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. 04, 1978
Filed:
Mar. 23, 1977
Erwin Salzer, Waban, MA (US);
Gould Inc., Newburyport, MA (US);
Abstract
In fuses exceeding a certain voltage rating it is necessary to establish series multibreaks to interrupt small overload currents. An initial break is formed in the helically wound fusible elements near the center thereof where the temperature is highest. If the arc voltage along this initial break does not exceed the circuit voltage, even after a number of cycles of arcing, secondary or tertiary breaks must be formed in series to the initial break. This is achieved according to the present invention by providing one or more quarter-turns of reduced pitch where the spacing between contiguous groups of windings is reduced and a low temporary current flashover is allowed to occur which results in the formation of secondary and tertiary breaks.