The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 1985
Filed:
May. 23, 1983
John Dimeff, San Jose, CA (US);
Clyde R Stewart, San Jose, CA (US);
Mark Telephone Products, Inc., Santa Clara, CA (US);
Abstract
A sensor for use on the front end of a flexible, resilient probe for use in an underground duct of the type which contains one or more current-carrying cables. The sensor is provided with a signal generating device for detecting a particular operating condition of a cable in the duct when the sensor moves through the duct adjacent to the cable. In one embodiment of the sensor, acoustical signals are sensed by a crystal when such acoustical signals originate from a leak in the pressurized sheath surrounding the cable. In another embodiment of the sensor, a coil senses the magnetic field surrounding the cable so that electrical shorts occurring in the cable can be monitored. In a third embodiment of the sensor, a heat detector is provided so that the sensor can detect hot spots in a duct.