Patent ID: 7714692

Claim:
A thermal overload trip apparatus, having bimetals for providing mechanical displacement according to an overload in a circuit and a shifter mechanism for transferring the mechanical displacement of the bimetals as a driving force, the apparatus comprising: a trip mechanism driven to a trip position by the driving force from the shifter mechanism when the overload is generated on the circuit; a release lever mechanism having one portion rotatably installed to contact the shifter mechanism so as to receive the driving force from the shifter mechanism and another portion installed to contact the trip mechanism, so that the release lever mechanism presses the trip mechanism and drive the trip mechanism to the trip position when there is the driving force from the shifter mechanism, or the release lever mechanism releases the trip mechanism when there is no driving force from the shifter mechanism, when the overload is generated in the circuit; an adjusting lever having a portion for rotatably supporting the release lever mechanism so as to operate the release lever mechanism to be horizontally moved by the rotation; an adjusting knob having an upper surface provided with a setting groove and a lower portion provided with a cam portion so as to set a trip operation position according to a rated current; and a means connected to the adjusting lever to rotate the adjusting lever so as to independently adjust a sensitivity to the trip operation current regardless of manipulation of the adjusting knob.