Patents by Inventor Wolfgang F. Liebisch

Wolfgang F. Liebisch 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).

  • Plastic extrusion
    Patent number: 4238435
    Abstract: A method of making elongated members of thermoplastic material which simulate natural bamboo by continuously extruding the material through a die, cooling the extruded material downstream of the die, gripping the cool material and transporting the material away from the die and slowing the speed of transport relative to the speed of extrusion at predetermined lengths of extrusion to produce regions of greater external cross-sectional dimensions to provide axially spaced nodes similar to those of bamboo.
    Type: Grant
    Filed: August 1, 1978
    Date of Patent: December 9, 1980
    Assignee: Victroplas Limited
    Inventor: Wolfgang F. Liebisch