GB2217916A

GB2217916A - Electric switch assembly

Info

Publication number: GB2217916A
Application number: GB8908032A
Authority: GB
Inventors: Minoru Nakahata; Nobuyuki Orito
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1988-04-19
Filing date: 1989-04-10
Publication date: 1989-11-01
Anticipated expiration: 2009-04-10
Also published as: GB8908032D0; KR890016605A; GB2217916B; CN1039144A; KR910009145B1; CN1018223B; DE3905146A1

Description

MD6560 0

TITLE OF THE INVENTION

Interrupting apparatus FIELD OF THE INVENTION AND RELATED ART STATEMENT 1. FIELD OF 711E INVENTION

The present invention relates generally to an interrupting apparatus, and more particularly to an interrupting apparatus for making or breaking a circuit in which a current is flowing. 2. DESCRIPTION OF THE RELATED ART

In conventional use of an interrupting apparatus for making or breaking a circuit in which a current is flowing, a disconnector having no current interrupting ability is utilized to make or break the circuit in which the current does not flow. On the other hand, a loadbreak switch or a contactor is utilized to make or break the circuit in which the current is flowing. Moreover, an interrupting apparatus is used in order to interrupt a short-circuit current, or the load-break switch or the contactor is used in cooperation with a fuse, and a similar function-to the interrupting apparatus is provided.

As mentioned above in the conventional art, an optimum device which is adequate for various purposes in function or economical problem have been employed. Though a device having both functions of the disconnector and the contactor is marketed, the device is not widely used 1 2 2 17 9 1, 6 because of its high expense. Consequently, plural switch gears having specific functions, respectively are combined for accomplishing contemplated action. In case that the fuse is employed in cooperation with the load-break switch or the contactor, the fuse Is fused in every interrupting operation of the system, thus an operation cost of the system including high expense of the fuse entailing exchange is expensive. Moreover, since the interrupting apparatus can not break the circuit where the voltage is applied, it is required that the interrupting switch is combined with a disconnector. Consequently, in an breaking operation of the circuit, the interrupting switch must firstly be opened, and the disconnector is secondly opened. Therefore, operation of the switch gear is troublesome because of its two--step operation. OBJECT AND SUMMARY OF THE INVENTION

An object of the present invention is to provide an interrupting apparatus which is convenience in operation and is inexpensive in operation cost.

The interrupting apparatus in accordance with the present invention is comprised of such that: a vacuum interrupter and a disconnector which are coupled in series are connected in series in an electric line; a part of force for making the vacuum interrupter is charged in a spring which is linked with a revolution mechanism for operating the vacuum interrupter; then the vacuum inter- 2 z e z.

1 rupter is opened by action of a first link mechanism activated by breaking operation of the disconnector; and in the aforementioned action, revolution of a revolution axis of the revolution mechanism which is driven by the charged force of the spring is retarded by a predetermined time period by a control mechanism; and subsequently the operation mechanism is activated by a second link mechanism which is driven after the predetermined time period of break of the vacuum interrupter; and thus the disconnector is opened.

That is to say, since revolution of the revolution mechanism which Is driven by the charged force of the spring is delayed from breaking of the vacuum interrupter, the disconnector is opened after the predetermined time period of breaking of the vacuum interrupter. BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 is a block diagram showing configuration of an interrupting apparatus in accordance with the present invention; FIG.2 is an example of an interlock mechanism in the interrupting apparatus of the present invention; FIG.3 and FIG.4 are timing charts showing opera tion of the interrupting apparatus of the present invention; F1G.5(a), FIG.5(b) and FIG.(c) are front views 3 1 of an operation mechanism of a vacuum interrupter in the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Configuration of an embodiment of an interrupting apparatus in accordance with the present invention is shown in FIG.1. Referring to FIG.1, a vacuum interrupter 1 having a pair of contacts 2 and 3 is connected at one terminal 3a in series with a fixed contact 5 of a disconnector 4. The other terminal 2a of the vacuum interrupter I is coupled to an electric line. The disconnector 4 comprises a moving contact 6 which contacts the fixed contact 5, and the terminal 6a of the moving contact 6 is coupled to an electric wire 7 which is introduced to a load, for example. A current detector 11 such as a current transformer is coupled to the electri wire 7. Output terminals of the current detector 11 i connected to an over-current relay 10. An operation mechanism 8 is a mechanism for making the contacts 2 and 3 of the vacuum interrupter 1 by manual operation, and the vacuum interrupter 1 is closed by moving a lever 14 in the direction of an arrow(A).

