Patents by Inventor Fred C. Liebertz

Fred C. Liebertz 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: 4796950
    Abstract: The seat and pedestal of a chair are joined by a knee-tilt mechanism which includes a first support fixed to the underside of the seat adjacent the front edge thereof, and a second support fixed to the pedestal and having a sidewardly extending support tube arrangement. The first support has bearing hubs rotatably engaged with the support tube to define a horizontal tilt axis. A restoring mechanism is disposed within the second support for exerting a restoring torque about the tilt axis for urging the seat toward its horizontal position. The restoring mechanism, in the preferred embodiment, employs a sleevelike spring member of an elastomeric material disposed on the tilt axis for developing a restoring torque which generally linearly increases as the seat tilts away from the horizontal position. A second spring coacts between the supports for generating a second restoring torque which is additive with the first torque to effectively cause a torque dwell to facilitate tilting beyond an intermediate position.
    Type: Grant
    Filed: February 9, 1987
    Date of Patent: January 10, 1989
    Assignee: Haworth, Inc.
    Inventors: Walter C. Mrotz, III, Donald L. Cool, Fred C. Liebertz