91 F.2d 472 (1st Cir. 1937), 3194, Warren Telechron Co. v. Waltham Watch Co.

Docket Nº:3194.
Citation:91 F.2d 472, 34 U.S.P.Q. 135
Case Date:June 30, 1937
Court:United States Courts of Appeals, Court of Appeals for the First Circuit

Page 472

91 F.2d 472 (1st Cir. 1937)

34 U.S.P.Q. 135




No. 3194.

United States Court of Appeals, First Circuit.

June 30, 1937

On Rehearing Aug. 31, 1937.

Harrison F. Lyman, of Boston, Mass. (Russell A. Warner, of Schenectady, N.Y., and Rowland V. Patrick and Fish, Richardson & Neave, all of Boston, Mass., on the brief), for appellants.

Herbert A. Baker, of Boston, Mass., for appellee.

Before WILSON and MORTON, Circuit Judges and MORRIS, District Judge.

MORTON, Circuit Judge.

This is an appeal by the plaintiffs in two patent cases from decrees for the defendant entered on final hearing in the District Court. The patents involved are No. 1,334,423 to Warren for an indicator for electrically driven clocks dated March 23, 1920, expired since suit was brought, and No. 1,892,552 to Holtz for alternating current motor and means of controlling the speed thereof dated December 27, 1932, application filed October 1, 1921.

As to the first patent: The defenses were that the patent was void for lack of invention and that the defendant's device did not infringe. Electric clocks operated on public lighting circuits are subject to the defect that they stop when the current stops, and when the current comes on again they resume operation without any indication of the stoppage-- and may therefore be seriously misleading. It occurred to the patentee that this defect could be cured by arranging an indicator or telltale, normally kept out of sight by magnetic attraction excited by the operating current and so arranged as to drop when the current failed. He embodied his idea in a more elaborate device in which a pendulum arrangement was held up by the magnetism of the clock motor. When released by the failure of the magnetism (on the cessation of the current) it swung back and forth for a short time and, if the current came on within 6 or 8 seconds, was recaptured by the magnetism of the motor and held in normal nonshowing position. If the stoppage of current lasted longer, the magnetic force when the current returned was no longer capable of recapturing the

Page 473

pendulum and it accordingly came to rest in a position showing that the clock had been stopped. The defendant does not use the pendulum construction. In its device the indicator shows if the current has stopped at all.

The present question is whether the broad claims covering the basic principle of the patentee's device are valid. The prior art shows no such apparatus. It was concededly a new idea to apply such an indicator to an electric clock; the patent is in this respect a pioneer patent. The District Judge thought the device in its essential particulars so simple as to be of doubtful patentability; but he decided the case on the ground that the patent was not infringed.

The difference between the plaintiff's device and the defendant's device on which he rested this finding is in substance that in the plaintiff's apparatus the force of gravity is used to bring the indicator into showing position after the current has failed; while in the defendant's device a light spring performs the same function. The District Judge held in effect that on such a simple device of doubtful patentability the patentee should be limited to the exact construction of the patent. This does not seem to us to be sound. There was no prior art by which to limit the claim. The force of gravity and a spring, when they accomplish the same result in substantially the same way, have long been regarded as typical equivalents. 'Indeed, the interchangeable use of weights and springs is the stock illustration for equivalents. ' Coxe, J. Kenney Mfg. Co. v. Mott Iron Works (C.C.) 137 F. 431, 433. To the same effect Imhaeuser v. Buerk, 101 U.S. 647, 656, 25 L.Ed. 945; Mueller Furnace Co. v. Groeschel (C.C.) 166 F. 917, 918-920. They are so in this case. The claims in suit are not limited to constructions operated by gravity; their language equally includes springs. If Warren's idea, of an indicator held out of sight by the current and dropped into position when the current failed, is patentable he ought not to be deprived of the benefit of his invention by a device which merely substitutes the pull of s spring for the pull of gravity.

Whether Warren's essentially simple device involves invention is a close question. The quality which constitutes invention is indefinable, as has often been said. McClain v. Ortmayer, 141 U.S. 419, 12 S.Ct. 76, 35 L.Ed. 800. It depends on a judicial estimate of the intellectual qualities of the group mind of those engaged in a given art, made in the light of what may be called common knowledge. It is a matter of feeling rather than of logic. There must be something not found in the mind of the skilled workman, an originating quality most frequently noticeable in works of art. Noticing a defect in existing apparatus, or the chance or need of improvement in it, is the first step in invention. That was clearly present here. Warren realized that electric clocks as then constructed were unreliable, because nobody could tell, without continuously watching them, whether they had been stopped for some period. Having noticed the defect the means to overcome it were not difficult. Electric indicators arranged to drop into showing position on breaking the controlling current were old. At the same time Warren solved the problem with great directness and simplicity by using the magnetism of the motor to control his indicator, as does the defendant. While the art of electric clocks was at that time a rather new art, the defect in question was present and nobody before Warren had thought of his simple and effective way of curing it.

The file wrapper and contents show that the Examiner gave the matter careful and competent attention. The patents which he first cited against the application were not anticipations, as he later recognized, and are not now relied on as anticipations. He concluded that the application, notwithstanding the simplicity of the device, showed invention. His judgment is not to be set aside unless we are satisfied that he was wrong and that the step which Warren took was obvious to anybody in that art. The District Judge held the patent valid and with some hesitation we reach the same conclusion. We are not prepared to say that a skilled workman in that art would have both noticed the defect in electric clocks to which the invention relates and would have found such a simple and direct way to overcome it. The claim of this patent in suit is valid and infringed.

As to the second patent: The defenses are invalidity of the patent for lack of invention and other reasons and that the defendant does not infringe. This patent is on an induction-reaction subsynchronous motor of constant speed for use on alternating currents. Such motors consist of field or stationary magnets having what is called 'shaded' poles, i.e., poles each of which is divided, one part being wound with an extra coil of insulated wire in series with the

Page 474

rest. The effect of this is to cause the magnetic impulses to lag slightly in the shaded portion. In such a field when it is subjected to alternating current, the magnetic waves change rapidly and progressively, the lines of force are said to 'rotate' around the field in which the rotor turns. It was well known that when a closed circuit in the rotor was cut by these lines of force a current was set up in it and that this current was attracted to, or 'tended to follow,' the lines of force by which it was created. This is the principle on which the induction element in the Holtz rotor rests. It was also known that if a rotor was provided with projections or 'polar pieces' of iron or steel, the magnetic waves from the field magnet would tend to lock into them, provided the rotor was turning at nearly the speed at which the waves went by, and to pull around such rotor at the speed of the alternations. This, very simply stated, is the principle of the reaction element in the Holtz rotor. One weakness of the reaction motor is that it is not self-starting, but must be brought nearly up to the speed of the magnetic waves before it will lock to them.

These principles had been worked out before 1900, largely by the great inventors Tesla and Elihu Thompson. With respect to the reaction motor they had noticed and mentioned 'a tendency to synchronize' the revolutions of the rotor with the alternations of the current (Thompson 1890). It should be observed, however, that between 'a tendency to synchronize,' and the precise continued synchronization essential to a timepiece is a long step. Coerper...

To continue reading