EP1914767B1

EP1914767B1 - Movable contact assembly for circuit breaker

Info

Publication number: EP1914767B1
Application number: EP07019935.1A
Authority: EP
Inventors: Jae-Kwan Seo
Original assignee: LS Industrial Systems Co Ltd
Current assignee: LS Electric Co Ltd
Priority date: 2006-10-17
Filing date: 2007-10-11
Publication date: 2015-04-08
Anticipated expiration: 2027-10-11
Also published as: EP1914767A1; CN101165832A; KR200437069Y1; ES2541539T3; MY162275A; RU2343582C1

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a movable contactor for a circuit breaker, and more particularly, to a movable contactor for a circuit breaker capable of reducing the number of assembly processes by reducing the number of components, and capable of reducing a production cost.

2. Description of the Background Art

EP o 225 207 A discloses a sub-assembly comprising a contact finger support cage and a connection pad of each pole is securedly united to an intermediate insulating partition of the case by a bracket and screw fixing device. The cage is pivotally mounted on a spindle positioned in bearings of the pad, and is connected to a switching bar by a mechanical link cooperating with a disengageable coupling, capable of breaking the linking system with the bar at the level of each pole.
US 5 210 385 A discloses a low voltage circuit breaker for high currents having multiple contacts of the same length and a stationary arc guiding horn having an intermediate edge extending over a short distance in the direction of movement of the front extensions of the contact fingers. A stationary arcing contact is arranged between the edge of the arc guiding horn and the stationary main contact.
Generally, a circuit breaker is connected to a circuit on which a current flows. The circuit breaker serves to supply a current onto the circuit at the time of a normal current occurrence, but to cut off the current on the circuit at the time of an abnormal current occurrence thereby to protect the circuit and components.
The circuit breaker comprises a cage having a receiving space therein; a plurality of fixed contactors having fixed contacts and fixed in the cage; a plurality of movable contactors having movable contacts so as to come in contact with the fixed contacts, and disposed in the cage so as to perform a relative motion with respect to the fixed contactors; a driving unit for driving the movable contactors; and a detecting unit for detecting an over-current, an abnormal current, etc. and thereby operating the driving unit.
One side of the movable contactor is connected to outlet side fixed contacts of the fixed contactor, and another side of the movable contactor is connected or separated to/from inlet side fixed contacts of the fixed contactor as the movable contactor is moved.
A plurality of extinguishing chambers for exhausting arcs generated when the movable contactor and the fixed contactor contact or are separated from each other are provided at an upper side of the movable contactor.
An operation of the circuit breaker will be explained as follows.
When a normal current occurs, the movable contactors are connected to the inlet side fixed contacts of the fixed contactors. Accordingly, power is introduced from the inlet side fixed contacts of the fixed contactors thereby to flow along a path inside the movable contactors. Then, the power flowing along the path inside the movable contactor is supplied to a load side through the outlet side fixed contacts of the fixed contactors.
When an over-current and an abnormal current are detected by the detecting unit, the driving unit is operated by an operation mechanism in the circuit breaker. As the driving unit is operated, the movable contactors are angle-rotated. Here, the movable contacts of the movable contactors are separated from the inlet side fixed contacts of the fixed contactors, thereby cutting off a current.
The angle-rotation of the movable contactor will be explained as follows.
Hinge shafts are coupled to lower ends of side plates disposed at both side surfaces of the movable contactor. The hinge shafts are rotatably coupled to a bracket, and the movable contactor is angle-rotated centering around the hinge shafts.
A load side connection terminal connected to the outlet side fixed contacts of the fixed contactor is coupled to the bracket. The load side connection terminal is connected to the outlet side fixed contacts of the fixed contactor.
However, the conventional structure has the following problems.
Since the hinge shafts are coupled to the side plates of the movable contactor, the number of components of the movable contactor is increased and the number of assembly processes is increased. Accordingly, an assembly productivity is lowered.
Furthermore, since the hinge shafts are additionally fabricated, a production cost for the movable contactor is increased.

