EP1387379B1 - Switch device - Google Patents

Description

• wobei der Schalter an einem Grundkörper einer Anlage und das Betätigungselement an einem Zusatzelement der Anlage anordenbar sind,
• wobei der Schalter und das Betätigungselement bei nicht gebrochenem Betätigungselement derart zusammenwirken, dass beim Überführen des Betätigungselements in eine Schaltstellung über eine mechanische Wirkkette zwangsweise ein Schaltkontakt des Schalters geöffnet wird.

The present invention relates to a switching device with a switch and an actuating element for the switch,

• wherein the switch can be arranged on a main body of a system and the actuating element on an additional element of the system,
• wherein the switch and the actuating element cooperate with not broken actuating element such that when transferring the actuating element into a switching position via a mechanical action chain forcibly a switching contact of the switch is opened.

It further relates to a system with such a switching device.

Such a switching device is for example from the DE 196 02 690 C1 known. Similar disclosure contents have that DE 297 17 313 U1 and the EP 0 635 612 B1 on.

From the DE 197 11 588 A1 is a switching device with a switch and an actuating element for the switch, in which the switch on a main body of a system and the actuating element can be arranged on an additional element of the system. When the actuator is not broken, the actuating element and a sensor device for detecting the presence of the actuating element cooperate in such a way that upon switching the actuating element into a switching position, a switching contact of the switch is reliably opened. The actuating element is designed such that a breakage of the actuating element causes an opening of the switch.

In machines and systems often safety switches are used, which movable safety devices such. B.

Monitor doors or covers. These protective devices separate man and machine (or system) for mutual protection. The safety switch mounted on the machine usually has a so-called drive head with a receptacle which receives a cover mounted on the separate actuator, often called key when closing the cover. A safety switch operated in this way makes it possible to operate the machine by closing a contact. Conversely, when opening the door or the cover, ie the extraction of the actuating element from the receptacle, the contact is again forcibly opened. Thus, a circuit is opened, so that the monitored machine or system can be transferred to a safe state or turned off.

Breakage of the actuator z. B. by external mechanical influences or fatigue is not recognized by the system in the normal safety switches of the prior art. In this case, the protective device can be opened without the system to be monitored forcibly transferred to the safe state or is switched off. This can result in a significant risk to an operator and / or the machine or system.

Also a breaking of other components susceptible to breakage, for example a switching wheel, via which the actuating element acts on the switching contact, or of the drive head, can not be detected by means of the measures described in the aforementioned prior art.

Due to these risks, protective devices of higher safety category must always have redundant two such safety switches, so that in case of failure of a safety switch opening the door or cover detected yet and the system can then be transferred to the safe state. In addition, to avoid breakage of the actuator, the actuators often made of expensive steel / plastic combinations or cast iron.

The object of the present invention is to further develop a generic switching device and a corresponding system with a switching device such that breaking of at least the actuating element is detected with certainty in a simple manner.

The object is achieved in that the actuating element is looped into a circuit in which the switching contact is also looped, so that the circuit is interrupted both by the opening of the switching contact and by a breakage of the actuating element.

Usually, the switch has a plunger, via which the switching contact can be actuated. The actuating element, in turn, generally acts on the plunger via a switching wheel arranged in a switch-fixed manner. To increase the reliability of errors, therefore, the drive head, the plunger and the ratchet wheel can be looped into the circuit.

If the switch has a receptacle for the actuating element, from which the actuating element is removed when transferred to the switching position with not broken actuator, and in the receptacle at least one contact is arranged, so that the circuit by removing the actuating element from the receptacle as such is interrupted, there is an even greater security.

If the actuating element has at least one predetermined breaking point and is looped into the circuit at least in the region of the predetermined breaking point, this results in even greater safety with regard to detecting an actuator breakage.

If the switch has at least one further switching contact which can be actuated together with the first-mentioned switching contact, the desired switching state of the first-mentioned switching contact can for example be detected as such. Thus, for example, a break in the circuit can be distinguished by the switching contact from an interruption of the circuit by a breakage of the actuating element.

If the further switching contact forcibly interrupts another circuit during the transfer of the actuating element into the switching position when the actuating element is not broken, the switch is designed with two channels. In this case, it is particularly possible that the actuating element is designed such that it is einschleifbar in the other circuit, so that the other circuit is interrupted by a breakage of the actuating element. It is even possible that the switch and the actuating element are designed such that the further switching contact is looped into the other einschleifbaren in the actuator circuit.

FIG 1

eine technische Anlage,

FIG 2

ein Beispiel eines Sicherheitsschalters und

FIG 3

ein weiteres Beispiel eines Sicherheitsschalters.

Further advantages and details emerge from the following description of an embodiment. This show in a schematic representation

FIG. 1

a technical facility,

FIG. 2

an example of a safety switch and

FIG. 3

another example of a safety switch.

According to FIG. 1 a system has a main body 1. On the base body 1, an additional element 2 is arranged, which is movable relative to the base body 1.

