Patent Grant
7843290
The present disclosure relates to subject matter contained in priority Korean Applications No. 10-2007-0080900, 10-2007-0080902 and 10-2007-0080903, filed on Aug. 10, 2007, which are herein expressly incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a molded case circuit breaker, and more particularly, to a molded case circuit breaker having a contact on mechanism.
2. Description of the Background Art
In general, a molded case circuit breaker is a protective electrical device to protect an electrical load equipment and an electrical line from an overload or overcurrent which may occur in an electrical circuit, by automatically breaking the electrical circuit. In such molded case circuit breaker, a position of a handle, which is manually manipulated by a user, may be divided into a mechanism release position by a switching mechanism (i.e., a TRIP position), a circuit opening position (i.e., an OFF position, in other words RESET position), and a circuit closing position (i.e., an ON position). When a fault current (or an abnormal current, etc.) occurs, the molded case circuit breaker performs a trip operation, and the handle indicates another position, except the on position. Meanwhile, due to a contact melt-adhered state of a movable contactor and a fixed contactor or any other reasons, when the contacts of the movable contactor and the fixed contactor are not separated from each other, a user manipulates the handle to move its position to the reset position, i.e., off position, such that the handle is moved to the on position or a position towards the on position indicating and warning to a user that the molded case circuit breaker is conducted. Here, the handle would automatically indicate the on position or a position near the on position, without indicating the off position (without being in the off position), thereby notifying the user of a conducted state in which the contacts of the movable contactor and the fixed contactor are currently contacted to each other. Such operation (function) is referred to as a “contact on operation (function).” The present invention is to provide a molded case circuit breaker having a mechanism performing the “contact on operation.”
In order to implement the contact on operation in which the handle automatically indicates the on position when the contacts are contacted and thusly in the conducted state, a position of a toggle pin serving as a connection means between an upper link and a lower link should not go beyond a position of a hinge point (i.e., a pivot) of a lever for rotatably supporting the handle. Here, the upper and lower links serve as a drive unit connected between a shaft for supporting and driving the movable contactor and the handle. That is, when viewed at the front, the toggle pin should be positioned at a left side of the hinge point (pivot). Meanwhile, in the tripped state, the position of the toggle pin should go beyond the position of the lever hinge point, i.e., at a right side of the hinge point. Accordingly, such respective positions during the contact on operation and in the tripped state are opposite.
In order to implement both the contact on operation and the trip operation, there is a need to adjust the position of the bending point between the upper link and the lower link as well as length ratio between the upper link and the lower link. Accordingly, there may be a structural problem of causing unstableness of the switching mechanism so as to satisfy the condition of the opposite positions.
In addition, a method for preventing the handle from going towards the off position by installing a stopper so as to restrict the lever may be proposed. Here, the handle would be stopped near the off position, not exactly at the off position. This may cause a problem of not performing the contact on operation when the contacts are contacted and thusly in the conducted state.
Therefore, it is an object of the present invention to provide a molded case circuit breaker having a contact on mechanism, which is stable without causing unstableness of a switching mechanism and enables a handle to accurately indicate an on position or a position towards the on position without installing a stopper.
To achieve this and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, in a molded case circuit breaker, which includes fixed contactors, a movable contactor which is movable to a position for contacting the fixed contactors or to a position for being separated from the fixed contactors, a switching mechanism for driving the movable contactor to contact to or be separated from the fixed contactors so as to open/close a circuit, a restricting unit for restricting the switching mechanism, and a handle for manually opening/closing the switching mechanism, the molded case circuit breaker, comprising: a contact on mechanism which trips the switching mechanism by releasing the restricting unit and automatically rotates the handle towards an on position even without manual power so as to indicate a conducted state when the handle is manipulated to move its position to an off position (or reset position) in a state that contacts of the movable contactor and the fixed contactors are melt-adhered to each other.
To achieve this and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, in a molded case circuit breaker, which includes a handle, which can indicate an ON position in which the molded case circuit breaker closes a circuit or an OFF position in which the molded case circuit breaker opens the connected circuit, and having a manual operation portion for manually operating the molded case circuit breaker; a lever having one end connected to the handle, rotatable together with pivoting by engagement with the handle, and providing a pivot point to the handle; a pivot shaft connected to another end of the lever so as to provide a pivot point to the lever; a side plate for fixedly supporting the pivot shaft; fixed contactors connected to a power source side or an electrical load side, a movable contactor which is pivotable to a position for contacting the fixed contactors and to a position for being separated from the fixed contactors; a shaft for supporting the movable contactor and providing the rotation driving force to the movable contactor; a pair of shaft driving pins for pivoting by engagement with the shaft so as to simultaneously drive the movable contactors of multi-phases; a lower link having a lower end thereof connected to the shaft so as to provide a rotation driving force to the shaft; an upper link for being connected by engagement with the lower link; a toggle pin for connecting an upper end of the lower link and a lower end of the upper link; a trip spring having both ends each supported by the toggle pin and the handle, charged with an elastic force at the ON position and discharging the elastic force during the trip operation so as to provide the rotation driving force to the shaft; a latch for restricting the trip spring so as to maintain the charged state; a latch holder for being pivotable to a position for restricting the latch and to a position for releasing the latch; and a nail disposed within a pivot track of the latch holder so as to press and pivot the latch holder, the molded case circuit breaker, comprising:
a contact on plate having a lower end thereof connected to one of the pair of the shaft driving pins, and which is vertically movable by being guided according to the pivot movement of the shaft driving pin;
a trip bar pivotably connected to an upper end of the contact on plate, and releasing and pivoting the nail; and
a lever pin connected to the lever, and rotating the nail by pressing the trip bar when the handle is manipulated to move to the off position (or reset position) in a state that contacts of the movable contactor and the fixed contactors are melt-adhered to each other in the on position, thereby tripping the molded case circuit breaker,
wherein a horizontal position of the toggle pin supporting a lower end of the trip spring should not go beyond the horizontal position of the pivot shaft such that, in a state that the contacts of the movable contactor and the fixed contactors are melt-adhered even though the handle is manipulated to move to the reset position (or off position), an elastic force for automatically rotating the handle toward the on position so as to indicate the conducted state even without having manual force can be provided.
