Coupling device for circuit breaker

Disclosed is a coupling device for a circuit breaker. A third coupler formed as a curved surface is provided between a first coupler coupled to an outer handle assembly, and a second coupler coupled to an inner handle. Under such configuration, even if the inner handle and the outer handle assembly are not concentric with each other, the third coupler may transmit a rotational force applied to the first coupler to the second coupler in a direction perpendicular to a shaft direction of the second coupler, in a state where the third coupler is inclined from an upper surface of the circuit breaker body. As a result, a user's force to rotate the outer handle can be transmitted to the inner handle. This can prevent a malfunction of the circuit breaker, and thus can enhance reliability of the circuit breaker.

CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. §119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2013-0057370, filed on May 21, 2013, the contents of which is incorporated by reference herein in its entirety.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to a coupling device for a circuit breaker, and particularly, to a coupling device for a circuit breaker, which is provided between an outer handle assembly and an inner handle mechanism.

2. Background of the Disclosure

Generally, a circuit breaker is an apparatus capable of breaking an electric circuit in order to protect the electric circuit, when an overload or a short circuit has occurred. The circuit breaker has a function to switch on/off a load in order to connect/disconnect an electric circuit, when an abnormal current such as an overload and a short circuit has occurred. Switching on/off a load is performed by a mechanical operation.

A circuit breaker body is installed at an inner space of a distribution board. An outer handle assembly, which includes an outer handle and which is configured to control an on/off operation of the circuit breaker body, is installed outside the distribution board.

The outer handle assembly is a device installed at a distribution board panel, and manipulated by a user from outside so as to control the circuit breaker.

The outer handle assembly allows an operation of the circuit breaker to be smoothly transmitted to outside of the distribution board panel. On the contrary, the outer handle assembly allows a force applied from outside, to be smoothly transmitted to the circuit breaker.

FIG. 1is a disassembled perspective view of a circuit breaker and an outer handle assembly in accordance with the conventional art,FIG. 2is a longitudinal sectional view illustrating a connection part of the circuit breaker and the outer handle assembly ofFIG. 1, andFIG. 3is a longitudinal sectional view illustrating an assembled state of the circuit breaker and the outer handle assembly ofFIG. 2.

Referring toFIG. 1, the conventional circuit breaker includes a circuit breaker body1installed in a distribution board; an inner handle2rotatably installed at the circuit breaker body1, and configured to manipulate the circuit breaker; and an outer handle assembly10installed at a distribution board panel5so as to manipulate the inner handle2, and connected to the inner handle2.

The outer handle assembly10includes a cover11installed at the distribution board panel5; an outer handle12rotatably installed at the cover11, and manipulated by a user from outside of the distribution board panel5; and a shaft13connected to the outer handle12, and configured to transmit an operation of the outer handle12to the inner handle2.

A coupling assembly20, configured to transmit a rotational force of the outer handle assembly10to the inner handle2, is coupled between the outer handle assembly10and the inner handle2.

The coupling assembly20includes a first coupler21coupled to the shaft13; a second coupler22coupled to the inner handle2; a coupling spring23disposed between the first coupler21and the second coupler22, and configured to allow the first coupler21and the second coupler22to be positioned on the same shaft; and a coupling bolt24configured to couple the first coupler21and the second coupler22to each other.

A key portion21ais formed at a center of one side surface of the first coupler21. A key groove portion22a, configured to insert the key portion21aof the first coupler21and configured to transmit a rotational force applied to the first coupler21through the shaft13to the second coupler22, is formed at a center of one side surface of the second coupler22in correspondence to the key portion21aof the first coupler21.

If a user rotates the outer handle12in a state where the circuit breaker and the outer handle assembly10have been assembled to each other, a rotational force of the outer handle12is transmitted to the shaft13and the first coupler21. Then the rotational force is transmitted to the inner handle2by the key portion21aof the first coupler21and the key groove portion22aof the second coupler22, thereby being used to turn on/off the circuit breaker.

However, the conventional circuit breaker may have the following problems.

Considering an assembly tolerance which may occur between the outer handle assembly10and the inner handle2, it is required to have a gap between the key portion21aof the first coupler21and the key groove portion22aof the second coupler22. However, in a case where the outer handle assembly10is not concentric with the inner handle2, the first coupler21and the second coupler22of the coupling assembly10are not concentric with each other as shown inFIG. 3. This may cause the key portion21to be partially detached from the key groove portion22a. As a result, a rotational force of the outer handle assembly10may not be precisely transmitted to the inner handle2. This may lower reliability of the circuit breaker.

