Walker Process Equipment, Inc. v. Food Machinery & Chemical Corp.
Background
Background
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Food Machinery sued Walker for patent infringement for aeration equipment for [sewage treatment](/wiki/Sewage_treatment "Sewage treatment") systems. Walker filed a counterclaim for treble damages under the antitrust laws, asserting that Food Machinery had "illegally monopolized interstate and foreign commerce by fraudulently and in bad faith obtaining and maintaining . . . its patent ... well knowing that it had no basis for . . . a patent." Walker alleged that Food Machinery had fraudulently sworn to the Patent Office (in an oath that the patent statute requires of applicants) that it neither knew nor believed that its invention had been in public use in the United States for more than one year prior to filing its patent application when, in fact, Food Machinery was itself a party to such prior use. Walker further asserted that the existence of the patent damaged Walker by depriving it of business that it would have otherwise enjoyed.382 U.S. at 173\-74\.

The district court granted Food Machinery's motion to dismiss the counterclaim, and the Seventh Circuit affirmed, on the grounds that no affirmative claim for relief existed based on fraud on the patent office. It was only a defense to an infringement claim.335 F. 2d 315 (7th Cir. 1964\).


How can a patent damage a business?