PURPOSE: To prevent an applicable event occurring when an other unfair key is inserted in mid-course by an additional simple structure.
CONSTITUTION: An inserting position identifying mechanism which is formed with a groove 10 and a protrusion 9 engaged with the groove 10 and allowed to be rotated only when a key 2 is inserted into a rotor 3 at regular position in a cylinder lock is provided between the edge of the key 2 and the inner peripheral surface 5 of a cylinder case 6. Also an annular groove 8 is engraved in the outer periphery of the rotor 3 avoiding tumblers 1 and 1 parts. Then protrusions 9 and 9 adjacent to the inner peripheral surface 5 opposed to the tumblers 4 and 4 at intervals equivalent to the thickness of the key 2 are provided in the cylinder case 6 with the protrusions engaged with the groove 8 at all times so that they can be moved slidably in the groove 8 when the rotor 3 is rotated. In the key 2, a groove 10 to engage with the protrusion 9 may be engraved at the edge of the key 2 on the opposite side of its notch at a position that matches the groove 8 of the rotor 3 so as to commonly use an extraction prevention means of the rotor 3 by the groove 8 and protrusion 9.
YOSHINO SHIGERU
YAMAMOTO TSUTOMU
Next Patent: CODE LOCK BODY AND SKI BOARD THEFT PREVENTION WIRE LOCK