Digital clock time display - with pinions on same centreline engaging one minute, ten minutes, and hour wheel gears

摘要

The time display of a digital clock uses less components for the stepper mechanism so that a less expensive design is combined with smaller overall dimensions. This mechanism has a drive pinion (18) which is integral with a shaft on which a second drive pinion (20) can rotate freely. The first pinion (18) mates with a toothed rim on the periphery of the one-minute drum (16) and with a toothed rim on the periphery of the ten minutes drum (19). The second pinion (20) mates both with another toothed rim on the drum (19) and with a toothed rim on the hour drum (21). The five time display cards on the drum (16) are turned over by a C-shaped recess in the housing. The gear ratio for the pinion (18) is so arranged that the ten minute drum (19) is turned by one-sixth of a full turn every two revolutions of the drum (16).