AU2004201557A1

AU2004201557A1 - Locking device of a plug-in electrical apparatus and switchgear apparatus comprising such a device

Info

Publication number: AU2004201557A1
Application number: AU2004201557A
Authority: AU
Inventors: Henri Lartizien; Robert Michel
Original assignee: Schneider Electric Industries SAS
Current assignee: Schneider Electric Industries SAS
Priority date: 2003-04-15
Filing date: 2004-04-14
Publication date: 2004-11-04
Also published as: KR101042866B1; KR20040090475A; EP1469571A1; FR2853989B1; FR2853989A1; TWI316317B; TW200503372A

Description

P001ool Section 29 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Locking device of a plug-in electrical apparatus and switchgear apparatus comprising such a device The following statement is a full description of this invention, including the best method of performing it known to me I us: LOCKING DEVICE OF A PLUG-IN ELECTRICAL APPARATUS AND SWITCHGEAR APPARATUS COMPRISING SUCH A DEVICE.

The present invention relates to a locking device of a propulsion device of a plug-in electrical switchgear apparatus, said propulsion device comprising a screw-and-nut system designed to drive said switchgear apparatus between a plugged-out position and a pluggedin position when an operating means of the screw is actuated.

Known plug-in circuit breakers are propelled by a screw-and-nut type system and can be positioned in three positions respectively a position enabling tests to be performed, a plugged-in position for operation of the circuit breaker and a position reserved for transport.

However, during the switchgear apparatus plug-in and plug-out operations, stresses are accumulated by the screw-and-nut system, which stresses are released when the circuit breaker opening and closing operations are performed. This results in disengagement or withdrawal of a switchgear apparatus being able to occur during these opening and closing operations.

This movement of the circuit breaker in the live plugged-in position can give rise to an internal arc at the level of the plug-in parts liable to cause damage to the assembly formed by the cubicle and circuit breaker.

The present invention overcomes this problem and proposes a locking device of a propulsion device of a plug-in electrical switchgear apparatus, and an electrical switchgear apparatus equipped with such a device.

For this purpose, the object of the present invention is to provide a device of the kind mentioned above, this device being characterized in that it comprises means for preventing rotation of the screw in the opposite direction after a plug-in or plug-out operation of the switchgear apparatus.

According to a particular embodiment of the invention, these means comprise a cog-wheel secured in rotation with the above-mentioned screw, and a spring blade actuated by an operating means between a position in which said spring blade engages between the teeth of the cog-wheel so as to perform latching preventing rotation of the screw in the opposite direction after a plug-in or plug-out operation of the switchgear apparatus, and a position in which the spring blade releases the cog-wheel so as to enable rotation of said screw.

But other advantages and features of the invention will become more clearly apparent from the following detailed description which refers to the accompanying drawings given for example purposes only, in which: -Figures 1 and 2 are side views of an electrical switchgear apparatus according to the invention, equipped with a locking device according to the invention, said figures representing said apparatus respectively in a plugged-out position and a plugged-in position, -Figure 3 is a top view of the propulsion case of the above-mentioned apparatus comprising a locking device according to the invention, -Figure 4 is a partial cross-sectional view of the previous figure, illustrating the locking device, -Figure 5 is a partial perspective view illustrating in particular the selector case comprising the propulsion device locking device, -Figure 6 is a longitudinal cross-sectional view of the previous figure, -Figure 7 is a partial perspective view illustrating the switchgear apparatus propulsion plate comprising the operating means, and -Figure 8 is a front view of the previous figure.

In figures 1 and 2, a plug-in electrical circuit breaker D can be seen, mounted mobile in a frame C between a plugged-out position (fig.1) and a plugged-in position (fig.2). The circuit breaker is in a plugged-out state when it is in a position called plugged-out in cubicle, a test position in cubicle, a position called extraction position or a transport position. The plugged-in position of the switchgear apparatus corresponds to a state enabling it to be put into operation. Movement of the switchgear apparatus between the two above-mentioned positions is performed by means of a propulsion device P able to be actuated by an operating means and illustrated in particular in figures 3 to 6. In these two positions respectively plugged-out and plugged-in, the circuit breaker D can take two positions as far as its contacts are concerned i.e. an open contacts position in which current flow is not established in the circuit breaker, and a closed contacts position in which current flow is established. Switching from the open position to the closed position is performed by means of a push-button B (figure 3) able to be actuated via a control panel 1 situated on a propulsion plate 4 of the switchgear apparatus.

