Patents by Inventor Peter A. Gray

Peter A. Gray 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).

  • Self-tapping, and self-tapping and self-drilling, rock bolts
    Patent number: 5433558
    Abstract: A self-tapping rock bolt having a discontinuous threaded profile with a plurality of cutting edges and at least one flute extending along the length of the rock bolt. The cutting edges are adapted to cut a threaded profile in the internal surface of a pilot hole so that the threaded profile of the rock bolt interlocks therewith. An internal axial hole is provided to enable water to be injected through the rock bolt as the threaded profile is being cut. The discontinuous threaded profile is tapered to form a lead-in section such that the height of the leading edge of each segment of the discontinuous threaded profile progressively increases from a leading end of the rock bolt.
    Type: Grant
    Filed: June 8, 1993
    Date of Patent: July 18, 1995
    Assignee: BHP Engineering Pty Ltd
    Inventor: Peter A. Gray