Patents by Inventor James M. Hammell

James M. Hammell 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).

  • Hydropneumatic monitoring device
    Patent number: 4574920
    Abstract: A hydropneumatic monitoring device in which a hydraulic fluid passageway is controlled by a piston and plunger spring biased in one direction and shiftable by air pressure in opposition to the bias for aligning a passageway-connecting bypass in the plunger with the passageway which is intersected by the plunger. Air pressure metered through the piston passes to an air passage. Air pressure failure or blockage in the air passage cause deviation of the piston and plunger from a state of open passageway equilibrium, for blocking the passageway.
    Type: Grant
    Filed: August 2, 1984
    Date of Patent: March 11, 1986
    Assignee: Lubriquip - Houdaille, Inc.
    Inventors: James J. Callahan, James M. Hammell