Patents by Inventor Gerhard Kastreuz

Gerhard Kastreuz 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).

  • Piston for a hammer drill having a separable part
    Patent number: 4192391
    Abstract: In a hammer drill a pair of pistons are spaced axially apart within a bore forming an air cushion between them. As the rear piston is reciprocated the other piston is also reciprocated and strikes against a drilling tool. The rear piston consists of a hollow cylinder with a headpiece forming an airtight closure across its end surface facing toward the other piston. The headpiece of the rear piston has a part which separates from the remainder of the headpiece when it is struck by the other piston affording communication between the air cushion and the interior of the hollow cylinder.
    Type: Grant
    Filed: June 6, 1978
    Date of Patent: March 11, 1980
    Assignee: Hilti Aktiengesellschaft
    Inventors: Gerhard Kastreuz, Volker Waschk