Trapped Key Interlock

SKORPION Trapped Key Interlocks

Designed and manufactured in the United Kingdom, SKORPION - Idem's Trapped Key System in Stainless Steel 316 or Die Cast Metal has been developed to provide extremely robust mechanical coded key safeguarding and interlocking for hazardous machinery and applications.

The system works on the principle of releasing heavy duty coded mechanical keys in a pre-determined sequence to ensure machine power has been isolated before any access can be made into areas where hazards or dangerous machinery is present.

Once the machine control has been isolated (achieved by turning the first key in the system) the removed key from the isolator is then used to release other trapped keys to enable access to the guarded areas.

Following release of the first key (isolator) safeguarding is achieved without the need for expensive and time consuming electrical wiring - thus making the system perfect for use in harsh and challenging environments and applications.


A trapped key guarding system is reliant upon the transfer of coded keys between a power isolation witch (or control switch) and a locking mechanism which is fixed on a guard or guard door.

The primary and essential feature of the system being that the removable key is trapped either in the guard lock, or in the power isolation switch.

The interlock on the guard is arranged so that the trapped key can only be released when the guard has been closed and locked - preventing the key from being returned to the isolator (or control switch).

Once the guard is closed and locked the key can then be transferred from the guard to the power isolator (or control switch).

Closing the switch traps the key preventing the key's removal while the isolator switch is in the 'ON' position.