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.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
Description will now be given in detail of the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
The molded case circuit breaker according to the present invention may include, in general, a pair of fixed contactors 1a and 1b, a movable contactor 2 which is movable to a position for contacting the fixed contactors 1a, 1b or to a position for being separated from the fixed contactors 1a, 1b, a switching mechanism (e.g., including 3, 3-1a, 3-1b, 4a, 4b, 4c, 6, 7, 8, 9) for driving the movable contactor 2 to contact to or be separated from the fixed contactors 1a, 1b so as to open/close a circuit, a restricting unit (e.g., including 12, 13, 14) for restricting the switching mechanism, and a handle 6 for manually opening/closing the switching mechanism.
The molded case circuit breaker according to the first embodiment of the present invention may include, in particular, a contact on mechanism (e.g., including 7, 7-1, 9, 10, 11), when the handle 6 is manipulated to move to the off position or reset position in a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, which trips the switching mechanism by releasing the restriction of the restricting unit and automatically rotates the handle 6 towards the on position, without having manual force, so as to indicate the conducted state.
More specifically, the molded case circuit breaker according to the first embodiment of the present invention may include the handle 6, which can indicate the ON position in which the molded case circuit breaker closes a circuit or the OFF position in which the molded case circuit breaker opens the connected circuit, and providing a manual operation portion for manually operating the molded case circuit breaker.
In addition, the switching mechanism of the molded case circuit breaker according to the first embodiment of the present invention may include the lever 7 having one end connected to the handle 6, pivotable together with the handle 6 by engagement with the handle 6, and providing a pivot point to the handle 6.
In addition, the switching mechanism of the molded case circuit breaker according to the first embodiment of the present invention may include a pivot shaft 8 connected to another end of the lever 7 so as to provide a pivot point to the lever 7, and a side plate 5 for supporting the pivot shaft 8. Here, the pivot shaft 8, for example, may be implemented as a rivet fixedly supported by the side plate.
In addition, the molded case circuit breaker according to the first embodiment of the present invention may include the fixed contactors 1a, 1b connected to a power source side or an electrical load side, the movable contactor 2 which is pivotable to the position for contacting the fixed contactors 1a, 1b and to the position for being separated from the fixed contactors 1a, 1b, the shaft 3 for supporting the movable contactor 2 and providing the rotation driving force to the movable contactor 2, and a pair of shaft driving pins 3-1a, 3-1b rotatable together with the shaft 3 by engagement with the shaft 3 so as to simultaneously drive the movable contactors 2 for multi-phases or poles.
In addition, the switching mechanism of the molded case circuit breaker according to the first embodiment of the present invention may include the lower link 4a having a lower end thereof connected to the shaft 3 so as to provide a rotation driving force to the shaft 3, the upper link 4b for being connected by engagement with the lower link 4a, the toggle pin 4c for connecting an upper end of the lower link 4a and a lower end of the upper link 4b, and the trip spring 9 having both ends each supported by the toggle pin 4c and the handle 6, charged with an elastic energy at the ON position and discharging the elastic energy during the trip operation so as to provide the rotation driving force to the shaft 3.
The restricting unit of the molded case circuit breaker according to the first embodiment of the present invention may include the latch 14 for restricting the trip spring 9 so as to maintain the charged state, the latch holder 13 for being pivotable to a position for restricting the latch 14 and to a position for releasing the latch 14, and the nail 12 disposed within a rotating track (a rotating locus) of the latch holder 13 so as to press and pivot the latch holder 13.
The contact on mechanism of the molded case circuit breaker according to the first embodiment of the present invention may include the contact on plate 10 having a lower end thereof connected to one 3-1b of the pair of the shaft driving pins 3-1a, 3-1b, and which is vertically movable by being guided according to the rotation of the shaft driving pin 3-1b; the trip bar 11 pivotably connected to an upper end of the contact on plate 10, and for releasing and rotating the nail 12; and the lever pin 7-1 fixed to the lever 7, and for rotating the nail 12 by pressing the trip bar 11 when the handle 6 is manipulated to move to the off position in a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other at the on position, thereby tripping the molded case circuit breaker.
The lever pin 7-1 may be implemented as a separate pin, or a protruding portion formed by embossing a corresponding position of the lever 7.
In a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are not separated from each other due to the contact melt-adherence or any other reasons, the user manipulates the handle 6 to move its position to the reset position (or off position). In order to indicate the conducted state of the molded case circuit breaker, an elastic force for automatically rotating the handle 6 towards the on position even in a state the user releases the handle 6 (i.e., without having manual force) should be provided. For this, a horizontal position of the toggle pin 4c supporting the lower end of the trip spring 9 should be at the left side of the pivot shaft 8, as shown in
In order to vertically guide the contact on plate 10 according to the rotation of the shaft driving pin 3-1b, the side plate 5 is provided with a guiding elongate hole 5-3 for vertically guiding the shaft driving pin 3-1b, and a stopping pin 5-1 protruding to limit an upward movement of the contact on plate 10. The contact on plate 10 is provided with an elongate recess portion 10c for surrounding the stopping pin 5-1, and restricting the upward movement of the contact on plate 10 by the stopping pin 5-1.
