Magnetic trip device for circuit breaker

Patent metadata

Field	Value
Publication number	US-10460897-B2
Application number	US-201715855619-A
Country	US
Kind code	B2
Filing date	Dec 27, 2017
Priority date	Jan 5, 2017
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

The present disclosure relates to a magnetic trip device for a circuit breaker capable of maintaining fault information indication until a user removes the cause of an accident subsequent to a trip operation and resets the magnetic trip device. The device comprises an actuator coil part having a plunger; an output plate; a micro switch outputting an electrical signal indicating a state of the circuit breaker; a switch driving lever mechanism rotating to press and releasing the micro switch; a driving lever bias spring elastically biasing the switch driving lever mechanism to rotate; an automatic reset mechanism pressing the plunger to a retracted position; and a driving lever latch rotating to a restraining position for preventing the switch driving lever mechanism from rotating to a first position, and a release position allowing the switch driving lever mechanism-to rotate to the first position.

First claim

What is claimed is:

1. A magnetic trip device for a circuit breaker, comprising:
an actuator coil part that has a plunger configured to move to an advanced position or a retracted position according to the magnetization or demagnetization of a coil;
an output plate that is rotatably provided on the movement path of the plunger to rotate in a first direction by the pressing of the plunger;
a micro switch that has an operation lever portion protruding outwardly and is configured to output an electrical signal indicating a state of the circuit breaker according to whether or not the operation lever portion is pressed;
a switch driving lever mechanism that is configured to rotate to a first position for pressing the operation lever portion or a second position for releasing the operation lever portion so as to open or close the micro switch;
a driving lever bias spring that is provided at a predetermined position to elastically bias the switch driving lever mechanism to rotate to the second position;
an automatic reset mechanism that is configured to press the plunger of the actuator coil part to the retracted position in connection with a main switching shaft of the circuit breaker subsequent to a trip operation; and
a driving lever latch that is configured to rotate to a restraining position for preventing the switch driving lever mechanism from rotating to the first position so as to allow the micro switch to maintain a trip indicating state subsequent to a trip operation even when the plunger is moved to the retracted position by the automatic reset mechanism, and a release position for allowing the switch driving lever mechanism to rotate to the first position, and the driving lever latch is provided adjacent to the switch driving lever mechanism.

2. The magnetic trip device of claim 1 , further comprising:
a manual reset lever that is provided at a position capable of pressing the driving lever latch and presses the driving lever latch to rotate to the release position while being moved by a manual operation force.

3. The magnetic trip device of claim 2 , wherein the driving lever latch comprises:
a rotating shaft portion;
a hook portion that extends from the rotating shaft portion toward the switch driving lever mechanism to restrain the switch driving lever mechanism; and
a release driving force receiving portion that extends from the rotating shaft portion to an opposite side of the hook portion to be brought contact with the manual reset lever,
wherein the manual reset lever comprises a pressing protrusion portion that is configured to press the release driving force receiving portion to rotate the driving lever latch to the release position.

4. The magnetic trip device of claim 3 , wherein a surface of the release driving force receiving portion facing the pressing protrusion portion is configured with an inclined surface.

5. The magnetic trip device of claim 3 , wherein a surface of the release driving force receiving portion facing the pressing protrusion portion is configured with a curved surface.

6. The magnetic trip device of claim 2 , further comprising a pair of guide members formed in a protruding manner on an inner wall surface of an enclosure of the magnetic trip device and formed in a predetermined length at a higher position and at a lower position than the manual reset lever respectively so as to guide the manual reset lever to horizontally move due to a manual operation force.

7. The magnetic trip device of claim 1 , wherein the switch driving lever mechanism comprises:
an arm that extends toward the operation lever portion of the micro switch and is rotatable to a first position for pressing the operation lever portion of the micro switch and a second position for releasing the operation lever portion; and
a switch driving lever that is capable of rotating the arm,
wherein the switch driving lever comprises:
a rotating shaft portion;
a first lever portion that extends from the rotating shaft portion toward the output plate and is rotatable according to the output plate;
an arm contact surface portion that contacts with the arm to transmit a driving force to the arm so as to rotate the arm to the first position or the second position; and
a third lever portion that extends upward from the rotating shaft portion to be restrained by the driving lever latch or released from the driving lever latch.

8. The magnetic trip device of claim 1 , further comprising a latch bias spring configured to apply an elastic force to the driving lever latch to rotate in one direction.

9. The magnetic trip device of claim 8 , wherein the latch bias spring is configured with a torsion spring.

10. The magnetic trip device of claim 1 , further comprising a return spring configured to apply an elastic force to the output plate to return to an initial position.

11. The magnetic trip device of claim 10 , wherein an elastic modulus of the return spring is larger than an elastic modulus of the driving lever bias spring.

Assignees

• Lsis Co Ltd

Inventors

• Lee Kyuho

Classifications

• H01H2071/467

  with history indication, e.g. of trip and/or kind of trip, number of short circuits etc. · CPC title

• H01H2071/042

  with different indications for different conditions, e.g. contact position, overload, short circuit or earth leakage · CPC title

• H01H73/12

  Means for indicating condition of the switch · CPC title

• H01H71/465 Primary

  Self-contained, easily replaceable microswitches · CPC title

• H01H9/167

  Circuits for remote indication · CPC title