PURPOSE: To simplify operation by providing a means to contain an operation steering wheel in a housing, a locking means provided with a rotatable lever, and an unlocking means to be operated from the inside of an enclosure.

CONSTITUTION: When a door is closed, a hand is inserted in an opening part 9 of an operation steering wheel 7 and the steering wheel 7 is rotated centering around a pin 27 to a position where the steering handle 7 is approximately inserted in the inside of the bottom of a housing 1. An angle member then enters an oval port 14 and coordinates with a matching member 5. A handle 7 then presses the steering wheel 7 and when a guide lamp makes contact with the side wall of a lever 42, springs 53 and 54 are worked so that the lever 42 is rotated upward to a stop position. Through the elastic energizing force of the lever 53, the lever 42 approaches below and the opening part 9 is situated inside a recessed part 50 of the steering wheel 7. Further, a lock is rotated at a cylinder 11, and after a lock part 42 is rotated and moved in the lever 42, a lock is removed from a cylinder 11 and a protection cover 28 is closed.