Circuit breaker with instant trip mechanism

Patent metadata

Field	Value
Publication number	US-10672579-B2
Application number	US-201815914738-A
Country	US
Kind code	B2
Filing date	Mar 7, 2018
Priority date	Mar 9, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

The circuit breaker according to the present invention comprises: a pair of contact mechanisms for switching a pair of circuits; a switching mechanism for driving the pair of contact mechanism to a circuit opening position or a circuit closing position; a trip bar rotatable to a first position for latching the switching mechanism or to a second position for releasing the switching mechanism; and an instant trip mechanism for pressing the trip bar to rotate to the second position, wherein the instant trip mechanism comprises a pair of armature assemblies and movable to a position for pressing the trip bar to rotate to the second position; and a pair of electromagnets provided to face the pair of armature assemblies and applies a magnetic attractive force to the pair of armature assemblies in response to the fault current on the circuit requiring an instant trip.

First claim

What is claimed is:

1. A circuit breaker comprising:
a pair of contact mechanisms that are provided to correspond to a pair of circuits corresponding to a pair of poles and switch the pair of circuits;
a switching mechanism that is commonly provided in the pair of contact mechanisms and drives the pair of contact mechanisms to a circuit opening position or a circuit closing position;
a trip bar that is rotatable to a first position for latching the switching mechanism in the circuit closing position or to a second position for releasing the switching mechanism to operate to the circuit opening position; and
an instant trip mechanism that presses the trip bar to rotate to the second position in response to a fault current on the circuit requiring an instant trip,
wherein the instant trip mechanism comprises:
a pair of armature assemblies that are provided to correspond to the pair of poles and movable to a position for pressing the trip bar to rotate to the second position; and
a pair of electromagnets that are provided to face the pair of armature assemblies and apply a magnetic attractive force to the pair of armature assemblies in response to the fault current on the circuit requiring an instant trip,

wherein each of the pair of electromagnets comprises a cutout groove portion that is provided at a side surface corner or an upper surface for guiding a conductive wire electrically connecting a movable contact arm of a corresponding contact mechanism among the pair of contact mechanisms and a terminal.

2. The circuit breaker of claim 1 , wherein each of the pair of armature assemblies comprises:
a first armature portion that is pivotally supported to be rotatable and has a cam surface portion for pressing the trip bar;
a second armature portion that is coupled to the first armature so as to be rotatable together and disposed to face the corresponding electromagnet; and
a coupling portion that couples the first armature portion and the second armature portion.

3. The circuit breaker of claim 2 , wherein the second armature portion is installed to at least partially overlap the facing electromagnet in order to increase a mutually facing area.

4. The circuit breaker of claim 2 , further comprising:
a pair of bimetals that are connected to the pair of circuits,
wherein the second armature portion is installed to surround each of the bimetal together with the facing electromagnet to form a closed loop of a magnetic path together with the corresponding electromagnet.

5. The circuit breaker of claim 2 , wherein the second armature portion comprises a base portion that is disposed to face the corresponding electromagnet; and
at least one wing portion extending from the base portion toward the corresponding electromagnet.

6. The circuit breaker of claim 5 , wherein mutually facing surfaces of the wing portion of the second armature portion and the electromagnet are formed as inclined surfaces to increase a mutually facing area.

7. The circuit breaker of claim 2 , wherein the electromagnet comprises:
a first electromagnet portion that is plate-shaped and disposed to face the corresponding second armature portion; and
a pair of second electromagnet portions that are wing-shaped and extend from the first electromagnet portion toward the corresponding second armature portion.

8. The circuit breaker of claim 7 , wherein a wing portion of the second armature portion comprises a stepped portion formed to have a shape corresponding to an end surface of the second electromagnet portion in order to increase the mutually facing area.

9. The circuit breaker of claim 2 , wherein the electromagnet is configured as an L-shaped conductive metal plate having a vertical plate portion and a horizontal plate portion, and
wherein the second armature portion comprises:
a base plate installed to face the vertical plate portion of the corresponding electromagnet; and
at least one wing portion extending from the base plate portion toward the corresponding electromagnet.

10. The circuit breaker of claim 2 , wherein the electromagnet comprises a first base plane portion facing the second armature portion and a first wing portion extending from the first base plane portion toward the second armature portion,
wherein the second armature portion comprises a second base plane portion disposed to face the first base plane portion of the electromagnet and a second wing portion extending from the second base plane portion toward the electromagnet and meshed with the electromagnet,
wherein any one of the first wing portion and the second wing portion comprises at least one concave portion formed to be concave on a surface facing the other of the first wing portion or the second wing portion, and
wherein the other of the first wing portion and the second wing portion comprises at least one convex portion formed to be convex to correspond to the concave portion.

11. The circuit breaker of claim 2 , wherein the electromagnet comprises a first base plane portion facing the second armature portion and a first wing portion extending from the first base plane portion toward the second armature portion,
wherein the second armature portion comprises a second base plane portion disposed to face the first base plane portion of the electromagnet and a second wing portion extending from the second base plane portion toward the electromagnet and meshed with the electromagnet, and
wherein the first wing portion and the second wing portion have a plurality of teeth meshed with each other.

12. The circuit breaker of claim 2 , wherein the electromagnet comprises a first base plane portion facing the second armature portion and a first wing portion extending from the first based plane portion toward the second armature portion,
wherein the second armature portion comprises a second base plane portion disposed to face the first base plane portion of the electromagnet and a second wing portion extending from the second base plane portion toward the electromagnet and meshed with the electromagnet, and
wherein the first wing portion and the second wing portion have meander surfaces or a plurality of step surfaces meshed with each other.

13. The circuit breaker of claim 10 , wherein the convex portion and the concave portion are formed in any one of a polygonal shape or a semicircular shape.

Assignees

• Lsis Co Ltd

Inventors

• Woo Sanghyun
• Lim Jeongjae
• Ham Seungjin

Classifications

• H01H71/2409

  combined with an electromagnetic current limiting mechanism · CPC title

• H01H83/144

  with differential transformer · CPC title

• H01H2071/249

  with part of the magnetic circuit being in the normal current path in the circuit breaker, e.g. yoke, fixed contact and arc-runner are made out of one single conductive element · CPC title

• H01H71/405

  in which a bimetal forms the inductor for the electromagnetic mechanism · CPC title

• H01H71/524

  the contact arm being pivoted on handle and mechanism spring acting between cradle and contact arm · CPC title