Application of Verle H. Erickson

343 F.2d 778, 52 C.C.P.A. 1230
CourtCourt of Customs and Patent Appeals
DecidedApril 15, 1965
DocketPatent Appeal 7359
StatusPublished

This text of 343 F.2d 778 (Application of Verle H. Erickson) 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
Application of Verle H. Erickson, 343 F.2d 778, 52 C.C.P.A. 1230 (ccpa 1965).

Opinion

ALMOND, Judge.

Verle H. Erickson appeals from the decision of the Board of Appeals affirming the examiner’s refusal to allow claims 15 through 20 in appellant’s patent application entitled “Method and Apparatus for Carburizing Metal.” 1 No claim was allowed.

The claimed invention is a method of hardening steel in the presence of a carburizing gas and is sufficiently described in appellant’s brief as follows:

“ * * * a gauge pressure of from one to fifteen pounds is selected and maintained in a furnace wherein carburizing gas is released and the carburizing temperature of approximately 1700 degrees F. is provided. The process is continued for a given length of time depending upon the depth of case hardness desired in the steel. Thus, if the pressure be 10 PSI and the desired case depth be .030 inches, then the carburizing temperature and pressure would be maintained for approximately 15 minutes to obtain the depth mentioned. Thus the application of pressure to the carburizing gas and maintaining the pressure throughout the process is deemed to be novél.”

Appellant asserts that one problem in case hardening has been the undesirable “grain growth” resulting when high temperatures are used to effect a fast process and that he has overcome this problem.

The application states :

“It is a particular object of this invention to provide apparatus and a method for carburizing wherein the time heretofore required can be considerably reduced without sacrificing results such as uniformity of *779 carburization and depth of carburiz-ipg in so-called case carburizing.” Claim 18 is illustrative:
“The combined method of carbur-izing and hardening a ferrous metal, comprising disposing said metal in a furnace and exposing said metal to an electrical induction wire and evacuating the gas from said furnace, injecting a carburizing gas into said furnace at a selected gauge pressure of from two pounds per square inch to fifteen pounds per square inch and surrounding said metal with the pressurized said car-burizing gas, electrically energizing said wire and thereby heat said metal to a gas carburizing temperature of substantially 1650 degrees Fahrenheit for a predetermined time, maintaining said selected gauge pressure during said predetermined time, and discontinuing the flow of electrical current in said wire and simultaneously quenching said metal for hardening same while it is at said temperature.”

The references relied on are:

Evans 2,565,957 August 28, 1951
Tauber 2,842,352 July 8, 1958
Fennell (British) 114,446 March 27, 1918
Metal Progress, Vol. 70, No. 6, Deo. 1956,
PP. 144-146

The examiner cited Carburizing 2 as showing that carburizing under pressures from one ounce above atmospheric to 15 psi and more has been common practice. This reference, however, was neither cited nor mentioned by the board in its decision.

Evans shows surface hardening of ferrous metal work pieces by heating with an induction coil with immediate quenching by a device disposed around the heating coil.

Tauber discloses a carburizing apparatus comprising housing means, exhaust and inlet means, and heating means.

Fennell teaches a process of gaseous carburizing of ferrous metal conducted under elevated pressure, with quenching immediately following the carburizing. The patentee states that “pressure of the gas or vapour may vary but a pressure of the order of about fifteen pounds to the square inch has given good results * * *.” Fennell also teaches that use of elevated pressure effects “a better, quicker and more effective and uniform” case-hardening.

Metal Progress describes “completely automatic equipment for carburizing and direct quenching which employs high-frequency induction heating * * The reference shows that the usual temperature is 1700 °F.

The examiner rejected claims 15-18 and 20 as unpatentable over Metal Progress in view of Fennell alone or also in view of Evans. The examiner pointed out that Metal Progress teaches a method of fast carburizing a ferrous metal. Metal Progress discloses the steps of disposing the metal in a furnace, introducing a carburizing gas in the furnace and heating the metal to a gas carburizing temperature and quenching the metal. The depth of carburizing desired is related to the length of time carburizing temperature is applied. The reference shows the desirability of rapid carburiz-ing which is achieved by increasing the absolute value of the environmental variable of temperature. It is further noted that Fennell teaches that rapid carburiz-ing is desirable and is achieved through increase of the absolute value of the environmental variable of pressure. The examiner asserted the position that:

“ *• * * a skilled artisan, practicing the process of Metal Progress would be led to increase the pressure therein according to the teachings of Fennell, given the suggestion of Fennell that carburizing under increased pressure will increase the rate thereof, the same *780 object that Metal Progress seeks to achieve. * * * ”

Appellant argues that his process and apparatus for case hardening in a very-short time avoids “undesirable grain growth.” This alleged advantage is not disclosed in appellant’s specification nor is there any proof of record relating to same. In this connection, the examiner, in view of the prior teachings of Metal Progress and Pennell, reasoned that a skilled artisan would know that increase of the variables, temperature or pressure, above atmospheric would increase the carburizing rate and would therefore be led to carburize under pressure at normal carburizing temperatures rather than work at abnormally high car-burizing temperatures, to avoid undesirable grain growth which occurs at high temperatures.

Appellant contends that while Fennell discloses carburizing in a high pressure vessel, the pressure is not of the magnitude disclosed by appellant, nor is it controlled or maintained as is done in appellant’s process and apparatus.

As we have noted, Fennell states that “a pressure of the order of about fifteen pounds to the square inch has given good results * * It is further noted that Fennell discloses that a “safety valve may be provided * * * to prevent excessive gas pressure being set up in the tube.” (Emphasis supplied.) We agree with the examiner, as did the board, that this teaching clearly shows that the pressure of 15 psi has been controlled throughout the carburizing process and that the safety valve performs that function or performs a back-up function to prevent equipment damage should another control device fail.

Claims 15, 16 and 18 are limited to a pressure of from two to fifteen pounds per square inch.

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Related

In Re Kaufmann
193 F.2d 331 (Customs and Patent Appeals, 1951)
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144 F.2d 896 (Customs and Patent Appeals, 1944)

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Bluebook (online)
343 F.2d 778, 52 C.C.P.A. 1230, Counsel Stack Legal Research, https://law.counselstack.com/opinion/application-of-verle-h-erickson-ccpa-1965.