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:
Oct. 08, 1991
Filed:
Aug. 21, 1989
John G Gamble, Hull, MA (US);
Matthew G Dillon, Hingham, MA (US);
Sigma Instruments, Inc., Weymouth, MA (US);
Abstract
A sensor in a faulted current indicator includes a coil and a magnetic arrangement passing through the coil and around a current-carrying conductor for coupling the coil to the conductor. The magnetic arrangement has given magnetic reluctance and forms a higher reluctance section, such as a gap, within the coil. Preferably the magnetic arrangement includes a U-shaped laminate and two core laminations joined to the U-shaped laminate by two gaps to allow for installation around the conductor. The ferromagnetic plate outside the coil shields the coil. The sensitivity of the sensor is increased by coating the inner surface of the U-shaped laminate and the core lamination surfaces contacting the U-shaped laminate with a high Ni content ferromagnetic material.