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:
Jan. 04, 1977
Filed:
Dec. 17, 1975
Frederick J Kozacka, South Hampton, NH (US);
The Chase-Shawmut Company, Newburyport, MA (US);
Abstract
A fuse for elevated circuit voltages is provided with first fusible element means having a relatively low resistance and wound substantially helically around a mandrel formed of insulating plates. The fuse is provided with a spring-biased blown fuse responsive device for indicating whether or not the fuse has blown, or for tripping a switching device with relatively movable contacts, e.g. a disconnect. The blown fuse responsive device is under the control of a second fusible element means which has a relatively high resistance. Said second fusible element means includes a plurality of spaced sections forming therebetween a voltage-responsive break-down spark gap. The mandrel for supporting the first fusible element has a perforation immediately adjacent the end thereof at which the blown fuse responsive device is arranged. Two contiguous sections of the second fusible element are spaced from each other and form a voltage responsive break-down spark gap. When an arc takes the place of the first fusible element means the arc-voltage causes a break-down of the aforementioned spark gap. This initiates a current flow through the second fusible element means, resulting in its fusion at a predetermined point thereof. This, in turn, causes operation of the blown fuse responsive device. The aforementioned mandrel performs functions in addition to supporting the first fusible element means. It forms the spark gap, defines its length with a very satisfactory degree of precision, and it receives the reaction of the spring forces biasing the blown fuse responsive device.