Mercoid Corp. v. Mid-Continent Investment Co., 320 U.S. 661 (1944)

Mercoid Corporation v. Mid-Continent Investment Co.

Nos. 54 and 55

Argued December 9, 1943
Decided January 3, 1944
320 U.S. 661

CERTIORARI TO THE CIRCUIT COURT OF APPEALS

FOR THE SEVENTH CIRCUIT

Syllabus

1. The owner of a system patent may not use it to secure a limited monopoly of an unpatented device employed in practicing the invention, even though the unpatented device is itself an integral part of the patented system. P. 665.

2. In a suit for infringement of a combination patent, misuse of the patent to protect an unpatented element from competition is a defense available to a contributory infringer. Leeds & Catlin Co. v. Victor Talking Machine Co. (No. 2), 213 U.S. 325, limited. P. 668.

3. Exercise by an equity court of its discretion to withhold relief from a patentee who has misused his patent to secure a limited monopoly of unpatented material cannot be foreclosed by the failure of the defendant to interpose that defense in earlier litigation to which the alleged infringer was privy. P. 670.

4. A judgment in a suit for infringement of a patent does not bar a claim based on § 4 of the Clayton Act which could have been, but was not, asserted as a counterclaim in the prior suit. P. 671.

Where the second cause of action between the parties is upon a different claim, the prior judgment is res judicata not as to issues which might have been tendered, but only as to those upon the determination of which the finding or verdict was rendered. P. 671.

5. A counterclaim based on § 4 of the Clayton Act may, under the Rules of Civil Procedure, be asserted in a patent infringement suit. P. 671.

133 F.2d 803 reversed.

Certiorari, 319 U.S. 737, to review a decree which affirmed in part and reversed in part a decree of the District Court, 43 F.Supp. 692, in a patent infringement suit.