In re Langdon, Patent Appeal No. 3490.

• Decision Date: 03 June 1935
• Docket Number: Patent Appeal No. 3490.
• Citation: 77 F.2d 920
• Parties: In re LANGDON.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

77 F.2d 920 (1935)

In re LANGDON.

Patent Appeal No. 3490.

Court of Customs and Patent Appeals.

June 3, 1935.

W. Bartlett Jones, of Chicago, Ill., for appellant.

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

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

GRAHAM, Presiding Judge.

An application was filed in the United States Patent Office by appellant, for a patent upon certain claimed new and useful improvements in metal protected mirrors. As a result of the proceedings in the office, claims 3 to 16, inclusive, and claims 27 to 33, inclusive, were rejected by the examiner. On appeal, the Board of Appeals reversed the examiner as to claims 15 and 16, and affirmed his decision as to all other claims. Claims 3, 4, 9, and 14 are thought to be typical, and are as follows:

"3. A mirror comprising a body of light-transmitting medium, an opaque relatively thin reflective silver film adherent to one surface of said body, a metallic protective coating metallically united to said silver film, the metal in said protective coating being chosen from a group in the periodic system separated from the group containing silver by at least three other groups and excepting nickel.

"4. A stable reflecting light comprising in combination a heated source of light and a mirror exposed to the heat of said light, said mirror comprising a body of light-transmitting medium, an opaque relatively thin reflective silver film adherent to one surface of said body, a metallic protective coating metallically united to said silver film, the metal in said protective coating being one chosen from Group VIII of the periodic system."

"9. A mirror comprising a body of light-transmitting medium, an opaque relatively thin reflective silver film adherent to one surface of said body, a metallic protective coating metallically united to said silver film, the metal in said protective coating, excepting nickel, being incapable of destroying the characteristic surface of silver under the conditions of normal exposure of said mirror, which conditions cause copper as a protective film to discolor or modify the reflecting surface of the silver film."

"14. A stable reflective light comprising in combination a heated source of light and a mirror exposed to the heat of said light, said mirror comprising a body of light-transmitting medium, an opaque relatively thin reflective silver film adherent to one surface of said body, and a protective nickel coating metallically united to said silver film."

The subject-matter of the invention is a mirror of glass, or other light transmitting medium, with a silver reflecting back coating, which silver coating is backed by another coating of a metal not belonging to the same group of the periodic system as silver, and which will not produce a tarnish or colored appearance in conjunction with the silver coating, as a result of the application of heat or light to the surface of the reflector. This second coating is, in turn, covered by a protective coating of paint, or other like substance. The substance of the claimed invention is that the practice in the prior art in the preparation of such mirrors has been to use a copper backing for the silver coat; that this copper backing, or backing of a similar metal of the same group or kind, will deteriorate by an admixture or alloying of the copper and silver coats; that the appellant has discovered why this discoloration takes place; that the same will not occur when a so-called "white metal" is used, or a metal which is in any of the groups from III to VIII of the periodic system. The appellant contends that his disclosure is new to the art and is inventive.

During the progress of the application through the Patent Office, the appellant, through his counsel, amended his application by eliminating any claim for a backing of the metal nickel as a secondary coating for the mirror, doing so in view of a patent to Liebig (British), No. 1255, which appellant had discovered, and which he cited. The appellant, also, in the progress of his claims, filed a number of affidavits in which the commercial success of appellant's product seems to be established.

The examiner cited two references as follows: Dake, 1,759,099, May 20, 1930; and Corbit, 1,835,636, December 8, 1931 — and rejected all the claims upon these references.

The Board of Appeals cited the same references relied upon by the examiner. In addition, the board recurred to the patent to Liebig. The board called...