Meanwhile, description of the construction of the contact on plate 10 and the trip bar 11 according to the first embodiment of the present invention will be given in detail with reference to
As shown in
More specifically, as shown in
As shown in
Hereinafter, description of the operation of the molded case circuit breaker according to the present invention when the handle is manipulated to the on position from the off position in
In the off position (i.e., reset position) as shown in
As the toggle pin 4c is moved downwardly with an inclination, the lower link 4a and the upper link 4b are folded together with a certain internal angle therebetween, as shown in
Here, as shown in
The shaft driving pin 3-1b positioned at an opposite side of the shaft 3 in a diametral direction is also rotated in the counter-clockwise direction, thus to be in an ascended position, as shown in
As the shaft driving pin 3-1b is moved to the ascended position, the contact on plate 10 having one end thereof connected to the shaft driving pin 3-1b is guided by the guiding elongate hole portion 5-3, the stopping pin 5-1 and the elongate recess portion 10c, thus to be vertically moved.
In the reset position (i.e., off position) as shown in
Here, as the shaft 3 is rotated in the counter-clockwise direction, the movable contactor 2 contacts the fixed contactors 1a, 1b. Then, the fixed contactors 1a, 1b are electrically connected to each other, thereby closing the circuit between the power source side and the electrical load side, thus to be in the conducted state.
Meanwhile, the off operation of the molded case circuit breaker having the contact on mechanism according to the first embodiment of the present invention will be described in detail with reference to
In the on position (
An elastic restoring force for restoring its original shape as a straight line is then applied to the trip spring 9, thereby moving a lower end of the trip spring to the right as shown in the drawing, thus to move the toggle pin 4c for supporting the lower end of the trip spring to the right.
As the upper link 4b is rotated in the counter-clockwise direction and the lower link 4a is rotated in the clockwise-direction, the upper link 4b and the lower link 4a are folded together with a certain internal angle therebetween. Accordingly, the shaft 3 is rotated in the clockwise-direction, thereby having the off state (breaking the circuit) in which the movable contactor 2 is separated from the fixed contactors 1a, 1b.
Here, since the latch 14 is restricted by the latch holder 13, the trip spring 9 is tensioned and charged with the elastic potential energy. Accordingly, the toggle pin 4c for supporting one end of the tensioned trip spring is moved to the right, while going beyond the pivot shaft 8 of the lever 7.
As the toggle pin is moved to the right, the lower link 4a and the upper link 4b are more tightly folded together (i.e., with smaller internal angle) than as shown in
That is, due to the movement of the toggle pin 4c to the right, the lower link 4a is upwardly moved from the position shown in
The shaft driving pin 3-1b positioned at an opposite side of the shaft 3 in the diametral direction is also rotated in the clockwise direction, thus to be in a descended position, contrary to as shown in
As the shaft driving pin 3-1b is moved to the descended position, the contact on plate 10 having one end thereof connected to the shaft driving pin 3-1b is guided by the guiding elongate hole portion 5-3, the stopping pin 5-1 and the elongate recess portion 10c, thus to be downwardly moved.
In the reset position as shown in
Here, as the shaft 3 is rotated in the clockwise direction, the movable contactor 2 is separated from the fixed contactors 1a, 1b. Then, the fixed contactors 1a, 1b are electrically disconnected from each other, thereby opening the circuit between the power source side and the electrical load side, thus to break the circuit.
Meanwhile, description of the contact on operation of the molded case circuit breaker according to the first embodiment of the present invention will be given in detail with reference to
When the molded case circuit breaker according to the first embodiment of the present invention performs a trip operation due to the fault current (e.g., overcurrent, etc.), even though the handle 6 is at the trip position as shown in
Here, in order to switch on the molded case circuit breaker in the tripped state, the handle 6 should be manipulated to move to the off position (reset position) first, and then to the on position.
Accordingly, the user manipulates the handle 6 to move its position to the off position. The lever 7 connected to the handle 6 is pivoted centering around the pivot shaft 8 in the clockwise direction (i.e., to the right in
Here, as the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are in the on state as shown in
As shown in
Accordingly, while being pressed by the lower end of the pivoting nail 12, the latch holder 13 is rotated centering around a latch holder support shaft (not shown) in the counter-clockwise direction. As the latch holder 13 is rotated, the latch 14 being restricted is released (in a released state if it has already been tripped), thus to perform the trip operation.
In the state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, if the handle 6 is manipulated to move to the off position, the toggle pin 4c maintains the position as shown in
Accordingly, the upper portion of the trip spring 9 having the lower end supported by the toggle pin 4c is bent to the right by the manipulation of the handle 6 to the off position (i.e., to the right in
The position (state) of the molded case circuit breaker according to the first embodiment of the present invention after the contact on operation is performed is the same as that of the molded case circuit breaker at the on position as shown in
According to the first embodiment of the present invention, in the condition that the molded case circuit breaker having the contact on mechanism should be tripped, when the contacts are not separated from each other due to the contact melt-adherence, etc., even though the user attempts to move the handle to the off (reset) position, the reset operation is unable to be performed. If the handle 6 is released, the on position is indicated, thus to notify to the user that the molded case circuit breaker is conducted. Accordingly, the user may appropriately take actions required for safety.
For instance, the user may break any further overcurrent conduction by manipulating a previous stage circuit breaker means such as a main circuit breaker in a previous stage near a power source side, and take actions of separating the molded case circuit breaker, which caused the disorder, from the wiring, replacing, repairing, and the like.
