EP0345656B1 - Security switch - Google Patents

Description

The invention relates to a safety switch which consists of a switch part, a control part and an actuating part according to the preamble of claim 1. Such safety switches are e.g. known from EP-A-0 175 156. In order to prevent danger to people from electrically powered machines, elevators and the like, the actuating part is attached to the door, flap or another movable part and this opposite the switch part with control part. The switch part has a contact plunger which can be moved in its longitudinal direction, with contact bridges carried by it, and fixed contacts opposite these, which are in the circuit of the motor of the machine or the like. The control part, through which the contact plunger of the switch part is actuated, has a housing with a slot into which the control bracket of the actuating part can be inserted.

The invention relates to such safety switches in which a control rod with a cross pin pulls the contact plunger out of the switch part in order to close the contacts. Such Safety switches are also designed so that when the control rod is pushed back, the contact plunger is inevitably pushed back again and the contacts are opened. The contact plunger can of course also carry normally closed contacts in addition to the aforementioned work contacts.

Safety switches of the type in question here have a switching wheel for moving the control rod, which is rotatably arranged in the housing of the control part and is provided with control arms which are acted upon by a front bar of the actuating part. The ratchet wheel then hits another control arm on a cross pin of the control rod and pulls it in the desired direction or pushes it back with another control arm.

The control brackets of the actuating part of such safety switches and the shape and arrangement of the switching wheel are designed in such a way that operation without the special control brackets, for example by some simple tool, is not possible.

However, if a person who wants to gain access without switching off the machine obtains such an actuating part, he can insert it into the slot in the control part and thereby turn on the switch and start the machine.

The invention has for its object to develop a safety switch of the aforementioned type so that this possibility of an impermissible Activation is no longer given.

This object is achieved by the features of claim 1. This prevents or at least makes it almost impossible for the safety switch to be switched on by inserting a loosely carried actuating part. Rather, the safety switch can only be switched on when the actuating part is attached to the door or the like. With this attachment, the slide plate below the control bracket of the actuating part is inevitably moved so that the switching wheel can be rotated and thereby grips the cross pin of the control rod. Only then can the control rod be tightened by the switching wheel and in turn bring the contact plunger in the switch part into the switch-on position.

If, on the other hand, the actuating part with its base part is not screwed onto the door or the like, the slide plate is not moved. This creates an opening on the front of the control bracket into which a control arm of the steering wheel can engage when it is rotated. This prevents the shifting of the switching wheel shaft, which is necessary for switching on, and the switching wheel rotates freely.

The slide plate is pressed by strong spring means in the direction in which the aforementioned opening is created on the front of the control bracket. These spring means are so strong that they cannot be overcome by hand when the operating part is loosely carried and inserted, but only in that the base part of the operating part is attached to a door or the like is screwed tight.

The displaceability of the switching wheel shaft from one limit position to the other can be achieved per se by various means. Preferably, the ends of the shaft of the ratchet wheel are mounted in two brackets arranged on both sides thereof, which can be pivoted about bearing journals so that the shaft of the ratchet wheel can reach one or the other limit position.

Preferably, the spring means that pull the ratchet together with the tabs into one limit position are torsion springs that are wound around the ends of the shaft. One end of each spring is connected to the ratchet wheel, while the other end is connected to or supported on the housing of the control part.

In this embodiment, the bearing pins of the two tabs can be mounted in fixed bearings in the housing.

However, if the housing of the control part is provided with two slots for introducing the control bracket of an actuating part, one of which is located in the front side and the other in the cover side of the housing of the control part, the safety switch according to the invention can be changed without changing the one slot be used on the other slot if the ratchet wheel is provided with further control arms and if the bearings of the tabs carrying the ratchet wheel are moved to a different position. This happens because the bearing pins of the tabs in two Setting levers are mounted, which in turn are stored in fixed bearings in the housing and can be pivoted between two limit positions. In one limit position of the actuating lever, the ratchet wheel can then be controlled through a slot in the cover side, in the other limit position through a slot in the front side of the housing.

Further developments of the safety switch according to the invention result from the following subclaims.

