FR2766633A1 - ELECTRICAL SWITCHING INSTALLATION - Google Patents

Abstract

The installation comprises a frame with introduction shelves, for inserting drawers (1) carrying switching devices, comprising first contacts in the frame and first complementary contacts (3, 4) on the drawers. A main circuit is closed by moving the first complementary contacts (3, 4) relative to the slide (1) towards the first contacts by means of a first actuator. Second contacts are provided in the introduction frame and complementary second contacts (7) on the drawer (1). An auxiliary electrical circuit is closed by moving the second complementary contacts (7) relative to the slide (1) in the direction of the second contacts by means of a second actuator. A locking device, when the second contacts and the second complementary contacts (7) come into contact, prevents the first complementary contacts (3, 4) from coming into contact with the first contacts.

Description

The present invention relates to an electrical switching installation

  comprising an introductory frame having a plurality of introductory shelves, into which drawers carrying switching devices can be inserted, comprising first connection contacts carried in the introductory frame and first complementary contacts provided on the drawers, capable of being electrically connected with each other to close a main electrical circuit by the fact that the first complementary contacts are moved relative to the drawer in the direction of the connection contacts by means of a first actuating member, and comprising second connection contacts carried in the insertion frame and second complementary contacts provided on the drawer, capable of being connected with each other to close an auxiliary electrical circuit, in particular an electrical test circuit, by the fact that the second complementary contacts are moved relative to the slide in the direction of the second connection contacts by means of a second actuating member, the first actuating member preferably also acting on the second complementary contacts to close the auxiliary electrical circuit simultaneously with the circuit

main electric.

  Such a switching installation is known from document DE 195 09 474 Ai. In this known switching installation, the first complementary contacts and the second complementary contacts are moved in the direction of contacting by actuating members independent of each other. In this case, the first complementary contacts are guided in displacement on the slide and they are moved in contact position only after completion of the introduction of the slide into the introduction frame to establish the operating position of the switching devices. provided on the drawer. Independently of this, the second complementary contacts can be connected with the second connection contacts by actuation of a second actuating member, namely contacts of a control connector,

  to run a device test.

  A problem with this known switching installation consists in that electrical discharges between the first complementary contacts and the first connection contacts can appear when starting up in the operating state by actuation of the first actuation member, when '' a voltage from the preliminary test phase still applies at the

control connector.

  The objective underlying the invention is to solve this problem and in particular to prevent the appearance of discharges during the setting in

  works in operating state.

  In a switching installation of the type mentioned in the introduction, this objective is achieved by the fact that a blocking device is provided which, when the second connection contacts and the second complementary contacts are brought into contact, prevents switching on. contact of the first complementary contacts

  with the first connection contacts.

  Thanks to the blocking device according to the invention, electrical discharges are reliably prevented, since bringing the first complementary contacts into contact with the first connection contacts is only possible after prior separation between the second complementary contacts and the second connection contacts. Consequently, no voltage originating, for example, from a preliminary test phase can no longer apply to the second complementary contacts. In other words, the drawer must be in the zero position when you want to close the electrical circuit

main.

  Preferably, a second blocking device is provided which, when the first connection contacts are brought into contact with the first complementary contacts, prevents detachment between the second complementary contacts and the second connection contacts. In this case, an accidental opening of the auxiliary electrical circuit is prevented when the main electrical circuit is closed. The locking devices are produced in particular in the form of mechanical locking devices. For example, the actuating members may each comprise a part forming a lock capable of being actuated by a key, the access opening of the lock for the key being capable of being closed by a slide for blocking. It is particularly preferable that the two locks are capable of being actuated with a single key. Thus, the actuation of the switching installation is simplified, and thanks to the blocking devices according to the invention, it is not necessary to run

  at the same time there is no risk of handling errors.

  In this case, it is possible to use as a key for example a simple square which cooperates with a lock part produced in correspondence of

the respective actuator.

  According to another development of the invention, indicator means are provided by which the actuation state of the drawer can be indicated, therefore in particular a zero position, a test position, and an operating position. Thanks to this development, another simplification of handling is obtained, since the operating state of the respective drawer is immediately visible and thus

  we can already prevent the attempt of a handling error.