Referring to
The molded case circuit breaker according to the second embodiment of the present invention may include, as a characterizing element, a contact on mechanism (e.g., including 7, 7-1, 9, 10, 11), when the handle 6 is manipulated to move to the off position or reset position in a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, which trips the switching mechanism by releasing the restricting unit and automatically rotates the handle 6 toward the on position, without having manual force, so as to indicate the conducted state.
More specifically, the molded case circuit breaker according to the second embodiment of the present invention may include the handle 6, which can indicate the ON position in which the molded case circuit breaker closes a circuit or the OFF position in which the molded case circuit breaker opens the connected circuit, and for providing a manual operation portion for manually operating the molded case circuit breaker.
In addition, the switching mechanism of the molded case circuit breaker according to the second embodiment of the present invention may include the lever 7 having one end thereof connected to the handle 6, pivoting by engagement with the handle 6, and providing a pivot point to the handle 6.
In addition, the switching mechanism of the molded case circuit breaker according to the second embodiment of the present invention may include a pivot shaft 8 connected to another end of the lever 7 and providing the pivot point of the lever 7, and a side plate 5 for fixing the pivot shaft 8. Here, the pivot shaft 8, for example, may be implemented as a rivet fixed to the side plate.
In addition, the molded case circuit breaker according to the second embodiment of the present invention may include the fixed contactors 1a, 1b connected to a power source side or an electrical load side, the movable contactor 2 which is pivotable to the position for contacting the fixed contactors 1a, 1b and to the position for being separated from the fixed contactors 1a, 1b, the shaft 3 for supporting the movable contactor 2 and for providing the rotation driving force to the movable contactor 2, and a pair of shaft driving pins 3-1a, 3-1b for rotating by engagement with the shaft 3 so as to simultaneously drive the movable contactors 2 for multi-phases (in other words multi-poles).
In addition, the switching mechanism of the molded case circuit breaker according to the second embodiment of the present invention may include the lower link 4a having a lower end thereof connected to the shaft 3 so as to provide a rotation driving force to the shaft 3, the upper link 4b connected by engagement with the lower link 4a, the toggle pin 4c for connecting an upper end of the lower link 4a and a lower end of the upper link 4b, and the trip spring 9 having both ends each supported by the toggle pin 4c and the handle 6, charged with an elastic energy at the on position, and discharging the elastic energy during the trip operation so as to provide the rotation driving force to the shaft 3.
The restricting unit of the molded case circuit breaker according to the second embodiment of the present invention may include the latch 14 for restricting the trip spring 9 so as to maintain the charged state, the latch holder 13 for being pivotable to a position for restricting the latch 14 and to a position for releasing the latch 14, and the nail 12 disposed within a pivot (rotating) track (locus) of the latch holder 13 so as to press and rotate the latch holder 13.
The contact on mechanism of the molded case circuit breaker according to the second embodiment of the present invention may include the contact on plate 10 having a lower end thereof connected to one 3-1b of the pair of the shaft driving pins 3-1a, 3-1b, and which is vertically movable by being guided according to the rotating movement of the shaft driving pin 3-1b; the contact on lever 11 pivotably connected at an upper portion of the contact on plate 10 and for driving the restricting unit to a restricting position or to a releasing position; the lever 7 for providing a pivot point of the handle 6; a lever extending portion 7a extending from the lever 7 and connected to the contact on plate 10, for rotating the contact on lever 11 by pivoting the contact on plate 10 when manipulating the handle to move to the OFF position in a state that the contacts of the movable contactor and the fixed contactors are melt-adhered to each other in the ON position, thereby moving the restricting unit to the releasing position; and the trip spring 9 having an upper end thereof connected to the handle 6, and for providing an elastic driving force for moving the switching mechanism to the trip position when the restricting unit is moved to the releasing position.
The restricting unit which can drive the contact on lever 11 to the restricting position or the releasing position can be implemented as the nail 12 according to the preferred embodiment. Accordingly, the restricting unit which can drive the lever extending portion 7a to the releasing position can also be implemented as the nail 12 according to the preferred embodiment.
When the user manipulates the handle 6 to move its position to the off position (reset position) in a state that the contacts of the movable contactor and the fixed contactors are melt-adhered to each other, the construction for connecting the contact on plate 10 serving to transfer a driving force to pivot the contact on plate 10 and the lever extending portion 7a is not shown. However, the contact on plate 10 and the lever extending portion 7a may be connected by coupling a concaved groove and a protruding portion, or by a connect pin. Alternatively, the lever extending portion 7a may be formed in a shape to be pressed by contacting the contact on plate 10.
In a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are not separated from each other due to the contact melt-adherence or any other reasons, the user manipulates the handle 6 to move its position to the reset position (or off position). In order to indicate the conducted state of the molded case circuit breaker, an elastic force for automatically pivoting the handle 6 toward the on position (i.e., contact on operation) even in a state the user releases the handle 6 (i.e., without having manual force) should be provided. For this, a horizontal position of the toggle pin 4c supporting the lower end of the trip spring 9 should be at the left side of the pivot shaft 8, as shown in
In order to vertically guide the contact on plate 10 according to the pivot movement of the shaft driving pin 3-1b, the side plate 5 is provided with a vertical guiding elongate hole (reference numeral not given) for guiding the shaft driving pin 3-1b. And the contact on plate 10 is provided with a first guiding elongate hole portion 10a vertically formed to receive a rotation center shaft of the contact on lever 11, and a second guiding elongate hole portion 10b for receiving a protruding portion 11a of the contact on lever 11 and for transferring a driving force to the contact on lever 11.
