Patent Application
20130168213
The present application claims priority under 35 U.S.C. ยง119(a) to Korean Patent Application No. 10-2011-0147818, filed on Dec. 30, 2011, the contents of which are hereby incorporated by reference herein in their entirety.
1. Field of the Invention
The present invention relates to a circuit breaker and, more particularly, to a circuit breaker having a mechanical trip mechanism enabling a circuit breaker to perform an emergency manual trip operation.
2. Description of the Related Art
In general, a circuit breaker is a device for selectively turning on or off or breaking a line between a power side and a load side in the occurrence of an overload, a short-circuit fault, an electric leakage, or an electric shock.
In the related art circuit breaker, a user may press an OFF button 6 to manually perform a breaking operation, or when a fault current is detected, a circuit is automatically broken (a trip operation) to change the circuit breaker into a broken state.
In the case of the manual breaking operation, as illustrated in
In case of an automatic trip for interrupting a fault current in a circuit, an overcurrent trip relay installed outside an opening and closing mechanism 10 detects a fault current and transmits a trip control signal to an actuator, and the OFF shaft 4 is rotated in a clockwise direction by the actuator to start a breaking operation.
No matter whether it is manual or automatic trip, when the OFF shaft 4 is rotated in the clockwise direction, a trip latch 7 is rotated in a clockwise direction so as to be released from a restrained state with respect to a main link 9 (or the trip latch 7 is rotated in a clockwise direction so as to be unlocked from the main link 9), and a breaking spring 2, which has been stretched in the closed state to charge elastic energy, discharges the elastic energy to pull a connection shaft 21 connected to one end portion of the breaking spring 2 to rotate it in a counterclockwise direction. Accordingly, the opening and closing shaft 20 is also rotated in the counterclockwise direction and the connection link is moved to the right in
In relation to the trip operation,
However, although the user presses the OFF button 6 so the OFF shaft 4 is rotated, if the trip latch 7 is not rotated in the clockwise direction and is not released from the main link 9, a trip operation of the circuit breaker is not actually performed, so a fault current cannot be interrupted.
Similarly, in the occurrence of an abnormal current, although the OFF shaft 4 is operated according to an automatic trip operation, if the trip latch 7 is not rotated in the clockwise direction due to several abnormal factors, the trip latch 7 is not released from the main link 9, resulting in failure of interrupting the fault current.
Thus, a circuit breaker that may reliably be changed into a broken state to cut off an electrical connection in the occurrence of an abnormal state in which the circuit breaker is not tripped in a manual manner or an auto-trip manner is required.
An aspect of the present invention provides a circuit breaker having a mechanical trip mechanism for allowing for an emergency manual trip operation in an abnormal state in which the circuit breaker is not tripped in a manual manner or auto-trip manner.
Another aspect of the present invention provides a
According to an aspect of the present invention, there is provided a circuit breaker including: a fixed contactor connected to a circuit; a movable contactor movable to a closed state in which the movable contactor is in contact with the fixed contactor and a broken state in which the movable contactor is separated from the fixed contactor, an opening and closing mechanism configured to convert a rotational motion of a plurality of links and a rotational shaft to enable the movable contactor to be brought into contact with the fixed contactor or separated therefrom; a trip latch locked to or unlocked from a main link provided in the opening and closing mechanism; and an OFF button configured to rotate the trip latch to unlock the trip latch from the main link when manually pressed.
