Western Electric Company v. La Rue

This was a bill in equity brought by La Rue, plaintiff in the court below, for the infringement of letters patent No. 270,767, issued to Edgar A. Edwards, January 16, 1883, for a new and useful improvement in telegraph keys.

In the specification the patentee stated that his invention related 'to telegraph keys or instruments used for transmitting telegraphic signals, and is an improvement on the well-known Morse key, being in substituting for the trunnions or pivots upon which the lever vibrates a torsional spring or strip of metal.' After describing the mechanism, as illustrated by his drawings, he made a further statement, as follows: 'When a telegraph key is constructed as herein described, the side or lateral movement is reduced to a minimum. The adjustment to trunnion setscrews is obviated. The torsional metal springs will not wear out, but last indefinitely. The adjusting screws, H, H', serve the purpose of regulating the amplitude of the lever movement, and also serve the purpose of regulating the retractile resistance of the torsion spring. By this arrangement a secondary retractile spring to resist the downward movement of the contact lever is not necessary. In ordinary telegraph keys a retractile spring is always supplied to regulate the force required to depress the lever, as well as pivots or trunnions on which the lever vibrates. In my invention the torsional spring not only takes the place of the pivots or trunnions, but, when used in connection with the adjusting screws, H, H', takes the place of the ordinary retractile spring. The construction of the key is thus simplified and cheapened by discarding one of the hitherto necessary features, viz., the retractile springs. I do not limit myself to the application of torsional springs to telegraph keys alone, as it is obvious the torsional strip or spring may be applied to other electrical instruments. Thus it may replace the pivots or trunnions of the relay and sounder.'

The defenses were, in brief, anticipation and non-infringement. Upon a preliminary hearing in the court below an injunction was granted, (28 Fed. Rep. 85;) and upon the final hearing (31 Fed. Rep. 80) plaintiff obtained a decree perpetuating the injunction, and for $110 damages for the infringement of the third claim of the patent, which reads as follows: 'The combination, in a telegraph key, of the lever fulcrumed upon the torsional spring, with the adjusting screws, H H', for regulating the amplitude of the lever movement, and the retractile resistanceof the torsion spring, substantially as described.' From this decree an appeal was taken to this court.

''Geo. P. Barton'', for appellant.

A. v. Briesen, for appellee.

Mr. Justice BROWN, after stating the facts as above, delivered the opinion of the court.