In re Slepian, Patent Appeal No. 2727.

• Decision Date: 25 May 1931
• Docket Number: Patent Appeal No. 2727.
• Citation: 49 F.2d 835,18 CCPA 1393
• Parties: In re SLEPIAN.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

18 CCPA 1393, 49 F.2d 835 (1931)

In re SLEPIAN.

Patent Appeal No. 2727.

Court of Customs and Patent Appeals.

May 25, 1931.

Wesley G. Carr, of East Pittsburgh, Pa. (Frederick W. Lyle, of Williamsburg, Pa., of counsel), for appellant.

T. A. Hostetler, of Washington, D. C. (Howard S. Miller, of Washington, D. C., of counsel), for Commissioner of Patents.

Before GRAHAM, Presiding Judge, and BLAND, HATFIELD, GARRETT, and LENROOT, Associate Judges.

GARRETT, Associate Judge.

This proceeding involves five claims, Nos. 22 to 26, inclusive, contained in an application filed by Slepian January 5, 1921, for alleged new and useful improvements in thermionic amplifying devices. Seven claims of the application were allowed by the United States Patent Office. Those at issue were rejected by the Examiner, whose decision was affirmed by the Board of Appeals of the United States Patent Office, and from the decision of the latter the appeal comes to this court.

The claims are divisible into two classes, Nos. 22 and 23 comprising one group, and Nos. 24, 25, and 26 the other. Nos. 22 and 24 are quoted as representative of these respective groups:

"22. In combination with a source of electro-motive force and a work circuit adapted to utilize a relatively large current, a pair of electrodes connected in said work circuit, a source capable of emanating electrons at a rate which is small relative to that necessary to supply said current, means to cause electrons from said source to impinge upon that portion of one of said electrodes which faces said other electrode, and means to vary the number of said electrons impinging upon said one electrode per second."

"24. In combination with an output circuit having a pair of electrodes connected thereto, a source of light, a photo-electric subtance, means to cause electrons emanating from said substance to impinge upon one of said electrodes, and means to vary the number of said electrons so impinging per second."

The references are: Langmuir, 1282439, Oct. 22, 1918; Slepian, 1450265, April 3, 1923.

From the decision of the Board of Appeals, we quote the following description of the device and its operation:

"The claims are drawn to a work circuit including a thermionic amplifier. In the form of the device shown in the drawings the amplifier is provided with a cathode, an anode and a control grid and in addition to these three electrodes it is provided with a potassium electrode which constitutes the source of primary electrons. The latter electrode is photo-electrically active and when subjected to the rays of a lamp emits primary electrons which travel toward the anode. Due to the presence of a magnetic field, however, they are diverted and strike that face of the cathode which is located toward the anode. The small number of high velocity primary electrons striking the cathode causes the emission therefrom of a large number of secondary electrons which pass to the anode. This large number of electrons permits a relatively high current value to flow through the output circuit connected to the tube."

It was the view of the tribunals of the Patent Office that claims 22 and 23 defined nothing patentable over the subject-matter of certain claims of appellant's patent of April 3, 1923, supra. Both tribunals pointed out that the only feature distinguishing the claims is that those of the application, to quote the Examiner, "recite means to vary the number of electrons emitted from the source of primary electrons."

Claims 24 and 25 call for the additional feature of a "source of light" and a "photo-electric substance" constituting the electron source, while claim 26 specifies the further matter of "means to vary the intensity of said light source." These three claims were rejected upon appellant's patent in view of Langmuir.

It is appellant's contention that the claims are for a general combination, and that the features of "(1) a photo-electric metal, and (2) a pair of electrodes arranged for secondary emission amplification,"...