Hazeltine Corporation v. General Motors Corporation

• Citation: 131 F.2d 34
• Decision Date: 19 October 1942
• Docket Number: No. 7798.,7798.
• Parties: HAZELTINE CORPORATION v. GENERAL MOTORS CORPORATION.
• Court: United States Courts of Appeals. United States Court of Appeals (3rd Circuit)

131 F.2d 34 (1942)

HAZELTINE CORPORATION v. GENERAL MOTORS CORPORATION.

No. 7798.

Circuit Court of Appeals, Third Circuit.

Argued March 4, 1942.

Reargued May 4, 1942.

Decided October 19, 1942.

Henry T. Kilburn, of New York City (Laurence B. Dodds, of New York City, and E. Ennalls Berl, of Wilmington, Del., on the brief), for appellant.

C. Blake Townsend and Drury W. Cooper, both of New York City, for appellee.

Before BIGGS, JONES, and GOODRICH, Circuit Judges.

GOODRICH, Circuit Judge.

This is an appeal from a judgment entered for the defendant in a suit for patent infringement. The subject matter is Trube Patent No. 2,111,483. Trube was plaintiff's assignor. The claims in suit are numbers 28 to 33, inclusive, and 35 to 38, inclusive, plaintiff having consented to dismissal as to other claims. The patent application was filed July 2, 1926; the patent issued March 15, 1938. This action was begun April 19, 1938 and final judgment entered June 13, 1941.

The alleged invention involves a means for improving reception in a radio receiving set. Both sides have supplied us with general propositions, admonitory in nature, designed, no doubt, to set a point of view. The plaintiff wants us to consider Trube's claimed invention as of the time it was made and in the light of historical facts surrounding it. This is sound enough. We are also invited to bear in mind certain other propositions which are likewise true; such as that the apparent simplicity of a new device often leads an inexperienced person to think it would have occurred to anyone familiar with the subject;¹ that it is the common history of important inventions, that their simplicity seems to the ordinary observer to preclude the possibility of inventive faculty;² that knowledge after the event is always easy.³ The defendant, in turn, gives us judicial authority that at least from 1925 onward, the radio art is a developed one and the standard of inventive art is necessarily higher than it was in the earlier history thereof⁴ and that absence of invention may be shown by simultaneous solution by half a dozen mechanical improvers, making alleged invention but natural advance.⁵ Neither side challenges the other's generalities in vacuo; neither would agree that the other's applied to this litigation. The Court has endeavored, as best it could, to bear them all in mind.

Turning, then, to the case at bar, we refrain from a recitation of the development of radio broadcasting and reception, and state no more of the background than is necessary to present the immediate problem.⁶ The patent in suit is aimed at solving a difficulty present in tuned radio-frequency receivers at the time application was made therefor. The difficulty was that the amplification varied with the frequency to which the receiver was tuned, increasing with increasing frequencies. Although it was possible to adjust a receiver so that a suitable amplification could be obtained at the top end of the broadcast range, i. e., 1500 k. c., if the receiver were then tuned to a low frequency station the amplification was so low, that the desired station would be practically inaudible. If on the other hand, the receiver were adjusted so that at the low frequency the desired amplification was attained, at the high frequencies, the amplification was so great that the receiver would become unstable and go into uncontrolled oscillations, manifesting themselves to the listener's ear as squeaking and whistling noises. Trube's patent sought to remedy this situation so that at any frequency the amplification would be uniform.

The solution offered admittedly employed known physical principles of condensers and inductances. These were that the reactances of condensers and inductances to increasing frequencies were opposite in effect, that of a condenser decreasing with increasing frequency, that of an inductance increasing with increasing frequency. Thus if the coupling element⁷ were a condenser, the amplification would decrease too rapidly with increasing frequency; if it were an inductance, the amplification would increase too rapidly with increasing frequency. It was claimed and supported by the offered evidence that Trube employed a compound radio frequency coupling consisting of a fixed condenser and a fixed inductance between the circuits of a receiver to transfer the energy received from the antenna through the receiver. The only variable was a condenser which could be tuned to different frequencies. The fixed condenser and inductance were placed in the circuits so as to be in aiding phase, or additive in effect, and the result was that as the variable condenser was tuned to different frequencies the amplification would be substantially uniform. Practically this meant that a radio listener, by turning one dial, would receive the various stations on the broadcast band at about the same amplification. Trube's application stated that a feature of his invention was to prevent the oscillations caused by feedback in the vacuum tubes.⁸

