Cardinal of Adrian, Inc., Cross-Appellee v. Peerless Wood Products, Inc., Cross-Appellants

ENGEL, Circuit Judge.

This patent infringement action arises out of the manufacture and use of latch-less door hinges of the type widely used on kitchen cabinets. The comprehensive opinion of District Judge Ralph M. Freeman is reported at 363 F.Supp. 1298 (E.D.Mich.1973). We repeat here only so much of the facts as are necessary to our decision.

Cardinal of Adrian is the owner by assignment of two patents, U.S. Patent No. 3,212,124 (the ’124 patent) and U.S. Patent No. 3,205,532 (the ’532 patent), issued to its president, Robert MacDonald. Both patents are for latchless door hinges which have…