The contact on lever 11 may include a nail rotating portion 11b disposed at one end of the contact on lever 11 for pressing the nail 12, and a driving force receiving portion 11a disposed opposite to the nail rotating portion 11b and protruding in an axial direction so as to receive the rotation driving force of the contact on lever 11.
A central portion of the contact on lever 11 in a lengthwise direction is supported by a center pin 11-1 penetratingly formed thereat and fixed to the side plate 5, thereby being rotatable centering around the center pin 11-1.
The first and second guiding elongate hole portions 10a, 10b of the contact on plate 10 are arc-shaped elongate hole portions, in which a center point of an arc is positioned outside an upper end of the contact on plate 10. With this construction, the respective rotation directions of the contact on plate 10 and the contact on lever 11 are opposite to each other.
Meanwhile, description of the on operation of the molded case circuit breaker according to the present invention will be given in detail with reference to
In the off position as shown in
Due to the downward movement of the toggle pin 4c with an inclination, the lower link 4a and the upper link 4b are folded together with a certain internal angle, as shown in
Here, as the toggle pin 4c is downwardly moved with an inclination, the lower link 4a is downwardly moved as shown in
Then, another shaft driving pin 3-1b positioned at an opposite side of the shaft 3 in the diametral direction is also rotated in the counter-clockwise direction, thereby being in an ascended position as shown in
As the shaft driving pin 3-1b is moved to the ascended position, the contact on plate 10 having one end thereof connected to the shaft driving pin 3-1b is guided by the guiding elongate hole (reference numeral not given), the center pin 11-1, the first and second guiding elongate hole portions 10a, 10b, thus to be upwardly moved.
Here, since the contact on plate 10 and the shaft driving pin 3-1b are ascended together, the contact on plate 10 is not rotated centering around the shaft driving pin 3-1b. Accordingly, the positions of the driving force receiving portion 11a and the center pin 11-1 of the contact on lever 11 may be changed to lower end walls of the respective first and second guiding elongate hole portions 10a, 10b as shown in
As the shaft 3 is rotated in the counter-clockwise direction, the movable contactor 2 contacts the fixed contactors 1a, 1b. Accordingly, the fixed contactors 1a, 1b are electrically connected to each other, thereby closing the circuit between the power source side and the electrical load side, thus to be in a conducted state.
Meanwhile, description of the off operation of the molded case circuit breaker according to the present invention will be given in detail with reference to
In the on position (
An elastic restoring force for restoring its original shape as a straight line is then applied to the trip spring 9, thereby moving a lower end of the trip spring 9 to the right as shown in the drawing, thus to move the toggle pin 4c for supporting the lower end of the trip spring to the right.
As the upper link 4b is rotated in the counter-clockwise direction and the lower link 4a is rotated in the clockwise-direction, the upper link 4b and the lower link 4a (in
Here, since the latch 14 is restricted by the latch holder 13, the trip spring 9 is tensioned and charged with the elastic potential energy. Accordingly, the toggle pin 4c for supporting one end of the tensioned trip spring is moved to the right, while going beyond the pivot shaft 8 of the lever 7.
As the toggle pin is moved to the right, the lower link 4a and the upper link 4b are folded together with a smaller internal angle than as shown in
That is, due to the movement of the toggle pin 4c to the right, the lower link 4a is upwardly moved from the position shown in
Another shaft driving pin 3-1b positioned at an opposite side of the shaft 3 in the diametral direction is also rotated in the clockwise direction, thus to be in a descended position, contrary to as shown in
As the shaft driving pin 3-1b is moved to the descended position as shown in
Here, since the contact on plate 10 and the shaft driving pin 3-1b are descended together, the contact on plate 10 is not rotated centering around the shaft driving pin 3-1b. Accordingly, the positions of the driving force receiving portion 11a and the center pin 11-1 of the contact on lever 11 may be changed to the upper end walls of the respective first and second guiding elongate hole portions 10a, 10b as shown in
As the shaft 3 is rotated in the clockwise direction, the movable contactor 2 is separated from the fixed contactors 1a, 1b. Accordingly, the fixed contactors 1a, 1b are electrically disconnected, thereby opening the circuit between the power source side and the electrical load side, thus to be in the off state (circuit breaking).
Meanwhile, in such abnormal state in
When the molded case circuit breaker performs the trip operation due to the fault current (e.g., overcurrent, etc.), even though the handle 6 is at the trip position (the intermediate position between the on position and the off position) as shown in
Here, in order to switch on the molded case circuit breaker in the tripped state, the handle 6 should be manipulated to move to the off position (reset position) first, and then to the on position.
Accordingly, the user manipulates the handle 6 to move its position to the off position as shown in
Here, as the contacts of each of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, similar to the on position as shown in
As shown in
Accordingly, while being pressed by the lower end of the pivoting nail 12, the latch holder 13 is rotated centering around a latch holder support shaft (not shown) in the counter-clockwise direction. As the latch holder 13 is rotated, the latch 14 being restricted (being in a released state if it has already been tripped) is released, thus to perform the trip operation.
In the state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, if the handle 6 is manipulated to move to the off position (reset position), the toggle pin 4c maintains the position as shown in
Accordingly, the upper portion of the trip spring 9 having the lower end supported by the toggle pin 4c is bent to the right by the manipulation of the handle 6 to the off position (i.e., to the right in
The position (state) of the molded case circuit breaker according to the present invention after the contact on operation is performed is the same as that of the molded case circuit breaker in the on position as shown in
In the condition that the molded case circuit breaker having the contact on mechanism according to the second embodiment of the present invention should be tripped, when the contacts are not separated from each other due to the contact melt-adherence, etc., even though the user attempts to move the handle to the reset position, the reset operation is unable to be performed. If the handle 6 is released, the on position is indicated, thus to notify to the user that the molded case circuit breaker is conducted. Accordingly, the user may appropriately take actions required for safety.