The additional element 2 is according to FIG. 1 formed as a cover 2. By means of the cover 2 is a danger or general effective range 3 of the system in operation relative to an operator 4 shieldable. The operator 4 is thus protected with the cover 2 closed against hazards emanating from the effective range 3. Conversely, if appropriate, the effective region 3 and objects arranged therein are also protected against access by the operator 4.

As in FIG. 1 indicated schematically, a switch 5 is arranged with a switching contact 6 on the base body 1. At the additional element 2, an actuating element 7 is arranged for the switch 5. When closing the cover 2, therefore, the switch 5 is actuated, so that the switching contact 6 is closed. Thus, an in FIG. 1 schematically indicated circuit 8 is closed, in which the switching contact 6 is looped. The closing of the circuit 8 is detected by a controller 9 for the system. Only when the switch contact 6 is closed operation of the system is possible, for. B. running a arranged in the active region 3 motor 10th

In contrast, when the cover 2 is opened, and the switching contact 6 is opened. The circuit 8 is interrupted. Due to the interruption of the circuit 8, the system is immediately transferred by the controller 9 in a safe state, z. B. the engine 10 is stopped. The opening of the circuit 8 thus influences the operating status of the system. The opening of the cover 2 thus corresponds to the transfer of the additional element 2 (and also of the actuating element 7) in a switching position.

The structure of the switch 5 and the actuator 7 will be described below in connection with FIG. 2 explained in more detail.

According to FIG. 2 the switch 5 has a ratchet 11 and a plunger 12. Above the switching wheel 11, the switch 5 has a receptacle 13 for the actuating element 7. The receptacle 13 is arranged in a drive head 5 ', in which the ratchet wheel 11 is mounted. When the cover 2 is opened and the actuator 7 properly the cover 2 is fixed, the actuator 7 is removed by opening the cover 2 from the receptacle 13.

By removing the actuating element 7 from the receptacle 13, the switching wheel 11 is rotated with proper interaction of the actuating element 7 and the ratchet wheel 11 such that the plunger 12 is engaged. So he will, as in FIG. 2 indicated by an arrow B, moved in a direction of engagement. The actuating element 7 initially acts on the switching wheel 11. The ratchet 11 in turn acts on the plunger 12 a. The plunger 12 then actuates the switching contact 6. The switching contact 6 is thus actuated via a mechanical chain of action, which comprises the actuating element 7, the switching gear 11 and the plunger 12.

The switching contact 6 is according to FIG. 2 designed as an opener. Due to the interaction of the switch 5 and the actuating element 7, the switching contact 6 is therefore forcibly opened upon transferring the cover 2 into the switching position, and thus the circuit 8 is interrupted by means of the switching contact 6.

By the above-described interaction of the actuating element 7, the ratchet 11 and the plunger 12, the forced breaking of the circuit 8 takes place only when both the actuator 7 and the drive head 5 ', the ratchet 11 and the plunger 12 are fully functional. In particular, these elements 5 ', 7, 11, 12 must not be broken. Thus, for example, if the actuating element 7 were broken, despite the opening of the cover 2, the actuating element 7 would not be removed from the receptacle 13. In a breaking of the switching wheel 11, it could happen that the switching wheel 11 is not rotated despite a removal of the actuating element 7 from the receptacle 13. If the plunger 12 were broken, it could happen that despite a twisting of the switching wheel 11 in a removal of the actuator 7 from the receptacle 13 of the plunger 12 is not engaged. Canceling the drive head 5 'would have similar consequences. Only when not broken elements 5 '7, 11, 12 so the above-described interaction of the switch 5 and the actuating element 7 is ensured.

In order to ensure interruption of the circuit 8 even in such cases, at least one of these elements 5 ', 7, 11, 12 looped into the circuit 8. This will be explained in more detail below with reference to the actuating element 7 and the drive head 5 '. The statements regarding the actuating element 7 and the drive head 5 'but are readily transferable to the ratchet wheel 11 and the plunger 12.

According to FIG. 2 are arranged in the receptacle 13 of the drive head 5 'contacts 14. In the actuating element 7, a conductor loop 15 is arranged. When the actuator 7 is inserted into the receptacle 13, the contacts 14 and the conductor loop 15 are in electrical connection with each other. If, therefore, the actuator 7 or the drive head 5 'breaks, the circuit 8 is forcibly interrupted, so that despite the transfer of the switching contact 6 in the closed position, the circuit 8 is interrupted. The system is therefore kept in a safe state by the controller 9 or transferred in case of a break during operation in the safe state.

By arranging the contacts 14 in the receptacle 13 is further ensured that even by removing the actuating element 7 from the receptacle 13 as such, the circuit 8 is interrupted. Even with a failure of the switching contact 6, therefore, the circuit 8 is interrupted.

According to FIG. 2 The actuating element 7 has a tapering region 16. The tapering region 16 serves as a predetermined breaking point 16 for the actuating element 7. It is apparent that the conductor loop 15 extends over the tapering region 16. The actuating element 7 is thus looped into the electric circuit 8 at least in the region of the predetermined breaking point 16. Similar measures are also the drive head 5 'possible.

