Fusible circuit breaker

Claim 1

A fuse-type circuit breaker for use in a circuit arranged to connect a voltage source to a load, the circuit including phase conductors defining a phase conductor path, and a circuit ground, the circuit breaker comprising: a housing; two current contacts fixed to said housing, said two current contacts including a first current contact connectable via a respective phase conductor to the load and a second current contact connectable via a respective phase conductor to the voltage source; a fuse link having two contact caps and a fuse element connected between said contact caps, said fuse element having a normal operating state in which said fuse element provides a short circuit between said contact caps and having a malfunction response state in which said fuse element provides an open circuit between said contact caps, said fuse link being mounted in said housing to be manually movable between an on position in which each said contact cap is electrically connected to a respective current contact and an off position in which each said contact cap is electrically disconnected from the respective current contact; an operating state indicator device for said fuse link, said indicator device including two input terminals disposed to each be electrically connected to a respective one of said contact caps at least when said fuse link is in said on position and circuit means connected between said input terminals and providing, between said input terminals, an electrical resistance which is very high relative to the normal operating state resistance of said fuse element, said circuit means comprising: a capacitor, a diode and a charging resistor connected together in series to form a first series circuit branch connected between said input terminals; and a light source and a discharge resistor connected together in series to form a second series circuit branch connected in parallel with said capacitor, said indicator device being operative to cause said light source to produce a blinking light signal only when said fuse link is in said on position and said fuse element is in its malfunction response state; a high-resistance auxiliary resistor having a first end connected to said first current contact and a second end connectable to the circuit ground at least when said fuse link is in said on position; and second circuit means connected to said light source and including a switch member selectively connecting said light source to the circuit ground for applying to said light source a rectified current to cause said light source to produce a continuous light signal only when said fuse link is in said on position and said fuse element is in its normal operating state, whereby said light source produces: a blinking light signal only when said fuse link is in said on position and said fuse element is in its malfunction response state; a continuous light signal only when said fuse link is in said on position, said fuse element is in its normal operating state, and said second circuit means is connected to the circuit ground; and no light output when said fuse link is in said off position or when said fuse link is in said on position and said fuse element is in its normal operating state and said second circuit means is not connected to the circuit ground.