Fig. 1

eine teilweise geöffnete und teilweise geschnittene Darstellung des erfindungsgemäß ausgeführten Sicherheitsschalters mit angesetztem Betätigungsteil wobei im Betätigungsteil nur das Schaltrad und die Steuerstange dargestellt sind;

Fig. 2 und 3

abgebrochene Teildarstellungen des Betätigungsteils in Fig. 1, mit schrittweise weiter eingeschobenem Betätigungsteil;

Fig. 4

eine Darstellung ähnlich Fig. 1 bei voll eingeschobenem Betätigungsteil;
(Bei den Fig. 1 bis 4 wird der an einer Tür angeschraubte Betätigungsteil deckelseitig eingeschoben )

Fig. 5

eine Darstellung ähnlich den Fig. 2 und 3, wobei das Betätigungsteil nicht festgeschraubt, sondern lose eingeführt wurde;

Fig. 6

eine Darstellung ähnlich Fig. 5, bei voll eingeschobenem Betätigungsteil;

Fig. 7

einen Vertikalschnitt durch die Welle des Schaltrades, in vergrößerter Darstellung;

Fig. 8

einen Schnitt längs der Linie VIII-VIII in Fig. 7;

Fig. 9

eine Ansicht einer Lasche 37 bzw. 38 gemäß Fig. 7;

Fig. 10

eine Ansicht eines Stellhebels 39 bzw. 40 in Fig. 7;

Fig. 11

eine vergrößerte und vervollständigte Darstellung des Steuerteils in Fig. 1;

Fig. 12

eine vergrößerte und vervollständigte Darstellung des Steuerteils in Fig. 4;

Fig. 13

eine Darstellung ähnlich Fig. 1, bei der jedoch im Unterschied dazu das Betätigungsteil stirnseitig eingeführt ist;

Fig. 14

eine vergrößerte und ergänzte Darstellung des Steuerteils in Fig. 13, ohne Betätigungsteil;

Fig. 15

eine Darstellung ähnlich Fig. 14 im voll eingeschalteten Zustand;

Fig. 16

eine vergrößerte und vervollständigte Darstellung des Steuerteils, ohne Betätigungsteil etwa entsprechend einer Lage der Teile zwischen den Phasen gemäß Fig. 5 und Fig. 6;

Fig. 17

eine vergrößerte und vervollständigte Darstellung des Steuerteils kurz vor Erreichen der in Fig. 6 dargestellten Phase;

Fig. 18

eine vergrößerte Darstellung des Betätigungsteils, bei der die Befestigungsmöglichkeit an einer Tür angedeutet ist;

Fig. 19

einen Längsschnitt durch das Betätigungsteil längs der Mittellinie der Befestigungsschrauben in Fig. 18 und

Fig. 20

einen Teilschnitt längs der Linie XX-XX in Fig. 11, wobei die Steuerstange 12 fortgelassen ist.

The invention is explained below in exemplary embodiments with reference to the drawing. Show

Fig. 1

a partially opened and partially sectioned representation of the safety switch according to the invention with attached actuating part, only the switching wheel and the control rod being shown in the actuating part;

2 and 3

broken partial representations of the actuating part in Figure 1, with the actuating part gradually pushed further;

Fig. 4

a representation similar to Figure 1 with the actuator fully inserted.
(In FIGS. 1 to 4, the actuating part screwed onto a door is pushed in on the cover side)

Fig. 5

a representation similar to Figures 2 and 3, wherein the actuating part was not screwed, but was inserted loosely.

Fig. 6

a representation similar to Figure 5, with the operating part fully inserted;

Fig. 7

a vertical section through the shaft of the ratchet wheel, in an enlarged view;

Fig. 8

a section along the line VIII-VIII in Fig. 7;

Fig. 9

a view of a tab 37 and 38 of FIG. 7;

Fig. 10

a view of an actuating lever 39 or 40 in Fig. 7;

Fig. 11

an enlarged and completed view of the control part in Fig. 1;

Fig. 12

an enlarged and completed view of the control part in Fig. 4;

Fig. 13

a representation similar to Figure 1, but in which, however, in contrast to this, the actuating part is inserted at the end;

Fig. 14

an enlarged and supplemented representation of the control part in Figure 13, without the operating part.

Fig. 15

a representation similar to Figure 14 in the fully switched on state.

Fig. 16

an enlarged and completed view of the control part, without the operating part approximately according to a position of the parts between the phases according to FIG. 5 and FIG. 6;

Fig. 17

an enlarged and completed view of the control part shortly before reaching the phase shown in Fig. 6;

Fig. 18

an enlarged view of the actuating part, in which the possibility of attachment to a door is indicated;

Fig. 19

a longitudinal section through the actuating part along the center line of the fastening screws in Fig. 18 and

Fig. 20

a partial section along the line XX-XX in Fig. 11, wherein the control rod 12 is omitted.