For instance, the user may block any further overcurrent conduction by manipulating a pre-stage circuit breaker means such as a main circuit breaker in a pre-stage, and take actions of separating the molded case circuit breaker, which caused the disorder, from the wiring, replacing, repairing, and the like.
Accordingly, when the user approaches and manipulates the molded case circuit breaker, the handle is at the on position or a position towards the on position indicating that the circuit is conducted, thereby preventing electric accidents which may occur, thus to protect a load equipment and a human life.
Description of the configuration and operation of the molded case circuit breaker having a contact on mechanism according to a third embodiment of the present invention will be given in detail with reference to
Description of the construction of the molded case circuit breaker and the operation thereof in the on state will be given in detail with reference to
The molded case circuit breaker according to the third embodiment of the present invention may include, in general, a pair of fixed contactors 1a and 1b, a movable contactor 2 which is movable to a position for contacting the fixed contactors 1a, 1b and to a position for being separated from the fixed contactors 1a, 1b, a switching mechanism (e.g., including 3, 3-1a, 3-1b, 4a, 4b, 4c, 6, 7, 8, 9) for driving the movable contactor 2 to contact or be separated from the fixed contactors 1a, 1b so as to open/close a circuit, a restricting unit (e.g., including 13, 14, 15) for restricting the switching mechanism, and a handle 6 for manually opening/closing the switching mechanism.
The molded case circuit breaker according to the third embodiment of the present invention may include, in particular, a contact on mechanism (e.g., including 7-1, 9, 10, 11, 12), when the handle 6 is manipulated to move to the off position or reset position in a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, which trips the switching mechanism by releasing the restricting unit and automatically pivots the handle 6 toward the on position, without having the manual force, so as to indicate the conducted state.
More specifically, the molded case circuit breaker according to the third embodiment of the present invention may include the handle 6, which can indicate the ON position in which the molded case circuit breaker closes a circuit or the OFF position in which the molded case circuit breaker opens the connected circuit, and providing a manual operation portion for manually operating the molded case circuit breaker.
In addition, the switching mechanism of the molded case circuit breaker according to the third embodiment of the present invention may include the lever 7 having one end connected to the handle 6, pivotable by engagement with the handle 6, and providing a pivot point to the handle 6.
In addition, the switching mechanism of the molded case circuit breaker according to the third embodiment of the present invention may include a pivot shaft 8 connected to another end of the lever 7 and providing the pivot point of the lever 7, and a side plate 5 for fixedly supporting the pivot shaft 8. Here, the pivot shaft 8, for example, may be implemented as a rivet fixed to the side plate.
In addition, the molded case circuit breaker according to the third embodiment of the present invention may include the fixed contactors 1a, 1b connected to a power source side or a electrical load side, the movable contactor 2 which is movable to the position for contacting the fixed contactors 1a, 1b and to the position for being separated from the fixed contactors 1a, 1b, the shaft 3 for supporting the movable contactor 2 and providing the rotation driving force to the movable contactor 2, and a pair of shaft driving pins 3-1a, 3-1b for pivoting by engagement with the shaft 3 so as to simultaneously drive the movable contactors 2 of multi-phases or poles.
In addition, the switching mechanism of the molded case circuit breaker according to the third embodiment of the present invention may include the lower link 4a having a lower end thereof connected to the shaft 3 so as to provide a rotation driving force to the shaft 3, the upper link 4b for being connected by engagement with the lower link 4a, the toggle pin 4c for connecting an upper end of the lower link 4a and a lower end of the upper link 4b, and the trip spring 9 having both ends each supported by the toggle pin 4c and the handle 6, charged with an elastic energy in the on position, and discharging the elastic energy during the trip operation so as to provide the rotation driving force to the shaft 3.
The restricting unit of the molded case circuit breaker according to the third embodiment of the present invention may include the latch 15 for restricting the trip spring 9 to maintain the charged state, the latch holder 14 for being pivotable to a position for restricting the latch 15 and to a position for releasing the latch 15, and the nail 13 disposed within a rotating locus of the latch holder 14 so as to press and pivot the latch holder 14.
The contact on mechanism of the molded case circuit breaker according to the third embodiment of the present invention may include
the shooter 12 for pressing the restricting unit thereby moving it to the releasing position when vertically moved;
the contact on plate 10 connected to the switching mechanism, and which is movable in up/down directions by being guided according to an operation of the switching mechanism;
the contact on lever 11 rotatably supported by the contact on plate 10, for pressing the shooter thereby providing a driving force for the shooter to vertically move when rotated;
the lever extending portion 7-1 extending from the lever 7, and upwardly moving the shooter 12 so as to drive the restricting unit to the releasing position by pressing and rotating the contact on lever 11 when the handle 6 is manipulated to move to the off position (or reset position) in a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other in the on position; and
the trip spring 9 having an upper end thereof connected to the handle 6, and providing an elastic driving force for moving the switching mechanism to the trip position when the restricting unit is moved to the releasing position.
In a state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are not separated from each other due to the contact melt-adherence or any other reasons, the user manipulates the handle 6 to move its position to the reset position (or off position). In order to indicate the conducted state of the molded case circuit breaker, an elastic force for automatically pivoting the handle 6 toward the on position even in a state the user releases the handle 6 (i.e., without having manual force) should be provided. For this, a horizontal position of the toggle pin 4c supporting the lower end of the trip spring 9 should be at the left side of the pivot shaft 8, as shown in
In order to vertically guide the contact on plate 10 according to the pivot movement of the shaft driving pin 3-1b, the contact on plate 10 is formed to have an “S” shape. A lower portion of the contact on plate 10 is connected to one shaft driving pin 3-1b of a pair of shaft driving pins 3-1a, 3-1b. A guiding recess portion 10a is formed at an upper portion of the contact on plate 10 in a horizontal direction. A support pin 5-1 inserted into the guiding recess portion 10a of the contact on plate 10 is fixedly provided at an upper right side (shown in the drawing) of the side plate 5 so as to support the upper portion of the contact on plate 10.
