| 摘要 |
A clock mechanism driven by a pulsed stepper motor and having planetary reduction gearing which provides a continuous but resilient connection between the motor and the minute hand of the clock at all times. The motor includes a permanent magnet rotor in direct driving relationship with the minute hand, and the rotor poles serve as a magnetic detent to hold the minute hand in discrete angular positions. The mechanism may be employed either in individual clocks or in the secondary clocks of a master-secondary clock system. In these latter embodiments the secondary clocks additionally include a pair of switches respectively controlled by the minute hand gearing and the hour hand gearing. The switches greatly facilitate the automatic resetting of the clocks in response to appropriate resetting signals from the master unit.
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