1 consists of a switch part 1, a control part 8 and an actuating part 21.

The parts are shown partly in view, partly in section. A contact plunger 2, which carries two movable contact bridges 3, is arranged longitudinally displaceably in the housing of the switch part 1. The upper contact bridge and the lower contact bridge each have two fixed contacts 4 opposite, the upper contact group is a normally closed contact, the lower one is a working contact.

At the lower end of the contact plunger 2 there is an annular groove 5 into which the fork 13 of a control rod 12 engages, which is guided in the control part 8 so as to be displaceable in its longitudinal direction. This control rod 12 carries at its lower end a cross pin 14, both ends of which are guided in guide grooves 15 in the rear and front walls of the housing 9 of the control part 8.

At the lower end of the control part 8 there is a slot 18 on the cover side and a slot 19 on the end face into which an actuating part can optionally be inserted. 1 to 6 the safety switch with cover-side insertion is shown.

Within the housing 9 of the control part 8 there is a ratchet wheel with a plurality of control arms 31, 32, 33, 34, 35 and 36, rotatable about a bearing shaft 11. The mounting of the shaft 11 is explained further below. 1 to 6, the parts used for this are omitted for the sake of clarity and only the switching wheel 10 is shown.

If the actuating part 21 fastened with its base part 22 to a door moves in the direction of the arrow 20 and is inserted with its control bracket 23 into the slot 18 of the control part, the end beam 24 of the control bracket hits the control arm 35 and rotates the switching wheel 10 in the direction of the Arrow 16.

At a distance from the end beam 24 is a driver 25, likewise carried by the control bracket, which projects upwards from it and, as will be explained below, serves to advance the ratchet wheel 10.

Below this driver 25 and the upper frame of the control bracket 23 there is a slide plate 26 extending in the longitudinal direction of the control bracket, which carries at its end facing the end beam 24 an upwardly angled slide web 29, the task of which will also be explained. A slide window 28 is located between this slide bar 29 and the end of the slide plate 26 fastened to the base part 22.

It should be noted in advance that the lower edge of the slide bar 29 is approximately in contact with the driver 25 because the base part 22 of the actuating part 21 is screwed to a door.

Fig. 2 shows the position of the aforementioned parts when the actuating part 21 is inserted a little further. As can be seen, the front bar 24 has pushed the control arm 35 in front of it and thereby rotated the ratchet wheel 10 counterclockwise. In this position, the driver 25 already comes into contact with the next control arm 36 of the switching wheel 10 and takes over the further advancement of the switching wheel.

With further insertion of the actuating part 21 then finally the control arm 36 touches the slider web 29. The ratchet wheel 10 can not yet be raised with the shaft in the new position 11 'to be described below, since it by the blocking area 31, which then abuts the cross pin 14, is prevented from doing so. A further insertion of the actuating part 21 is possible, however, in that the slide plate 26 designed as a leaf spring bends into the position shown in dashed lines in FIG. 2. The slide bar 29 then allows the control arm 36 to be rotated further under the action of the driver 25, the shaft 11 of the ratchet wheel still remaining in its place.

As soon as the blocking area 31 of the ratchet wheel has passed under the cross pin 14, the ratchet wheel 10 can be raised with its shaft 11 into the upper position 11 'shown in FIG. 3. This increase is brought about by the slide plate 26 designed as a leaf spring with its front slide web 29. This new position is shown in Fig. 3. As can be seen, the blocking area 31 has now passed completely under the cross pin 14 and the latter engages in the cutout between the control arms 31 and 32.

The aforementioned shift is possible by a special suspension of the shaft 11, which will be explained in more detail below.

With further forward movement of the actuating part, its base part 22 finally comes into contact with the housing 9 of the control part, as shown in FIG. 4. During the movement from the position shown in Fig. 3 in the position shown in FIG. 4, the control arm 32 has gripped the cross pin 14 of the control rod 12 and guided downward, so that the fork 13 of the control rod pulls the contact plunger 2 of the switch part downward and thereby upper contact group opens while the lower contact group is closed.

If the base part 22 of the actuating part is not screwed to a door or the like, but is held loosely by a person, the slide bar 29 is not in contact with the underside of the driver 25, as in the positions according to FIGS. 1 to 4 , but has a certain distance from it, so that a gap remains between the driver 25 and the slide web 29. As can be seen from FIG. 5, the control arm 36, pushed by the driver 25, then plunges into this gap and the switching wheel is not raised. Even when the driver 25 is advanced, the ratchet wheel 10 is rotated further and its shaft 11 remains in the previous position.

