Kwikset Locks, Inc. v. Hillgren. Hillgren v. Kwikset Locks, Inc.

Carl A. Hillgren is the holder of United States Letters Patent No. 2,403,597, issued July 9, 1946, for an invention of a “Door Lock”. Kwikset' Locks, Inc., is the owner of United States Letters Patent No. 2,489,160, issued to Adolf Schoepe and Albert S. Lord, jointly, on October 20, 1947, on a “Doorknob and Method of Making Same”, and assigned to Kwikset on November 22, 1949. Hill-gren brought suit in the United States District Court for the Southern District of California, charging Kwikset, Adolf Schoepe, and Karl Reinhard (hereinafter referred to collectively as “Kwikset”) with infringement of its “Door Lock” patent and seeking an injunction and damages. Kwikset answered, denying infringement and alleging that Hill-gren’s patent is void as anticipated. Kwikset in addition sought affirmative relief by way of counter-claim for injunction and damages based upon the allegation that Hillgren was infringing Kwikset’s patent on a “Doorknob and Method of Making Same”. Hillgren denied the charge of infringement and attacked the validity of Kwikset’s doorknob patent.

The complaint and counter-claim were tried together. After hearing all the evidence, the court found that Hillgren’s “Door…