In re Smith

147 F.2d 1009, 32 C.C.P.A. 872, 64 U.S.P.Q. (BNA) 556, 1945 CCPA LEXIS 406
CourtCourt of Customs and Patent Appeals
DecidedFebruary 7, 1945
DocketNo. 4955
StatusPublished

This text of 147 F.2d 1009 (In re Smith) is published on Counsel Stack Legal Research, covering Court of Customs and Patent Appeals primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
In re Smith, 147 F.2d 1009, 32 C.C.P.A. 872, 64 U.S.P.Q. (BNA) 556, 1945 CCPA LEXIS 406 (ccpa 1945).

Opinion

Hatfield, Judge,

delivered the opinion of the court:

This is an appeal from the decision of the Board of Appeals of the United States Patent Office affirming the decision of the Primary-Examiner rejecting all of the claims (Nos. 5 to 10, inclusive, and 13 to 19, inclusive) in appellant’s application for a patent for an alleged invention relating to a space current discharge device.

Counsel-'for appellant moved to dismiss the appeal as to claims 6 and 9. The motion will be granted.

[873]*873The remaining claims may be divided into two groups — Nos. 5, 7, 8, 10, Í3, 18, and 19 comprising one group, of which claim 5 is illustrative, and Nos. 14, 15, 16, and 17 comprising the other group, of which claim 14 is illustrative.

Claims 5 and 14 read:

5. A space current discharge device comprising an evacuated envelope, a hollow cathode in said envelope having an interior, thermionic electron-emitting surface, an anode in said envelope outside said hollow cathode, an easy-to-ionize gas in said envelope, a heater element inside said hollow cathode to be independently heated to incandescence for ionizing said gas in said hollow cathode and maintaining the interior surface of said hollow cathode at a temperature of copious thermionic electron emission to produce a discharge between said interior cathode surface and said anode at a relatively low voltage, and a second gas having an ionizing voltage higher than said discharge voltage within said envelope, said second gas having a relatively high pressure compared to said easy-to-ionize gas.
14. An electrical discharge device comprising a sealed envelope containing electrodes including an anode and a thermionic electrode having a cavity of large internal surface provided with a relatively small opening for the passage of electrons from the interior of said cathode to said anode to maintain the discharge between said cathode and anode and an alkaline earth oxide coated on the interior walls of said cavity, said walls being positioned in shielding relation to one another, a filamentary heater positioned in said cavity, and an attenuated gaseous atmosphere in said envelope at a pressure sufficiently high to neutralize space charge.

The references are:

Smith, 1,S7S,338, September 20, 1932;
Smith, 2,201,817, May 21, 1940;
Hull, 2,236,289, March 25, 1941.

Appellant’s involved application discloses an electrical space current discharge device comprising an evacuated envelope which contains a hollow box-like cathode and an anode located outside the cathode. Thé hollow cathode is provided with a termionic electron-emitting surface or coating (“preferably in the form of an oxide of one or more of the alkali metals”) and a heater element which, when the tube is in operation, is heated “to incandescence,” as called for by claim 5, “for ionizing” an easy-to-ionize gas (preferably caesium) in the cathode and maintaining the interior surface of the cathode “at a temperature of copious thermionic electron emission to produce a discharge between said interior cathode surface and said anode at a relatively low voltage.” (It is stated in the brief of counsel for apel-lant that thermionic electron-emitting surfaces or coatings “emit copious quantities of electrons when heated to temperatures of thermionic emission.”)

In addition to the caesium, appellant’s envelope is provided with a monatomic gas, such as argon, having, as stated in claim 5, “an ionizing voltage higher than said discharge voltage within said envelope, [874]*874said second gas having a relatively high pressure compared to said easy-to-ionize gas.”

It appears from appellant’s application that, among other things, the monatomic gas serves to prevent disintegration of the thermionic c-lectron-emitting surface or coating of the hollow cathode.

Although two patents (Nos. 1,878,338 and 2,201,817) of appellant are cited as references, the Board of Appeals relied upon patent No. 2,201,817 in rejecting tire first group of claims (Nos. 5, 7, 8, 10, 13,18, and 19), and held that those claims were unpatentable over claims 39, 40, 41, and 42 of the patent.

It is unnecessary that we state in detail the invention disclosed in appellant’s patent No. 2,201,817. It is sufficient to say that the patent relates to electronic discharge apparatus and a method of operating the same, and, so far as the issues here are concerned, is quite similar to appellant’s involved application.

It will be obseiwed that appealed claim 5 calls for a heater element inside the hollow cathode.

It is contended here by counsel for appellant that in appellant’s patent (No. 2,201,817) the heater element “is carefully separated and shielded from the hollow cathode chamber * * * by being placed in a separate adjacent closed chamber.”

In clainl 39 of the patent the heater element is stated to be within the hollow cathode structure and independently heated for the precise purpose called for by appealed claim 5. The only difference between appealed claim 5 and claim 39 of the patent, so far as the location of the heater element is concerned, is that in claim 5 the heater element is stated to be inside the hollow cathode, whereas in claim 39 it is stated to be within the hollow cathode structure. No contention is made here that claim 5 contains any other patentable subject matter over claim 39 of the patent.

Claims 5 and 7 differ from each other only in that claim 7 calls for an alkali metal vapor in the envelope and a second gas which is referred to as a monatomic gas.

Claim 40 of appellant’s patent calls for an alkali metal vapor and a monatomic gas inside the envelope. It is obvious, therefore, that the feature relied iipon for lending patentability to claim 7 is set forth in claim 40 of the patent.

Appealed claim 8 calls for caesium vapor and a second gas (argon) inside the envelope.

Claim 41 of the patent calls for both caesium and argon.

Appealed claim 10 recites that the heater element inside the hollow cathode is to be “independently heated to a temperature of incandescence sufficiently to ionize the gas within said hollow cathode by ir-radiationP (Italics not quoted.)

[875]*875Claim 42 of appellant’s patent calls for a “heater element inside said hollow cathode structure to be independently heated to maintain said coating on said surface at a temperature of electron emission to sustain an arc-like discharge between said hollow cathode structure and said anode.”

The purpose and function of the heater element as set forth in claim 10 and claim 42 of appellant’s patent is precisely the same, and, in our opinion, the use of the word “irradiation” in appealed claim 10 does not patentably distinguish that claim from claim 42 of appellant’s patent.

Appealed claim 13 is admittedly similar to appealed claim 5, except that it specifies caesium vapor as the low pressure gas and a monatomic gas of relatively high pressure. It is also similar to appealed claim 8 which, as hereinbefore noted, calls for caesium and argon inside the envelope.

Appealed claim 18 is similar to appealed claim 5, except that it does not call for a monatomic gas.

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

Related

Raytheon Mfg. Co. v. General Electric Co.
34 F. Supp. 40 (N.D. New York, 1940)

Cite This Page — Counsel Stack

Bluebook (online)
147 F.2d 1009, 32 C.C.P.A. 872, 64 U.S.P.Q. (BNA) 556, 1945 CCPA LEXIS 406, Counsel Stack Legal Research, https://law.counselstack.com/opinion/in-re-smith-ccpa-1945.