5 and 6, the control arm 32 then no longer grips the cross pin 14 of the control rod 12, so that it is not pulled down. The switching wheel runs through empty and the contact plunger 2 in the switch part 1 is not moved.

FIG. 7 shows the position of the parts which enable the shaft 11 to be displaced and which have been omitted in FIGS. 1 to 6 for the sake of clarity.

The ratchet wheel 10 is rotatably supported on the shaft 11, which projects from the ratchet wheel on both sides. On both ends of the ratchet wheel there are annular grooves 45 and 46 for receiving torsion springs 47 and 48, which are concentrically wound around the ends of the shaft 10 outside these annular grooves and each extend into an approximately tangentially extending arm 50 which, as shown in FIG. 8 can be seen on a (unspecified) Rib of the housing wall supports. The inner ends 51 and 52 are held in slots in the ratchet wheel which extend tangentially from the ring grooves.

As can be seen in FIGS. 7 and 8, these two torsion springs press the shaft of the ratchet wheel into its position 11 and also exert a torque in a clockwise direction on the ratchet wheel 10.

The shaft 11 is supported in tabs 37 and 38, the shape of which can be seen in FIG. 9. The bores 54 of these tabs receive the shaft 11. At their other ends, the tabs are provided with bores 53, in which they are pivotally mounted about journals 43 and 44. These journals have a collar in the middle and are received at their other ends by bores 55 of the adjusting levers 39 and 40, the shape of which can be seen in FIG. 10.

These control levers are provided with bores 56 for mounting in bearings 41 and 42 fixed to the housing by means of further bolts. The sector of each actuating lever projecting radially outside of the bore 56 serves, as will be discussed below, to block the switch.

In Fig. 11, the simplified representation of Fig. 1 of the control part is supplemented. The position of the ratchet wheel 10 at the beginning of the insertion movement of the actuating part and the position of a tab 37 and an actuating lever 39, shown partly in broken lines, can be seen here. The representation of FIG. 11 is a section along the line VIII-VIII with respect to the latter movable parts 7, but for the sake of clarity the torsion springs have been omitted.

FIG. 12 again shows an enlarged and supplemented sectional view of the actuating part according to FIG. 4, namely in the end position with the actuating part fully inserted and the transverse pin 14 pulled down in the switched-on position.

FIG. 13 shows a representation of the entire safety switch, as in FIG. 1, but here the actuating part is not inserted on the cover side, as in FIG. 1, but rather on the end side, namely through the slot 19.

For this purpose, the adjusting levers 39 and 40 were pivoted into their other limit position and the bearing journal 43 visible in the drawing has thereby been pivoted into its other limit position 43 ', which can be seen from the outside through the housing slot 57. Accordingly, the tabs 37 and 38 have pivoted and the shaft 11 of the ratchet wheel 10 can now be pivoted along another arc that corresponds to the insertion of the actuating part through the front slot.

The control part 8 with the position of its movable parts according to FIG. 13 is again shown enlarged in FIG. 14 for a clearer illustration, although the actuating part is omitted there.

As can be seen, the control arm 35 of the switching wheel 10 is not acted upon by the end beam of the actuating part here, but rather the correspondingly designed control arm 33. When the actuating part is pushed in further, the driver 25 then grips the control arm 34 of the switching wheel.

Fig. 15 shows the control part with the operating part fully inserted (not shown), in which case the control arm 32 has again gripped the transverse pin 14 on the control rod 12 and pulled downward, so that the switch 1 is switched over.

16 and 17 serve to supplement and clarify the representation of FIGS. 5 and 6, in which a non-screwed but loosely held actuating part is inserted on the cover side.

18 shows the actuating part in an enlarged view. The control bracket 23 with the front bar 24 and the top-side driver 25 is carried by a base part 22, which mainly comprises a rigid base body 58.

The slide plate 26 arranged below the driver 25 and displaceable in the longitudinal direction of the control bracket has a slide window 28 above the window 68 of the control bracket. At its (left in FIG. 18) end, the slide plate 26 is held by a retaining web 59 which is within the corresponding U -shaped base body 58 of the base part 22 is located and also, together with the slide plate 26, is displaceable in the longitudinal direction of the control bracket 23.

The base 22 is fastened to a door or the like by means of screws 61 and 62.