  According to a particular development of the invention, the first actuator comprises a threaded shaft in rotation, preferably by means of a key, in particular a square key, which moves during a rotation the first complementary contacts by compared to the drawer and which thus brings them into engagement with the first connection contacts of the introduction frame and which simultaneously switches an angled lever, which is coupled by one of its rocking arms to a cursor guided in movement on the shaft and moves by its other arm the second complementary contacts relative to the drawer and thus brings them into engagement with the second connection contacts. Thanks to this development, the main electrical circuit and the auxiliary electrical circuit are particularly favorably closed simultaneously by the sole actuation of the first actuating member, and thanks to the angled lever it is possible to advantageously carry out different directions of contacting. In particular, the direction of contacting of the second contacts may extend perpendicular to the direction of contacting of the

first contacts.

  According to another development of the invention, there is provided in the drawer a movable insert transverse to the direction of introduction, which carries the second complementary contacts and which is moved in the direction of bringing into contact when the first member of the actuation actuation, the second complementary contacts being guided at their turn in displacement in the direction of contacting on the insert and

  being moved by actuation of the second actuator.

  Thanks to this development, it is reached that the second contacts can be brought into contact with one another as desired by actuation of the first actuation member or of the second actuation member, either to execute a test of the device, or for

establish the operating state.

  According to another development of the invention, the drawer and the movable insert each comprise, on the front face directed towards the opening side of the introduction frame, a front wall having a passage opening for the key, in mutual alignment in zero position, but offset from each other in the actuation position of the first actuator. Thanks to the passage openings which are in mutual alignment only in the zero position, the blocking device according to the invention is produced in a structurally simple manner.

  for actuation of the second actuator.

  According to another development of the invention, the second actuating member comprises a rack movable in the direction of movement of the second complementary contacts by a toothed shaft, which attacks on the one hand the second complementary contacts and on the other hand an end d '' a rocking lever, on the other end of which is articulated a slide which is guided in displacement on the interior face of the front front wall of the drawer parallel to this wall and which covers, during an actuation of the second actuation member , a passage opening in the front wall of the drawer for the key to activate the threaded shaft, while it releases it in the zero position. This development favorably actuates the second contacts and simultaneously blocks the first actuating member. Preferably, the second shaft is locked against rotation as long as no key is inserted, in order to ensure that the second complementary contacts are moved in the direction of contacting when the first is actuated. actuator and during movement of the insert, and

  that no opposite rotation of the second shaft occurs.

  According to another development of the invention, the drawer can be covered by a door mounted on the introduction frame, by providing a locking element which prevents the door from opening when the first and / or second contacts are closed. This development represents another safety aspect, which prevents damage to the switching installation by extraction of the

  drawer in test or operating position.

  Preferably, a hook arranged on the movable insert serves as a locking element which cooperates with a stop provided on the door. In this case, the hook is capable of being triggered manually, in particular against the force of a return spring, by providing

  a hook access opening for emergency release.

  This development ensures that the door can be opened in special emergency cases, even when the first and / or

  the second contacts are connected to each other.

  According to another development of the invention, the two actuating members for the first and second contacts each include a drive bar guided in displacement in the drawer, one of which moves the first complementary contacts and the other the second complementary contacts in the direction of contacting, as well as a toothed wheel rotatably mounted in the drawer and meshing with the drive bar, wheel by which the associated drive bar is capable of being actuated. This development allows a particularly compact realization of the

  drawer and is therefore particularly suitable for smaller drawers.

  In this case, the drive bars each attack an arm of a bent lever rotatably mounted in the drawer, the other arm of which is

  coupled to the first or second complementary contacts.

  Thanks to this, it is possible to choose the direction of contacting independently of the direction of movement of the drive bars, in particular perpendicular thereto, and the two directions of contacting are preferably equal to one

1 5 the other.

  According to another development of the invention, the second toothed wheel is arranged in a frame guided in movement in the drawer parallel to the second drive bar, frame on which is coupled a third drive bar which meshes with the first wheel and which is moved by it simultaneously with the first drive bar. Thanks to this development, the second complementary contacts can be moved in the direction of contacting as desired by actuation of the first or

second actuators.

  Preferably, the gears are capable of being actuated by means of a key and they are locked against rotation when the key is removed. To this end, the toothed wheels may include a central housing for the key, in particular a key.

  square, the housing can be covered by a plate.

  Both the rotation of the toothed wheels and the locking are thus carried out in a particularly simple manner. Thanks to the blocking against rotation, it is ensured during an actuation of the first actuating member that the second complementary contacts are simultaneously displaced, that the toothed wheel does not rotate in the direction

  opposite and that the second drive bar is thus not stopped.

