GB2246239A

GB2246239A - Switching device

Info

Publication number: GB2246239A
Application number: GB9115554A
Authority: GB
Inventors: Minoru Nakahata; Nobuyuki Orito
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1990-07-19
Filing date: 1991-07-18
Publication date: 1992-01-22
Anticipated expiration: 2011-07-18
Also published as: DE4129295C1; KR920003354A; JPH0479708A; FR2665030B1; GB2246239B; GB9115554D0; JP2793701B2; FR2665030A1

Abstract

A switching device comprises a plurality of interengageable switch modules 20, each switch module 20 comprising a plurality of switches housed within a casing, each switch including a terminal to which an electrical connection can be made from outside of the casing, and a terminal 11b arranged to be connected to a respective bus bar 18 within the casing. The casing of each switch module 20 includes a cylindrical portion into which a rectangular portion is inserted. Flanges at both ends of the cylindrical portion are engageable with the flanges of the casings of adjacent switch modules 20. The switches within each casing are arranged parallel to the flanges and the switch terminals 11b within the casing are arranged substantially on a line passing through the centre of the circular opening of the casing. <IMAGE>

Description

SWITCHING DEVICE The present invention relates to a switching device, and,

more specifically, to a switching device accommodating a plurality of switches in a casing.

Conventional switching devices have a structure, for example, as shown in Japanese Patent Application Laidopen (Kokai) 60-261312. Fig. 7 is a schematic diagram showing a conventional switching device and Figs. 8 and 9 are elevational and said views respectively of the conventional switching device. Figure 10 is a perspective view of a casing of the switching device. In the figures, denoted 1 are vacuum switches, 2a, 2b, and 2c are switches having rotatable moving-contact assembly. Denoted 3 is a casing for accommodating these switches 1, 2a, 2b, and 2c in insulating gas atmosphere. This casing forms T-shaped cylindrical portion with three-way openings, as shown in Fig. 10. Reference numerals 4a, 4b, and 4c are bushings supported by the casing 3 and used for electrically connecting one end of each switch 2a, 2b, and 2c to equipment located out of the casing.

In the switching device having the structure as described above, closing switches 2a and 2c causes bushings 4a and 4c to be electrically connected each other. Further, closing switches 1 and 2b causes bushing 4b to be connected to the bushings as a branch circuit. As a 1 result, power is supplied to electric equipment which is connected to the bushing 4b, such as transformer not shown.

With the conventional switching device thus far described, since it is difficult to assemble electrical equipment as described above in the casing, a large casing is required to carry out the assembly work with ease. Moreover, there is another drawback that since a plurality of switches are accommodated in one casing, it is not possible to add more switches and the direction to pull out the bushings for replacement is restricted to one direction.

It is therefore an object of the present invention to provide a switching device in which the casing is miniaturized; addition of switches is carried out with ease; and pulling-out direction of the bushing is flexibly selected.

A switching device according to the present invention is formed by combining a plurality of switch units, the switch unit each comprising: a cylindrical casing having flanges at both opening ends thereof; and a plurality of switches accommodated in the casing as being parallel to the surface of the flange, one contact of the switch being introduced out of the casing through bush- ing.

Further, the casing comprises a cylindrical portion with notched body and a rectangular casing which is 2 1 1 i 1 i 1 1 z 1 i J 1 1 k inserted in the notch and has flat mounting surfaces provided on at least two surfaces thereof.

The other contact of the plurality of switches each is arranged substantially on a line passing through the center of the circular opening of the cylindrical body.

The foregoing object and advantages will be better understood from the following description with reference to the accompanying drawings, in which:

Figure 1 shows a structure of the switching device according to an embodiment of the present invention; Figures 2 and 3 show elevational and side views of principal part of the switching device; Figures 4A, 4B, 4C, and 4D are elevational view, left side view, right side view, and bottom view of a casing of the switch unit; Ficrure 5 is a single line diagram electrically 0 0 describing the configuration of the switching device shown in Fig. 1; Figure 6 shows the rough structure of the switching device according to another embodiment of the present invention; Figure 7 shows a rough structure of the conventional switching device; Figures 8 and 9 are elevational and side views illustrating detailed structure of the switching device described in Fig. 7; and Figure 10 is a perspective view of the casing of the 3 conventional switching device.

