Patent ID: 8279718

Claim:
A calendar mechanism, comprising: a first date indicator which, being rotatable around a first central axis of rotation, includes a first date character indication portion which, being circular as a whole, indicates the ones column of the date, a circular first date indicator gear portion which, being formed on the inner periphery of the first date character indication portion, receives a torque, and a drive cam portion which, being formed on the back side of a first date character indication surface portion, defines an endless ring-shaped cam face; a drive cam lever which includes a driven lever portion whose one end portion abuts against the drive cam portion as a cam follower, and an operating lever portion which, being integral with the driven lever portion, includes a first fan-shaped gear portion at the leading end portion, wherein the one end portion of the driven lever portion is spring loaded in such a way as to be biased toward the cam face of the drive cam portion, and when the driven lever portion is pivoted in a condition in which the one end portion is in abutment with the cam face of the drive cam portion, the first fan-shaped gear portion of the operating lever portion is pivoted in accordance with the pivoting of the driven lever portion; a second date indicator which, being rotatable around a second central axis of rotation, includes a second date character indication portion which indicates the tens column of the date, and a second fan-shaped gear portion meshing with the first fan-shaped gear portion; and a stationary support including a positioning/locking portion, wherein the cam face of the drive cam portion, as well as including a second and third cam face portion corresponding to a case in which the tens column of the date is 1 and 2, and including a fourth cam face portion corresponding to a case in which the tens column of the date is one of 0 or 3, includes an invalid cam face portion corresponding to a case in which the tens column of the date is the other of 0 or 3, wherein the calendar mechanism is configured in such a way that in the case in which the tens column of the date is the other of 0 or 3, one portion of the drive cam lever abuts against the positioning/locking portion, causing the cam follower of the driven lever portion to come near to and face the invalid cam face portion of the cam face of the drive cam portion, but to remain in a condition out of contact with the invalid cam face portion.