Radio Corp. v. Splitdorf Electrical Co.

14 F.2d 643, 1926 U.S. Dist. LEXIS 1384
CourtDistrict Court, D. New Jersey
DecidedAugust 24, 1926
DocketNo. 1669
StatusPublished
Cited by6 cases

This text of 14 F.2d 643 (Radio Corp. v. Splitdorf Electrical Co.) is published on Counsel Stack Legal Research, covering District Court, D. New Jersey primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Radio Corp. v. Splitdorf Electrical Co., 14 F.2d 643, 1926 U.S. Dist. LEXIS 1384 (D.N.J. 1926).

Opinion

BODINE, District Judge.

The patent in suit is United States letters patent No. 1,173,-079, to E. F. W. Alexanderson, assignor to the General Electric Company. The specifications in part state:

“The present invention relates to the selection of oscillations of a given wave length from mixed oscillations, and comprises systems suitable for tuning out interferences in radio-telegraphy. * * *
“In accordance with the present invention, selective tuning is secured by the use of a plurality of resonant circuits arranged in cascade in such a manner that the selectivity of the system increases in geometric ratio with the number of circuits employed. The selective circuits are respectively interlinked by a relay controlling a separate source of energy to initiate oscillations corresponding to potential oscillations impressed upon the relay. As each tuned circuit is more or less opaque to disturbing oscillations differing in frequency from the oscillations to be selected, a certain percentage of the disturbances is eliminated in each circuit of the series, so that the purity of the incoming train of oscillations progressively increases as it is successively relayed. The relay preferably used for this purpose is an electron discharge tube having an incandescent cathode, an anode and a grid.”

The claims in suit are 1, 2, 3, 6, 7, and 9 to 12, inclusive. For convenience, the claims fall into tw;o groups 1, 2, 9, and 12, and 3, 6, 7,10, and 11. It was conceded by the defendant that 1, 2, 9, and 12 read upon its device. It was also conceded at the argument that claim 3 was substantially like claim 2. Counsel for the plaintiffs was content that the court should withdraw from consideration, without prejudice, claims 6, 7, 10, and 11. Claims 1, 2, 3, 9, and 12 will be considered.

The claims are as follows:

“1. The method of selecting sustained oscillations of a given frequency from disturb[644]*644ing oscillations differing therefrom in frequency which consists in impressing all the oscillations upon a circuit, resonant to the frequency of the oscillations to he selected, thereby reducing the effect of disturbing oscillations in accordance with the degree of tuning of the resonant circuit, and controlling by means of the oscillations in said circuit an independent source of energy to initiate oscillations in step therewith and impressing the second set of oscillations upon a second circuit resonant to the frequency of the oscillations to be selected. ’

“2. A receiving apparatus for electromagnetic waves comprising a plurality of tuned circuits largely opaque to oscillations of other than a given frequency, means linking adjoining circuits, said means comprising a souree of energy and an energy transmitting apparatus varying in conductivity with impressed oscillations for initiating oscillations in step with received oscillations and means associated with the last circuit of the series for detecting the oscillations.

“3. A tuned receiving system for detecting sustained oscillations of a given frequency comprising a plurality of circuits resonant to the frequency of the oscillations to be detected and arranged in cascade, relay devices joining -each of said circuits to another comprising an evacuated envelope, an electron-emitting cathode, a cooperating anode, and a grid, said device being connected to one of said circuits at the cathode and grid and to another circuit at the cathode and anode and a local source of energy in the second circuit.”

“9. The combination of an electrical discharge device comprising an envelope, a cathode adapted to emit negative charges, an anode and means for controlling a discharge between said electrodes, a circuit electrically resonant to variable current of a given frequency, electrical connections between said circuit and' the discharge controlling means of said device, a second circuit resonant to variable current of the same frequency, a source of electrical energy in circuit with the electrodes of said device, and means for impressing a variable current initiated by said source of energy upon the second resonant circuit.”

“12. A system for selecting electrical oscillations of a given frequency from oscillations differing therefrom in frequency comprising a series of resonant circuits largely opaque to oscillations of other than the given frequency, and means linking adjoining circuits, said means comprising a source of elec-' trie energy and an energy-transmitting apparatus varying in conductivity in accordance with oscillations impressed thereon from one circuit whereby oscillations are set up by said source of energy in another linked resonant circuit of said series having the same frequency as the impressed oscillations.”

The questions for determination-are, first, Is the patent invalid for lack of invention? and, second, Is the patent completely anticipated by the prior art? These questions are so closely related that they must be considered together.

Broadly, the patent provides, in the radio art, for an arrangement of parts in such a way that the tuning is done in geometrical progression or by successive filtration, with audion tubes used in the way specified in the patent. Somewhat more specifically, Alexanderson repeats the signal currents tuned in the grid circuit into the plate circuit, by means of an audion system, and then selects in another tuned circuit, thereafter detecting. This selection by repetition may be in two tuned circuits so connected, or in three tuned circuits, separated by audions, as in Fig. 2 of the patent, shown below.

The invention may be better understood if son» slight reference be made to the wireless art Through the air electromagnetic waves are transmitted. These rapidly oscillatory waves are similar to light and have the same velocity. To receive them a metallic conductor is erected which intercepts the waves from all stations passing over a given region. The function of the receiving system is to render intelligible to the senses the waves received, and also to separate the waves from different stations. This is the problem which the patent in sidt meets, and Alexanderson was the first to do it.

The method of the patent is to receive the signal in a circuit of practical and operative sharpness and to repeat the signal and again select, and so on, repeating and selecting as many times as may be necessary to obtain the desired result.

Mr. Prank Waterman, the well known engineer, stated the operation of the Alexander-son system as follows: [645]*645net of the first circuit should he again submitted to the selective action, the energy of the signal so submitted the second time being not the energy of the first circuit which was derived from the air, or from the original transmitted signal, but energy derived from a local battery, so that it was, in fact, a repetition, and so that the disadvantages which come from the transfer from circuit to circuit need not have to be encountered and overcome. The difference is fundamental, and the difference in result very marked indeed.’’

[644]*644“In the Alexanderson patent the idea of transference of the received energy from one circuit to another is entirely abandoned.

Free access — add to your briefcase to read the full text and ask questions with AI

Related

Hall v. Anderson
W.D. Washington, 2024
Rodriguez v. Koenig
N.D. California, 2020
Radio Corporation of America v. EJ Edmond & Co.
20 F.2d 929 (S.D. New York, 1927)

Cite This Page — Counsel Stack

Bluebook (online)
14 F.2d 643, 1926 U.S. Dist. LEXIS 1384, Counsel Stack Legal Research, https://law.counselstack.com/opinion/radio-corp-v-splitdorf-electrical-co-njd-1926.