Nampak Cartons Ltd v Rapid Action Packaging Ltd

This is an appeal from a decision of the Hearing Officer, Mr Stephen Probert, in an application in the Patent Office by Nampak Cartons Limited (“Nampak”) for revocation of UK Patent No 2,397,593 (“the Patent”). The Patent is in the name of the Respondent Rapid Action Packaging Limited (“RAP”), and relates to cartons for sandwiches.

In response to the application for revocation RAP applied to amend the principal claim of the Patent to read as follows:

“A carton for a diagonally cut sandwich or like foodstuff formed from a blank of card and having triangular end walls connected by rectangular sidewalls to form a triangular prism-shaped container, one side wall of the container being hinged to another wall of the container to provide an opening for insertion/ removal of foodstuff and to form a lid for closing the opening, the edges of the opening having out-turned flanges, and the periphery of the lid overlying the out-turned flanges encircling the opening when the lid is in the closed position whereby the lid can be bonded to the flanges to close the carton; wherein the carton is formed from a card which is heat sealable on the surface which forms the inner side of the container, the periphery of the lid of the container being bonded by heat sealing to the out-turned flanges encircling the opening of the container to seal the contents of the container and wherein the bonded lid/flanges are adapted to be torn apart to open the container for access to the sandwich therein by dual parallel lines of partial cut along the flanges, one being at the junction between the flange and the wall adjacent to the inside face of the lid and the other being part way across and on the other side of the flange so that the flanges can split to allow the lid to be opened."

As the Hearing Officer explained at [4] in his Decision, the result is that when the hinged lid of a carton according to the invention is opened, the flange of the carton delaminates, with part of the flange material remaining bonded to the lid. All that is left of the flange is a de-laminated portion of reduced width. This is achieved by means of the spaced apart lines of partial cut on opposite sides of the flange, one being at the junction of the flange and the lid and one part way across the flange.

The technique of allowing opening of a cardboard package by means of spaced apart partial cuts approaching from opposite sides of the card is well known. It is used on Twining’s tea cartons and other cardboard packaging. It is called a “Concora” cut.

The attack on the Patent was based on lack of inventive step. The following documents were the principal starting points relied on:

The Hearing Officer rejected all three attacks after hearing expert evidence from one expert in packaging from each side. He concluded that the other attacks were less good than those three and therefore rejected those as well.

In relation to Rigby, the Hearing Officer explained that it disclosed Concora cuts along the sides, but that the cuts were made in the lid and not in the flange. He noted that Rigby explained that a benefit of providing the cuts in the lid is that the portion of the lid left on the flange will increase its rigidity.

In relation to Meyers the Hearing Officer noted that it showed two methods of creating the opening. In the first there is a single microcut in the flange, so that the flange remaining after opening is the same width as before. The flange does not delaminate between cuts on the flange, but between a single cut and the outer edge of the flange. In the second method, there are two cuts, but it is the lid which delaminates and not the flange, and the delamination occurs inboard of the flange for the special purpose of creating a lip for re-closure.

In Spiral Packs, the reader is told to use “tear strips formed by lines of weakening”. The Hearing Officer held that this did not disclose the invention or render it obvious either.

Nampak challenge the Hearing Officer’s decision in relation to all three citations. Mr Henry Ward presented the appeal on behalf of Nampak and Mr John Baldwin QC responded for RAP.

By CPR 52.11, as applied by CPR 63.17(1), this appeal is limited to a review of the decision below unless the court considers in an individual case that it would be in the interests of justice to hold a rehearing.

It was also common ground that, in those circumstances, before this court interferes with the decision of the Hearing Officer, it should be satisfied that he erred in principle or was clearly wrong.

Two factors are present in this case which mean that I should be particularly careful to accord respect to the Hearing Officer’s Decision. The first is the warning of Lord Hoffmann in Biogen v Medeva [1997] RPC 1 at page 45 concerning findings of obviousness. He concludes that well-known passage by saying:

“Where the application of a legal standard such as negligence or obviousness involves no question of principle but is simply a matter of degree, an appellate court should be very cautious in differing from the judge's evaluation.”

Secondly, amongst the factors to be taken into account in deciding the degree of reluctance to be exercised in relation to interfering with such a decision on an appeal, are (a) the standing and specialist experience of the court or tribunal appealed and (b) whether the court or tribunal appealed from heard oral evidence. These are points made clearly in the judgment of Robert Walker LJ in South Cone Inc v Bessant and others (trading as Reef) [2002] EWCA Civ 763 at [26] – [28].

