DE2711539C2 - Arrangement for monitoring the function of movable locking means - Google Patents

Description

35

The main patent relates to an arrangement for the electrical monitoring of the function of movable ones Locking means, electrical switches being assigned to the locking means.

The invention according to the main patent is based on the object of an arrangement for electrical Monitoring of the function of movable locking devices Teln according to the type identified at the outset to the effect that an electrical Monitoring in a similarly simple manner is also possible in areas at risk of explosion, in particular for those cases in which useful solutions are already available for electrical monitoring, however, the open switches used are not used, taking into account explosion safety may be.

For an improved solution to this problem it is proposed according to the invention that three small contactors are in three separate circuits and two of them are assigned as control contactors each to one of the limit switches to be monitored for synchronism and the third is provided as a monitoring contactor for the two control contactors eo, in the feed line of the monitoring contactor normally closed contacts of the control contactors and the monitoring contactor arranged parallel to the rest contact, a self-holding contact, while in the feed line for the first control contactor working ** contact the Uberwachungsschützes and a normally closed contact of the second KontrollschOtzes and parallel to it are a self-holding contact and in the supply line to the second control contactor for each a Working contact of the monitoring contactor and the first control contactor and a self-holding contact are arranged in parallel, and that in the output of the arrangement in front of electrical switching means for the control of further subsequent functions a self Erheitskreis is provided in which a normally open contact of the control contactors and a normally closed contact of the monitoring contactor are arranged in series.

As a result, a relay can be dispensed with in comparison to the arrangement according to the main patent. The order is therefore easier and cheaper.

The invention is explained below using an exemplary embodiment explained in more detail.

While, according to the main patent, it does not matter in which order the control contactors for the limit switches tighten, the arrangement according to FIG. 1 a clear sequence is provided in the switching cycle. The limit switches 611 and b 12 are in the supply lines to the Kontroüschützen el! and el2, while the monitoring contactor el3 determines whether both limit switches are open or both control contactors c 11, c 12 have dropped out.

In the supply line to the monitoring contactor e 13, normally closed contacts el 1/4) and el2 / 4 are arranged one behind the other, with the contact el 1/4 lying parallel to the work contact e 13/4 of the monitoring contactor e 13.

Lie in the supply line to the control contactor one behind the other a normally closed contact el2 / 2 of contactor c 12 and a normally open contact el3 / 2. Parallel to the A self-holding contact c11 / 2 of the control contactor is provided for both of the aforementioned contacts.

Are in the supply line to the control contactor el2 one behind the other one working contact el 1/3 and one working contact el3 / 3. In parallel with these two Contacts is a self-holding contact el2 / 3 of the control contactor e 12.

Regardless of the sequence in which the limit switches 611, bi2 are actuated , the arrangement for closing the safety circuit according to FIG. it guarantees the following switching sequence.

First the control contactor picks up, opens the safety circuit with c 13/1 and prepares the control contactor to be switched on. If the limit switch 611 is closed, the control contactor c 11 picks up, closes its self-holding contact e 11/2 and releases it in the supply line to the control contactor el2. If the limit switch b 12 has already been actuated, the control contactor 12 picks up and closes its self-holding contact el2 / 3. At the same time, the normally closed contact cl2 / 4 in the feed line to the monitoring contactor c 13 is opened, so that this contactor drops out and the safety circuit is closed.

If one of the two limit switches b 11 or b 12 opens, the associated control contactor ell or el2 drops, which interrupts the safety circuit. Switching on again is only possible when the monitoring contactor c 13 has picked up. However, this is only the case if the second limit switch is also open and the control protection has fallen off as a result. If the limit switches are not synchronized, the safety circuit therefore always remains open.

1 sheet of drawings

Claims (1)

27 Π Claim; Arrangement for the electrical monitoring of the function of movable locking means, the locking means being assigned electrical switches, characterized in that three small contactors fell, c 12, c 13) are in three separate circuits and two of them as control contactors fell, c 12) each to one of the assigned to synchronism with to monitoring limit switch (bit, b 12) and the third one is provided as a monitoring contactor (c 13) for the two control contactors fell, cl2), with normally closed contacts fei 1/4), cl2 in the feed line of the monitoring contactor fc 13) / 4) the control contactor fell, cl2) and parallel to the normally closed contact (c 11/4) a self-holding contact (c 13/4) of the monitoring contactor are arranged, while in the supply line to the first control contactor fell) a work contact (c 13 / 2) of the monitoring contactor and a rest contact (c 12/2) of the second control contactor and parafle! there is also a self-holding contact fei 1/2) and in the supply line to the second control contactor (c 12) there is a working contact (c 11/3, c 13/3) of the monitoring contactor and the first control contactor and, in parallel, a self-holding contact fc 12/3) are arranged (Fig. 1), and that a safety circuit (Fig. 2) is provided in the output of the arrangement in front of electrical switching means for the control of further subsequent functions, by each one working contact for U / 1, cl2 / l) of the control contactors and a break contact fc 13/1) of the monitoring contactor are arranged in series.