Application of Skoner

• Decision Date: 12 June 1975
• Docket Number: Patent Appeal No. 75-551.
• Citation: 517 F.2d 947
• Parties: Application of Daniel C. SKONER et al.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

517 F.2d 947

Application of Daniel C. SKONER et al.

Patent Appeal No. 75-551.

United States Court of Customs and Patent Appeals.

June 12, 1975.

Gerald K. White, Thaddeus A. Zalenski, Pittsburgh, Pa., for appellants.

Joseph F. Nakamura, Washington, D. C., for the Commissioner of Patents; Henry W. Tarring, II, Washington, D. C., of counsel.

Before MARKEY, Chief Judge, and RICH, BALDWIN, LANE and MILLER, Associate Judges.

BALDWIN, Judge.

This appeal is from the decision of the Patent and Trademark Office Board of Appeals affirming the rejection of claims 1-5 in application serial No. 144,567, filed May 17, 1971, for a "Method of Coating Ferrous Substrates With Zinc Vapor."¹ We affirm.

The Invention

Appellants' invention relates to a method for providing adherent vapor-deposited zinc coatings on ferrous substrates in a vacuum. Appellants have found that good adhesion of zinc to a ferrous substrate, particularly in a high speed, continuous coating process, can be obtained by wire brushing the substrate surface to a critical degree, without the necessity of employing processing temperatures resulting in substantial alloying of the iron and zinc or re-evaporation of the zinc. The degree of wire brushing which is required must be sufficient to not only remove the oxide layer present on the substrate, but severe enough to make the substrate rough on a microscale so that it will exhibit low specular reflectivity with a dull appearance to the unaided eye. Appellants have further found that wire brushing, if not carried out with sufficient severity, will merely remove the surface oxide layer and polish the substrate surface. This polished condition, according to appellants, is "inimical to good zinc adhesion."

Claims 1 and 4 are illustrative:

1. A method of providing an adherent zinc coating on a ferrous substrate comprising passing said substrate into an evacuated chamber having a pressure less than about 10-3 torr, wire brushing said substrate in said chamber with sufficient severity to remove any oxide layer present on the substrate area to be coated and to abrade the surface of the substrate to cause the surface to be rough on a microscale, exhibit low specular reflectivity, and have a dull appearance to an unaided eye, and vapor depositing zinc onto the brushed surface of the substrate.

4. A method of providing an adherent zinc coating on a ferrous substrate comprising passing said substrate into an evacuated chamber having a pressure less than about 10-3 torr, wire brushing said substrate, monitoring the reflectivity of the brushed substrate surface, and when the monitored reflectivity indicates that the brushed surface is in a polished condition predictive of resulting poor zinc adhesion increasing the severity of the wire brushing operation sufficiently to remove any oxide layer present on the substrate area to be coated and to abrade the surface of the substrate to cause the surface to be rough on a microscale, exhibit low specular reflectivity, and have a dull appearance to an unaided eye, and thereafter vapor depositing zinc onto the substrate brushed surface.

Claims 3 and 5 recite the additional step of cleaning the substrate of contaminants which, if not removed, cause polishing of the substrate through wire brushing.

The Rejection

The examiner rejected claims 1-5 under 35 U.S.C. § 103 as being unpatentable over Baer et al., U.S. Patent No. 3,012,904. Baer et al. relate to coating of the type wherein a metal such as aluminum or zinc is vaporized in a vacuum and condensed on a metallic surface. Baer et al. teach that in order to obtain a strong adherent bond between a thick vapor-coated layer and base, "the oxide coating plus other surface contaminants must be removed as completely as possible prior to coating." This is taught to be accomplished by abrasive means such as grit or sandblasting, rotating flexible contour-conforming abrasive flaps, wire brushing, abrasive wheels, and roughened surfaces such as sandpaper, or by milling or machining.

It was thus the examiner's position, as expressed in his answer, that:

If there is any difference in the degree of roughening encompassed by Baer et al. and that defined in the appealed claims it is a difference of degree and not of kind. It is the Examiner's opinion that it would involve merely routine experimentation to determine the optimum degree of wire brushing and abrading which would prepare the Baer et al. ferrous substrate for the "strongly adherent, dense metal coatings" * * *.

Claims 4 and 5 call for "monitoring the reflectivity of the brushed substrate surface." Although Baer et al. do not recite such a feature, the examiner continued:

It is considered to be obvious to one of ordinary skill in this art to monitor the condition of the substrate to ensure that the proper amount of brushing has resulted because * * * in order to assure that all oxide coating is removed from the substrate, severe abrading is necessary and this would inherently produce a surface with low reflectivity.

The board affirmed the examiner's rejection notwithstanding its observation that "the reference does not disclose that the metal substrate is roughened on a microscale, exhibits low specular reflectivity or has a dull appearance to the unaided eye."

With regard to the rejection of claims 1-3, the board based its decision on three grounds. First, it is unrealistic to assume that Baer et al. merely removes the oxide coating by light brushing, which would only polish the substrate surface, "since it would appear that such an operation would require careful control of the abrasion conditions and the reference makes no mention of such conditions or indicates anywhere that the surface of the metal substrate is polished." Second, "the reference disclosure indicates that wire brushing is equivalent to abrasive papers, abrasive wheels, sand blasting or cutters, the use of which would hardly polish the surface." Third, the board felt that "the use of a roughened surface to improve adhesion is elementary in the coating art and * * * Baer et al. in their process obviously produce such a roughened surface."

Addressing itself to the rejection of claims 4 and 5, the board agreed with the examiner that it would be obvious to monitor a surface to ensure proper brushing while adding that "a low reflectivity would be inherently obtained by the process of Baer et al.."

In appellants' request for reconsideration, it was asserted that the board raised a new ground of rejection by placing emphasis upon the equivalency of the various surface preparation techniques disclosed by Baer et al. To rebut the board's position, a Rule 132 affidavit was filed. The affiant concluded that neither an abrasive brush nor sandpaper is equivalent to a...