The facts of the present case are not complicated. That means that there is a temptation to be drawn in to deciding the case afresh oneself. That is a temptation which needs to be resisted.

In their first ground of Appeal Nampak fasten on the following observation of the Hearing Officer at [11] and [12] of his Decision:

“Both parties filed evidence in the form of witness statements from expert witnesses. Mr Riley was the applicant's expert; Mr Clough was the patentee’s expert. There is no doubt that both Mr Riley and Mr Clough are rightly described as experts; both men have had many years of experience in the food packaging industry. The gist of Mr Riley's evidence was that the invention was obvious; the gist of Mr Clough's evidence was that it was not obvious. Both experts were cross-examined at length during the hearing, and neither expert changed his mind to any material extent. I formed the impression that Mr Riley knew more about patent law than Mr Clough, and he also seemed to have more experience of being cross-examined. Nevertheless, both men came across as honest witnesses who were doing their best to assist the tribunal.

Although the fundamental difference of opinion between the experts meant that their evidence was not directly helpful to me in deciding this case, it was useful in as much as they agreed on the identity of the notional person (or team) skilled in the art they were also able to help me determine what would be the common general knowledge of that person (or team).”

Later, at [36] when dealing with Spiral Packs, he said this

“Ultimately, the experts, Messrs Riley and Clough, were unable to help me with this question because their evidence was not conclusive.”

Mr Ward submitted that these passages show that the Hearing Officer had failed to consider the expert evidence, and had simply substituted his own view as to obviousness. Not only was the Hearing Officer so stating, but the decision contains evidence, so Mr Ward submits, that this is what he actually did. For example he drew attention to the Decision at [29] where the Hearing Officer said this:

“The arrangement in Meyers, with a single micro-cut along the side edges, appears to work well enough without the extra micro-cut. At the hearing, it was suggested that it would be obvious to add the second micro-cut in order to make it easier to open the package – i.e. because there would be less material to tear. But it seems more likely to me that if one wanted to modify Meyers to make it easier to tear the lid off, one would be more likely to make the flanges narrower.”

The evidence on adding a micro-cut to Meyers was in fact as follows. At [11] of his second report Mr Riley said that if the delamination of the board was likely to be relatively difficult to achieve, parallel lines of offset partial cuts may be chosen. However, a package designer would understand that either a single line or dual lines of partial cut could be used if required and may test both during production of a carton prototype.

In cross-examination Mr Clough appeared to agree that whether or not one would be interested in using a double or single cut depended on whether or not the side flanges were difficult to open. He did not suggest then or subsequently that it would be obvious simply to reduce the width of the side flange.

Accordingly Mr Ward submits that there was common ground as to how the skilled person would react faced with a difficulty in delaminating the side flanges. It was not open to the Hearing Officer in those circumstances to substitute his own view as to how the skilled person would have reacted.

Mr Baldwin submitted that in the Decision at [11] – [12] and [36] the Hearing Officer was simply explaining that, as is often the case, the experts were not in agreement on the ultimate issue of obviousness. He submitted that there was no basis for contending that the Hearing Officer had disregarded all the evidence merely because the experts were at odds on the ultimate issue. He reminded me of a passage in the judgment of Jacob LJ in Rockwater Limited v Technip France SA (formerly Coflexip SA) [2004] EWCA Civ 381 at [15] –[18] where he explained that the value of expert evidence in patent cases is firstly as teachers of the relevant background common general knowledge, and secondly as providing reasons why the skilled person would find the invention obvious or not. He recalled what he had said in Routestone v Minories Finance [1997] BCC 180 at 188 citing Wigmore, Evidence that, absent reasons, the expert’s assertion of obviousness was “empty rhetoric”. At [18] he said:

“Because the expert’s conclusion … as such … is of little value it does not really matter what the actual attributes of the real expert witness are. What matters are the reasons for his or her opinion.””

In relation to the Decision at [29] Mr Baldwin submitted that there was ample evidence to justify the conclusion reached by the Hearing Officer that the skilled person would be more likely to narrow the flange. Firstly he said that the physics was fully explained in the evidence by Mr Riley, Nampak’s own expert. In particular there is an interplay between the various considerations: width of flange, difficulty of opening and whether to use one or two lines of partial cut. He was accordingly faced with evidence which suggested that reducing the width of the flange was one factor. He also drew attention to the evidence of Mr Riley in cross-examination where he expressly drew attention to a flange with a single cut, which would, if it were sufficiently narrow, allow the flange to delaminate “happily”. It was open to the Hearing Officer to assess which option the skilled person was more likely to take.

