Western Electric Co v. La Rue

• Decision Date: 13 April 1891
• Citation: 11 S.Ct. 670,35 L.Ed. 294,139 U.S. 601
• Parties: WESTERN ELECTRIC CO. v. LA RUE
• Court: U.S. Supreme Court

139 U.S. 601

11 S.Ct. 670

35 L.Ed. 294

WESTERN ELECTRIC CO.

v LA RUE.

April 13, 1891.

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.

The invention covered by this patent consists in the use in a telegraph key of a flat strip of metal supported at either end upon posts by means of adjustable screws, and to the center of which the lever is fastened. The torsional action of this piece of metal serves as a spring support for the lever. The main object of the invention is the substitution of this torsional spring for the ordinary pivotal support previously used, which consisted of tapering pivots or gudgeons projecting from the sides of the lever into the bearings. The testimony indicates that the pivots require very exact construction and adjustment; that they are apt to wear loose in their sockets; and that inexperienced operators are apt to turn the screws, which carry these sockets, too far or not far enough, thereby rendering the motion of the lever either too difficult or too easy. For this somewhat objectionable pivotal support, the patentee substitutes a flat torsional spring, fastened at either end by ordinary screws to the top of posts or supports. Upon the middle of this spring is riveted the lever of the key, which carries regulating screws for controlling the extent of its vibrations. The specification describes the manner in which, by means of this torsional spring, the lever is enabled to play freely between its points of contact without the use of the ordinary retractile spring.

The defendant is making a telegraph sounder under letters patent No. 352,317, granted November 9, 1886, to Charles D. Haskins, an employe of the defendant company, who had previously superintended the construction of keys under the direction of plaintiff, LaRue, and was consequently familiar which his device. In this patent Haskins states the object of his invention to be 'to provide convenient means for supporting the armature and armature lever in the proper position relative to the electro-magnet, and to dispense with the employment of trunnions or a pivoted support,' and admits that 'it has heretofore been proposed to support a lever of a key or an armature upon a flat torsional spring.' The following extracts from his specification (omitting the letters) are pertinent, in connection with the question of infringement: 'A spring or plate of resilient metal is attached at its central part to the lever by means of a screw, or in any other convenient manner. The ends of this spring are respectively secured to the posts by screws. * * * The lever is preferably not dependent for its retractile force upon the [torsional] spring, although it may be so, but is assisted by a coil-spring extending from an arm secured to the lever, preferably immediately beneath the spring, C. * * * The invention has been described in connection with a telegraphic sounder; but it is evident that the torsion spring may be applied to the armature lever of any telegraphic receiving instrument, or to the lever of any telegraphic key, without departing from the spirit of the invention.' The 'torsional spring,' or, as he sometimes terms it, the 'flat spring,' or 'flat supporting spring,' is made an element in each claim of his patent.

So far as the testimony discloses, La Rue was the first to apply...