Court of Appeals for the Second Circuit July 1, 1952, 219, Docket 22265 (Lukens Steel Co. v. American Locomotive Co.)

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SWAN, Chief Judge.

This is a patent infringement suit involving patent No. 2,078,056, issued April 20, 1937 to Everett Chapman and thereafter assigned to the plaintiff. In addition to the usual defenses of invalidity and non-infringement the defendant pleaded es-toppel, and by -counterclaim asserted that the patent was held upon a constructive trust.