Mercoid Corp. v. Milwaukee Gas Specialty Co.

EVANS, Circuit Judge.

This appeal involves the validity and infringement of patent No. 1,958,482, owned by the defendant, who charged the plaintiff with its infringement. Following this notice, plaintiff brought this suit which is for a declaratory decree, and defendant answered and counterclaimed. It also sought and secured a reissue patent, No. 21,038. Plaintiff filed an amended complaint covering the reissue patent, and defendant again answered and counterclaimed, and in its counterclaim it charged plaintiff with infringing claims 10, 12, 13, 14, and 21 of the old patent and claims of the…