Mr Baldwin also pointed to the evidence of Mr Clough in his report, where he said

“I had never come across putting lines of weakness in the flanges to cause the flanges to split and it would never have occurred to me to do so as no-one would want to weaken the flanges”.

By sticking to a single cut at the junction of the flange and the side of the carton, one avoids making any cut in the flange.

The first question for decision is whether the Decision at [11] and [12] and [36] should be read as Mr Ward suggests, namely as a statement by the Hearing Officer that he was disregarding the expert opinion evidence. In my judgment the Decision should not be so read. Firstly, the Hearing Officer only says that he did not find the expert evidence “directly” helpful. Later he says that the experts were not “ultimately” able to help. This suggests to me that he is simply recording the (admittedly common) position that experts employed by the respective parties take opposing stances. But the fact that he said that it was not directly or ultimately helpful suggests that it was helpful indirectly, or prior to the ultimate question. Secondly, the Decision can only be read as Mr Ward suggests if one takes the matters specifically mentioned by the Hearing Officer (skilled addressee and common general knowledge) as being an exhaustive list of the matters on which he found the opinions of the experts helpful, and as therefore excluding the reasoning of the experts leading up to their assertions about obviousness. But that is quite plainly not the case as other passages in the decision make clear. In particular the Hearing Officer relied extensively on the patentee’s expert’s view that one would not weaken the flanges.

The second question is whether the Decision at [29] is a specific example of the Hearing Officer reaching a conclusion which was not open to him on the evidence. I do not think this point is made out either. There was no evidence that the skilled person who implemented Meyers would encounter a problem with the ease of separation of the lid. The common view of the experts was in relation to what might be done if there was a problem. But Meyers shows a carton which is supposed to open and close with a single microcut, as the Hearing Officer records in the first sentence of [29]. So the evidence of the document itself, read in the light of the simple physics which Mr Riley described, tells the skilled person to make the flange narrow enough to allow it to open as described. In these circumstances I do not think that the Hearing Officer’s conclusion can be challenged as an example of substituting his own judgment for the opinions of the experts.

Accordingly I am not persuaded that the first ground of appeal shows an error of the kind which would be necessary to entitle me to reopen the issues investigated by the Hearing Officer.

Nampak submit that the question of obviousness over Spiral Packs was essentially a question of construction of the document, and in particular the phrase “tear strips formed by lines of weakening”, and that the Hearing Officer arrived at an incorrect interpretation. Alternatively they submit that Nampak’s case of obviousness over common general knowledge was ignored by the Hearing Officer. These two grounds of appeal overlap to a degree, and I will deal with them together.

The Hearing Officer reached the conclusion that the skilled person would have interpreted the phrase as suggesting:

"a removable strip of paperboard material provided by two pairs of micro-cuts - one pair on either side of the strip - an arrangement that I referred to during the hearing is "double Concora”.”

In support of this conclusion the Hearing Officer relied on the Paperboard Reference Manual, a 1993 publication, which he considered to be part of the common general knowledge. He illustrates his conclusion by reference to an illustration of a tear strip, which appears in that case to be created simply by two lines of ordinary perforations.

Although it is not entirely clear from simply reading the Decision, there was evidence before the Hearing Officer that a narrow tear strip could be formed by lines of perforation as shown in the Paperboard Reference Manual, or by opposed double Concora cuts. I am satisfied that there was ample evidence to suggest that Spiral packs would be read by the skilled person as teaching one or other or both of these methods. As Mr Ward accepted during argument, the phrase in question is not specific. The skilled person is in fact left with a variety of tear strip options as to how to proceed in the light of this very general teaching. The Hearing Officer concluded that these options were significantly different from the inventive concept which uses a single Concora arrangement in the bonded flanges. It is very hard, in fact, to see how one could describe the arrangement defined in the Patent as a “tear strip”. He was perfectly entitled to reach that conclusion in the light of the evidence before him, all of which, as he expressly states at [41], he had considered in reaching it.