The contact on lever 11 is rotatably supported by a pivot shaft or pivot support pin (reference numeral not given) fixed to the contact on plate 10. In this embodiment, the contact on lever 11 is a member formed to have an approximately crescent shape, and includes a driving force receiving portion for rotating centering around the pivot shaft and receiving a rotation driving force from the lever extending portion 7-1, and a driving force transferring portion for transferring a driving force to upwardly move to the driving force receiving portion 12c of the shooter 12 by rotation. In addition, the contact on lever 11 may be positioned to be contacted within a rotating locus of the lever extending portion 7-1 in order to receive the rotation driving force from the lever extending portion 7-1. However, whether or not the contact on lever 11 is contacted by the lever extending portion 7-1 is determined by the position of the contact on plate 10 supporting the contact on lever 11.
Such relative positions and operations of the lever extending portion 7-1, the contact on plate 10 and the contact on lever 11 will be better understood by the following explanations of the on, off, trip and contact on operations of the molded case circuit breaker of the present invention.
Meanwhile, the shooter 12 which is vertically movable and rotates the nail 13 by pressing is a member having an approximately bar shape, and includes a driving force receiving portion 12c extending within the rotating locus of one end of the contact on lever 11. The shooter 12 may include a base portion 12a, a body portion 12b upwardly extending from the base portion 12a, the driving force receiving portion 12c horizontally extending from a central portion of the body portion 12b in the lengthwise direction so as to be within the rotating locus of the one end of the contact on lever 11, and a nail driving portion 12d disposed at an uppermost end of the body portion 12b, and having a sharp fore-end and an inclined surface contacting the nail 13 so as to rotate the nail 13.
A shooter having such shapes and configuration, and its construction to guide and support a vertical movement of such shooter may be described with reference to the shooter which disclosed in Korean Patent No. 10-0574423 (Title of the invention: a circuit breaker having a pressure trip device) filed on Oct. 7, 2004 in Korea, registered on Apr. 20, 2006 by the applicant of the present invention. The cited shooter is guided to be vertically movable between outer walls of the two adjacent single pole breaking units for each electrical pole (the main parts shown in
Description of the operation of the molded case circuit breaker according to the present invention when the handle is manipulated to move from the off position to the on position as shown in
As shown in
As the toggle pin 4c is moved downwardly with an inclination, the lower link 4a and the upper link 4b are folded together with a certain internal angle therebetween as shown in
Here, as shown in
Another shaft driving pin 3-1b positioned at an opposite side of the shaft 3 in the diametral direction is also rotated in the counter-clockwise direction, thus to be in an ascended position, as shown in
As the shaft driving pin 3-1b is moved to the ascended position, the contact on plate 10 having one end thereof connected to the shaft driving pin 3-1b is guided by the guiding recess portion 10a and the stopping pin 5-1, thus to be upwardly moved and then stopped.
In the reset position as shown in
Here, as the shaft 3 is rotated in the counter-clockwise direction, the movable contactor 2 contacts the fixed contactors 1a, 1b. Then, the fixed contactors 1a, 1b are electrically connected, thereby closing the circuit between the power source side and the electrical load side, thus to be in the conducted state.
Meanwhile, the off operation of the molded case circuit breaker having the contact on mechanism according to the present invention will be described in detail with reference to
In the on position (
An elastic restoring force for restoring an original shape as a straight line is then applied to the trip spring 9, thereby moving a lower end of the trip spring to the right as shown in the drawing, thus to move the toggle pin 4c for supporting the lower end of the trip spring to the right.
As the upper link 4b is rotated in the counter-clockwise direction and the lower link 4a is rotated in the clockwise-direction, the upper link 4b and the lower link 4a are folded together with a certain internal angle therebetween. Accordingly, the shaft 3 is rotated in the clockwise-direction, thereby having the off state (circuit breaking) in which the movable contactor 2 is separated from the fixed contactors 1a, 1b.
Here, since the latch 14 is restricted by the latch holder 13, the trip spring 9 is restricted by being tensioned, so that the elastic potential energy charged status of the trip spring 9 is maintained.
As the toggle pin 4c is moved to the right, an internal angle between the lower link 4a and the upper link 4b is becomes much smaller than as shown in
That is, due to the movement of the toggle pin 4c to the right, the lower link 4a is upwardly moved from the position shown in
Another shaft driving pin 3-1b positioned at an opposite side of the shaft 3 in the diametral direction is also rotated in the clockwise direction, thus to be in a descended position as shown in
As the shaft driving pin 3-1b is moved to the descended position, the contact on plate 10 having one end thereof connected to the shaft driving pin 3-1b is guided by the stopping pin 5-1 and the guiding recess portion 10a fixed to the side plate 5, thus to be slantly descended.
In the reset position as shown in
Here, as the shaft 3 is rotated in the clockwise direction, the movable contactor 2 supported by the shaft 3 is also rotated in the clockwise direction, thereby being separated from the fixed contactors 1a, 1b. Then, the fixed contactors 1a, 1b are electrically disconnected, thereby opening the circuit between the power source side and the electrical load side, thus to break the circuit.
