The case of Allied Signal Inc. v. Du Pont Canada Inc. has led to a somewhat unusual order from the Canadian Federal Court Trial division, namely that a single patent claim may be valid only in part.

The claim in question involved the use of one of two different varieties of nylon or a mixture of the two in the production of a sheet molding compound. The judge concluded that the specification had given sufficient information as to the use of one of the nylon varieties but insufficient information as to the other. He thus proposed an order to the effect that the patent was invalid to the extent that it covered the nylon variety whose use had been insufficiently described. This was questioned and a further hearing was held to settle the terms of the order. The judge noted that there was no authority to support his view that a claim could be held to be only partially valid. However, no authority was cited to show that an order of this type was improper. In the present case there was no ambiguity as to the proposed order since only two possibilities existed that were not meshed together but were quite separate and distinct so that the claim could easily be read to exclude the offending nylon variety.~ The judge concluded "as a matter of equity, while the patent claim with respect to (one variety of nylon) cannot stand because of insufficient disclosure, I can see no good reason why the plaintiff should lose its patent over the nylon for which there was sufficient disclosure".

June 1994 Index