The part of operation mechanism 8 per se is known and, for instance, disclosed in the Japanese published unexamined patent application Sho 61024110, andthe detailed mechanism thereof is shown in FIG.5(a), FIG.5(b) and FIG.5(c). The mechanism as shown in FIG.5(a) 4 is mounted on a back side of a frame 8a of the operation mechanism 8 as shown in FIG.2. Closed state of the contacts 2 and 3 of the vacuum interrupter 1 is shown FIG.5(a). The contact 2 is a moving contact, and is pivotally mounted on an axis 137. The axis 137 is connected to an shaft 27 having a lever 25 fixed thereon with a shaft 136, and is rotated together with the lever 25. An extension spring 107 is provided between the contact 2 and the frame 8a of the operation mechanism 8, and is expanded and charged by which is affixed on a lever 26 1 moving of the lever 1.4 n the direction of the arrow (A) as shown in FIG. 5(c) when the contact 2 is closed to the contact 3. The lever 26 is pivotally mounted on the shaft 27. Moreover a link 28 is pivotally, mounted on an end portion of the lever 25 with an pin 29, and a link 30 is pivotally mounted on one end portion of the lever 26 with an pin 32. Both the other ends of the links 28 and 30 are pivotally connected with a pin 33. A roller 34 is put on the pin 33, and an outer surface of the roller 34 contacts a bow-shaped concave portion of an arm 38. A compression spring 36 is put on a pin 31 which is affixed on the link 28, and both ends of the spring 36 are suspended by the pin 29 and 32, respectively. Thus the spring 36 energizes the lever 25 and 26 so that an angle between the levers 25 and 26 is made to widen. A pin 37 is affixed on the frame 8, and thereby, the lever 26 is held at the position as shown in FIG.5(a). A roller 38b which is mounted on an end portion of the arm 38 contacts a latch surface 43a of a latch 43, and the arm 38 is held at the position as shown in FIG.S(a).

Referring to FIG.1, the moving contact 6 of the disconnector 4 is driven by an operation mechanism 9, and a driving force therefor is given by a spring or an electric magnet which is omitted in illustration. The overcurrent relay 10 is activated by an output of the current detector 11, and thereby trigger mechanism 24 of the operation mechanism 8 as shown in FIG-5(a) is activated.

An interlock mechanism 12 controls action of the operation mechanism 9 of the disconnector 4 which is in operative connection with the operation mechanism 8 of the vacuum interrupter 1. As shown in FIG.2, the interlock mechanism 12 comprises a first link mechanism and a second link mechanism. The first link mechanism is composed of an operation link 123, an interlock operation lever 121, a trip link 126 and a lever 151. The second link mechanism is composed of driving levers 127 and 128 and a driving link 130. The interlock operation lever 121 is pivotally mounted on an axis 122 which is affixed on the frame 8a, and one end thereof is connected to the operation link 123 with a pin 124. The other end of the operation link 123 is connected to an break operation 6 p lever (not shown) of the operation mechanism 9. One end of the operation lever 121 is connected to the trip link 126 with a pin 125. The trip link 126 is connected at an upper portion with a lever 151 for activating the operation mechanism 8 in breaking operation. The lever 151 is connected to an axis 44 of the latch 43 of the operation mechanism 8 as shown in FIG.5(a), and is rotated together with the latch 43. The driving lever 127 is pivotally mounted on the axis 122, and the driving lever 128 is pivotally mounted on an end of the driving lever 127 with a pin 129. Moreover, a driving link 130 is connected to the end portion of the driving lever 127 with a pin 131, and the driving link 130 is communicated to an break operation latch (not shown) of the operation mechanism 9. A shaft 27a of the lever 14 is affixed to the lever 2G of the operation mechanism 8 as shown in FIG.5(a), and an interlock rod 141 is provided at a lower end of the lever 14. BY mean of the interlock mechanism 12, when the interrupting apparatus is opened, the vacuum interrupter is firstly opened, and then the moving contact 6 of the disconnector 4 is opened by activation of the operation mechanism 9 after a predetermined time period.

Operation of the embodiment is elucidated hereafter. FIG.3 and FIG.4 are timing charts showing operation of the embodiment. Referring to these timing charts, a high level in the respective waveforms 7 represents make state of the contact, and a low level represents break state thereof. Referring to F1G.3, a waveform (A) represents make or break of the vacuum interrupter 1, and the waveform (B) represents make or break of the disconnector 4.

Operation for making the interrupting apparatus is elucidated hereafter. Referring to FIG.5(c), the lever 14 is rotated in the direction of the arrow (A) in order to make the vacuum interrupter 1 by manual operation, and the lever 25 and the shaft 27 is rotated clockwise through the links 28 and 30. Consequently the shaft 137 is rotated clockwise by the pole shaft 136 which is connected to the shaft 27, and the contact 2 contacts the contact 3. In this process, the spring 7 is extended and a force is charged therein.