SUMMARY OF THE INVENTION

Therefore, an object of the present disclosure is to provide a movable contactor for a circuit breaker capable of reducing the number of assembly processes by reducing the number of components, and capable of reducing a production cost.
To achieve these and other advantages there is provided a method of producing a movable contactor for a circuit breaker as claimed in claim 1.
The foregoing and other objects, features, aspects and advantages of the present disclosure will become more apparent from the following detailed description of the present disclosure when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE 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:

FIG. 1 is a side view showing a part of a circuit breaker to which a movable contactor according to a first embodiment of the present invention is applied;
FIG. 2 is a perspective view showing a movable contactor for a circuit breaker according to a first embodiment of the present invention;
FIG. 3 is a perspective view showing a shaft-integrated side plate of the movable contactor for a circuit breaker according to a first embodiment of the present invention;
FIG. 4 is a sectional view showing the shaft-integrated side plate; and
FIG. 5 is a sectional view showing a process for fabricating a shaft portion of the shaft-integrated side plate.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.
Hereinafter, a movable contactor for a circuit breaker according to the present invention will be explained in more detail with reference to the attached drawings.
FIG. 1 is a side view showing a part of a circuit breaker to which a movable contactor according to a first embodiment of the present invention is applied; FIG. 2 is a perspective view showing a movable contactor for a circuit breaker according to a first embodiment of the present invention; and FIG. 3 is a perspective view showing a shaft-integrated side plateof the movable contactor for a circuit breaker according to a first embodiment of the present invention.
As shown, a movable contactor D for a circuit breaker comprises a cage 10 having a certain shape; a plurality of fingers 20 coupled to one side of the cage 10 with a predetermined interval therebetween; and a shaft-integrated side plate 40 having a certain area, having a shaft portion 41 protruding from one side thereof with a certain length, and coupled to both side surfaces of the cage 10 thereby covering the fingers 20.
A bracket 50 having a certain shape is disposed below the cage 10, and a load side connection terminal 60 is coupled to the bracket 50.
The load side connection terminal 60 is connected to an outlet side fixed contacts C2 of a fixed contactor C of the circuit breaker. The fingers 20 and the load side connection terminal 60 are connected to one another by lead wires (not shown).
The bracket 50 includes a lower portion 51 having a certain width and length; side portions 52 curvedly-extending from both ends of the lower portion 51; and shaft inserting grooves 53 formed at the side portions 52. The shaft inserting groove is formed in a sphere shape of which one side is opened.
The load side connection terminal 60 is coupled to the lower portion 51 of the bracket 50 by bolts 61.
The shaft portion 41 of the shaft-integrated side plate 40 is rotatably inserted into the shaft inserting groove 53.
A through hole is formed in the shaft portion 41 of the shaft-integrated side plate 40. Preferably, the shaft portion 41 has a ring-shaped section having a certain thickness.
The shaft-integrated side plate 40 includes a base portion 42 having a certain thickness and area, a plurality of engaging holes 43 penetratingly formed at the base portion 42, and a shaft portion 41 extending from a lower portion of the base portion 42 with a certain length.
As shown in FIG. 4, a through hole 44 is penetratingly formed inthe shaft portion 41. Preferably, the through hole 44 is formed to have a curved edge.
The shaft portion 41 has a ring-shaped section having a certain thickness.
Preferably, the shaft portion 41 has a thickness thinner than that of the base portion 42.
The shaft portion 41 of the shaft-integrated side plate 40 is formed by protruding a part of the base portion 42. More concretely, as shown in FIG. 5, a part of the base portion 42 is pressed to be protruded as a semi-sphere shape. Then, a central portion of the protruded portion is punched thereby to form a through hole. Then, the protruded portion is pushed thus to form the shaft portion 41 protruding with a predetermined outer diameter and length.
The shaft-integrated side plate 40 is respectively coupled to both sides of the cage 10 by bolts 11. The bolts 11 are respectively inserted into the engaging holes 43 thus to be coupled to the cage 10. Herein, the shaft portion 41 of the shaft-integrated side plate 40 is outwardly disposed.
A lower portion of the cage 10 and the shaft-integrated side plate 40 are disposed in the bracket 50. The shaft portion 41 of the shaft-integrated side plate 40 is rotatably inserted into the shaft inserting groove 53 of the bracket 50.
A connecting unit B connected to a driving unit A of the circuit breaker is provided at one side of the cage 10. The connecting unit B is disposed at an opposite side to the fingers 20.
An operation and effects of the movable contactor for a circuit breaker according to the present invention will be explained in more detail.
When a normal current (power) is supplied to the circuit breaker, a contact terminal 30 of the movable contactor come in contact with the inlet side fixed contacts C1 of the fixed contactor C. Here, the power is supplied to the finger 20, the lead wire, and the load side connection terminal 60 via the inlet side fixed contacts C1. The power supplied to the load side connection terminal 60 is provided to a load unit (not shown) through the outlet side fixed contacts C2 of the fixed contactor C.
When an abnormal current (power) is detected from the circuit breaker, the driving unit A pulls the connecting unit B. As a result, the movable contactor D is angle-rotated centering around the shaft portion 41 of the shaft-integrated side plate 40. As the cage 10 is angle-rotated centering around the shaft portion 41, the contact terminals 30 respectively coupled to the fingers 20 are separated from the inlet side fixed contacts C1 of the fixed contactors C. Accordingly, the abnormal current is prevented from flowing to the load unit.
In the present invention, the shaft portion 41 of the movable contactor D that serves as a rotating axis is formed by protruding a part of the shaft-integrated side plate 40. Accordingly, the number of components of the movable contactor D is reduced. As a result, a production cost for the movable contactor D is reduced thereby to enhance a price competitiveness.
Since the number of components of the movable contactor D is reduced, the number of assembly processes for the movable contactor D is reduced. Accordingly, an assembly productivity for the movable contactor D is enhanced.
Furthermore, since the shaft portion 41 is formed by protruding a part of the shaft-integrated side plate 40, the shaft-integrated side plate 40 has a decreased weight.
The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims.
As the present features 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,

