| 摘要 |
Tumbler discs are supported within a cylinder for rotation therein between locked and unlocked positions. The cylinder itself is rotatably supported within an outer casing into which it may be loaded from the front and held in place by a hidden externally-threaded collar. When the tumbler discs are in the locked position, they support a locking bar in engagement with a slot in the cylinder and an aligned groove in the outer casing to prevent the cylinder from being rotated relative to the outer casing. The first tumbler disc may include a concentric portion of reduced diameter and increased thickness communicating with the front of the outer casing and serving as a freely rotatable spinner until a key is engaged with the tumbler discs. Driving portions of the key are angularly coded for rotating the tumbler discs to the unlocked position as the key is turned in one direction. When the tumbler discs are in the unlocked position, peripheral lugs on some of the tumbler discs are positioned in abutment upon a stop portion of the cylinder, and notches in all of the tumbler discs are aligned with the slot in the cylinder to form a groove for receiving the locking bar so that the cylinder and the tumbler discs may be freely rotated together relative to the outer casing as the key is turned further in the same direction. In the unlocked position one of the tumbler discs may be releasably engaged with the cylinder so that the cylinder and tumbler discs may also be freely rotated together relative to the outer casing as the key is turned in the opposite direction. This same tumbler disc may be disengaged from the cylinder under control of the key. A locking member protruding through an opening in the rear of the outer casing is rotatably driven by the cylinder to lock and unlock a structure in which the outer casing is embedded.
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