Patents by Inventor Donald L. Hirst

Donald L. Hirst 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).

  • Grinding apparatus with touch-top work surface
    Patent number: 5549509
    Abstract: A grinding apparatus has a cylindrical grinding wheel assembly mounted on a vertical drive shaft extending from an electric motor through a horizontal work table. The apparatus includes a pressure sensitive electrical switch for activating the motor in response to downward force on the work table. The work table is supported on a housing adapted to contain the motor and can be interchanged with work tables of various sizes. The grinding wheel assembly has a drive half and a grinding wheel half driven by the drive shaft.
    Type: Grant
    Filed: July 6, 1994
    Date of Patent: August 27, 1996
    Assignee: Inland Craft Products Co.
    Inventors: Donald L. Hirst, Richard K. Wiand