Subsequently, a stopper 49 abuts on a roller 48 put on a shaft 32 mounted at an end portion of the arm 26 after the above-mentioned operation of the lever 14, the arms 25 and 26 are held by the stopper 49 under the condition that a counterclockwise torque is applied shaft 27 in FIG.5(a). Status of the contact in the above mentioned operation is shown by a rise edge (a) of the waveform (A) in FIG.3. Then, the disconnector 4 is closed by mean of a charged spring or an electric magnet, for example operated by manual make operation of the operation mechanism 9. This closed status of the disconnector 4 is 8 Z! shown by a rise edge (b) of a waveform (B) in FIG.3. As a result, the vacuum interrupter 1 and the disconnector 4 are closed, and a current flows into the electric wire 7.

In breaking operation of the interrupting apparatus, as shown in FIG.2, firstly the operation mechanism 9 of the disconnector 4 is operated for breaking it. Then the operation link 123 is lifted up by the manual operation as shown in FIG.2, and the operation lever 121 which is connected to the operation link 123 with the pin 124 is rotated counterclockwise on the shaft 122. Consequently, the trip link 126 is drawn downward, and the lever 151 is rotated clockwise. Furthermore in this operation, the pin 125 pushes the end of the lever 128, which is then rotated counterclockwise. Consequently, the lever 128 is tilted as shown by a dotted line 128a. On the other hand, the latch 43 of the operation mechanism 8 which is connected to the shaft 44 of the lever 151 as shown in FIG.5(a) is rotated clockwise, and the roller 38b is dislocated from the latch surface 43a of the latch 43. Since the strength of the spring 107 is larger than that of the spring 36 or the spring 42, the lever 25 is rotated counterclockwise by a force of the spring 107 which is superior than the force of the spring 36 through the shaft 136. Consequently, the contact 2 is separated from the contact 3, and then the pin 33 connecting between the link 28 and 30 moves in a 9 direction far from the shaft 27, and thereby the arm 38 is rotated clockwise against the force of the spring 42 as shown in FIG.5(b). Status of the contacts 2 and 3 of the operation mechanism 8 is represented by a fall edge (c) of a waveform (A) in FIG.3. - In the above-mentioned operation, when the links 28 and 30 are shifted from the state as shown in FIG.5(a) to a state as shown in FIG.5(b), an end portion 30a of the link 30 pushes a pin 51 of the stopper 49, and the stopper 49 is rotated clockwise. Consequently, the roller 48 is released from the stopper 49. The lever 26 is rotated counterclockwise by force of the spring 36 as shown in FIG.5(c). The shaft 27A of the lever 14 in FIG. 2 is rotated counterclockwise responding to rotation of the lever 26. Consequently, the interlock rod 141 which is affixed on the shaft 27a pushes downward the lever 128 tilted by counterclockwise rotation, thus the driving lever 127 is rotated counterclockwise on the shaft 122. The driving link 130 is pulled up by the action of the driving lever 127, and the operation mechanism 9 of the disconnector 4 is activated and the contact 6 is separated from the contact 5 in the above-mentioned action. The roller 34 of the link 30 rolls on the convex portion 38b of the arm 38 and travels from right end to leftward as shown by an arrow G in FIG. 5(b) and the links 28 and 30 are extended by the force of the spring 107 as shown in S 1 4 FIG.5(b). Subsequently, since a bending force of the spring 42 is made to be stronger than that of the spring 36, the roller 34 is pressed by the arm 38, and returns toward the shaft 27. Thus a height of the link mechanism is shortened as shown in FIG.5(c). A predetermined time period is required for the action of the link mechanism from after extension to return, for example 0.05---0.1 second. Therefore, the interlock rod 141 pushes the lever 128 after the predetermined time period of break of the contacts 2 and 3, and the contact 6 of the disconnector 4 is separated after the predetermined time period of break of contact 2 and 3. A timing chart showing the abovementioned action is shown by a waveform B in FIG.3. Referring to FIG.3, break of the contact 6 is shown by a fall edge (d), and the fall edge (d) is retard from the fall edge (c) showing break of the contact 2 and 3 by the predetermined time period tl, In case that an over-current or a short-circuit current flows in the electric wire 7, the current detector 11 detects abnormal state of the current, and the over current relay 10 is activated by the output of the current detector. A trigger device 24 which is mounted on the frame 8a as shown in FIG.5(a) is driven by the output signal of the over-current relay 10, and a plunger 24a of the trigger device 24 pushes an end portion 46 of the latch 43 and rotates the latch 43 clockwise.

