Patents Assigned to Shinn Hua (China) Machinery Co., Ltd.
  • Patent number: 5992149
    Abstract: A control unit for hand-operated hydraulic jack comprises a control handle (1), a small hand-operated pump (2), a lifting cylinder (4), an inlet pipe and an outlet pipe, wherein the inlet pipe of said lifting cylinder (4) is connected with the small hand-operated pump (2) having a back-moving spring through a lifting oil circuit having a non-return valve (3), which the small hand-operated pump (2) is controlled by the control handle (1); said lifting oil circuit with a non-return valve (3) has an underload-accelerating oil circuit for quickly lifting the load when underloaded; and a release valve is provided on the outlet pipe of said lifting cylinder (4). This unit has the function of quickly lifting the load when underloaded, as well as increasing the force for lifting load when have loaded, and it can be operated simply and reliably.
    Type: Grant
    Filed: October 1, 1997
    Date of Patent: November 30, 1999
    Assignees: Shinn Hua (China) Machinery Co., Ltd., Xuanzhe Hu
    Inventor: Xuanzhe Hu