However, earlier in the decision, at [38] to [40], the Hearing Officer first summarises the respective positions of the experts and then rejects an attempt that was made in the course of cross-examination to lead the patentee’s expert Mr Clough step-by-step from Spiral Packs to the inventive concept. This involved, for example, relying on advantages of the invention such as its economy in the number of cuts which it would require the skilled person to perform. He considered that at least some of these perceived advantages would rely on an element of hindsight. It is only then that the Hearing Officer reaches his conclusion as to the teaching of the phrase in question.

The Hearing Officer was fully entitled to reject the obviousness attack based on Spiral Packs, as based on step-by-step hindsight reasoning. In broad terms this attack was the same as that based on common general knowledge.

I was taken with care through the relevant passages in the expert evidence and the cross-examination. Mr Ward submitted that it established that (a) a system of Concora cuts is something that the skilled person would have considered (b) that locating the cuts in the flange rather than the body involved less risk of compromising the integrity of the carton (c) any solution should avoid any flange inboard of the sides to allow the user free access to the sandwich. Accordingly there was effectively only one decision to make: does one put the Concora cuts into the lid or into the flange? As to this latter decision there was much to be said for putting the cuts into the flange (economy of cuts and aesthetics) and little for putting it into the lid.

In my judgment the Hearing Officer was plainly entitled to reject the attack based on obviousness in the light of Spiral Packs or based upon common general knowledge. In both cases the logic relied heavily, as the Hearing Officer observed, on spotting that the score line used for the corner of the carton wall could be used as the first microcut. Whilst it is undoubtedly correct that this is an advantage of placing the cuts in the flange, the Hearing Officer was entitled on the evidence to conclude that the skilled person would not have perceived this advantage without the patent. The skilled person would not naturally have associated whatever score or cut was made at this corner with creating an opening means for the carton. As Mr Baldwin succinctly put it, putting this cut to “double duty” was part of what was clever about the invention.

Accordingly I reject the challenge to the Decision based on these two grounds.

Lastly, Nampak submit that the Hearing Officer failed to apply the structured approach to a decision on the question of obviousness laid down by the Court of Appeal in Pozzoli SPA v BDMO and others [2007] EWCA Civ 588.

The structured approach is well known: the Hearing Officer set it out at [8] of the decision. The second step of the analysis requires the court to identify the inventive concept of the claim or construe it. At [19] of the decision the Hearing Officer identified the inventive concept in the following words

"The majority of the features in claim 1 were already well known to a skilled worker. Having read the submissions of the parties, and having also read the patent and the evidence in this case, I conclude that the inventive concept is a cardboard sandwich carton with dual parallel lines of partial cut along the flanges, one being at the junction between the flange and the wall adjacent the inside face of the lid and the other being partway across and on the other side of the flange so that the flanges can split (i.e. delaminate between the cuts) to allow the lid to be opened.”

Whilst the structured approach is of assistance to judges in the analysis of evidence, not every slip in its application opens the decision to attack based on error of principle. Mr Ward’s criticism is that, having arrived at the inventive concept, the Hearing Officer did not limit himself when considering obviousness to differences between the item of prior art in question and the inventive concept. For example in [24] the Hearing Officer appears to rely on the different method of sealing and opening the front edge of the package in Rigby, whereas the particular method of sealing the front edge did not form part of the inventive concept. In similar vein, in [31] the Hearing Officer points out that Meyers does not appear to be a hermetically sealed package, whereas the claim does not require hermetic sealing either.

I do not think there is anything in these points. Firstly, the extent of the error, if there was one, is failing to spell out in [11] that the flanges are sealed all round to the lid. There is no dispute, as a matter of construction, that this is what the claims require. There could be no conceivable basis for omitting this requirement from the claims, particularly as it formed a feature of differentiation over some of the prior art: Rigby and Meyers. Secondly, the Hearing Officer was right to observe that it was not open to him to “cherry pick” individual features from items of prior art without considering the whole of the disclosure. Rigby and Meyers do not contain any disclosure as to how one would arrange a carton to be sealed by Concora cuts all round the lid. Each of them therefore had to introduce some special opening means. A further step in the reasoning process through which the skilled person would have to go was therefore whether the methods used in Rigby and Meyers could be used when the seal goes all round. To the extent that he needed to, the Hearing Officer was entitled to reinforce his decision on obviousness by reference to this feature of the claim. His failure to spell the feature out at [11] of the Decision is irrelevant.

In the light of the conclusions I have reached it is not necessary for me to consider points raised by a Respondent’s Notice served by RAP. For the above reasons I propose to dismiss the appeal.