John P Leach

US Patent:

46382836, Jan 20, 1987

Filed:

Nov 19, 1985

Appl. No.:

6/799711

Inventors:

Gerhard Frind - Altamont NY
James J. Carroll - Clifton Park NY
John H. Van Noy - Pittsburgh PA
John G. Leach - Hickory NC
Radha K. Ranjan - Hickory NC

Assignee:

General Electric Company - Schenectady NY

International Classification:

H01H 8504

US Classification:

337162

Abstract:

An exothermically assisted electric fuse, having at least one exothermic body disposed in heat transfer relationship with at least a portion of each fusible element of the fuse, a triggering circuit for initiating an exothermic reaction in response to an overcurrent through the fuse, and a containment body partially enclosing the exothermic body for directing the heat energy released by the exothermic reaction. The containment body is disposed so as to confine and direct the heat energy in a direction which is substantially perpendicular to a plane containing the portion of the fusible element which is in heat transfer relationship with the exothermic body. In a preferred embodiment of such a fuse, the fusible element is wound around a support so that the fuse windings form the general shape of a cylinder, and the containment body is disposed so that the heat energy is directed in a radial direction with respect to the cylinder formed by the fuse windings. The exothermic body preferably comprises a two-part structure in which a mixture of boron and potassium perchlorate acts as a primer for a larger body of exothermic material formed from a mixture of aluminum and potassium perchlorate.