Arc extinguishing unit of molded case circuit breaker

Patent metadata

Field	Value
Publication number	US-10840047-B2
Application number	US-201916657324-A
Country	US
Kind code	B2
Filing date	Oct 18, 2019
Priority date	Mar 29, 2019
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

The present disclosure relates to an arc extinguishing unit of a molded case circuit breaker with a barrier provided between a fixed contact and a movable contact when a circuit is cut off. The arc extinguishing unit includes fixed contacts fixed to part of a base assembly case; movable contacts that contact or are separated from the fixed contacts; and an arc extinguishing part that extinguishes an arc generated when the movable contacts are separated from the fixed contacts. The arc extinguishing part includes a pair of side plates; multiple grids installed at a fixed interval between the side plates; and arc barriers each rotatably installed on the side plates, and configured to open between the movable contacts and the fixed contacts by being rotated when a current flows on the circuit, and to close between the movable contacts and the fixed contacts when the current is cut off.

First claim

What is claimed is:

1. An arc extinguishing unit of a molded case circuit breaker, comprising:
fixed contacts fixed to part of a base assembly case;
movable contacts that come in contact with or are separated from the fixed contacts; and
an arc extinguishing part configured to extinguish an arc generated when the movable contacts are separated from the fixed contacts,
wherein the arc extinguishing part includes:
a pair of side plates installed on the base assembly case;
multiple grids installed at a fixed interval between the pair of side plates; and
arc barriers each rotatably installed on the pair of side plates and configured to open between the movable contacts and the fixed contacts by being rotated by the movable contacts when a current flows on the circuit, while in a cut-off state, to close between the movable contacts and the fixed contacts.

2. The arc extinguishing unit of claim 1 , wherein part of the side plates is provided with a mounting part to which the arc barrier is installed, and the mounting part includes an arc-shaped recess in which the barrier is rotatably installed.

3. The arc extinguishing unit of claim 2 , further comprising an elastic member providing an elastic force to the arc barrier, and
wherein the mounting part includes a mounting groove in which the elastic member is installed.

4. The arc extinguishing unit of claim 2 , wherein the lower part of the mounting part is incised to provide an actuation part for the arc barrier to operate.

5. The arc extinguishing unit of claim 3 , wherein the arc barrier includes:
a shaft part formed in a cylindrical shape and fitted into the recess, and configured to function as a rotary shaft;
a plate part interposed between the movable contacts and the fixed contacts; and
a connection part that connects the shaft part and the plate part.

6. The arc extinguishing unit of claim 5 , wherein an incision part is provided at a midsection of the recess, in which the connection part is operated.

7. The arc extinguishing unit of claim 6 , wherein the plate part includes:
a shield plate extended in the opposite direction from the shaft part based on the connection part; and
a latch plate extended in a direction orthogonal to the shield plate.

8. The arc extinguishing unit of claim 7 , wherein the arc barrier includes:
a first arc barrier provided to one of the pair of side plates (first side plate); and
a second arc barrier provided to the other (second side plate) of the pair of side plates, and
wherein the shield plate of the first arc barrier has a shorter length than the shield plate of the second arc barrier, and
wherein, in the cut-off state, the shield plate of the first arc barrier is placed higher than the shield plate of the second arc barrier.

9. The arc extinguishing unit of claim 8 , wherein, when the circuit is in an on-state, the arc barrier is interposed between the movable contacts and the fixed contacts, while in an on-state, the movable contacts push and rotate one of the first arc barrier and the second arc barrier downwards, and the other is pushed by the one arc barrier, and
wherein, when the circuit is in an off-state, the first arc barrier and the second arc barrier are rotated upward by the resilience of the elastic member as the movable contacts are released.

Assignees

• Lsis Co Ltd

Inventors

• Oh Kihwan
• Oh Kyunghwan
• Kim Younghwan

Classifications

• H01H73/18 Primary

  Means for extinguishing or suppressing arc {(magnet coil acting as blow-out device H01H71/38)} · CPC title

• H01H73/04

  Contacts · CPC title

• H01H9/34

  Stationary parts for restricting or subdividing the arc, e.g. barrier plate · CPC title

• H01H9/362

  Mounting of plates in arc chamber · CPC title

• H01H9/32

  Insulating body insertable between contacts · CPC title