Electric Pipe Line, Inc. v. Fluid Systems, Incorporated

MEDINA, Circuit Judge.

Plaintiff and defendant are competitors in the business of furnishing plans, drawings, parts and instructions for the installation of heating systems for schools, industrial plants, churches, public buildings and the like. As defendant claimed that plaintiff was a direct and contributory infringer of its Lines Patent No. 2,224,403, issued to Harold A. Lines of West Haven, Connecticut, on December 10, 1940, and had warned plaintiff and its customers that legal action would be instituted if unauthorized use was made of the patented system, plaintiff took the initiative and…