U.S. Court of Appeals for the Seventh Circuit, 1941

Mercoid Corp. v. Milwaukee Gas Specialty Co.

Mercoid Corp. v. Milwaukee Gas Specialty Co.
U.S. Court of Appeals for the Seventh Circuit · Decided March 13, 1941 · Evans
119 F.2d 370; 48 U.S.P.Q. (BNA) 672; 1941 U.S. App. LEXIS 3711 (Federal Reporter, Second Series)

Mercoid Corp. v. Milwaukee Gas Specialty Co.

Opinion of the Court

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 reissue patent 10, 11, 12, 13, 14, 17, 18, 20, 21, and 24.

The patents covered a “Magnetic Switch,” and the decision turned on the scope of the original claims and the validity of the new claims in the reissue patent.

Narrow and specific issues are presented, both as to the validity of the reissue claims in question and the infringement of the original and reissue claims. Infringement of the early patent is dependent upon the scope of its claims in controversy. These specific questions were squarely met and decided in the opinion of Judge Duffy and that opinion meets our approval. That opinion may be found in Mercoid Corporation v. Milwaukee Gas Specialty Co., D.C., 33 F.Supp. 681, and we herewith adopt it.

The decree is affirmed.

Case-law data current through December 31, 2025. Source: CourtListener bulk data.