Application of Tanczyn

202 F.2d 785, 40 C.C.P.A. 886
CourtCourt of Customs and Patent Appeals
DecidedMarch 11, 1953
DocketPatent Appeal 5927
StatusPublished
Cited by6 cases

This text of 202 F.2d 785 (Application of Tanczyn) 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 Tanczyn, 202 F.2d 785, 40 C.C.P.A. 886 (ccpa 1953).

Opinion

JOHNSON, Judge.

This is an appeal from the decision of the Board of Appeals of the United States Patent Office affirming the holding of the Primary Examiner rejecting as unpatentable over the prior art claims 10, 12, and 13, the only remaining claims in appellant’s application for a patent on an “Alloy Steel and Products.”

The appealed claims relate to wrought and polished stainless steel products, such as sheet, strip, wire and the like, which are substantially free from surface imperfections such as black spots, blisters, pits and inclusion lines. According to appellant, these imperfections, which are objectionable in many classes of service, are a common occurrence when such products are fashioned by rolling and polishing from “straight chromium” stainless steels having up to 3% nickel.

Appellant has found that such surface defects in this type of stainless steel are due to the presence of certain large complex silicate inclusions. In some way, apparently not fully understood these imperfections cause a difference in the reflectivity of the highly polished surfaces, thereby giving the appearance of dark spots or black spots. According to appellant, his investigation into the causes of the complex silicate inclusions revealed that manganese promotes the development of such inclusions in this type of steel, depending upon the amounts of chromium and silicon present. This is said to be due to- the powerful reducing power of manganese with respect to silica in the fire brick of the furnace and related production equipment. He discovered also that the surface defects could be eliminated by keeping the manganese content to a minimum, at least below 0.2%, and maintaining a certain definite relationship between chromium, manganese and silicon content. Appellant believes that when the allegedly critical proportions of ingredients disclosed by him are maintained, objectionable large silicate inclusions arc changed to small harmless silica inclusions; in any event, a highly polished product free of surface-defacing inclusions is claimed to be assured. It is stated by appellant in his application that manganese was regarded as a desirable ingredient in such steels by the prior art, and that heretofore it has been customary for steels similar to that here involved to have manganese contents in excess of 0.2%, which appellant claims to be the critical upper limit. The latter statements have not been challenged by the Patent Office tribunals.

Claims 12 and 13 differ slightly from each other and from claim 10, which is regarded as representative and reads as follows:

“10. In manufactures of the class described, wrought and polished *786 straight chromium stainless steel sheet, strip, wire, and like products containing large amounts of chromium and small amounts of manganese and silicon which products are substantially free of surface-defacing complex silicate inclusions and comprise 10% to 27% chromium, up to about 0.2% manganese and from incidental amounts up to about 1% silicon with said manganese content restricted to amounts beneath the curve in the accompanying diagram corresponding to the specific amount of said chromium, and the remainder substantially all iron.”

The “curve in the accompanying diagram” recited in the claim refers to a diagram in appellant’s specification which shows a series of curves for various specific values of chromium content (10%, 15%, 20%, 25% and 30%) in his stainless steel products. Each curve defines, for a steel of that chromium content, the critical upper limit on the maximum permissible quantity of manganese in the steel for any specific silicon content in order to avoid undesirable complex silicate inclusions, as distinguished’ from the harmless simple silica inclusions. It is stated in the specification that other chromium curves and upper permissible limits on manganese may be arrived at in the diagram by interpolation. As may be seen from claim 10, the claims cover a wrought and polished steel product having a chromium content within a certain range, manganese content of 0.2% or less, and silicon content of 1% or less, with the further qualification that the manganese content for any particular silicon content shall be restricted to a value beneath the curve for the particular chromium content, as determined from the above-mentioned diagram.

The references relied on by the Patent Office are: “Stainless Iron and Steel,” by J. H. G. Monypenny, 2nd Ed., 1931, page 109, alloy under Table IX, and page 306, alloy No. A; also page 520, “Book of Stainless Steel,” by E. E. Thum, 2nd Ed., 1935, pages .154 to 156.

On page 360 of Monypenny, there is disclosed a copper-bearing stainless steel sample, designated “alloy. ,A,”. which contains 0.17% manganese, 0.28% silicon and 12.1% chromium. Page 109 of that reference discloses stainless steel test bars having 0.13% manganese content, 0.14% silicon and 12.2% chromium. Counsel for appellant concedes that allow A has^manganege, silicon and chromium contents which answer to the requirements of the diagram referred to in the appealed claims. He contends, however, that the alloy on page 109, if carefully plotted on the diagram, falls just outside the critical limits. The Solicitor for the Patent Office replies that it falls just within the critical limits if plotted correctly. In view of appellant’s concession with respect to alloy A, we think it immaterial which party is right as to the latter alloy, and we shall assume, for the purpose of this opinion, that the solicitor is correct.

Monypenny also discloses on page 520 that stainless steel having about 12 to 14% chromium and 0.3% carbon is used for the manufacture of cutlery to produce a knife “which will retain its polish perfectly under ordinary domestic use.” Thum discusses the polishing of stainless steel sheet and strip and indicates that steel mills now furnish polished stainless steel products in a number of different finishes. In neither case does the reference make any mention of manganese or silicon content.

The examiner rejected the claims as un-patentable over the steel alloys disclosed on pages 109 and 306 of Monypenny in view of the disclosure on page 520 of Monypen-ny, and in Thum, that stainless steel alloys are commonly wrought and highly polished. The examiner held that the two alloys disclosed by Monypenny met the composition recited in the claims, and that there was no invention in processing the same into polished’products since the cited references disclosed that it was common to produce highly polished sheets from such chromium steels.

The Board of Appeals agreed with these holdings of the examiner and accordingly sustained’ the rejection. The board also indicated that it agreed with the examiner that our holding in In re Cooper, 134 F.2d 630, 30 C.C.P.A., Patents, 946, was controlling in this case, whereas it disagreed with appellant’s argument that the case of *787 Becket v. Coe, 69 App.D.C. 51, 98 F.2d 332, was determinative.

In Becket v. Coe, supra, Becket had discovered and claimed an allegedly new deep-drawing stainless steel. The prior art references disclosed broad ranges which included the more restricted ranges of Becket’s claimed alloy.

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Bluebook (online)
202 F.2d 785, 40 C.C.P.A. 886, Counsel Stack Legal Research, https://law.counselstack.com/opinion/application-of-tanczyn-ccpa-1953.