According to an embodiment of the present invention, when an auto-trip operation is not possibly performed in an abnormal state, mechanical trip mechanism performs an emergency manual trip operation to reliably change the circuit breaker into a broken state. Also, a condition in which the circuit breaker is not changed into a broken state by a manual operation is basically prevented, thus obtaining stability and reliability.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
Hereinafter, a mechanical trip mechanism of a circuit breaker according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
The circuit breaker includes an opening and closing mechanism 10 converting a rotational motion of a plurality of links and a rotational shaft to compress a closing spring 1 and generating driving force according to elastic restoring force of the closing spring 1, an opening and closing shaft 20 connected to an opening and closing mechanism and transmitting driving force generated by the opening and closing mechanism, a fixed contactor 40, a movable contactor 30 movable to a closed state in which the movable contactor 30 is in contact with the fixed contactor 40 and a broken state in which the movable contactor 30 is separated from the fixed contactor, an overcurrent trip relay (not shown) outputting a control signal to trip the opening and closing mechanism 10 when an abnormal current is generated, and an actuator (not shown) for tripping the opening and closing mechanism by a control signal from the overcurrent trip relay. The configuration of the circuit breaker is the same as that of the related art circuit breaker, so a detailed configuration and operation thereof will be omitted.
In a closed state of the circuit breaker, the main link 9 and the trip latch 7 are locked, a contact load is applied to a contact portion 97 of the main link 9 and the trip latch roller 73, and a locked state of the main link 9 and the trip latch roller 73 is maintained. When the circuit breaker is changed from a closed state to a broken state, the trip latch roller 73 is released from a state of being locked to the main link 9, a contact load is changed into an open load, and the open load is applied to the trip latch roller 73 by the main link 9.
When the circuit breaker normally operates, the OFF shaft 4 in an upper portion of the opening and closing mechanism 10 is rotated in a clockwise direction according to a manual and auto-trip operation, and accordingly, the trip lath 7 is rotated in a clockwise direction based on the rotational shaft 72 of the trip latch 7, and thus, the trip latch roller 73 locked in the main link 9 is released. Thus, in order for the circuit breaker to be actually changed from the closed state to the broken state, the trip latch 7 should be rotated in the clockwise direction based on the rotational shaft 72 of the trip latch 7 to release the trip latch roller 73 locked in the main link 9.
Hereinafter, the mechanical trip mechanism of the circuit breaker according to an embodiment of the present invention will be described in detail.
First, a configuration of the mechanical trip mechanism of the circuit breaker according to an embodiment of the present invention will be described.
In
As illustrated in
As illustrated in
The protrusion member 75 may be integrally formed with the trip latch 7 or may be separately formed and coupled to the trip latch 7. When the protrusion member 75 is separately formed, the protrusion member 75 may be coupled to the trip latch 7 according to a certain method known in the art. For example, the protrusion member 75 may be coupled to the trip latch 7 according to a coupling method such as welding, caulking coupling, bolt fastening, or the like.
Referring to
In the case of the second embodiment illustrated in
Hereinafter, an operation of the mechanical trip mechanism in the circuit breaker according to an embodiment of the present invention will be described.
In the circuit breaker according to an embodiment of the present invention, when the user manually presses the OFF button 6 provided on a front portion of the circuit breaker, the OFF button rotates based on the button support pin 64. At the same time, the lever member 65 of the OFF button is rotated. Thus, as shown in
Also, in the second embodiment, similarly, when the OFF button 6 is operated manually, the second lever unit 65b of the lever member 65 provided in the OFF button 6 directly pressurizes the edge portion 74 of the trip latch 7, and thus, the trip latch 7 is rotated in the clockwise direction. As the trip latch 7 is rotated in the clockwise direction, the trip latch roller 73 locked in the main link 9 is released, thus executing a trip operation of the circuit beaker.
As described above, in the circuit breaker according to an embodiment of the present invention, since the OFF button 6 includes the mechanical trip mechanism as an emergency manual trip means, the trip latch 7 can be directly rotated in the clockwise direction in association with an operation of the OFF button 6 to release the trip latch roller 73 locked in the main link 9. Thus, even when an auto-trip operation is not possibly performed in an abnormal situation, the circuit breaker can be change into a broken state through the emergency manual trip operation. In addition, a situation in which the circuit breaker is not changed into a broken state through a manual operation is fundamentally prevented.
As the present invention may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2011-0147818 | Dec 2011 | KR | national |
