Patents by Inventor Helmar Nafe

Helmar Nafe 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: 5273217
    Abstract: A method of crushing material between cooperating jaws of a crushing jaw assembly of a demolition tool includes the steps of applying a closing force to at least one of the jaws for urging the jaws toward one another; and imparting a vibratory motion to at least one of the jaws while the closing force is applied.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: December 28, 1993
    Assignee: Krupp Maschinentechnik Gesellschaft mit beschrankter Haftung
    Inventors: Robert-Jan Bartels, Helmar Nafe, Jurgen Winkler
  • Patent number: 5199658
    Abstract: A demolition tool includes a carrier body and two tool blades mounted thereon to define a tool mouth for receiving material to be crushed. The demolition tool further has a hydraulic cylinder including a cylinder housing as well as first and second chambers defined therein. A piston rod is received in the cylinder housing and projects therefrom for moving at least one of the blades. First and second pistons are spacedly affixed to the piston rod and bound the first and second chambers, respectively. Hydraulic fluid is introducible into the first and second chambers for exposing the pistons to pressure to generate a force for moving the piston rod in a working direction. A control unit is operatively connected to the chambers for controlling admission of hydraulic fluid thereto. The control unit has a first position in which the control unit admits hydraulic fluid solely to the second chamber and a second position in which the control unit admits hydraulic fluid under pressure to the first chamber.
    Type: Grant
    Filed: February 14, 1992
    Date of Patent: April 6, 1993
    Assignee: Krupp Maschinentechnik Gesellschaft mit beschrankter Haftung
    Inventors: Robert-Jan Bartels, Helmar Nafe, Hans-Dieter Piotrowski