| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for displaying periods that form an annual cycle, which overcome various shortcomings of conventional devices and accurately displays the periods even in moments between periods.SOLUTION: A mechanism for controlling the duration for displaying periods includes at least; a drive member 2 for driving an indicator member 1; a cam 4 that controls the duration for displaying the periods; means of driving the cam; and a first differential gear 6 with two inputs and one output, a first input comprising a reference drive wheel 8 configured to complete one revolution in one reference period, a second input comprising an actuation member 10 configured to cooperate in concert with the cam 4, and the output comprising the drive member 2 for the indicator member 1. The cam 4 has a profile configured such that the actuation member 10 operates in concert with the first differential gear 6 to move the drive member 2 for the indicator member 1 forward or backward in accordance with the duration of the period to be displayed relative to the reference period.SELECTED DRAWING: Figure 1 |
