Patents by Inventor Sideny Lieberman

Sideny Lieberman 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).

  • Temperature compensating hydraulic door closer
    Patent number: 4148111
    Abstract: Hydraulic door closer apparatus comprises a cylinder, a piston disposed in the cylinder, linkage means coupled to the piston for transmitting forces between the piston and a door, and a hydraulic circuit for controlling movement of the piston in the cylinder. A temprature responsive control element is provided in the hydraulic circuit to alter the characteristics of the circuit in response to changes in ambient temperature or temperature of the fluid within the closer.
    Type: Grant
    Filed: November 30, 1977
    Date of Patent: April 10, 1979
    Assignee: Reading Door Closer Corp.
    Inventor: Sideny Lieberman