Fig. 18 shows the position of the slide plate 26 with its front slide bar 29 in the screwed-on state of the actuating part. As can be seen, there is between the slide bar 29 of the slide plate 26 and the driver 25 of the control bracket no gap into which a control arm of the ratchet wheel could plunge, so that it is raised to the switchable position.

As soon as the base part 22 of the actuating part is not screwed tightly to a door or the like, but is kept free, the slide plate 26 is advanced so that the slide web 29 reaches the position 29 'shown in broken lines in FIG. 18. Then there is a gap between the slide bar and driver and the control arm 36 of the ratchet wheel can dip into this gap, as shown in FIG. 17. The switching wheel is not raised to the switchable position and it spins freely without detecting the cross pin 14.

The attachment of the base part 22 of the actuating part to a door and the resulting displacement of the slide plate 26 against a spring force is clear from FIG. 19. As can be seen, the base body 58 of the base part is angled inwards twice at its two ends and accommodates the holding web 59 of the slide plate 26 already mentioned. This retaining web is provided near its ends with holes for the shafts of the fastening screws 61, 62 to pass through. These screws each have a collar 63 or 64 on their shank, which lies when the screws are screwed into the door on the edges of the respective bore in the holding web 59 and thus presses this holding web against the door.

At its two ends, outside the aforementioned bores, the retaining web 59 is provided with slightly projecting, resiliently angled resilient ends 69 and 70. Before the base body 58 firmly the door is screwed on, the retaining web assumes the position 59 'shown in dashed lines in FIG. 19, in which said spring ends 69 and 70 rest on the inwardly angled edges 71 and 72 of the base body 58. The bundles of the two screws 61 and 62 then also take the dashed layers 63 'and 64'.

The slide bar 29 of the slide plate 26 is then so far away from the driver 25 in the position 29 also shown in dashed lines that the said gap remains between the slide bar and the driver.

When the screws 61 and 62 are screwed into the threaded bores in the door, the edges 71 and 72 of the base body 58 come into contact with the door. When the screws are tightened further, the spring ends 69 and 70 of the retaining web 59 are then elastically bent back until finally the retaining web 59 also lies snugly against the door. The slide web 29 now assumes its position directly on the driver 25, which is not particularly shown in FIG. 19.

The screws 61 and 62 provided with the collars 63 and 64 are inserted into the openings in the base body 58 through keyhole-like extensions (not shown).

In Fig. 20, the locking pin 65 already mentioned in the discussion of Figs. 11 and 14 is shown, which is inserted through the square openings 30 in the opposite walls of the housing 9 and with its head 66 rests on the one housing wall, while the one on his other end protruding from the housing Cross hole 67 a padlock can be introduced.

This cross bolt is then in the way of the sector-like projection on each of the two control levers 39 and 40 and thus prevents their switching.

If the switch for cover-side operation is installed and the control levers 39 and 40 are in the position shown in Fig. 11, it is sufficient to move these control levers to the other limit position (see Fig. 14) and then insert and lock the locking bolt to disable the switch.

Conversely, when the switch is set to front-end operation.

This adjustment of the actuating lever ensures that the actuating part 21 screwed to a door can be fully pushed in by the movement of the door in the direction of the safety switch without the cross pin 14 being gripped by the switching wheel 10.

Claims (12)

1. Safety switch, consisting:

   - of a switch part (1) with a contact ram (2) which is guided displaceably in its longitudinal direction with contact bridges (3) which are supported by the latter and with fixed contacts (4) which are opposite these contact bridges;

   - of a control part (8) with a control rod (12) which is guided displaceably in its longitudinal direction and is coupled to the contact ram, having a transverse pin (14), having a rotatable switch wheel (10) with a first control arm (32) for entraining the transverse pin in the switched-on position and a second control arm (31) for returning the transverse pin to the switched-off position, and having a third (35) and a fourth (36) control arm for rotating the switch wheel (10) in one sense of rotation (16) or in the opposite sense of rotation; and

