Patents

• Author: International Law Group

Whirlpool Corporation during the 1970s came up with a clever dual action agitator for clothes washing machines. It used the lower part of the shaft for the customary back-and-forth oscillating activity but also put in an upper sleeve to serve as a helical auger. In the manner of a post-hole digger, the auger turned in a uniform direction, thus moving water and clothing down onto the oscillating vanes of the agitator below to bring about more consistent scrubbing.

Due to certain mechanical variations, Whirlpool was able to secure three Canadian patents. It charged in litigation that General Electric and its subsidiary Camco, Inc. (GE) had turned out an infringing mechanism in its washers which it was marketing mainly in the U.S. and but also to some extent in Canada. The first Whirlpool patent featured a drive shaft powering the dual agitator. Secondly, patent '803 used a clutch device instead of a drive shaft. The trial judge held that both of these patents provided for rigid vanes on the lower agitator. The third patent ('734) also furnished a choice of drive modes. In one setup, the upper auger ran "intermittently" and in the other it operated continuously. The trial judge held that the '734 patent was valid and that GE's devices were infringing it.

GE then took the case to the Federal Court of Appeal. There it focused on two challenges to the validity of the '734 patent. Its main point was that it amounted to impermissible "double- patenting." By this it meant that Whirlpool's intermittent drive claims were substantially the same as in the invention set out in the earlier claims of the '803 patent. In the alternative, GE maintained that the use of flexible vanes was an obvious and non- inventive twist to the rigid vanes specified in the '803 patent, thus did not justify patent protection. GE also denied that its devices were infringing the claims that involved a continuous drive.

The Federal Court of Appeal dismissed GE's appeal and the latter obtained review in the Supreme Court of Canada. Agreeing with the lower court, the Supreme Court also dismisses the appeal.

In the Supreme Court's view, the first step in patent litigation is for a court to construe the claims by "purposive construction" in the area of both validity and infringement issues. This approach requires the courts to identify, aided by the skilled reader, the specific descriptive words or phrases that the claim uses to limn the "essential" aspects of the invention. The...