Meanwhile, description of the trip operation of the molded case circuit breaker according to the present invention will be given in detail with reference to
If a large current flows in the electrical line due to a short circuit fault or the like, an electromagnetic repulsive force is generated between the movable contactor 2 and the fixed contactors 1a, 1b, thereby pivoting the movable contactor 2 by being separated from the fixed contactors 1a, 1b, thus to generate an arc. An arc gas formed by the generated arc and surrounding air is discharged through an outlet (not shown) by a momentarily great pressure. The shooter 12 having a lower portion disposed to communicate with the outlet is lifted by the arc gas pressure, thereby rotating the nail 13. Accordingly, as the latch holder 14 rotated by the rotation of the nail 13 is released from its restriction, the trip spring 9 discharges the charged elastic potential energy, thereby being contracted to be its original state. The toggle pin 4c for supporting the lower end of the trip spring 9 is upwardly lifted. The lower link 4a is rotated in the clockwise direction and the upper link 4b is rotated in the counter-clockwise direction. The latch 15 connected by engagement with the upper link 4b is rotated in the counter-clockwise direction by the shaft or pin (reference numeral not given, but referring to the uppermost circle among the 3 dotted circles within the upper link in
Here, the shaft 3 is rotated in the clockwise direction by the shaft driving pin 3-1a connected to the lower link 4a rotating in the clockwise direction, and the movable contactor 2 supported by the shaft 3 is also rotated in the clockwise direction, thereby performing the trip operation in which the movable contactor 2 is separated from the fixed contactors 1a, 1b.
Meanwhile, description of the contact on operation of the molded case circuit breaker according to the present invention will be given in detail with reference to
When the molded case circuit breaker performs a trip operation due to the fault current (e.g., overcurrent, etc.), even though the handle 6 is at the trip position as shown in
Here, in order to switch on the molded case circuit breaker in the tripped state, the handle 6 should be manipulated to move its position to the off position first, and then to the on position.
Accordingly, the user manipulates the handle 6 to move its position to the off position. The lever 7 connected to the handle 6 is pivoted centering around the pivot shaft 8 in the clockwise direction (i.e., to the right in
Here, as the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, thus to be in the on position as shown in
Accordingly, due to the contact on lever 11 rotating in the counter-clockwise direction, the shooter 12 for upwardly pressing the driving force receiving portion 12c is upwardly moved. Then, the nail 13 is pressed by the nail restricting portion 12d of the shooter 12, thereby rotating in the clockwise direction. The latch holder 14 is rotated in the counter-clockwise direction. Accordingly, the latch 15 restricted by the latch holder 14 is released and thusly receives a driving force by the elastic potential energy of the trip spring via the upper link 4b, thereby rotating in the counter-clockwise direction, thus to perform the trip operation. Here, most of user releases the handle 6 by a relatively loud trip noise from the switching mechanism, which occurs during the trip operation.
In the state that the contacts of the movable contactor 2 and the fixed contactors 1a, 1b are melt-adhered to each other, the toggle pin 4c maintains the position as shown in
Accordingly, the upper portion of the trip spring 9 having the lower end thereof supported by the toggle pin 4c is bent to the right by the manipulation of the handle 6 to the off position (i.e., to the right in
The position (state) of the molded case circuit breaker according to the present invention after the contact on operation is performed is the same as that of the molded case circuit breaker in the on position as shown in
According to the present invention, in the condition that the molded case circuit breaker having the contact on mechanism should be tripped, when the contacts are not separated from each other due to the contact melt-adherence, etc., even though the user attempts to move the handle to the off (reset) position, the reset operation is unable to be performed. If the handle 6 is released, the on position is indicated, thus to notify to the user that the molded case circuit breaker is conducted. Accordingly, the user may take actions required for safety.
For instance, the user may block any further overcurrent conduction by manipulating a pre-stage circuit breaker means such as a main circuit breaker in a pre-stage, and take actions of separating the molded case circuit breaker, which caused the disorder, from the wiring, replacing, repairing, and the like.
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 |
|---|---|---|---|
| 10-2007-0080900 | Aug 2007 | KR | national |
| 10-2007-0080902 | Aug 2007 | KR | national |
| 10-2007-0080903 | Aug 2007 | KR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4401872 | Boichot-Castagne et al. | Aug 1983 | A |
| 4528531 | Flick et al. | Jul 1985 | A |
| 4679016 | Ciarcia et al. | Jul 1987 | A |
| 4731921 | Ciarcia et al. | Mar 1988 | A |
| 4978816 | Castonguay et al. | Dec 1990 | A |
| 5142112 | Parks et al. | Aug 1992 | A |
| 5165532 | Pipich et al. | Nov 1992 | A |
| 5184717 | Chou et al. | Feb 1993 | A |
| 5200724 | Gula et al. | Apr 1993 | A |
| 5213206 | Beck et al. | May 1993 | A |
| 5361052 | Ferullo et al. | Nov 1994 | A |
| 5430422 | Gibson | Jul 1995 | A |
| 5543595 | Mader et al. | Aug 1996 | A |
| 6031438 | Runyan | Feb 2000 | A |
| 6084191 | Kataya et al. | Jul 2000 | A |
| 6166344 | Castonguay et al. | Dec 2000 | A |
| 6222143 | Lawson et al. | Apr 2001 | B1 |
| 6985059 | Subramanian et al. | Jan 2006 | B2 |
| 7045733 | Bresciani et al. | May 2006 | B2 |
| 20050051414 | Subramanian et al. | Mar 2005 | A1 |
| 20080122563 | Song | May 2008 | A1 |
| Number | Date | Country |
|---|---|---|
| 10-275553 | Oct 1998 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20090039988 A1 | Feb 2009 | US |
