Abstract: A trigger assembly for a trigger operated device including two trigger members movable between an aligned and and out of alignment condition in response to a predetermined condition of the device being monitored, a releasable catch holding the trigger members in their aligned condition, and a tripping mechanism operable to release the catch when the predetermined condition being monitored occurs. The trigger assembly may also include a reset mechanism for restoring the trigger members to their aligned condition when the condition being monitored is restored to some desired condition.