MOLD CASED CIRCUIT BREAKER

Abstract

A mold cased circuit breaker is disclosed that enables a user to easily discern an actually connected state between stationary contactors and movable contactors and forcibly separates a connection therebetween if there arises electrical fault, wherein the circuit breaker comprises: a first isolation link hinged at a lower end thereof to a shaft unit and selectively engaged at an upper end thereof with a lateral surface of a lever; a second isolation link centrally formed with an oblong hole for accommodating a guide pin protruded on a side plate and linked at one end thereof to an upper end of the first isolation link; and an isolation lever adjacently positioned at one end thereof to the other end of the second isolation link, and so positioned at the other end thereof as to selectively engage with a nail, and rotatably mounted at the side plate to rotate the nail by way of operation of the second isolation link.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the present description and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the present disclosure.

FIG. 1 is a cross-sectional view illustrating a structure of the conventional mold cased circuit breaker.

FIG. 2 is a plan illustrating a tripped state of a mold cased circuit breaker according to the prior art.

FIG. 3 is a plan illustrating a reset state of a mold cased circuit breaker according to the prior art.

FIG. 4 is a plan illustrating a closed state of a mold cased circuit breaker according to the prior art.

FIGS. 5 and 6 illustrate plan where movable contactors and stationary contactors are closed engaged.

FIG. 7 is a perspective view of principal parts of a mold cased circuit breaker.

FIG. 8 is a front view illustrating a tripped state of a mold cased circuit breaker.

FIG. 9 is a front view illustrating a reset state of a mold cased circuit breaker.

FIG. 10 is a front view illustrating a closed state of a mold cased circuit breaker.

FIG. 11 is a front view illustrating an isolated state of a mold cased circuit breaker.

Claims

1. A mold cased circuit breaker comprising: a pair of stationary contactors respectively connected to a power source side and a load side within a base on a point symmetric alignment; a pair of side plates each spaced at a predetermined distance apart on the base with the stationary contactors being positioned therebetween; a lever secured at a top end thereof with a handle, rotatably mounted on the side plates and manipulated in a closed state, a tripped state and a reset state; a latch rotatably mounted at one end thereof on the side plates, and rotated by the lever if the lever moves to a reset condition; a latch holder rotatably mounted on the side plates and selectively restraining the other end of the latch; a nail rotatably mounted on the side plates, resiliently supported to the side plates and selectively restraining the latch holder; a shaft unit mounted with movable contactors selectively connected at both ends thereof to the stationary contactors by rotation, discretely arranged from the lever at a lower section of the lever, and rotatably mounted between the pair of the stationary contactors; an upper link hinged at an upper end thereof to the latch; a lower link hinged at an upper end thereof to a lower end of the upper link via a toggle pin, and hinged at a lower end thereof to the shaft unit; a main spring secured at an upper end thereof to an upper end of the lever and secured at a lower end thereof to the toggle pin; and contactor separation means separating the movable contactors from the stationary contactors by cooperating with the lever if the movable contactors and the stationary contactors are engaged.

2. The circuit breaker as claimed in claim 1, wherein the contactor separation means comprises: a first isolation link hinged at a lower end thereof to the shaft unit and selectively engaged at an upper end thereof with a lateral surface of the lever; a second isolation link centrally formed with an oblong hole for accommodating a guide pin protruded on the side plate and linked at one end thereof to an upper end of the first isolation link; and an isolation lever adjacently positioned at one end thereof to the other end of the second isolation link, and so positioned at the other end thereof as to selectively engage with the nail, and rotatably mounted at the side plates to rotate the nail by way of operation of the second isolation link.

3. The circuit breaker as claimed in claim 2, wherein the first isolation link is formed at an upper end of the first isolation link with a lug contacting a lateral surface of the lever when the lever is rotated to a reset position.

4. The circuit breaker as claimed in claim 2, wherein the shaft unit comprises: a disc rotatably mounted on the side plate; movable contactors laterally mounted at the disc and selectively engaged at both ends thereof with the pair of stationary contactors by rotation; and a pair of rods mounted relative to a rotation center of the disc by penetrating the disc and the movable contactors.

5. The circuit breaker as claimed in claim 4, wherein the pair of rods comprises: a first rod that comes adjacent to the handle if the handle is placed in a closed position; and a second rod symmetrically arranged relative to a rotation center of the first rod, wherein the lower link is pierced at a lower end thereof by the first rod, and the first isolation link is pierced at a lower end thereof by the second rod.

6. The circuit breaker as claimed in claim 2, wherein the latch holder restricts the other end of the latch when the latch is rotated downward at the other end by the lever.

7. The circuit breaker as claimed in claim 6, wherein the nail restricts the latch holder when the latch holder restrains the latch.

8. The circuit breaker as claimed in claim 6, wherein the nail releases the latch holder by rotation of the isolation lever.

9. The circuit breaker as claimed in claim 1, wherein a lever pin is mounted at a lower end of the lever for connecting the lever to the side plate, and the side plate is mounted with a latch pin for connecting one end of the latch and the side plates, and toggle pin is positioned between the lever pin and the latch pin when the lever is moved to a closed position.

10. The circuit breaker as claimed in claim 1, wherein the upper link is lopsidedly formed with a stopper toward the latch pin for preventing the upper link and the lower link from being positioned on a straight line and for supporting the upper link.