Trapped Key Interlock Systems

Rotary Key Switch Rotary key switches are used for electrical isolation of machinery to enable safe access. Once the power has been turned off, the key can then be withdrawn and used in the next sequence of operation such as unlocking an access hatch or allowing valves to be operated. The rotary key switch can either be mounted in a panel or purchased in an IP65 enclosure. Solenoid Key Release Unit The solenoid release unit is used for electrical isolation of a machine's power to enable safe access. It only allows the trapped key to be removed once a signal is given to its internal locking mechanism, and after power has been turned off to ensure a safe condition. The key is rotated 90° and then removed which changes the state of the unit's contacts. The key can then be used in the next sequence of the operation. Electronic Timed-Delay Unit The electronic timed-delay is a failsafe timer and/or motion sensing solenoid locking key unit. Certain operations require an elapsed time before entry to, or removal of materials. These delayed times should be adhered to for safety or correct operating procedures. The electronic timed delay unit provides an ideal solution by trapping the key within the unit for a preset time after a stop signal has been made. When this time has elapsed the previously trapped key can be withdrawn and used in the next sequence of operation. Valve Lock, 3 port spool The 3 port spool valve is used for pneumatic isolation of machinery to enable safe access. It only allows the trapped key to be removed once pneumatic power has been turned off ensuring a safe condition. The previously trapped key can then be withdrawn and used in the next sequence of operation.