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:
Dec. 26, 1978
Filed:
Apr. 13, 1977
Hitachi, Ltd., , JP;
Abstract
A thermal time-delay switch comprises contacts which are normally engaged, a first bimetallic element associated with one of the contacts to separate the contacts from each other with temperature rise in the first bimetallic element, a second bimetallic element associated with the other of the contacts to bring the contacts into engagement with each other with a temperature rise in the second bimetallic element, and a heating resistor provided for each of the first and second bimetallic elements to heat it. The relative displacement between the contacts caused by the first bimetallic element with the temperature rise therein is larger than that caused by the second bimetallic element, so that the contacts are separated from each other substantially independent of voltage fluctuations over a wide range of a voltage source feeding the two heating resistors when the heating resistors have been connected to the voltage source for a given period of time.