A preferred embodiment of the present invention will now be described with reference to accompanying figures. Figure 1 shows a structure of the switching device according to an embodiment of the present invention.. Figures 2 and 3 are elevational and side views of principal part of the switching device. Figures 4A, 4B, 4C, and 4D are elevational view, left side view, right side view, and bottom view of a casing of the switch unit shown in Figs. 2 and 3 respectively. In the figures, denoted 5 is the casing which comprises a cylindrical portion 7 having flange 6 at each end thereof, and a rectangular casing 8 having flat mounting portions 8a formed on two surfaces inserted in a notch provided on the casing body, as shown in Fig. 4. Reference numeral shows a mounting frame 9 for mounting bushings 10 described below. Denoted 10 are bushings mounted on the mounting frame 9 and penetrating the rectangular casing 8, and one end thereof is to be connected with connector to a cable out of the casing. Numeral 11 show three vacuum valve circuit breakers which are connected with fixed terminals to the one end of the bushings and are arranged substantially parallel to the surface of the flange. The vacuum valve circuit breakers each include a movable contact and a fixed contact. The movable contact is connected to an insulating rod 13 via movable terminal 11b arranged substantially on a line passing through the center the 4 1 1 1 j; 1 1 i i i i i 1 i j 1 1 1 i 1 k casing 7 as shown in dashed line in Fig. 2. Numeral 14 shows an operation mechanism, which is connected to the insulating rod 13 via an operation rod 15, a link 16 and a main shaft 17. Further, the components described above such as the casing 5 and the main shaft 17 form a vacuum valve circuit breaker unit 20. A switching device 30 is formed by combining the vacuum switch units 20 in a plurality of stages as shown in Fig. 1. When the movable contacts are connected to each other with a resilient conductor, a system of which configuration is described in a single line diagram shown in Fig. 5 is obtained. The vacuum valve circuit breaker unit 20 has a function as a three vacuum valve circuit breakers. That is, the operation rod 15 rotates in accordance with the movement of the operation mechanism and switching operation is performed by lifting and dropping the insulating rod 13.

The switching device 30 comprising the vacuum valve circuit breaker units 20 as shown in Fig. 1 is capable of being connected to remaining vacuum valve circuit breaker units between the vacuum valve circuit breaker units 20 at both ends, as illustrated in Fig. 5.

Further, the bushing has a function as a disconnecting switch as being connected with connector to a cable.

With the switching device according to one embodiment of the present invention as described above, since three vacuum valve circuit breakers 11 each is accommodated in a separate casing 5 and the breakers are arranged substantially parallel to the surface of the flanges provided on the opening of the casing at both ends thereof, working space properly secured makes assem bly work in the casing 5 easier than before to assemble the vacuum valve circuit breaker unit 20, preventing the casing 5 from being bulky. When the vacuum valve circuit breaker unit 20 assembled by the above method is combined in a required number to form the switching device 30, as shown in Fig. 1, increasing or decreasing the number of vacuum valve circuit breaker units becomes easy. Besides, pulling-out direction of the bushing is flexibly selected.

Further, since the casing 5 is fabricated by combining, at the notched portion, the cylindrical portion 7 of which body is notched and a rectangular casing 8 having flat mounting surfaces 8a on at least two surfaces, assembly work for each casing can be carried out with ease and reliable sealing characteristics of the casing is expected.

In the above embodiment, a vacuum valve circuit breaker 11 is used as a switch as an example, similar effect may be expected for other switches besides the vacuum valve circuit breaker, such as load switch, disconnecting switch and the combination of a vacuum valve circuit breaker 11 and a disconnecting switch 19 as exemplified in Fig. 6.

