Confusion about generally elliptical cone shapes

The IPKat thought he knew all there was worth knowing about what would be classified as being of a "generally elliptical cone shape", when he read the judgment of Mr Justice Patten in Ancon Ltd v ACS Stainless Steel Fixings Ltd back in October 2008 (IPKat commentary here). How wrong he was. After Patten J decided that Ancon's patent, although valid, was not infringed because ACS's product did not include a head having a generally elliptical cone shape, Ancon decided to appeal. They now have the result they originally wanted, thanks to a judgment delivered by Lord Justice Jacob yesterday.

The judgment, although unusual, could have been very unusual indeed had the other judge involved, Lord Justice Waller, not agreed with Jacob LJ, because the usual third member of the Court of Appeal was not present due to illness. The parties were willing to accept the risks of having a hung decision, which appears to have paid off for Ancon at least.

What puzzles and troubles the IPKat, however, is the highly unusual, not to say bizarre, way in which Jacob LJ decided to interpret the wording of claim 1 of the patent in question, which reads:

1. A channel assembly (21) adapted to be attached to a building structure, said channel comprising a spine (29), two side walls (28) and lips (27) defining a slot (25) in the channel and adapted to restrain a fixing in the channel, said spine (29) being provided with anchors (31) for casting into concrete, said side walls (28) being inclined inwardly towards the spine (29) and further including a fixing (30) having a head (33) with inclined sides characterised in that the head (33) has a generally elliptical cone shape. [IPKat emphasis applied]

One of the embodiments in the patent (see illustration, above right) showed what this would mean in practice. The head, shaped to fit a matching channel, was of an elliptical shape to allow it to lock into the channel when turned, and was cone-shaped to allow it to more closely fit the channel. This combination had the effect of improving engagement between the two parts, which together served as a secure mounting assembly for hanging heavy things from.


As all European patent attorneys will immediately recognise, the positioning of the characterising clause in the claim clearly indicates that the generally elliptical cone shape of the head was also what persuaded the EPO that the claimed invention was distinguished over the closest prior art document, which was identified during opposition proceedings as GB782428. This characterising feature should be reasonably clear from the selection of figures from this document shown on the left.

What the IPKat fails to understand is how, given all this, the term "generally elliptically cone shape" could be applied to the alleged infringing article (pictured below right). The IPKat's own conclusion would most definitely be that it would be stretching the bounds of credulity quite a bit to imagine that such a shape could be described as being in any way a generally elliptical cone. He wonders therefore whether Jacob LJ has indulged a bit too much in the "meticulous verbal analysis" that, quoting Lord Diplock in Catnic, he specifically warns against (paragraph 19). If the alleged infringement could be described as being generally elliptically cone-shaped, then why would the corresponding component in the closest prior art document not be described as such? Is the IPKat missing something obvious here, or is this a judgment that is just plain wrong?

Merpel simply wonders what it is about building products that makes such contentious legal decisions.