SUMMARY OF THE DISCLOSURE

Therefore, an aspect of the detailed description is to provide a coupling device for a circuit breaker, capable of precisely transmitting a rotational force of an outer handle assembly to an inner handle, even if the outer handle assembly and the inner handle are not concentric with each other.

To achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a coupling device for a circuit breaker, comprising: an outer handle assembly installed outside a distribution board having a circuit breaker body; an inner handle rotatably installed at the circuit breaker body, and configured to manipulate a circuit breaker; and a coupling assembly installed between the outer handle assembly and the inner handle, and configured to transmit a rotational force of the outer handle assembly to the inner handle, wherein the coupling assembly includes a first coupler coupled to the outer handle assembly; a second coupler coupled to the inner handle, and restricted by the first coupler in a shaft direction; and a third coupler coupled between the first coupler and the second coupler, and configured to transmit a rotational force applied to the first coupler to the second coupler.

Even if the inner handle and the outer handle assembly are not concentric with each other, the third coupler may transmit a rotational force applied to the first coupler to the second coupler in a direction perpendicular to a shaft direction of the second coupler, in a state where the third coupler is inclined from an upper surface of the circuit breaker body. As a result, a user's force to rotate the outer handle can be transmitted to the inner handle. This can prevent a malfunction of the circuit breaker, and thus can enhance reliability of the circuit breaker.

One or more first coupling protrusions, which protrude from the outer handle assembly in a shaft direction, may be formed at the first coupler. One or more second coupling protrusions, which protrude from the outer handle assembly in a shaft direction in correspondence to the first coupling protrusions, may be formed at the second coupler. The third coupler may be inserted between the first coupling protrusion and the second coupling protrusion.

An overlapped length between the first coupling protrusion and the second coupling protrusion in a shaft direction may be longer than a contact length between the first coupling protrusion or the second coupling protrusion and the third coupler in a shaft direction.

The third coupler may include: a body portion provided at an inner side of an inner circumferential surface of the first coupling protrusion and the second coupling protrusion; and a plurality of sliding protrusions radially protruding from an outer circumferential surface of the body portion, each sliding protrusion disposed between a side surface of the first coupling protrusion in a circumferential direction and a side surface of the second coupling protrusion in a circumferential direction, and configured to transmit a rotational force applied to the first coupler to the second coupler, wherein two side surfaces of the sliding protrusion in a circumferential direction, which contact the side surface of the first coupling protrusion in a circumferential direction and the side surface of the second coupling protrusion in a circumferential direction, are formed as curved surfaces.

The two side surfaces of the sliding protrusion in a circumferential direction may be formed in an oval shape having a long axis and a short axis.

A coupling spring, configured as a compression coil spring, may be provided between the first coupler and the second coupler. The coupling spring may be inserted into the third coupler.

A height of the sliding protrusion in a shaft direction may be higher than that of the first coupling protrusion or the second coupling protrusion in a shaft direction.

The two side surfaces of the sliding protrusion in a circumferential direction may be formed to point-contact the first coupling protrusion and the second coupling protrusion in a radius direction.

The side surface of the first coupling protrusion or the second coupling protrusion in a circumferential direction, which contacts the side surface of the sliding protrusion in a circumferential direction, may be formed to have a curved surface.

DETAILED DESCRIPTION OF THE DISCLOSURE

Hereinafter, a coupling device for a circuit breaker according to the present invention will be explained in more detail with reference to the attached drawings.

FIG. 4is a disassembled perspective view of a circuit breaker and an outer handle assembly according to the present invention.FIG. 5is a disassembled perspective view of a coupling assembly of the circuit breaker ofFIG. 4.FIG. 6is a longitudinal sectional view illustrating an assembled state of a coupling assembly in a case where an inner handle and an outer handle assembly ofFIG. 5are concentric with each other. AndFIG. 7is a longitudinal sectional view illustrating an assembled state of a coupling assembly in a case where an inner handle and an outer handle assembly ofFIG. 5are not concentric with each other.

