Patents by Inventor John T. Back

John T. Back 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).

  • Large dimensional thermoplastic articles
    Patent number: 4943463
    Abstract: Thermoplastic articles such as fenders, of large cross-sectional dimensions, may be made by extrusion without shrinkage voids by extruding a first stream of theremoplastic as a hollow profile, and extruding a second stream of molten thermoplastic by a second extruder and forcing same under pressure into the hollow profile to till the voids of shrink-age on cooling.
    Type: Grant
    Filed: August 21, 1987
    Date of Patent: July 24, 1990
    Assignee: Oy Wiik & Hoglund AB
    Inventor: John T. Back
  • Method for extrusion production of large dimensional thermoplastic articles
    Patent number: 4704244
    Abstract: Thermoplastic articles such as fenders, of large cross-sectional dimensions, may be made by extrusion without shrinkage voids by extruding a first stream of thermoplastic as a hollow profile, and extruding a second stream of molten thermoplastic by a second extruder and forcing same under pressure into the hollow profile to fill the voids of shrinkage on cooling.
    Type: Grant
    Filed: November 9, 1984
    Date of Patent: November 3, 1987
    Assignee: Oy Wilk & Hoglund AB
    Inventor: John T. Back