Patents Assigned to Wittur GmbH
  • Patent number: 6422349
    Abstract: The hydraulic or pneumatic drive for lifting and lowering loads, in particular for lifts, has a working cylinder (11) forming a pressure chamber (14) connected to a pressure fluid source (39) and subjected to a pressure fluid. It also has a lifting piston (1) tightly guided in the working cylinder and a guide rod (15) arranged in the working cylinder. The guide rod (15) projects into the interior of the lifting piston (1) which tightly encloses the guide rod (15). The end (4) of the lifting piston (1) which projects into the pressure chamber (14) forms an annular face (5) which is subjected to pressure fluid. The interior of the lifting piston (1) forms an additional pressure chamber (7) subjected to pressure fluid and which is connected to its own pressure fluid source (40).
    Type: Grant
    Filed: October 29, 1999
    Date of Patent: July 23, 2002
    Assignee: Wittur GmbH
    Inventor: Sead Veletovac