  The direction of bringing the first and second complementary contacts into contact preferably extends in the direction of introduction. The indicating device and the plate are preferably actuated

  also through the drive bars.

  Advantageous embodiments of the invention also emerge from the

  drawings and description of the figures.

  Exemplary embodiments of the invention are illustrated in the drawings and will be described in the following. The figures show diagrammatically: FIG. 1 a section through a drawer according to the invention; Figure 2 actuating elements for use in the embodiment of Figure 1, in enlarged illustration in the zero position; Figure 3 the actuating elements of Figure 2 in the test position; Figure 4 the actuating elements of Figure 2 in the operating position; Figure 5 a perspective illustration of the actuating members of a second embodiment of the invention; Figure 6 the top view on the actuating members of Figure 5, the elements being partially removed and in the zero position; Figure 7 an illustration according to Figure 6, but in the test position; and Figure 8 an illustration according to Figure 6, but in the operating position. The drawer 1 illustrated in FIG. 1 of an electrical switching installation is made in the form of a box and it has on its rear wall 2 situated in the direction of introduction several contacts 3 and 4 which are capable of being brought into contact as complementary contacts with connection contacts not illustrated here in an introduction frame, which is not illustrated either, of the switching installation according to the invention. The complementary contacts 3 and 4 each include here a movable contact slide in the direction of contacting along a contact rail 6. Only one contact slide 5 has been illustrated. The contacts 3 can be used for particular to the connection of a main electrical circuit, while the contacts 4 are used for example for the

  connection to a power supply.

  The second complementary contacts are produced in the form of a control connector 7 illustrated only diagrammatically, which is movable perpendicular to the direction of introduction I into the drawer 1 and which can be connected to a corresponding socket in the introduction frame. As can be seen in FIG. 2, the connector 7 is arranged on an insert 8 movable transversely to the direction of introduction I, therefore in the direction of contacting II of the connector 7 in the drawer 1. The connector 7 is located on a support 9 which in turn is guided in displacement on the insert 8 in the direction of bringing II into contact with the connector 7. For this purpose, a rack 10 driven in the direction of bringing into contact II via a shaft 11 attacks the support 9 The shaft 11 can be turned by means of a key not illustrated here which is capable of being brought into engagement with a front side of the shaft 11. For this purpose, passage openings 14 and 15 have been provided. in mutual alignment in the front front wall 12 of the insert 8 and in the front front wall 13 of the drawer 1. By turning the shaft 11, the rack 10 is moved in the direction of contacting II and the connector 7 is thus connected to the associated socket. This

  test position is illustrated in figure 3.

  A bent lever 16 attacks the insert 8 by one of its arms 17 and it is

  rotatably mounted around a rotation point 18 in the drawer 1.

  The other arm 19 of the bent lever 16 is coupled to a first slide which is guided in displacement on a threaded shaft 21. By turning the threaded shaft 21, the slide 20 moves and thus causes the bent lever 16 which moves to in turn the insert 8 in the direction of contacting II of the connector 7. During the rotation of the threaded shaft 21, a second slide 22 is simultaneously moved in the direction of introduction I, which is coupled with the first complementary contacts 3, 4, in particular through an element

  common comb which is not shown here.

  A rotation of the threaded shaft 21 therefore leads on the one hand to bringing the first complementary contacts 3, 4 into contact with the associated connection contacts in the introduction chassis and on the other hand to a connection of the connector 7 with the associated socket. This operating position is illustrated in FIG. 4. By moving the insert 8, the passage opening 14 is also displaced relative to the passage opening 15, so that these are no longer in alignment with the one with the other. Consequently, it is no longer possible to insert a key and bring it into engagement with the shaft 11. This means that rotation of the shaft 11 is not possible when the shaft

threaded 21 is turned.

  The actuation of the threaded shaft 21 is carried out in turn by means of a key, preferably being able to use the same key as for the actuation of the shaft 11. Another opening has been provided for. passage 23 in the front wall 13 of the drawer 1, through which

  can insert the key and bring it into engagement with the threaded shaft 21.

