Patents by Inventor John R. Bruce

John R. Bruce 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).

  • Method for the manufacture of piston rings
    Patent number: 4937937
    Abstract: A method for the manufacture of piston rings from a metal strip, at least includes providing rings having a predetermined non-circular profile, by the metal strip being first bent to a uniform radius of curvature at least 2 percent less than the minimum radius of curvature in the predetermined profile, then the curved strip being bent back to increase the radii of curvature of all the constituent portions of the strip forming the ring to the desired values of the predetermined profile.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: July 3, 1990
    Assignee: T&N Technology Limited
    Inventor: John R. Bruce