Patents by Inventor Lawrence E. White

Lawrence E. White 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: 5060762
    Abstract: The hydraulic elevator system includes a synchronized telescoping cylinder with inner and outer reciprocating plungers mounted in a fixed cylinder. An hydraulic fluid pressure intensifier is connected to the pressure chamber for the outer plunger, and to the pressure chamber for the inner plunger. Solenoid valves control the flow of hydraulic fluid between the pressure intensifier and the two plunger pressure chambers. Switches mounted on the outer plunger control operation of the solenoid valves. When the inner plunger is too low relative to the outer plunger, when the elevator reaches the bottom landing, the pressure intensifier will raise the pressure in the inner plunger pressure chamber to appropriately lift the inner plunger. When the inner plunger is too high relative to the outer plunger, when the elevator reaches the bottom landing, the pressure intensifier will lower the pressure in the inner plunger pressure chamber, thus lowering the inner plunger.
    Type: Grant
    Filed: May 24, 1990
    Date of Patent: October 29, 1991
    Assignee: Otis Elevator Company
    Inventor: Lawrence E. White