11 Consequently, the roller 38b is released from the latch surface 43a, and the arm 38 rotates clockwise. Then the lever 151 is rotated clockwise by the shaft 44 which is connected to the latch 43. But since the pin 152 of the lever 151 moves in an oblong hole 126A, the trip link 126 is not driven. After then, as mentioned above, the same action is accomplished, and the contact 2 is separated from the contact 3 and the shaft 27a is rotated counterclockwise. In this operation, however, since the trip link 126 is not pulled downward, a pin 152 which is affixed on the lever 151 becomes apart from rounded ends of an aperture 126A of the trip link 126. Thus, position of the lever 128 is maintained as illustrated by a solid line in FIG.2. Thus even if the shaft 27a rotates counterclockwise, the interlock rod 141 does not touch the lever 128, and the driving link 130 is not lifted upward. Therefore, the operation mechanism 9 is not activated, and the disconnector 4 maintains the closed state. The timing of this above-mentioned action is shown by a fall edge(e) of a waveform A in FIG.4. In this case, the disconnector 4 is opened by manual operation of the operation mechanism 9. Open of the disconnector 4 is represented by a fall edge (f) of a waveform B in FIG.4.

In the above-mentioned embodiment, the operation mechanism 8 of the vacuum interrupter 1 of manual operation is disclosed. But in a large size vacuum interrupter, 12 J_ 4 an operation mechanism is driven by an electric motor or an oil hydraulic machine.

As mentioned above in the interrupting apparatus of the present Invention, the disconnector is in operative connection with the vacuum interrupter, and the disconnector is opened through the operation mechanisms 8 and 9 after a predetermined time period of break of the vacuum interrupter. Therefore, in the break operation of the interrupting apparatus the vacuum interrupter is firstly opened, and then after lapse of predetermined time period the disconnector is opened. Accordingly, break operation of the interrupting apparatus for disconnecting current or voltage can be carried out by a single operation. Furthermore, since expendables such as fuse is not employed in the interrupting apparatus, a maintenance expense is reduced. As addi.tional advantage, since a vacuum interrupter and a disconnector of manual operation types which are relatively inexpensive can be used in cooperation with each other, a total cost can be reduced.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been change(] in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the Invention as hereinafter claimed.

1-3

Claims

WHAT IS CLAIMED IS

1. An interrupting apparatus comprising: a vacuum interrupter connected in series to an electric circuit, a disconnector coupled in series with said vacuum interrupter in said electric circuit, a revolution mechanism for driving said vacuum interrupter, a spring being in operative connection with said revolution mechanism for charging force to be used for turning ON of the interrupter in a process of turning OFF of said vacuum interrupter, a first link mechanism to be driven by breaking operation of said disconnector for breaking said vacuum interrupter, a control mechanism for retarding revolution of said revolution mechanism which is driven by said charged force of said spring by a predetermined time period after discharge of said charged force of said spring in breakin action of said vacuum interrupter, a second link mechanism to be driven after said predetermined time period of breaking of said vacuum interrupter being triggered by action of said control mechanism, and an operation mechanism for breaking said disconnector by action of said second link mechanism.

14 9 11 Y 1

2. An interrupting apparatus in accordance with claim 1, wherein said first link mechanism comprises a pin and said second link mechanism comprises a driving lever which is pivotally mounted on said second link mechanism, and when said first link mechanism is driven by breaking operation of said disconnector, said driving lever is rotated by said pin so that an Interlock rod affixed on said revolution mechanism drives said second link mechanism through said driving lever.

3. claim 1, wherein An interrupting apparatus in accordance with said first link mechanism comprises a trip link moving rectilinearly and having an oblong aperture at one end portion, and a lever pivotally mounted on a frame of said revolution mechanism and having a pin linked with said oblong aperture, said pin pushing said trip link only when said trip link is at a driven state.

is

4. An electric switch apparatus having first and second switches connected in series whereby a circuit into which the apparatus is series connected is broken by opening either switch, the switches having respective operating mechanisms which are interconnected so that on initiation of a first switch-opening operation, for opening the first switch, the second switch is opened initially and the first switch is automatically opened after the opening of the second switch.

5. Apparatus according to claim 4, in which a second switchopening operation enables opening of the second switch without automatically opening the first switch.

6. Apparatus according to claim 4 or claim 5, comprising means to open the second switch automatically in response to an over-current signal indicating an excessive current.

7. Apparatus according to claim 6 as dependent on claim 5, in which the said opening means opens the switch by the said second switching operation.

8.

Apparatus according to any one of claims 4 :t h - 17 to 7, in which the second switch is better suited than the first switch to break a circuit in which large currents are flowing.

9. Switch apparatus substantially as herein described with reference to the accompanying drawings.

pubUahed 1989 atThe Patent Offtoe. St HOUBC, 65171 HolbomIOndonWC1R4TP. Purther Coplesmaybe Obtalned from The Patent O=Ioe. wee Brancil, st Itary _ Orpington, xent m's 310. P11nted by W'.11t1Plex teChMqucs ltd, St MWY. KOnt, C;OIL 1187