Patents by Inventor Robert J. Welchel

Robert J. Welchel 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: 4194534
    Abstract: When a Hydraulically operated valve is used to control the operation of a hydraulic elevator, it is required to do so in a manner such that as the elevator cab approaches a floor level in either direction, it is first decelerated through a transition cycle and after that moved slowly a short distance through a creeping cycle to the floor level where it stops. In the up direction, an extra heavy load cuts the transistion time and adds objectionably to the time needed for up leveling. The compensating valve of the invention is interposed in the hydraulic line of the operating valve which normally is depended on to cause deceleration for transition, replacing the deceleration valve. A plunger in the compensating valve is shifted by an increase in hydraulic pressure resulting from an extra heavy load.
    Type: Grant
    Filed: April 17, 1978
    Date of Patent: March 25, 1980
    Assignee: Elevator Equipment Co.
    Inventors: William A. P. Lawrence, Robert J. Welchel