As shown, in a circuit breaker having a coupling device according to the present invention, a circuit breaker body1configured to selectively break an electric circuit may be installed in a distribution board. An inner handle2, configured to manipulate the circuit breaker, may be installed on an upper surface of the circuit breaker body1. An outer handle assembly10, configured to manipulate the inner handle2from outside, may be installed at a distribution board panel5.

The outer handle assembly10may include a cover11installed at the distribution board panel5; an outer handle12rotatably installed at the cover11, and manipulated by a user from outside of the distribution board panel5; and a shaft13connected to the outer handle12, and configured to transmit an operation of the outer handle12to the inner handle2.

A coupling assembly100, configured to transmit a rotational force of the outer handle assembly10to the inner handle2, may be coupled between the outer handle assembly10and the inner handle2.

The coupling assembly100may include a first coupler110coupled to the shaft13; a second coupler120coupled to the inner handle2; a third coupler130provided between the first coupler110and the second coupler120, and configured to transmit a rotational force applied to the first coupler110to the second coupler120; a coupling spring140inserted into the third coupler130, and configured to allow the first coupler110and the second coupler120to be positioned on the same shaft as two ends thereof are supported at the first coupler110and the second coupler120; and a coupling bolt150configured to couple the first coupler110and the second coupler120to each other.

Coupling holes111and121may be penetratingly-formed at the first coupler110and the second coupler120in a shaft direction, respectively, so that a coupling bolt150can be inserted thereinto.

The inner handle2and the outer handle assembly10may not be concentrically assembled to each other. Accordingly, an inner diameter of the coupling holes111and121may be formed to be larger than an outer diameter of the coupling bolt150, so that the first coupler110and the second coupler120can be restricted by the coupling bolt150with a gap therebetween, the gap large enough for the first coupler110and the second coupler120not to be detached from each other in a shaft direction.

A plurality of coupling protrusions (hereinafter, will be referred to as first coupling protrusions)112may be formed at an edge of one side surface of the first coupler110in a circumferential direction with a constant gap therebetween. A plurality of coupling protrusions (hereinafter, will be referred to as second coupling protrusions)122may be formed at an edge of one side surface of the second coupler120in a circumferential direction with a constant gap therebetween. The second coupling protrusions122are formed in correspondence to the first coupling protrusions112, and are configured to transmit a rotational force applied to the first coupler110through the shaft13to the second coupler120, by being engaged with the first coupling protrusions112.

As shown inFIG. 6, the first coupling protrusion112and the second coupling protrusion122may be formed to have a height high enough for them to overlap each other. The first coupling protrusions112may be formed in a circumferential direction with a constant gap therebetween, and the second coupling protrusions122may be formed in a circumferential direction with a constant gap therebetween. Sliding protrusions132of the third coupler130to be explained later are inserted between the first coupling protrusions112and the second coupling protrusions122. A side surface112aof the first coupling protrusion112in a circumferential direction may contact one side surface132aof the sliding protrusion132in a circumferential direction. A side surface122aof the second coupling protrusion122in a circumferential direction may contact another side surface132bof the sliding protrusion132in a circumferential direction.

The third coupler130may be provided with a body portion131for inserting the coupling spring140thereinto. The sliding protrusions132, configured to transmit a rotational force applied to the first coupler110to the second coupler120, may be formed on an outer circumferential surface of the body portion131. In this case, the sliding protrusion132may be inserted into a space between the side surface112aof the first coupling protrusion112in a circumferential direction, and the side surface122aof the second coupling protrusion122in a circumferential direction. The sliding protrusions132may be radially protruding from an outer circumferential surface of the body portion131in a circumferential direction, with a constant gap therebetween.

The body portion131may be formed in a ring shape, so that the coupling spring140can be inserted thereinto. Preferably, the two side surfaces132aof the sliding protrusion132in a circumferential direction are formed to have an oval shape. More concretely, the two side surfaces132aof the sliding protrusion132of the third coupler130in a circumferential direction are preferably formed to always point-contact the first coupling protrusion112of the first coupler110and the second coupling protrusion122of the second coupler120. Under such configuration, even if the first coupler110and the second coupler120are not concentric with each other as shown inFIG. 7, the third coupler130has the same inclination angle as the first coupler110. Accordingly, the third coupler130can transmit a rotational force applied to the first coupler110to the second coupler120in a direction perpendicular to a shaft direction of the second coupler.

