At last -- "generally elliptical cone shape" interpreted

Now here's another case belatedly noted from last week. It's Ancon Ltd v ACS Stainless Steel Fixings Ltd [2008] EWHC 2489 (Pat) is a Patents Court decision for England and Wales from Mr Justice Patten.

Ancon owned a patent for a channel assembly. Channel assemblies had been used in the construction industry for a long time, typically being comprised of a metal channel, with lugs or restraining anchors, which was cast into the concrete structure of a building. The channel had shaped sides with an open aperture on its face into which the head of a bolt could be inserted. The bolt was moved along the channel to its required position and then turned 90 degrees so as to lock against the internal walls of the channel. This assembly could be used to fix components like brackets on to the structure of the building, to support masonry or some other form of external cladding.

Claim 1 of the patent covered the channel and its shape, together with a bolt head with inclined sides and a "generally elliptical cone shape". Claims 3 and 6 covered the effect of the shape of the head which, when rotated, created a camming action that forced the head against the lips of the channel. The top of the bolt remained generally elliptical despite its truncation and flattened sides, and the bolt as a whole assumed a generally elliptical shape. Even in the case of a variant of the truncated elliptical cone, the two right-angled corners at the base did not interfere with the ellipse at the top and each embodiment retained an identifiable elliptical shape and was generally conical.

Ancon alleged that the patent had been infringed by the ACS 31/21 channel assembly, which was made up of a channel and T-head bolt assembly which was used to provide heavy duty fixings for use in the construction industry. AS denied infringement and counterclaimed for invalidity of the patent for anticipation and obviousness.

The construction of the patent turned principally upon the meaning of the phrase "generally elliptical cone shape", raising the question of how literal or exact that term was intended to be. Ancon said there was nothing in the teaching of the patent that regarded the precise shape of the top surface as of any technical importance for the purposes of the invention; accordingly it was the surfaces against which camming took place that needed to embody the "generally elliptical cone shape". But according to ACS the "generally elliptical cone shape" was a -- and perhaps the -- defining feature of Ancon's channel assembly patent, even when the cone shape at the head was truncated or reduced by the creation of flattened areas and sides. In ACS's view the bolt in its 31/21 channel assembly was neither elliptical nor cone-shaped and did not infringe the claims in the patent. If however the claims in the patent were not to be construed as restricted to generally elliptical cone shaped heads, the teaching in Ancon's patent was already covered by the bolt and channel assemblies described in the prior art and was in any event both obvious and insufficient.

Patten J dismissed both the claim and the counterclaim.

* As to what the claims meant, the court always had to ask what the person skilled in the art would have understood the patentee to be using the language of the claim to mean. Did the patentee, by the use of a particular word or phrase, choose to describe his invention (and so limit his monopoly) according to the strict technical meaning of the term, or did he use it in a more descriptive and therefore less exact way?

* In this case the use of the phrase "generally elliptical cone shape" in the claims determined their scope and there was nothing in claim 1 which allowed the addressee to assume that the claim was not limited to what constituted a 'generally elliptical cone shape'. Anyway, the ACS fixing in its 31/21 assembly was not a generally elliptical cone shape. On this basis there was no infringement.

* The prior art cited by ACS did not emcompass the invention described in Ancon's patent, so the challenge to its validity failed.

The IPKat notes the judge's reliance on, among other decisions, that of the House of Lords in Kirin-Amgen Inc. v Hoechst Marion Roussel Ltd, in which Lord Hoffmann rewrote, clarified or invented the British law on claim construction, depending on how you read the law that came before it. He is a simple Kat who has never felt that a complex test is needed and he mourns the passage of Catnic Components Ltd v Hill & Smith Ltd [1982] RPC 183 -- a decision that seems to be floating in a sort of precedental limbo, no longer authoritative but still worthy enough to cite. Merpel says she's not sure if the techniques employed in interpreting patent claims are really there to clarify what the patentee means or to hide the means by which the claim's interpreter justifies an intuitive hunch as to how the skilled addressee would understand them.

The IPKat's favourite cone shape here