Patents by Inventor Fred A. Topham

Fred A. Topham 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: 5044604
    Abstract: A valve is provided preferably having a moulded plastic valve plug with a plurality of preferably arcuate grooves circumferentially spaced in the forward surface of the plug. The arcuate grooves distribute fluid flowing between the plug and valve seat substantially equally about the periphery of the valve plug. Fluid is also directed by the grooves to flow between a sealing surface of the plug and the valve seat in an outward radial direction substantially parallel to the valve seat. The resulting fluid flow reduces cavitation, valve stem chatter, noise and vibrations as well as reducing erosiion of the valve seat. An inner portion of the plug is made of a relatively high tensile strength material having a low thermal expansion rate whereas an outer portion of the plug including the plug sealing surface is made of a material having a relatively low surface hardness.
    Type: Grant
    Filed: August 31, 1990
    Date of Patent: September 3, 1991
    Inventors: Fred A. Topham, Joseph A. Toth, Michael F. Wilson