Locking in prevented – the new safety switch STF prevents uninten-tional locking inside a danger area.

The STF is based on the proven principle of the EUCHNER safety switch STP with spring-actuated guard locking. However, the STF also has a latch for the guard locking pin. As a result it is no longer possible for maintenance or cleaning personnel to become unintentionally locked inside the danger area. A safety guard and therefore also the guard locking always remain in their actual state when the STF is isolated electrically (for example system shutdown, power fail-ure…).

The guard either remains locked, i.e. the user cannot enter the danger area at all if the guard locking is closed and the power fails at the same time. Or the guard can be opened and closed as required. In this case (guard locking already open and power failure) there is no danger of unintentional locking inside the danger area, for example, due to the guard slamming shut. The guard locking cannot be activated in the opened state if there is a power failure due to the latch on the guard locking pin, locking inside is therefore prevented.

Due to the combination of a plastic switch housing with a metal head, the STF is very robust and is for use in all applications in which high locking forces are re-quired.
The safety switch STF with guard locking will be available from autumn 2006