If you turn the key to the right into basic position, a hydraulic lift for example can be controlled (2 push-button functions).
If you combine the hydraulic lift with a limiting switch a mechanical lock (24V and/or 230V) is activated inside the key switch.
You cannot pul the key out afterwards. (lock set by zero position)
If the voltage of 24V or 230V is not maintained anymore, the mechanical lock is released (deactivated).
You can pull out the key only at zero position. Therefore you can be sure that the hydraulic lift is always set back to basic position.
The key switch is available whether with or without EMERGENCY STOP push-button.