Patents by Inventor Mark F. Hoffstein

Mark F. Hoffstein 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).

  • Inverted cell pad material for grinding, lapping, shaping and polishing
    Patent number: 4841680
    Abstract: A polishing pad material is provided with a cellular polymeric layer containing elongated cells normal to the major surfaces of the material, such that the cell openings on the polishing surface of the material comprise a majority of the surface area, and the cells have a mean diameter of about 50 to 200 microns with the diameter of the surface openings being preferably larger than the cell diameters below the surface. The cells are preferably cone-shaped and have a depth at least 1.5 times the diameter of the surface openings. The pad material is formed from a poromeric material, preferably polyurethane elastomer, with microporous cell walls having pore diameters less than 0.1 times the diameter of the cells.
    Type: Grant
    Filed: September 20, 1988
    Date of Patent: June 27, 1989
    Assignee: Rodel, Inc.
    Inventors: Mark F. Hoffstein, Takehisa Shinagawa