United States v. De Forest Radio Telephone & Telegraph Co.

D. Delaware

United States v. De Forest Radio Telephone & Telegraph Co.

18 F.2d 338, 1927 U.S. Dist. LEXIS 1063

CourtDistrict Court, D. Delaware

DecidedFebruary 15, 1927

DocketNo. 549

StatusPublished

Cited by1 cases

This text of 18 F.2d 338 (United States v. De Forest Radio Telephone & Telegraph Co.) is published on Counsel Stack Legal Research, covering District Court, D. Delaware primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook

United States v. De Forest Radio Telephone & Telegraph Co., 18 F.2d 338, 1927 U.S. Dist. LEXIS 1063 (D. Del. 1927).

Pincite

Opinion

MORRIS, District Judge.

In the four-party interference in the Patent Office of De Forest v. Langmuir v. Armstrong v. Meissner, the Court of Appeals of the District of Columbia awarded priority to De Forest (54 App. D. C. 391, 298 F. 1006), and pursuant thereto patent No. 1,507,016 was issued to De Forest on September 2,1924. Thereafter the suit at bar was instituted, under R. S. § 4915 (Comp. St. § 9460), by Meissner and his assignee, the United States of America, against the other parties to the interference, their assignees, and a licensee, to obtain a decree authorizing the issuance of a patent to Meissner for the'invention defined in the counts in the interference. In their respective answers the General Electric Company, assignee of Langmuir, and Westinghouse Electric & Manufacturing Company, assignee of Armstrong, each here sets up a counterclaim asserting ownership of the invention under their several assignments, and prays for the same relief as does the plaintiff. De Forest and his assignee, De Forest Radio Telephone & Telegraph Company, allege priority of De Forest. The American Telephone & Telegraph Company, alleged by the plaintiff to be a licensee under the De Forest patent, by its answer asserts an interest in the invention under each of the applications but takes the position that the patent to De Forest was properly issued.

The issue here, as in "the interference in the Patent Office, is mainly that of priority. The dates awarded the several parties in the Patent Office proceeding are those to which they here severally make claim, namely, De Forest, August, 1912; Armstrong, January 31,1913; Meissner, April 9,1913; and Langmuir, August 1, 1913; but each of the junior parties under that allotment denies that his senior or seniors are entitled to the respective dates claimed. Consequently the first question for consideration is whether, for the subject-matter in' issue, De Forest is entitled to the date claimed by him. The subject-matter is defined by the pleadings, in the language of the counts of the Patent Office proceedings, thus:

“1. Means for producing sustained electrical oscillations comprising an oscillatory circuit having two electrodes in an exhausted receptacle and a second circuit coupled thereto having a conducting body interposed between said electrodes.

[340]*340“2. Means for producing sustained electrical oscillations comprising an oscillatory circuit having two electrodes, a second circuit coupled thereto having a conducting body interposed between said electrodes, and means for varying the frequency of the produced oscillations.

“3. The method of producing electrical alternating currents which consists in causing current to flow in one of two coupled circuits and varying the flow of current in the first circuit by impressing the potential induced in the second circuit upon a conducting body interposed between two electrodes in the first circuit.”

These counts were framed with care in the Patent Office, and were inserted by amendment in his appfieation by each of the parties to the interference. I think they are clear. Their elements and steps have for their object the production of electrical oscillations or alternating currents. The oscillations must be sustained, not damped. Taking the first count as iUustrative, the means comprise an oscillating circuit, or one in which alternating current may flow; two electrodes — plate or wing and filament; an exhausted reeeptaele-^a radio tube or audion; a second or grid filament circuit, coupled to the first circuit, and having a conducting body, a grid, interposed between the plate and filament. An added element of the second count consists of means for varying the, frequency of the oscifiations produced. The three electrode radio tube or audion was old. The circuits with which it had been connected before the invention defined by the claims consisted in the main of a grid filament, or input circuit, and a plate filament, or output circuit, each of which might contain one dr more electrical devices.

The novel feature of the first count, as I understand it, Ees in its so eoupEng the two circuits that electrical energy from one may be transferred, fed back, from one to the other in such manner as to produce “sustained electrical oscillations” or alternating currents. Such transfer of energy involves the general functioning of’the tube — described with particularity in Armstrong’s exhibits Nos. 6-32 and 6-33 — as well as its connected circuits. Broadly and generaUy stated, the functioning of the tube rests upon the long-known scientific fact that, if a second element or electrode be placed within an electric light bulb and given a positive potential, an electric current, or stream of electrons carrying a negative charge, flows, unidireetionally, from the incandescent filament to the cold, second electrode. This principle was made use of in the radio art by heating the filament of the radio tube by a battery, known as the A battery, and impressing a high positive potential upon the plate by a battery, known as the B battery, put in the plate circuit.

As the current passes through the tube in one direction only, the tube functions as a rectifier of alternating current; the alternations in the opposite direction being blocked or barred. As the B battery suppEes direct current only, that current, when permitted to flow steadily and uniformly, is without variation, and so without means of causing the diaphragm of the telephone, connected with the plate circuit, to vibrate. But the functioning of the grid under the influence of the alternating current of the input, or grid filament, circuit increases and decreases the flow of current passing in the tube from the filament to the plate, and thereby .causes, the direct current of the plate circuit to pulsate. The variations or pulsations passing through the telephones cause their diaphragms to vibrate and so be heard. If the tube does not amplify, the variations or pulsations in the plate circuit current are of no greater magnitude than are the waves of the input or grid filament circuit; but, if the tube is an amjpEfier, the pulsations created in the plate current wifi be similar in character to the variations in -the input circuit, but of greater magnitude.

By the invention of the counts in suit these magnified pulsations in the current of the plate circuit are transferred back through a coupling between the circuits to the input circuit. There they augment the variations in the current of that circuit, and, consequently, the variations in the potential of the grid. Employing its increase of energy to bring about a new magnification in the pulsations of the plate circuit current, the grid starts the cycle of steps afresh. Repetition produces, not only regeneration, but eventually, if the lapse of an. infinitesimal fraction of time may be so referred to, the electrical oscifiations of the counts. Meissner’s denial of the right of De Eorest successfully to claim August, 1912, as his date of invention is a denial that De Forest then had a conception of the production of alternating current by feedback or regenerative action, and that, if he had, he was not diEgent in reducing that conception to practice.

To estabEsh his conception and reduction to practice at the time claimed by him, De Eorest refies in the main upon the contemporaneous record of the things actually done by him, or by Yan Etten, his instructed assist[341]*341ant, on August 6 and August 29, 1912, as shown by his notebooks. The authenticity of the hooks and the regularity of the entries therein are not questioned.

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