To provide a locking cylinder capable of obtaining an extremely large number of different locking numbers.
A plurality of guide plates 17a, 17b are attached at every equal distance in the inside of the inner cylinder 10 built in the outer cylinder 1 to form a tumbler chamber 18 between adjacent guide plates 17a, 17b. Key ways 21 are provided respectively in top plugs 12 provided at the guide plates 17a, 17b and at the end of the inner cylinder 10. Two sheets of tumblers selected from the plurality of platy tumblers T1-T5 are arranged at both sides of the key way 21 in the respective insides of the plurality of tumbler chamber 21 to support them to be freely rockable and respective tumblers are elastically held so that the protrusions 24, 29 are disclosed in the key way 21 by the tumbler spring 32. Each tumbler is displaced to the unlocking position by inserting the operation key 40 into the key way 21 to make the lock member 15 radially transferable to the inside and make the inner cylinder 10 freely rotatable.
Higashio Masahiro
Torii Kazuhisa