside the two slots.  The pins in the slots stop the rod from rotating relative to the tube.  
79.	What are the differences between the Mercedes net and claim 1?  Essentially the difference is there is no insert as required by the claim and of course necessarily therefore none of the features which relate to the insert.  The question is, whether viewed without knowledge of the invention, do these differences constitute steps which would have been obvious to a person skilled in the art or do they require invention.  
80.	I will first consider the reaction of a person skilled in the art to the Mercedes net if they are presented with it in 1993.  I was provided with a sawn‑off end of the Mercedes net and it was possible to hold that end and rattle it in the courtroom.  However, I do not accept that that is a fair way of assessing how significant the rattle or squeak of this design is.  
81.	In my judgment, however, a person skilled in the art looking at this in 1993 would see metal to metal contacts.  Mr. Van Lieshout referred to this at paragraph 91 of his report.  The metal to metal contacts are: first, the rod sliding inside the tube; second, the pins bearing on the metal bar; third, the pins which would be able to rattle in the slot; and fourth, the spring bearing on the inside of the tube.  This may squeak rather than rattle.
82.	I accept it may well be that Mercedes were happy with this design when it was made and may even still have been happy with it in 1993, but I reject the idea that in 1993 these metal to metal contact points would not have been of concern to a skilled person working in a firm like BOS or an equivalent on security nets at the time.  In my judgment a person skilled in the art looking at this product has a serious motivation to look to improve the design from the point of view of rattle and squeak.  
83.	Mr. Van Lieshout's opinion was that the obvious way to do that was to create a plastic insert based on the existing Mercedes arrangement and then slot that inside a metal tube which would obviously necessarily be wider in order to accommodate the new arrangement.  This would eliminate the metal to metal contacts.  If the person skilled in the art did so, the defendant submitted the result would be a product within claim 1.
84.	There was an argument about whether the result would indeed be within claim 1.  The argument was that the arrangement would not be within the claim because the spring would then bear on a pin in the insert instead of the insert material itself, but the defendant submitted that would be a trivial change.  In my judgment such an arrangement with a pin would be within claim 1 anyway, even with a pin, but I also think that even if that was not the case it would be completely trivial to change it in such a way as to make the spring bear on the plastic insert directly, if one had gone down this route in the first place.
85.	The real issue therefore is whether Mr. Van Lieshout's approach to the plastic insert was itself obvious.  Dr. Goodhead's opinion was that it was not obvious.  His view was that it introduced unnecessary complexity and he also submitted that it was contrary to DFM (design for manufacture) principles.  However, the cross‑examination demonstrated that design for manufacture is a complex business, particularly bearing in mind a document called Boothroyd which was put to Dr. Goodhead in cross‑examination.  It was clear that Dr. Goodhead had not looked into the matter in any detail.  It was not possible to say whether Mr. Van Lieshout's proposal was good or bad from a design for manufacturing perspective, particularly bearing in mind Boothroyd.
86.	Dr. Goodhead also proposed another solution, which in his opinion was more obvious, to deal with part of the metal to metal problem.  This was advanced in particular in relation to Opel, which is similar to Mercedes.  It was to place plastic collars on the ends of all the pins.  Mr. Van Lieshout, on the other hand, did not think this was a practical way forward.  It involved a good number of fiddly little plastic collars.  I accept Mr. Van Lieshout's evidence, especially given that he has more experience of making security nets than Dr. Goodhead.
87.	There was a debate about the number of parts of various proposals involved, but I reject the idea that counting numbers of parts is necessarily all that important.  Other matters are equally significant, such as the nature of the parts in question and questions like how are they to be fitted.
88.	Finally, Dr. Goodhead explained that one cannot simply take a part, such as a metal tube with slots, and change the material from which it is made from metal to plastic and assume that that can be done without further ado.  It may look superficially simple but such changes have design consequences.  It is possible to make very thin walls out of bits of metal.  In injection moulding, making very thin walls out of plastic is much more difficult.  I accept that this is a consideration for the person skilled in the art.  A person skilled in the art would know that one could not simply make a plastic part with necessarily the same dimensions as a metal part.  It needs to be considered.  However, in my judgment that sort of consideration is well within the skill of a person skilled in the art.
