The latest development from safety specialist, Euchner is a twin-headed switch that can be used with two adjacent machine access or cell enclosure guards. Previously, it would have been necessary to use two separate switches for this purpose, involving not only additional material costs, but also extra control circuitry and monitoring facilities.
The new switches are double-headed versions of the proven STP and SGP safety switch ranges, featuring a combination of plastic housings with robust metal actuating heads and internal cams that can cope with locking forces of up to 2,500N. They also offer IP67 protection rating.
The use of a single safety switch for the control of two guards or doors has obvious cost saving advantages. The doors can be hinged or sliding varieties, and typically would be used where a machining cell is located alongside an associated preparation, loading or palletising enclosure. Controlled access to either station can be maintained for purposes of safety during production, inspection, cleaning or general maintenance procedures.
Two switches are available, including the SGP Twin, which is supplied without guard locking. Manual padlocking is available, however, to ensure the switch actuators cannot be removed from the switch head. The second switch is the STP Twin, which incorporates guard locking, an independently operated electronic shot-bolt mechanism that can be key operated or automatically released when a monitored machine has stopped or is otherwise safe. The mechanical key release feature can be used as a lockout for the guard locking function to prevent unintentional guard locking. This ensures that personnel are not trapped within a machining or production cell if a safety door is accidentally closed.