Abstract: The locking device includes a support having a first plate rotatably mounted thereon. Four radially extending locking bars are rotatably mounted on the first plate such that the rotation thereof moves the bars between locked and unlocked positions. A second plate movably mounted on the support between first and second positions is provided with means engagable with the first plate to prevent the rotation thereof when the second plate is in the first position. A projection is mounted on the lock cylinder and is movable with respect thereto along an arcuate path upon actuation of the cylinder. The projection is engagable with the given portion of the first plate to rotate same as the projection is moved.