D & H Electric Company, a Corporation v. M. Stephens Mfg., Inc., a Corporation and Jack McLoughlin Doing Business as McLoughlin Sales

An action alleging patent infringement was brought in the District Court by the D & H Electric Company against M. Stephens Mfg., Inc. and Jack MeLoughlin, d/b/a McLotighlin Sales. From a judgment holding no infringement, plaintiff appeals. No appeal is taken by defendants from that portion of the judgment which held plaintiff’s patent valid.

The patent in suit is for a coupling device used in connecting spiraled flexible conduits (which carry electric wires) to junction boxes. Appellant, as assignee of the patent, has, since 1946, made and sold over four million of said coupling devices. The device is described in its claim, as finally allowed by the Patent Office, as follows:

In other words, the ribs extend partially around the tubular member of the coupling so as not to fit the convolutions of the conduit as a thread, but the two to engage as would a nut with a thread different from that of the bolt and, owing to the fact that the tube is made up of twisted steel ribbons the forcing of the mismatched threads expands the tube so as to allow the insertion to “jump” the threads. Thus, the patent in suit has basically two major concepts. It covers a combination of elements in a…