US 5,014,036 A · Thermal and current sensing switch

Abstract

A thermal and current sensing switch which brakes an associated electric circuit when an overcurrent is supplied to the electric circuit or the temperature of the electric apparatus rises beyond a predetermined temperature. The thermal and current sensing switch comprises a housing, fixed conductors fixed to the housing with the base ends thereof extended within the housing; a current fuse placed in the housing with the opposite terminals thereof in contact with the fixed conductors; a first spring biasing the current fuse away from the fixed conductors, a second spring pressing the current fuse against the fixed conductors against the force of the first spring, and a temperature sensing element provided between the housing and the second spring. When the ambient temperature rises beyond a predetermined temperature, the temperature sensing element reduces the force of the second spring to allow the first spring to separate the current fuse from the fixed conductors to break the electric circuit. The current fuse and the temperature sensing element are isolated electrically and thermal from each other so that the same are able to function independently.

Claims7

Dependent claims

A thermal and current sensing switch comprising:

a housing having a cavity;
a pair of fixed conductors fixed to said housing, said fixed conductors having base ends extending in said cavity of said housing;
a current fuse placed within said cavity of said housing, said current fuse having opposite terminals in contact respectively with said base ends of said fixed conductors;
a separating elastic member biasing said current fuse away from said fixed conductors;
a pressing elastic member providing a resilient pressing force pressing said opposite terminals of said current fuse in opposition to the bias of said elastic member and pressing said opposite terminals of said current fuse against said base ends of said fixed conductors;
and
a thermal sensing element which reduces the resilient pressing force of said pressing elastic member when the temperature of said thermal sensing element rises beyond a predetermined temperature to permit said current fuse to be separated from said fixed conductors.

4 more elements

Dependencies are inferred from the claim text.

Thermal and current sensing switch

Life of this patent

Thermal and current sensing switch

Life of this patent

Abstract

Claims7