This one sounds good to me.
>An "interlock" connects two components of a device or two devices. An example
>of an interlock is mechanical latch on an optional sorter that connects the
>base printer with the sorter.
I would define an interlock as:
A switch or sensor used to stop operation of the device due to the
opening of a door, cover or other component of the device in order
to prevent injury to a human or improper operation of the device.