  The passage opening 23 can be covered by a plate 24 which is guided in movement in the drawer 1 parallel to its front front wall 13 and which is actuated by a lever 25 mounted in rotation on the insert 8 and articulated by the one of its ends 26 on the plate 24 and by its other end 27 on the rack 10. When the rack 10 moves in the direction of contacting II by rotation of the shaft 11, the lever 25 is tilted around from its point of rotation 28 and the plate 24 is thus moved in front of the passage opening 23 (FIG. 3). When the rack 10 is deployed, therefore in the test position of the connector 7, the introduction of a key through the passage opening 23 and thus a rotation of the threaded shaft 21 are prevented. Thus, in the test position, the contacts 3 and 4 cannot be connected to the associated connection contacts. This is only possible when the connector 7 has been brought back before.

in the zero position.

  In addition, there is provided in the region of the connector 7 a hook 29 which is deployed laterally together with the connector 7 out of the drawer 1, when the shaft 11 or the threaded shaft 21 has been turned. The hook 29 then cooperates with a stop which is provided on a door not illustrated here, which is articulated on the introduction frame and which covers the drawer 1. In the test position and in the position

  operation, an opening of the door is thus blocked.

  A leaf spring 29a which is fixed on the door and which has an opening in which the hook 29 engages serves as a stop. For an emergency opening of the door, the leaf spring 29a can be tilted by an auxiliary member capable of being introduced through an opening in the door or between the door and the introduction frame, so that the hook 29 is released. Thanks to this development, the door can be opened in the event of an emergency also in the position of

test or operation.

  In the second embodiment, the drawer comprises the actuating members illustrated in FIGS. 5 to 8. A first drive bar 31 and a second drive bar 32 are guided laterally in movement parallel to one another. another in a housing 30. The two drive bars 31 and 32 each have a row of holes 33, 34 into which a respective toothed wheel 35, 36 engages in rotation in the housing 30. By turning the toothed wheels 35 and 36, the drive bars 31 and 32

  are moved in the housing 30.

  The first drive bar 31 and the second drive bar 32 each attack an arm 37, 38 of a bent lever 39, 40 pivotally mounted in the housing 30, of which the other respective arm 41, 42 displaces contacts complementary provided in the drawer relative to it, in order to connect them with the connection contacts in the introduction frame. The two directions of bringing the first and second complementary contacts into contact extend in the same direction with respect to each other and perpendicular to the direction of movement of the two drive bars 31 and 32 which are displaced at turn in opposite directions to each other

for actuation.

  The second toothed wheel 36 is rotatably mounted in a frame 43 guided in movement in the housing 30 parallel to the second drive bar 32. A third drive bar 44 is articulated on this frame 43 and it is arranged between the first drive bar 31 and the second drive bar 32 and moving parallel thereto. The third drive bar 44 also has a row of holes 45. The first toothed wheel 35 engages in such a row of holes 45 that the third drive bar 44 is moved during the rotation of the first wheel gear 35 in the direction of actuation of the second drive bar 32. Thanks to this, by turning the first gear 35, the first drive bar 31 and the second drive bar 32 are moved simultaneously in the direction of actuation, so the first complementary contacts are connected to the first connection contacts just as the second complementary contacts are connected to the second connection contacts. The two toothed wheels 35 and 36 are provided on the front side with a respective recess 46, 47 of square shape, in which a square key can be threaded to turn the toothed wheels 35, 36. At least the second toothed wheel 36 is here provided with an anti-rotation element which is undone when the key is put in place. Thanks to this, it is ensured that the second toothed wheel 36 does not rotate during movement by the third drive bar 44, but that it takes the second

  drive bar 32 and thus actuates the bent lever 40.

  By turning the second toothed wheel 36 by means of a key, the second drive bar 32 is moved downwards by itself and the second bent lever 40 is thus tilted so that its second arm 42 moves towards the in the plane of Figure 7, and that

  moves the second complementary contacts relative to the drawer.

  This is the test position. By turning the first toothed wheel 35, the first drive bar 31 is moved upwards and thus the first bent lever 39 is tilted so that its second arm 41 moves rearward in the plane of Figure 8 , and that it moves the first complementary contacts relative to the drawer. By turning the first gear 35, the third drive bar 44 is simultaneously moved with the second gear 36 downward. The second toothed wheel 36 here takes the second drive bar 32, so that the latter is also moved downwards and thus causes the second bent lever 38 to tilt so that its second arm 42 is again tilted towards the 'rear in the plane of the drawing and thus also moves the second complementary contacts relative to the drawer. This is the operating position. A plate 48 and a window 49 are arranged on the middle drive bar, which are moved with the third drive bar 44 when the latter is moved. When the drive bar 44 is moved downward, the plate 48 covers the opening in front of the square-shaped recess 47 of the second toothed wheel 36 and thus prevents the introduction of a key into the opening of the second toothed wheel 36. In addition, when the third drive bar 44 is moved downward, the number I appears in place of the number 0 behind the window 49, as an indication for the operating position of the drawer . The second toothed wheel 36 can therefore be actuated only in the zero position. In place of the indication of numbers, one can also use other indications,

  for example colored symbols.