Further, in the above embodiment, the vacuum valve circuit breakers 11 are arranged on one line parallel to the surface of the flange 6. However, similar effect may 6 1 1 1 1 1 1 i 1 1 i 1 i i 1 i i 1 1 1 be expected in case that even the vacuum valve circuit breakers deviate in front of and behind each other as long as the movable contact 11b is not overlapped to the vacuum valve circuit breakers as seen from the flange side.

In addition to the above, when the casing 5 is fabricated in such a manner that the length of the cylindrical portion thereof is less than one-half of the diameter of the cylindrical portion, flat surfaces of the rectangular casing 8 need not to be reinforced to resist pressure applied, resulting in reduction in its weight.

As described above, the present invention described in claim 1 provides a switching device which is formed by combining switch units comprising: a cylindrical casing having flanges at both end thereof; and a plurality of switches accommodated in the casing as being parallel to the surface of the flange, one terminal of the switch being introduced out of the casing through bushing. As a result, assembling work is performed with ease; the casing of the unit is miniaturized; and increasing or decreasing numbers of the units is carried out with ease.

Further, in the invention according to claim 2, the casing comprises a cylindrical portion with notched body, and a rectangular casing inserted in the notch and having a flat mounting surface on at least two surfaces of the casing, permitting easier fabrication work for each casing and reliable sealing characteristics.

Further, in the invention according to claim 3, 7 since the other terminal of the plurality of switches each is arranged on a line passing through the center of the cylindrical portion, pulling-out direction of the bushing is flexibly selected in assembly work and the bushings are arranged with ease in consideration with erection location.

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Claims

1. A switching device comprising a plurality of interengagable switch modules, each switch module comprising a casing housing a plurality of switches, each switch including a terminal to which an electrical connection can be made from outside of the casing, and a terminal arranged to be connected to a respective bus bar within the casing.

2. A switching device as claimed in Claim 1, in which each casing is substantially cylindrical and includes a flange at each end.

3. A switching device as claimed in Claim 2, in which the switch modules are arranged such that at least one flange of each switch module overlies a flange of another switch module.

4. A switching device as claimed in any one of the preceding claims in which the number of bus bars is equal to the number of switches in each switch module.

5. A switching device as claimed in Claim 4, in which the bus bars are arranged to lie on a line passing substantially through the center of each casing.

6. A switch module for use in a switching device a claimed in any one of the preceding claims.

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7. A switching device comprising: a cylindrical casing having flanges at both opening ends thereof; and switch units each having a plurality of switches which are accommodated in the cylindrical casing as being arranged parallel to surfaces of the flanges, a terminal of the switches each being pulled out from the casing, said switch units being combined in a plurality of stages at said surfaces of the flange.

8. A switching device as claimed in Claim 7, wherein said casing comprises a cylindrical portion with notched body; and a rectangular casing inserted in the cylindrical casing and having flat mounting surfaces provided on at least two surfaces thereof.

9. A switching device as claimed in Claim 7 or 8, wherein the other terminal of said plurality of switches each is arranged substantially on a line passing through the center of circular opening of the cylindrical casing.

10. A switching device substantially as hereinbefore described with reference to Figure 1 of the accompanying drawings.

11. A switch module for use in a switching device, the switch module being substantially as hereinbefore described with reference to Figures 2 to 4 of the accompanying drawings.

Published 1992 at The Patent Office. Concept House. Cardiff Road. Newport. Gwent NP9 I RH. Fur-,!,.,.- copies may be obmined frorn Sales Branch. Unit 6. Nine Mile Point. Cminfelinfach. Cross Keys. Neu-pori. NP1 7HZ. Printed by Multiplex techniques lid. St 'Marv Cray. Kent- 51 k 1 i 1 j i i 1 1 i i