Patents by Inventor John W. Metcalf

John W. Metcalf 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).

  • Convertible electric tester for use with a flashlight and including a jack plug with tubular shunt
    Patent number: 4021732
    Abstract: An electric tester usable for one type of test by tapping into the battery current of a flashlight, or for an alternate type of test as a shunt across the terminals of units in a power line to determine their conductivity. The tester is a jack with a plug having terminals suitable to tap as mentioned for the first type of test. For the second type the invention provides a connector bridging the terminals to convert the jack plug into a shunt applicable as stated.
    Type: Grant
    Filed: May 27, 1975
    Date of Patent: May 3, 1977
    Inventor: John W. Metcalf