Patents by Inventor Stewart P. T. Fraser

Stewart P. T. Fraser 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 machines
    Patent number: 4134552
    Abstract: A grinding mill of the kind comprising a generally cylindrical grinding chamber defined by a screen having a shaft supporting a plurality of grinding hammers rotatable therein and being enclosed in a chamber to which suction is applied characterized by the provision of instrumentality for sensing the pressure within the enclosure surrounding the screen and actuating a safety device in the event that the pressure falls below a pre-determined value.
    Type: Grant
    Filed: September 12, 1977
    Date of Patent: January 16, 1979
    Assignee: Simon-Barron Limited
    Inventors: Stewart P. T. Fraser, Paul A. Fellowes-Freeman