Patents by Inventor Roy R. Thompson, Jr.

Roy R. Thompson, Jr. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4213600
    Abstract: Apparatus for recovering silver from spent photographic processing solutions is disclosed. The silver recovery apparatus includes a cylindrical container in which a plurality of fluid permeable layers of a chemical reduction agent are disposed in interleaved relation with a plurality of fluid permeable layers of a non-reactive filter material. The interleaved combination of the layers defines a fluid permeable flow path through the container. The chemical reduction agent in each reduction layer comprises a metal which is electropositive with respect to silver. In a preferred embodiment, the chemical reduction agent disposed in an adjacent pair of reduction layers comprises first and second metals occupying relatively different positions in the electromotive series, respectively, thereby producing a galvanic effect which enhances the precipitation of silver.
    Type: Grant
    Filed: August 7, 1978
    Date of Patent: July 22, 1980
    Inventor: Roy R. Thompson, Jr.