Patents Assigned to Ludwig Hettich Schraubenfabrik GmbH & Co.
  • Thread forming screw
    Patent number: 5674035
    Abstract: A thread forming screw for concrete, masonry, rock, or similar material. The size ratios of various portions of the screw are defined to reduce thread engagement which, in turn, reduces screw-in torque. A burr in the screw's thread includes bow-shaped cutting teeth to facilitate screw-in.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: October 7, 1997
    Assignee: Ludwig Hettich Schraubenfabrik GmbH & Co.
    Inventors: Stefan Hettich, Ulrich Hettich