Patents by Inventor Dwight Letchworth

Dwight Letchworth 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).

  • Electronically controlled apparatus for electrolytic depilation
    Patent number: 4155363
    Abstract: Apparatus for "depilation" or "electrolysis" including a current source, a plurality of filament electrodes (needles), and electronic circuitry for individually stabilizing the electrode currents at a predetermined value irrespective of withdrawal of selected needles, variations in the effective resistance of the hair and power supply transients.A programmed current interrupt circuit is also shown, and apparatus for skin conditioning in both current polarities is included, using the basic electronic control circuitry.
    Type: Grant
    Filed: June 15, 1978
    Date of Patent: May 22, 1979
    Assignee: International Electrolysis Group Inc.
    Inventors: Dwight Letchworth, Donald A. Colton