In figures 1 and 2, it can be seen that the frame C on which the circuit breaker D is mounted comprises a propulsion case 2, more particularly illustrated in figure 3, a case called selector case 3 and a propulsion plate 4.

Referring to figures 3 to 6, it can be seen that the above-mentioned propulsion device P comprises an endless screw 5 on which there is fitted a nut 6 secured to the switchgear apparatus, the screw 5 being able to be driven in rotation by means of a crank (not shown) constituting an operating means, rotation of the screw when the operating means is actuated resulting in movement of the switchgear apparatus between the two abovementioned plugged-in and plugged-out positions.

Referring to figures 5 and 6, it can be seen that the selector case 3 comprises a position selector 7 for commanding the switchgear apparatus position change. As can be seen in figure 8, this selector 7 can be placed in four different positions a,b,c,d. As can be seen in figures 7 and 8, the switchgear apparatus propulsion plate 4 comprises a hole 9 to enable the operating crank of the screw 5 to pass through, this hole 9 facing a recess 10 provided inside the screw 5. This hole 9, in certain positions of the selector 7, called locking positions, is able to be blanked off by a slide 11 driven by the selector 7 so as to prevent actuation of the screw 5 by the crank, and therefore movement of the switchgear apparatus.

The slide 11 also comprises a hole 12 able to be moved to face the hole 9 situated in the plate 4 to enable action to be performed on the screw 5 in certain positions of the selector 7.

According to the invention, this switchgear apparatus comprises another locking device designed to prevent movement of the circuit breaker either in the plugged-out position or in the plugged-in position. This device comprises a cog-wheel 13 fitted at the end of the screw 5 and secured in rotation with said screw 5, and a spring blade 14 secured to the above-mentioned slide 11. This spring blade 14 is arranged so as to be able to engage between the teeth of the cog-wheel 13 when movement of the slide 11 takes place, and to perform latching. This latching is designed to prevent movement of the switchgear apparatus in the opposite direction when the apparatus is moved to the plugged-in or plugged-out position.

Operation of the device of the invention will be described in the following with reference to the figures.

The position selector 7 can take four positions. To operate this selector 7, in certain positions thereof, an opening order has to be given to the circuit breaker by means of the push-button B. To access this button B, a cache D has to be swivelled, said cache D being able to be padlocked according to the interlocks.

When the selector 7 is in position a (figure the propulsion P system is unlatched, i.e. the lateral latching fingers 8 are retracted. The propulsion screw 5 is in a latched locked position, the circuit breaker being able to be fitted in the cubicle or removed therefrom. The propulsion screw 5 is locked in the sense that it cannot be driven by means of the crank as the hole 9 for inserting said crank is blanked off by the slide 11. Moreover, in this position, the spring blade 14 is engaged between the teeth of the cog-wheel 13 and performs latching of the wheel. The push-button B has to be actuated to achieve a change of state of the selector 7. When the operator modifies the position of the selector 7 and moves the latter from position a to position b, the selector 7 drives the lateral latching fingers 8 which immobilise the circuit breaker in the cubicle in the test position or transport position. The circuit breaker is plugged out. As the slide 11 has remained immobile, the propulsion screw is still locked. The spring blade 14 is engaged between the teeth of the cog-wheel 13 thus performing latching and locking of the propulsion screw 5 preventing movement of the switchgear apparatus.

