In some occasions, it is required to perform an interlocking sequence involving simultaneous electrical and mechanical operations. This can be done activating a mechanism with a key that may be trapped or released, depending on the position, and acts consequently on the electrical contacts.

This mechanism is a commutator.

Some of these devices need to incorporate an interlock cylinder.

We can add an HERPE cylinder.

This type of commutators have several applications. As the key is turned, the commutator contacts change their position and trigger some actions: electrical — de/activation of the device where the mechanism is installed, mechanical — the key gets trapped or released. Sometimes, more than one key is required for the interlocking sequence. Key selectors allow to get more than one key from just one, so that the interlocking sequence can be performed without errors.

As an example, in a key selector with two keys, when one of the cabinet locks is released, the other is trapped and cannot be released.

If the free key is inserted in its corresponding lock and turned, the other one can be released and, consequently, the former is trapped.