Patents by Inventor Harald Holzapfel

Harald Holzapfel 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).

  • Patent number: 5971117
    Abstract: A piston-cylinder aggregate comprising a cylinder in which an axially movable piston rod is arranged is provided. The piston rod has two pistons, which are separated from each other and which produce a damping force of a variable magnitude depending on the piston rod's stroke position. The piston-cylinder aggregate has a bypass area defined in its inner wall along a portion of the length of the cylinder, so that the damping force is at least reduced in the stroke area of the bypass, and the two pistons have a separation equal to or less than the length of the bypass, such that depending on the position of the piston rod, a damping force of variable magnitude is produced. For example, when both pistons are disposed within a section of the cylinder defined by the bypass area, the dampening force exerted by the piston rod is minimized, while when both pistons are outside the bypass area, the dampening force in both stroke directions is maximized.
    Type: Grant
    Filed: May 6, 1997
    Date of Patent: October 26, 1999
    Assignee: Fichtel & Sachs AG
    Inventors: Manfred Grundei, Hans Reimer, Harald Holzapfel