When the operator wants to perform plug-in of the switchgear apparatus, he gives an opening order by actuating the push-button B and moves the selector from position b to position c. During its movement, the selector 7 moves the slide I I in translation, releasing the cog-wheel 13 belonging to the propulsion screw 5, from the spring blade 14, which spring blade 14 being securedly fixed in translation to the slide 11. This movement of the slide 11 also releases the crank insertion hole 9, the hole 12 provided in the slide 11 being moved to face the hole 9 provided in the switchgear apparatus propulsion plate 4 for insertion of the crank. In this position, it is then possible to act on the propulsion screw so as to perform plug-in of the switchgear apparatus. After this plug-in has been performed, the operator moves the selector 7 from position c to position d. This results on the one hand in movement of the slide 11 so that said slide 11 blanks off the crank insertion hole 9, and on the other hand in engagement of the spring blade 14 between the teeth of the cog-wheel 13 so that this spring blade 14 prevents movement of the switchgear apparatus in the opposite direction, i.e. plug-out. The circuit breaker D is then in a plugged-in and latched position, and the propulsion screw 5 is locked. The push-button B is released and can be used to perform the different operations. Latching of the screw 5 takes place naturally during actuation of the position selector 7.

A cog-wheel system latched by a spring blade has thus been achieved by means of the invention, enabling movement of the propulsion screw in rotation either in the closed or open locked test position, or in the closed or open locked plugged-in position or in the open transport position, in fact in any functional position taken by the apparatus, to be prevented.

This system can be adapted to suit all screw-and-nut type switchgear apparatus propulsion systems.

Naturally the invention is not limited to the embodiment described and illustrated which has been given for example purposes only.

The invention thus applies to any switchgear apparatus that is mobile on a frame and lockable, such as for example a disconnecting carriage designed to connect a top busbar to cables or to a bottom busbar.

On the contrary, the invention encompasses all the technical equivalents of the means described as well as combinations thereof if the latter are achieved according to the spirit of the invention.

Claims

1. Locking device of a propulsion device of a plug-in electrical switchgear apparatus fitted in a frame, said propulsion device comprising a screw-and-nut system designed to drive said switchgear apparatus between a plugged-out position and a plugged-in position when an operating means is actuated, said device comprising means for preventing rotation of the screw in the opposite direction after a plug-in or plug-out operation of the switchgear apparatus, characterized in that these means comprise a cog-wheel (13) secured in rotation with the above-mentioned screw and a spring blade (14) actuated by an operating means between a position in which said spring blade (14) engages between the teeth of the cog-wheel (13) so as to perform latching preventing rotation of the screw in the opposite direction after a plug-in or plug-out operation of the switchgear apparatus D, and a position in which the spring blade (14) releases the cog-wheel (13) so as to enable rotation of said screw

2. Locking device according to claim 1, characterized in that the switchgear apparatus D comprising a position selector designed to enable switching of said switchgear apparatus to different positions, the above-mentioned spring blade (14) is secured to a slide (11) mounted sliding inside the frame between a position in which the spring blade (14) is engaged between the teeth of the cog-wheel (13) and a position in which the spring blade (14) is no longer engaged between the teeth of the cog-wheel said slide (11) being actuated between these positions by the above-mentioned selector

3. Locking device according to claim 2, said switchgear apparatus comprising a propulsion plate comprising a first hole for passage of a means for actuating the propulsion screw between the above-mentioned plugged-in and plugged-out positions of the switchgear apparatus D, characterized in that the above-mentioned slide (11) comprises a hole called the second hole (12) able to be moved by the selector to a position facing the above-mentioned first hole so as to enable the operating means to be inserted in the two holes (9,12) and action to be performed on the screw or to a position in which the two holes (9,12) are not superposed so as to prevent insertion of the operating means.

4. Locking device according to any one of the foregoing claims, characterized in that it is put into operation in the test position, in the plugged-in position and in the transport or extraction position of the switchgear apparatus D. Electrical switchgear apparatus comprising a locking device according to any one of the foregoing claims.

6. Circuit breaker comprising a locking device according to any one of the foregoing claims.

7. Electrical disconnection carriage designed to connect a top busbar to cables or to a bottom busbar, characterized in that it comprises a device according to any one of the foregoing claims. DATED this 14th day of April, 2004 SCHNEIDER ELECTRIC INDUSTRIES SAS WATERMARK PATENT TRADIEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN. VICTORIA 3133