According to FIG. 2 the switch 5 has a further switching contact 17, which is actuated together with the switching contact 6. It is designed as a feedback contact, by means of which the target switching state of the switching contact 6 via a further circuit 18 of the controller 9 can be fed. According to FIG. 2 the further switching contact 17 is designed as a closer. He could also be designed as an opener. If also the other switching contact 17 would be formed as a normally closed contact, the transferring of the additional element 2 (or of the actuating element 7) into the switching position would result in proper functioning of the switch 5 and the actuating element 7, in particular with the drive head 5 'not broken and the actuating element 7 not broken , Also, the other switching contact 17 forcibly opened, the circuit 18 are thus forcibly interrupted.

According to FIG. 2 For example, the drive head 5 'and the actuation element 7 (or another element susceptible to fracture, eg the indexing wheel 11 or the plunger 12) are not looped into the further circuit 18. But this would also be possible without further ado. In this case, the further circuit 18 would be forcibly interrupted at a fraction of the respective element 5 ', 7, 11 and 12, respectively.

The representation of FIG. 3 corresponds essentially to that of FIG. 2 , The only significant difference is that according to FIG. 3 the grinding of the actuating element 7 in the circuit 8 not via the receptacle 13, but over a separate line 19 takes place. In particular, in this embodiment, a grinding of the actuating element 7 (or other fracture-prone element 5 ', 11, 12) in a circuit independent of the switching contact 6 in a simple manner possible.

Finally, it should be mentioned that a mixed form between the embodiment according to FIG. 2 and the embodiment according to FIG. 3 is possible. Thus, in particular in the receptacle 13, a single contact 14 may be present and the circuit 8 may be continued via the line 19. In this case, a return in the form of the conductor loop 15 is not required in particular in the actuator 7. Rather, in this case, a single, continuous electrical connection may be present.

Due to the grinding of the circuit 8 in the actuator 7, it is in particular no longer necessary to provide the bed actuator 7 with a soul of steel or cast iron. Rather, the actuating element 7 may be formed as a simple injection-molded part, in which a sheet metal, aluminum or copper strip is inserted.

Claims (12)

1. Switch device with a switch (5) and an actuation element (7) for the switch (5),

   - with the switch (5) able to be arranged on a base body (1) of a system and the actuation element (7) on a supplementary element (2) of the system,

   - with the switch (5) and the actuation element (7) when the actuation element (7) is not broken, interacting in such a way that, when the actuation element (7) is moved into a switch position, a switch contact (6) of the switch (5) is forced to open via a mechanical actuation chain,
   characterised in that
   the actuation element (7) is looped into a circuit (8) into which the switch contact (6) is also looped, so that the circuit (8) is interrupted both by opening the switch contact (6) and also by breaking the actuation element (7).
2. Switch device according to claim 1,
   characterised in that,
   the switch (5) has a plunger (12), via which the switch contact (6) is able to be actuated.
3. Switch device according to claim 2,
   characterised in that
   the plunger (12) is also looped into the circuit (8).
4. Switch device according to claim 2 or 3,
   characterised in that
   the switch (5) has a switching wheel (11), via which the actuation element (7) acts on the plunger (12).
5. Switch device according to claim 4,
   characterised in that
   the switching wheel (11) is also looped into the circuit (8).
6. Switch device according to one of the preceding claims,
   characterised in that
   the switch (5) has a receptacle (13) for the actuation element (7), from which the actuation element is removed (7) when moved into the switch position with a non-broken actuation element (7), and that at least one contact (14) is arranged in the receptacle (13), so that the circuit (8) is also interrupted by the removal of the operating element (7) from the receptacle (13) as such.
7. Switch device according to one of the preceding claims,
   characterised in that
   the actuation element (7) has at least one intended breakpoint (16) and that the actuation element (7), at least in the area of the intended breakpoint (16), is looped into the circuit (8).
8. Switch device according to one of the preceding claims
   characterised in that
   the switch (6) has at least one further switch contact (17) which is able to be actuated in conjunction with the first-mentioned switch contact (6).
9. Switch device according to claim 8,
   characterised in that
   the further switch contact (17) is opened when the actuation element (7) is moved into the switch position with a non-broken actuation element (7).
10. Switch device according to one of the preceding claims,
    characterised in that
    the actuation element (7) is embodied such that it is able to be looped into a further circuit (18), so that the further circuit (18) is also interrupted by a break in the actuation element (7).
11. Switch device according to claim 9 and 10,
    characterised in that
    the switch (5) and the actuation element (7) are embodied such that the further switch contact (17) is looped into the further circuit (18) able to be looped into the actuation element (7).
12. A system with a base body (1) and a supplementary element (2) able to be moved in relation to the base body (1),

    - with a switch (5) with a switch contact (6) being arranged on the base body (1) and an actuation element (7) for the switch (5) being arranged on the supplementary element (2),

    - with the switch (5) and the actuation element (7) interacting when the actuation element (7) is not broken such that, when the supplementary element (2) is moved into a switch position, the switch contact (6) is forced open via a mechanical actuation chain and thus a circuit (8) is interrupted,

    - with the interruption of the circuit (8) influencing an operating state of the system,
    characterised in that
    the actuation element (7) is also looped into the circuit (8), so that this circuit (8) is also interrupted by breaking the actuation element (7).

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