Deep fat fryer patent almost gets its chips

What better way is there for any intellectual property enthusiast to celebrate a birthday than to share some chips with his friends -- or at least to sit down and write something on patent infringement as it affects the production of that popular comestible. The IPKat and Merpel therefore salute occasional guest contributor Paul England (Taylor Wessing) on notching up another birthday and thank him for the following note on a recent ruling from the Patents Court, England and Wales:

Deep fat fryer patent almost gets its chips
English chips
It is perhaps a testament to the enduring love affair between the British and chips [called "French fries" by our American cousins, who reserve the term "chips" for something quite different, notes Merpel] – and its commercial value, moreover – that a deep fat fryer dispute, Jarden Consumer Solutions (Europe) Limited v SEB SA & Groupe SEB UK Limited [2014] EWHC 445 (Pat), has made it to the Patents Court and then on to judgment, in which Mr Justice Arnold has held that Jarden Consumer Solutions’s ‘Breville Halo Health fryer’ infringed claims 10, 11 and 13 of SEB SA’s European Patent for a fryer able to coat food automatically in a thin layer of fat as it cooks (EP (UK) 2 085 003). However, this has come at the expense to SEB of losing claims 1, 3 and 8 of its patent (claims 1 and 3, would otherwise also have been infringed).
Jarden’s revocation case was built on the alleged obviousness of the patent over three pieces of prior art relating to cooking devices: Vogt, Herbst and Siu (explained below). Expert evidence was given on these issues by both parties, together with factual evidence and, in what must be a first for the Patents Court, chip cooking experiments.
SEB's frying pan
Arnold J explains in his decision that there are two basic ways in which the frying of food can be achieved. One is deep fat frying (immersion in oil), the other shallow (the food is cooked on a hot surface, covered in a layer of oil). Deep-fat frying ensures more even cooking of food because there is no temperature difference between the side contacting the hot surface and the side exposed to the air, as is the case with shallow frying. Despite the disadvantages that deep frying is recognized as having, it remains the only way of preparing some foods, especially chips. However, the patent claims an alternative method to deep frying foods, including chips. It is a method described by the specification of the patent as ‘dry frying’ because it does not involve immersing the food oil or fat, either partially and/or temporarily during the cooking cycle. Instead, it uses a process of ‘mingling’: automatically stirring and mixing the food to coat it in a thin film of oil, and cooking with a directed flow of heat.
Obviousness
The prior art was assessed as follows in the obviousness case:
* Siu – Arnold J construed Siu as also disclosing a dry fryer. This meant that the only difference between Siu and claim 1 of the patent is the feature of a removable cooking vessel, a common feature in the field and, in the judge's judgment, obvious. The additional features of claim 3 are disclosed by Siu, and so this claim is invalid also.
* Herbst – this prior art also discloses a dry fryer. The difference between Herbst and claim 1 is the absence in Herbst of a receiver means that is removably mounted in a main body. Instead, it discloses a removable vessel on a stand. Arnold J held that providing Herbst with such a cool touch outer body would have been an obvious improvement and involved no technical difficulty. It is also something the skilled team would be likely to want from a marketing point of view. Claim 1 is thus obvious over Herbst. The specific feature of a hinged lid added by Claim 3 over Herbst, did not require invention, neither did the feature of a “substantially sealed chamber”. Claim 8 of the patent requires the food stirrer to stay still whilst the vessel rotates, the converse of the disclosure of Herbst. Nonetheless, what matters is relative movement between the two, and the common general knowledge included motorized rotating stirrers and bowls at the priority date. Accordingly Claim 8 is also obvious.
* Vogt – this prior art was advanced as rendering claims 10, 11 and 13 obvious. Vogt is a paper proposal by an individual inventor, unclear in certain respects and published 32 years before the priority date of the patent in suit. This raised the issue of whether, as a matter of fact, it could be relied upon by Jarden as a document that the skilled team would pay any attention to at all. The judge thought not. However, even if it were, it was held that all the features of a cool outer body, a hinged lid and the addition of bowl rotation, discussed in the context of the prior art, and missing from Vogt, would together require a non-obvious re-design. Further, it would not be obvious to dispense with the external hotplate and to rely instead on radiant heaters in a manner contrary to the teaching of Vogt.
Infringement
The Halo Health includes what is referred to as a “stirrer”, which consists of a bar (green in the diagram) and a paddle attached to a hub (purple in the diagram).
During cooking, the hub and paddle are mechanically connected and rotate together. The bar remains stationary relative to the cooking vessel and the rotating hub and paddle. The cooking vessel and the paddle push the food round so that it rises up over the bar and tumbles down on to the other side. The paddle is spring mounted and so when it meets the stationary bar, it is briefly slowed as the tension of the spring is taken up and then forced over the bar creating an acceleration as the tension is released. This results in a brief “flick” of the paddle twice in each revolution. Experiments conducted by Jarden to cook 800g of chips using the Halo Health demonstrated that if the paddle or the bar were removed the chips were not mingled to produce chips coated in a film of oil, as they would be if the apparatus were fully constituted.
Claim 1 – SEB’s primary case on claim 1 was that the stirrer means in the Halo Health consist of the bar, the receiver means (the cooking vessel) moves relative to the bar, as a result there is mingling and it is immaterial if the paddle does not move relative to the bar but does contribute to the mingling. Their secondary case was that the stirrer means in the Halo Health consist of the combinationof the bar and the paddle, both the cooking vessel and the paddle move relative to the bar and, as a result, there is mingling.
Arnold J did not accept SEB’s primary case, because it was shown by the experiment that the paddle is necessary to create mingling. However, the judge did accept the secondary: the flick of the paddle as it passes over the bar makes an important contribution to the stirring and mixing of the food with the oil and the resultant mingling. Thus both the bar and the paddle move relative to the cooking vessel, and both kinds of movement contribute to the stirring and mixing.
Claim 3 – the lid of the Halo Health does form a “substantially sealed” chamber and therefore this requirement of claim 3 is satisfied.
Claim 8 – is the stirrer means stationery relative to the main body of the fryer? As already determined in respect of the secondary case in claim 1, it is not, and so claim 8 is not infringed.
Because the main heater of the Halo Health is “mounted on the main body”, the remaining requirements of claims 10, 11 and 13 are also satisfied.
This is a textbook obviousness and infringement analysis, and one that would serve as a case study in patent courses for the next few years. One can only admire the judge for what must have been the constant temptations of the nearest chip van in order to write it.