Patents by Inventor David V. Williamson

David V. Williamson 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).

  • CONDUIT LOCATING METHOD AND APPARATUS
    Publication number: 20150377838
    Abstract: An apparatus for use with at least one associated elongated conduit having first and second axial extremities and for facilitating the identification of the location of the second axial extremity of the associated conduit when presented with the first axial extremity thereof which includes an audio generator having an emitter port having an acoustic output amplitude equal to or greater than 110 dB measured at 2 inches from said emitter port.
    Type: Application
    Filed: June 25, 2014
    Publication date: December 31, 2015
    Inventors: David A. James, David V. Williamson
  • On-off switch with time delay
    Patent number: 3943375
    Abstract: An on-off switch having a time delayed "off" position provided by a series-connected PTC thermistor.
    Type: Grant
    Filed: December 23, 1974
    Date of Patent: March 9, 1976
    Assignee: GTE Sylvania Incorporated
    Inventor: David V. Williamson