  The plate 48 has a rising slope not illustrated here and it is tilted relative to the third drive bar 44, so that it covers the square opening 46 of the first wheel

toothed 35 during tilting.

  There is provided on the second drive bar 32 a spout, not illustrated, which cooperates with the rising slope and which causes the plate 48 to tilt in front of the opening 46 of the first toothed wheel 35 when the second drive bar moves. 32. When the second gear 36 is rotated, therefore in the test position of the drawer, the introduction of a key into the first gear 35 is thus not possible. Likewise, the first toothed wheel 35 can be turned only in the zero position of the drawer. This means that the second toothed wheel 36 must first be turned back, before the first wheel 35 can be turned to start up.

the operating state.

  The second exemplary embodiment represents a particularly compact embodiment of the invention; a handling error and the appearance of discharges are therefore prevented, by the fact that the establishment of the operating position of the drawer is only possible after prior return of the latter, when the drawer is

  was previously in the test position.

  The following list is a legend relating to the numerical marks

  mentioned above and appearing on the drawings.

  List of references 1 drawer 2 rear wall 3 contact 4 contact slide contact 6 contact rail 7 control connector 8 insert 9 rack support 11 shaft 12 front wall 1 5 13 front wall 14 passage opening passage opening 16 bent lever 17 arms of 16 18 point of rotation of 16 19 arms of 16 first slide 21 threaded shaft 22 second slide 23 passage opening 24 lever plate 26 end of 25 27 end of 25 28 point of rotation 29 hook 29a leaf spring housing 31 first bar d drive 32 second drive bar 33 row of holes 34 row of holes first gear 36 second gear 37 arm 38 arm 39 bent lever bent lever 41arm 42 arm 43 frame 44 third drive bar row of holes 46 square recess 47 square recess 48 plate 49 window I direction of contacting of 3, 4 It direction of contacting of 7

Claims (21)