89.	I think the key to this is the skilled person's motivation.  The Mercedes design is one with clear problems caused by metal to metal contacts and the person skilled in the art has a clear direction to go in, to put in plastic parts of some kind somewhere to go between the metal contacts.  Is that enough to say that Mr. Van Lieshout's proposal is obvious?  I wondered whether the obvious route was just to go to the Opel design.  Although I have not explained it in detail, the Opel design had some metal to metal contacts but also had plastic sleeves to address the metal to metal contact issue.  The plastic sleeves eliminated some of the risk of rattle and squeak, but they did not eliminate all the metal to metal contacts.  
90.	In the end I prefer the approach of Mr. Van Lieshout.  For one thing his experience is closer to that of a person skilled in the art.  More so, I think it would be very obvious indeed to address metal to metal contacts.  Some way forward would have to be taken and in my judgment Mr. Van Lieshout's way forward would be obvious.  Inserting plastic somehow would be necessary and the Mercedes design has a structure which is more or less there to be used as a starting point to make an insert essentially with the same arrangement, only from plastic.
91.	Mr. Colley suggested that this would involve a number of independent design steps.  To some extent I agree, but this is where the issue of motivation is so important.  In this case I think there was a strong motivation to work in that direction.  Although it is true that dimensions need adjustment, overall in my judgment claim 1 is obvious.
Claim 7 
92.	Claim 7 requires the insert to have a wider part in which to receive a spring member.  An insert which was simply a precise copy in plastic of the Mercedes part would not satisfy claim 7.  
93.	Mr. Van Lieshout's evidence was that claim 7 was obvious.  He dealt with this partly based on his view about the Opel system.  One thing Mr. Van Lieshout also said was that a skilled person working from the Mercedes design would consider it advantageous to use a larger diameter spring, because the tube in the Mercedes system is very narrow.  That would necessarily require a larger diameter part of the insert to accommodate the spring.  The result would be within claim 7.  Dr. Goodhead addressed the points on Opel, but did not address the point on a larger diameter spring.  
94.	The space for the spring plainly has to be large enough to accommodate the spring.  There is nothing inventive about having a particular diameter of spring and I accept Mr. Van Lieshout's evidence that given the narrow nature of the Mercedes design, a somewhat larger diameter spring would be advantageous.  To accommodate a larger spring would obviously require some widening of the insert and that in turn may well mean that the plastic wall of the material of the insert would be narrow in that region.  I bear in mind Dr. Goodhead's evidence that thin plastic walls in the context of injection moulding are difficult, but as I have said before, in my judgment a person skilled in the art will take that into account as part of their ordinary skill.
95.	The fact that to accommodate a larger spring may involve narrowing a plastic wall on the insert does not turn this into an inventive thing to do.  I accept that the skilled person would not necessarily create a widened part of the insert for the spring, or necessarily widen the spring at all, but in my judgment there is nothing inventive in doing this.
96.	Accordingly claim 7 is obvious.
Claim 9
97.	Over Mercedes claim 9 stands or falls with claim 7.  The insert which Mr. Van Lieshout described in his evidence and which I have addressed already has slots which secure the rod from rotation with respect to the insert.  Accordingly, I do not need to deal with claim 9.  It is also obvious if claim 1 is obvious.
Claim 14  
98.	This calls for a flange at the end of the bar.  In my judgment there is nothing inventive here.  A flange is an obvious expedient to stop dirt getting inside and for decorative purposes and I do not propose to spend time on claim 14.  It is obvious. 
Opel
99.	The Opel Net is like the Mercedes net.  The top bar is very similar to Mercedes but has extra plastic collars fitted to the shank of the retainer rod between the rod and the tube.  Opel also has extra energy absorbing slots for pins to slide inside.   The Opel net has a lower fixing arrangement like the Volvo net.
