US 2009/0040004 A1Published application

Thermal overload trip apparatus and method for adjusting trip sensitivity thereof

AssigneeLS Industrial Systems Co., Ltd.

InventorKyung-Ku LEE

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Abstract

A thermal overload trip apparatus capable of minimizing inferiority caused by a variation when manufacturing an adjusting means and simply adjusting sensitivity by duplicating the means for adjusting a sensitivity of a trip operation current, comprising, a trip mechanism driven to a trip position by a driving force from a shifter mechanism on occurrence of an overload on a circuit; a release lever mechanism for driving the trip mechanism to the trip position by pressing it when there is the driving force from the shifter mechanism or for releasing the trip mechanism when there is no driving force, on occurrence of the overload on the circuit; an adjusting lever for operating the release lever mechanism to be horizontally moved by rotation; an adjusting knob having an upper surface having a setting groove and a lower portion having a cam portion; and a means independently adjusting the sensitivity of the trip operation current regardless of manipulating of the adjusting knob.

Claims8

Dependent claims

A thermal overload trip apparatus, in the thermal overload trip apparatus having bimetals for providing mechanical displacement according to an overload on 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 on 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 of trip operation current regardless of manipulating of the adjusting knob.

3 more elements

A method for adjusting a trip sensitivity of a thermal overload trip apparatus, in the thermal overload trip apparatus comprising bimetals for providing a mechanical displacement according to an overload on a circuit, a shifter mechanism for transferring the mechanical displacement of the bimetals as a driving force, a trip mechanism driven to a trip position by the driving force from the shifter mechanism when the overload is generated on the circuit, 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 on 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 adjusting screw connected to the adjusting lever to rotate the adjusting lever so as to independently adjust sensitivity of trip operation current regardless of manipulating of the adjusting knob, the method comprising:

setting an initial position of the adjusting knob;
assembling components forming the thermal overload trip apparatus;
conducting a predetermined over current to the thermal overload trip apparatus assembled in the assembling step for a predetermined time;
and
adjusting the adjusting screw by rotating the adjusting screw until a trip operation occurs under a state that the adjusting knob is maintained at the initially set position;

2 more elements

Dependencies are inferred from the claim text.