Claims

A method of producing a movable contactor for a circuit breaker comprising the following steps:
providing a cage (10);

providing a plurality of fingers (20) disposed in the cage (10);

providing a shaft-integrated side plate (40) including a base portion (42) having a certain thickness and area;

forming a shaft portion (41) of the shaft-integrated side plate (40); coupling the shaft-integrated side plate (40) respectively to both sides of the cage (10) by bolts (11), thereby covering the fingers (20); and

inserting the shaft portion (41) of the shaft-integrated side plate (40) rotatably into a shaft inserting groove (53) of a bracket (50), to which a load side connection terminal (60) connected to a fixed contactor (C) is coupled, characterised in that the step of forming the shaft portion of the shaft-integrated side plate (40) comprises:
- pressing a part of the base portion (42) to be protruded as a semi-sphere shape;

- then, a central portion of the protruded portion is punched thereby to form a through hole;

- then, the protruded portion is pushed thus to form the shaft portion (41) protruding with a predetermined outer diameter and length, hereby the shaft portion is formed as one body with the shaft-integrated side plate.
The method of claim 1, wherein the shaft portion (41) has a ring-shaped section having a certain thickness.
The method of claim 1, wherein the shaft-integrated side plate (40) comprises:
the base portion (42) having a certain thickness and area;

a plurality of engaging holes (43) penetratingly formed at the base portion (42); and

the shaft portion (41) extending from a lower end of the base portion (42) with a certain length.
The method of claim 3, wherein the through hole (44) is penetratingly formed in the shaft portion (41).
The method of claim 4, wherein the through hole (44) is formed to have a curved edge.
The method of claim 3, wherein the shaft portion (41) has a ring-shaped section having a certain thickness.
The method of claim 3, wherein the shaft portion (41) has a thickness thinner than that of the base portion.