Walker Process Equipment, Inc. v. Food MacHinery & Chemical Corp.

The question before us is whether the maintenance and enforcement of a patent obtained by fraud on the Patent Office may be the basis of an action under § 2 of the Sherman Act,1 and therefore subject to a treble damage claim by an injured party under § 4 of the Clayton Act.2 The respondent, Food Machinery & Chemical Corp. (hereafter Food Machinery), filed this suit for infringement of its patent No. 2,328,655 covering knee-action swing diffusers used in aeration equipment for sewage treatment systems.3 Petitioner, Walker Process Equip*174ment, Inc. (hereafter Walker), denied the infringement and…