Pull cord switch

The pull cord switch is a special form of an emergency stop switch (on machines, vehicles and systems or on rides such as roller coasters). A tightly stretched rope is operated as a pull cord with hand, foot or another part of the body and thus opens the contact in the cable switch, and it clicks into place. There are also the terms "emergency pull-wire" and "safety rope pull switches" ( English rope pull safety switch ).

The rope can be led around corners with eyelets. So you can expand the reach of a (endangered) person.

The tension of the rope and an opposing spring keep the contact tongue in the switch in the middle position. In this position the contact is closed.

The contact is positive opening. If the contact surfaces are welded or glued, the actuating force is sufficient to destroy the contact tongue and thus interrupt the circuit. The switch must then be replaced.

literature

• Reinald Skiba : Taschenbuch Betriebliche Sicherheitstechnik . 3. Edition. Schmidt Erich Verlag, 1991, ISBN 978-3-503-02943-3 .