Patents by Inventor Robert J. Pardis

Robert J. Pardis 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: 4063161
    Abstract: A fault locator of the earth potential gradient type for locating faults in underground, unshielded, insulated, electrical power cables includes a high voltage pulsing unit for generating and applying high voltage pulses to a faulted power cable. The pulses pass through the power cable, out of the electrical fault, through the earth and back to the pulsing unit. The passage of the pulses through the earth forms potential differences between locations in the earth. These potential differences are monitored by a monitoring unit formed by a fault locator meter and a pair of probes inserted into the earth. The fault locator meter includes a galvanometer for indicating the potential differences and a control circuit that has high gain, automatic gain control, automatic needle centering, automatic earth potential offset compensation and a momentary contact switch to reduce the power drain.
    Type: Grant
    Filed: April 14, 1975
    Date of Patent: December 13, 1977
    Assignee: Joslyn Mfg. and Supply Co.
    Inventor: Robert J. Pardis