100.	Compared to Mercedes, Opel has an additional difference from claim 1 because it has a different lower fixing arrangement.  So there is an extra step here as compared to Mercedes.  One would need to change the fixing arrangement, as well as make all the other changes, to end up with a system inside claim 1.    
101.	The defendant submitted that it would be obvious to replace the fixing arrangement of Opel with the roller blind arrangement of Mercedes.  
102.	The obviousness case over Opel in relation to the plastic insert is very similar to (but not the same as) the argument over Mercedes.  However, in my judgment, this is a weaker case than Mercedes because of the fixing arrangement.  If the claim was not obvious over Mercedes, then I doubt it would be obvious over Opel too given that there is an additional step required to change the lower fixing arrangement.  
103.	Accordingly, I do not need to grapple with Opel.
Ament
104.	Ament (DE 4010209) discloses a security net like the patent.  The difference is in the top fixing arrangement.  This can be seen in Figures 2 and 4, as follows:

105.	The familiar mushroom ended retainer rod and tube can be seen.  There is an energy absorbing mechanism whereby the conical part 29/31 is pulled inside beads 26 and 25 to absorb energy.
106.	The differences from claim 1 are that there is no spring, no insert and no relationship between the spring and the insert.  
107.	Mr. Van Lieshout's view was that it was obvious to put a spring into Ament to address rattling.  I did not understand Dr. Goodhead to disagree with that, but in any case I would accept Mr. Van Lieshout's evidence.  In my judgment, any person skilled in the art in 1993 looking at Ament would say it needs a spring to bias it, addressing rattle and maybe for other reasons.  I note that the two commercial designs, Opel and Mercedes, have springs.  
108.	From there Mr. Van Lieshout said the obvious way to put in a spring was in a manner set out in Figure 5 of his report.  That would be a structure inside claim 1 of the patent.  
109.	Dr. Goodhead was asked about this.  He accepted the following:  That Mr. Van Lieshout's solution was "one of many different equally straightforward engineering solutions that you could take, if that is what you wanted to do."  This gives rise to a powerful case that the invention is obvious over Ament.  
110.	However, in cross‑examination, Mr. Van Lieshout explained that, in coming to his proposal in Figure 5, he had been instructed that he did not need to consider the energy absorbing means.  At first sight this seems reasonable since energy absorbing means are not in claim 1.  
111.	Mr. Colley submitted that the energy absorbing function at some level was within claim 1, in that safety nets inherently absorb energy.  I reject that submission.  Apart from anything else, see claim 2 of the patent.  Moreover, the fact that nets have a “one time” use does not mean they have to have any specific energy absorbing features.  So perhaps the instruction to Mr. Van Lieshout was legitimate?  I find this a troubling point.  It seems as though the patentee could be getting the benefit of an unclaimed difference over Ament.
112.	However, the problem is that the energy absorbing feature is part of the particular Ament structure.  It seems to me that on the evidence I have I do not know what Mr. Van Lieshout would have done if he had taken the energy absorbing part of Ament into account in his design.  Perhaps he would have come up with his proposal but perhaps not.  Perhaps it was obvious to ignore the energy absorbing mechanism in Ament but that is not Mr. Van Lieshout's evidence.  He was instructed to ignore it.
113.	In my judgment, that means I cannot place weight on Mr. Van Lieshout's reasons why this claim is obvious over this piece of prior art and I reject the attack based on Ament.
Common General Knowledge Alone  
114.	I do not need to address this.  As far as I am aware, as opposed to a submission starting from Opel and Mercedes which are themselves common general knowledge, there was no separate case advanced.
Conclusion
115.	In my judgment, the Volvo net does not infringe.  All the relevant claims are obvious over the Mercedes net.  They are not obvious over Butz or Ament and I do not need to decide the case over Opel.  I will hear the parties.
(See separate transcript for proceedings after judgment)