As shown inFIG. 6, an overlapped length between the first coupling protrusion112of the first coupler110and the second coupling protrusion122of the second coupler120in a shaft direction is preferably longer than a contact length between the first coupling protrusion112or the second coupling protrusion122and the sliding protrusion132of the third coupler130in a circumferential direction in a shaft direction. That is, as shown inFIG. 6, a length (H1) of the sliding protrusion132of the third coupler130in a shaft direction may be longer than a length (H2) of the first coupling protrusion112and the second coupling protrusion122in a shaft direction.

The same components as those of the conventional art are provided with the same reference numerals.

The coupling device for a circuit breaker according to the present invention may have the following effects.

If a user rotates the outer handle4in a state where the inner handle2and the outer handle assembly10have been assembled to each other, a rotational force of the outer handle4is transmitted to the shaft13and the first coupler110. Then the rotational force is transmitted to the inner handle2via the first coupling protrusions112of the first coupler110, the sliding protrusions132of the third coupler130, and the second coupling protrusions122of the second coupler120, thereby being used to turn on/off the circuit breaker.

As shown inFIG. 6, in a case where the inner handle2and the outer handle assembly10are concentric with each other, the sliding protrusions132of the third coupler130transmit a rotational force applied to the first coupling protrusions112of the first coupler110, to the second coupling protrusions122of the second coupler120, in a direction perpendicular to a shaft direction of the second coupler. Accordingly, a user's force to rotate the outer handle can be transmitted to the inner handle2.

On the other hand, as shown inFIG. 7, even in a case where the inner handle2and the outer handle assembly10are not concentric with each other, one side surface112aof the first coupling protrusion112of the first coupler110in a circumferential direction point-contacts one side surface132aof the sliding protrusion132of the third coupler130in a circumferential direction. At the same time, one side surface122aof the second coupling protrusion122of the second coupler120in a circumferential direction point-contacts another side surface132bof the sliding protrusion132of the third coupler130in a circumferential direction. Accordingly, the third coupler130transmits a rotational force applied to the first coupler110to the second coupler120in a direction perpendicular to a shaft direction of the second coupler120, in a state where the third coupler130is inclined from an upper surface of the circuit breaker body. As a result, a user's force to rotate the outer handle12can be transmitted to the inner handle2.

A coupling assembly according to another embodiment of the present invention will be explained as follows.

That is, in the aforementioned embodiment, two side surfaces of the sliding protrusion of the third coupler are curved surfaces of an oval shape, whereas a side surface of the first coupling protrusion and a side surface of the second coupling protrusion which contact the two side surfaces of the sliding protrusion are planar surfaces. However, in this embodiment, as shown inFIG. 8, two side surfaces of the sliding protrusion of the third coupler in a circumferential direction are planar surfaces, whereas a side surface of the first coupling protrusion and a side surface of the second coupling protrusion which contact the two side surfaces of the sliding protrusion are curved surfaces.

Even in a case where the inner handle2and the outer handle assembly10are not concentric with each other, the first coupling protrusion112of the first coupler110point-contacts the sliding protrusion132of the third coupler130, and the second coupling protrusion122of the second coupler120point-contacts the sliding protrusion132of the third coupler130. The third coupler130may transmit a rotational force applied to the first coupler110to the second coupler120in a direction perpendicular to a shaft direction of the second coupler, in a state where the third coupler is inclined from an upper surface of the circuit breaker body. As a result, a user's force to rotate the outer handle12can be transmitted to the inner handle2.

Although not shown, even in a case where two side surfaces of the sliding protrusion of the third coupler are curved surfaces, and a side surface of the first coupling protrusion and a side surface of the second coupling protrusion which contact the two side surfaces of the sliding protrusion are also curved surfaces, the aforementioned effects can be obtained.

The aforementioned curved surface may have a circular shape as well as an oval shape.

In the coupling device for a circuit breaker according to the present invention, even if the inner handle and the outer handle assembly are not concentric with each other, the third coupler may transmit a rotational force applied to the first coupler to the second coupler in a direction perpendicular to a shaft direction of the second coupler, in a state where the third coupler is inclined from an upper surface of the circuit breaker body. As a result, a user's force to rotate the outer handle can be transmitted to the inner handle. This can prevent a malfunction of the circuit breaker, and thus can enhance reliability of the circuit breaker.