Patents by Inventor by Vivian Thomas, executrix

by Vivian Thomas, executrix 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: 4838308
    Abstract: A three-port multipurpose pilot-operated vapor (air) or liquid (hydraulic) control valve with two semi-independent poppet segments which can be used for most basic control functions, including: two position (on-off), relief, pressure reducing and pressure control. The poppet segments are independent except for a poppet stem fixed to one segment but slidably attached to the second segment. This connection allows both pilot fluid pressure and main port pressure acting on the second poppet segment to partially control the movement of the first segment. A pilot piston may also be included to fully or partially control one or both poppet segments. The semi-independent poppet segments also allow the valve to function as a two-way when one segment is held closed. Combinations can also provide four-way control braking, counterbalance and regenerative functions. Conversion of multipurpose valve from one function to another, normally only requires minor adjustment.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: June 13, 1989
    Inventors: Charles E. Thomas, deceased, by Vivian Thomas, executrix