Claims   1. Electrical switching installation comprising an introductory frame having a plurality of introductory shelves and into which drawers (1) carrying switching devices can be inserted, comprising first connection contacts carried in the frame introduction and first complementary contacts (3, 4) provided on the drawers, capable of being electrically connected with each other to close a main electrical circuit by the fact that the first complementary contacts (3, 4) are displaced relative to the drawer (1) in the direction of the connection contacts by means of a first actuating member (21, 22), and comprising second connection contacts carried in the insertion frame and second complementary contacts (7) provided on the drawer (1), capable of being connected with each other to close an auxiliary electric circuit, in particular an electric circuit ique test, by the fact that the second complementary contacts (7) are moved relative to the slide (1) towards the second connection contacts by means of a second actuating member (10, 11), the first member actuator (21, 22) preferably also acting on the second complementary contacts (7) to close the auxiliary electrical circuit simultaneously with the main electrical circuit, characterized in that a locking device (24) is provided, which when the second connection contacts and the second complementary contacts (7) come into contact, prevents the first complementary contacts from coming into contact   (3, 4) with the first connection contacts.   2. Electrical switching installation according to claim 1, characterized in that a second blocking device (13, 14) is provided which, when the first connection contacts are brought into contact with the first complementary contacts (3 , 4), prevents detachment between the second complementary contacts (7) and the second connection contacts.   3. Electrical switching installation according to one or other of the   Claims 1 and 2, characterized in that devices are provided mechanical blocking.   4. Electrical switching installation according to claim 3, characterized in that the actuating members each comprise a key and a part forming a lock, and in that the access opening (23) of the lock part for the key may be blocked by a slide (24) for blocking.   5. Electrical switching installation according to claim 4, characterized in that the two locks are capable of being   operated with a single key.   6. Electrical switching installation according to any one of   previous claims, characterized in that provision is made   indicator means by which the actuation state of the drawer (1) can be indicated.   7. Electrical switching installation according to any one of   previous claims, characterized in that the first member   actuator comprises a threaded shaft (21) in rotation preferably by means of a key, in particular a square key, by which the first complementary contacts (3, 4) are moved relative to the drawer (1) and are thus brought into engagement with the first connection contacts of the insertion frame and which simultaneously switches an angled lever (16), which is coupled by one of its arms (19) to a cursor (20) guided in movement on the shaft (21) and moves by its other arm (17) the second complementary contacts (7) relative to the drawer and thus brings them into   engagement with the second connection contacts.   8. Electrical switching installation according to claim 7, characterized in that there is provided in the drawer (1) an insert (8) movable transversely to the direction of introduction (I), which carries the second complementary contacts (7 ) and which is moved in the direction of contacting (II) when the first actuating member (21) is actuated, the second complementary contacts (7) being guided in turn in displacement in the direction of contacting ( II) on the insert (8) and being moved by actuation of the second actuating member (11). 9. Electrical switching installation according to claim 8, characterized in that the slide (1) and the movable insert (8) have on the front face a front wall (12, 13) having a respective passage opening (14, 15) for the key, in mutual alignment in zero position, but in offset relative to each other in position   actuating the first actuating member (21).   10. Electrical switching installation according to one or other of the   claims 8 and 9, characterized in that the second member   actuation comprises a shaft (11) by which a rack (10) is movable in the direction of contacting (II) of the second complementary contacts (7), which attacks on the one hand the second complementary contacts (7) and d on the other hand one end (27) of a rocking lever (25), at the other end (26) of which is articulated a slide (24) guided in movement on the inside of the front front wall (13) of the drawer (1) parallel to this wall, and said slide covering, upon actuation of the second actuating member (11), a passage opening (23) in the front wall (13) of the drawer (1) for the key to operate the threaded shaft, while releasing it in zero position.   11. Electrical switching installation according to claim 10, characterized in that the shaft (11) is blocked against a   rotation, as long as no key is entered.   12. Electrical switching installation according to any one of   previous claims, characterized in that the drawer (1) is   capable of being covered by a door mounted on the insertion frame, and in that there is provided a locking element (29) which prevents the door from opening when the first and / or   second contacts (3, 4, 7) are closed.   13. Electrical switching installation according to claim 12, characterized in that a hook (29) arranged on the insert (8) serves as a locking element which cooperates with a stop provided on the door. 14. Electrical switching installation according to claim 13, characterized in that a leaf spring (29a) serves as a stop and has an opening in which the hook (29) engages, and in that the leaf spring ( 29a) is capable of tilting remotely by means of an auxiliary member pluggable through an opening in the door or between the door and the introduction frame,   to carry out an emergency trip.   15. Electrical switching installation according to any one of   Claims 1 to 6, characterized in that the two organs   actuators each comprise a drive bar (31, 32) guided in movement in the drawer, one of which displaces the first complementary contacts and the other the second complementary contacts in the direction of contacting, as well as a toothed wheel (35, 36) rotatably mounted in the drawer and meshing with the drive bar (31, 32), wheel by which the bar   associated drive (31, 32) is capable of being actuated.   16. Electrical switching installation according to claim 15, characterized in that the drive bars (31, 32) each attack an arm (37, 38) of a bent lever (39, 40) rotatably mounted in the drawer , the other arm of which (41, 42) is coupled to the first or   to the second complementary contacts.   17. Electrical switching installation according to one or other of the   claims 15 and 16, characterized in that the second gear   (36) is arranged in a frame (43) guided in movement in the drawer parallel to the second drive bar (32), frame on which is coupled a third drive bar (44) which meshes with the first toothed wheel (35) and which is displaced by it   simultaneously with the first drive bar (31).   18. Electrical switching installation according to claim 17, characterized in that the toothed wheels (35, 36) are capable of being actuated by means of a key and locked against a   rotation when the key is removed.   19. Electrical switching installation according to claim 18, characterized in that the toothed wheels (35, 36) comprise a central housing (46, 47) for the key, in particular a square key, and in that the housings (46 , 47) can be covered with of a plate (48).   20. Electrical switching installation according to any one of   claims 15 to 19, characterized in that the directions of implementation   contact of the first and second complementary contacts are mutually equal and both extend in particular introduction direction.   21. Electrical switching installation according to any one of   claims 15 to 20, characterized in that the indicating device and   the plate (48) can be actuated via the drive bars (32, 44).