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:
Apr. 16, 1991
Filed:
Jul. 30, 1990
Applicant:
Inventor:
Stephen A Mrenna, Brighton Township, Beaver County, PA (US);
Assignee:
Westinghouse Electric Corp., Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01H / ; H01H / ; H01H / ;
U.S. Cl.
CPC ...
337 70 ; 337 82 ; 335 42 ; 335 45 ;
Abstract
A circuit breaker with a thermal trip has a calibration opening in the electrically insulating housing through which a tool may be inserted and rotated to distort a support plate on which a bimetal is mounted to calibrate the thermal trip after the circuit breaker has been fully assembled and enclosed within the insulating housing. A tamper indicating seal in the form of a destructible film secured over the calibration opening by an adhesive having an adhesive strength exceeding the tensile strength of the destructible film provides a visual indication of any subsequent attempts to tamper with the calibration setting.