   - of an actuating part (21) which can be introduced into a slot (18) in the housing (9) of the control part (8) and which acts by means of an end beam (24) upon the third (35) or fourth (36) control arm of the switch wheel (10) when guided in or out, and thereby rotates the switch wheel in one sense of rotation (16) or the other,

   characterised in that the shaft (11) of the switch wheel (10) in the housing (9) of the control part (8) can be displaced transversely to its longitudinal direction between two limiting positions (11, 11′) in one (11′) of which the first control arm (32) of the switch wheel engages the transverse pin (14) of the control rod (12) when the switch wheel rotates in one sense of rotation and, on further rotation, thereby draws the contact ram (2) into the switched-on position, whilst, in the other limiting position (11) of the shaft of the switch wheel (10), as it rotates, the first control arm (32) thereof moves past the transverse pin without engaging and entraining it; in that, furthermore, the second control arm (31) is in the form of a segment which prevents premature displacement of the shaft (11) of the switch wheel (10) into the position necessary for grasping the transverse pin (14), the shaft of the switching wheel being drawn by spring means (47, 48) into the one limiting position (11) preventing the transverse pin (14) from being engaged; and in that the control bar (23) of the actuating part (21) comprises behind its end beam (24) acting on the third control arm (35) of the switch wheel (10) a closeable opening (68) in which the fourth control arm (36) engages on further rotation, whilst, when the opening is closed, the fourth control arm (36) and thus the switch wheel (10) are urged against the action of the spring means (47, 48) into the other limiting position (11′) of its shaft, the control bar (23) comprising below its end beam (24) and its opening (68) a slide plate (26), which can be displaced in its insertion direction with respect thereto, with a slide window (28) and a slide web (29) at its front, free end which, in the front limiting position (29′) uncovers the opening (68) in the control bar but which, in the rear limiting position, closes said opening, the slide plate (26) being urged by spring means (69, 70) into its front limiting position whilst a retaining web (59) in the base member (58) of the actuating part (21), which retaining web supports this slide plate, draws the slide plate (26) back against the spring force when the actuating part is secured to a door or the like and thus closes the opening (68) behind the end beam (24) of the control bar (23).
2. Safety switch according to Claim 1, characterised in that the ends of the shaft (11) of the switch wheel (10) are mounted in two cover plates (37, 38) which are disposed on either side thereof and can be pivoted about bearing pins (43, 44) in such a way that the shaft of the switch wheel can pass into one (11) or the other (11′) of the limiting positions.
3. Safety switch according to Claim 1 or 2, characterised in that the spring means which draw the switch wheel (10) into the one limiting position (11) are torsion springs (47, 48) which are wound about the ends of the shaft (10) and of which the first ends are rigidly connected to the switch wheel and of which the other ends are connected to the housing (9) of the control part (8) or are supported on these parts.
4. Safety switch according to Claim 2 or 3, characterised in that the bearing pins (43, 44) of the cover plates (37, 38) are mounted in two adjusting levers (39, 40) which are in turn mounted in fixed bearings (41, 42) in the housing (9) and can pivot between two limiting positions in one of which the switch wheel (10) can be controlled through a slot (18) in the cover side and in the other of which it can be controlled through a slot (19) in the end face of the housing (9).
5. Safety switch according to Claim 4, characterised in that the bearing pins (43, 44) of the cover plates (37, 38) can be adjusted through arcuate housing slots (57).
6. Safety switch according to Claim 4 or 5, characterised in that the cover plates (37, 38) can be locked in each of their limiting positions.
7. Safety switch according to any one of Claims 4 to 6, characterised in that the adjusting levers (39, 40) comprise at their ends remote from the bearings (41, 42) projections having limiting edges extending approximately radially; and in that, in the housing walls accommodating the fixed bearings (41, 42) apertures (30) are provided which allow the introduction of a locking bolt (65) lying in front of the limiting edges of the projections.
8. Safety switch according to Claim 7, characterised in that the locking bolt (65) comprises at one end a head (66) and at the other end a transverse bore (67) for mounting a padlock.
9. Safety switch according to any one of Claims 1 to 8, characterised in that the slide plate (26) in the control bar (23) of the actuating part is in the form of a leaf spring.
10. Safety switch according to any one of Claims 1 to 9, characterised in that the slide web (29) at the front end of the slide plate (26) extends inclined upwards in the direction towards the switch wheel.
11. Safety switch according to any one of Claims 1 to 10, characterised by a cam (25) which is disposed behind the end beam (24) of the control bar (23), which projects, in the inserted state, from the control bar in the direction of the switch wheel (10), and which is at such a distance from the end beam (24) that the gap therebetween is closed in the one limiting position of the slide plate (26) but is uncovered in the other.
12. Safety switch according to any one of Claims 1 to 11, characterised in that the control rod (12) of the control part (8) is freely rotatable with the contact ram (2) of the switch part (1) but is rigidly connected in the longitudinal direction; and in that the housing (9) of the control part (8) has a square cross-section which permits the control part (8) to be plugged together with the switch part (1) in four positions offset by 90° in each case.

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