Whether a patent shows invention is a question of fact and the findings of the trier of fact upon this issue are not to be disturbed unless clearly erroneous or not supported by substantial evidence. Keyes v. Grant, 1886, 118 U.S. 25, 6 S.Ct. 974, 30 L.Ed. 54;⁹ St. Paul Plow Works v. Starling, 1891, 140 U.S. 184, 196, 197, 11 S.Ct. 803, 35 L.Ed. 404; Thomson Spot Welder Company v. Ford Motor Company, 1924, 265 U.S. 445, 446, 447, 44 S.Ct. 533, 68 L.Ed. 1098; United States v. Esnault-Pelterie, 1936, 299 U.S. 201, 57 S.Ct. 159, 81 L.Ed. 123.¹⁰ The trier of fact in this case was, of course, the trial judge. Under Rule 52(a) of the Rules of Civil Procedure, 28 U.S.C.A. following section 723c, the trial judge is to "find the facts specially and state separately his conclusions of law thereon * * *." This however he did not do, and his opinion incorporates both facts and conclusions of law without designating either specifically. The failure of the trial judge to comply literally with the provisions of Rule 52(a), although it has been characterized as a "dereliction of duty",¹¹ is not always a ground for reversal and remand with instructions to make specific findings as required by the Rule. The latter course of action has been adopted where there was an inadequate statement of facts upon vital issues and where such factual issues were not resolved.¹² If, however, the opinion of the trial judge afforded a "clear understanding of the basis of the decision below" and resolved the major factual disputes, the mere formal requirement of separation of findings of fact and conclusions of law has been held not sufficient to necessitate a reversal.¹³ In this case, a reading of the trial judge's opinion reveals a full discussion and treatment of the major factual issues which leaves no doubt as to which facts the court accepted and relied upon in rendering its decision. These we can treat as findings of fact and so do.

The trial court has found that the Trube patent here in litigation was void for want of invention. If that conclusion is supported by the evidence it settles the case and there is no need for further discussion of other points raised by the defendant. Our conclusion is that this finding by the trial judge is clearly supportable in view of the evidence. The best way to set this out, we believe, is to state briefly the various elements claimed in Trube's patent and compare his alleged invention with the contemporaneous knowledge in the radio art out of which it evolved.

The plaintiff sets out Trube's claim 36 as typical of the claims in suit. It describes: "A tunable radio-frequency coupling system comprising a resonant circuit including inductive and capacitive elements, only one of said elements being adjustable for tuning said circuit over a wide range of radio frequencies, another circuit to be coupled therewith, fixed reactance coupling means including inductance for providing coupling therebetween which varies with frequency in one sense as said tunable circuit is tuned over said range, and fixed reactance coupling means including capacitance for providing coupling therebetween which varies with frequency in the opposite sense, said coupling means being relatively poled in aiding phase, whereby the coupling variation of one said means at least partially compensates for the coupling variation of the other said means." When one analyzes this claim with the evidence in the case the reason for the conclusion that no invention is found on behalf of the plaintiff's assignor becomes apparent.

(1) Magnetic and inductive elements; individually and in combination. As stated in our recital of the facts and again in the claim, the alleged invention makes use of the principle of combined coupling, that is the use of capacitance and inductance (condensers and transformers) to transfer energy from one circuit to another circuit. This principle is not new. The plaintiff, itself, admits that "both kinds of coupling were known prior to Trube and that the general characteristic of the coupling effect of each with changing frequency was known in theory." And the plaintiff's chief witness, Professor Hazeltine, stated that as early as 1918 he knew that inductive and capacitive coupling could be used together advantageously in a vacuum tube coupling circuit. In evidence, too, was an excerpt from the book of Professor Morecroft, of Columbia University, treated by both sides as a scientist of authority in radio-physics. His book, "Principles of Radio Communication", published in 1921, gives a circuit diagram showing the combined use of capacitive and inductive coupling and the text of Professor Morecroft's book states, as a fact, that the combination is used in certain radio receivers.¹⁴ The plaintiff's witness, Axel G. Jensen, a former student both at the University of Copenhagen and at Columbia, stated that he was familiar with the behavior of tuned coupled circuits through instruction...