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. 02, 1991
Filed:
Aug. 07, 1989
Applicant:
Inventor:
Thomas Yeh, South Weymouth, MA (US);
Assignee:
Sigma Instruments, Inc., Weymouth, MA (US);
Primary Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 59 ; 361 93 ; 361 95 ;
Abstract
A fault indicator which senses current in a cable, resets in response to a minimum current and arms a trip arrangement in response to current rising a predetermined amount with respect to time. If the rising current also opens a circuit breaker within a predetermined time and cuts off current to the cable, the indicator trips. If no zero current occurs within the time period, the trip arrangement is disarmed for the next current rise.