Electronic timepiece with calendar device
AssigneeCitizen Watch Co., Ltd.
InventorsTakeo Mutoh, Yasuo Kitajima, Haruhiko Higuchi, Hiroyuki Koike
Life of this patent
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Abstract
An electronic timepiece has a calendar advancement device resistant to external shock and capable of achieving date correction in a short time. A date dial advancement transducer (51) is activated in response to a date dial drive signal generated by a 24-hour switch. A date advancement mechanism (a date gear train) (52) employs a Geneva wheel for stabilizing the date dial (70). A bounding restraint lever is regulated using an eccentric cam or the like provided coaxially with the Geneva wheel.
Claims20
An electronic timepiece having a date dial as a rotating indication panel for dates on a calendar, comprising:
- a calendar advancement device, including
- a 24-hour switch for generating a date dial drive signal every twenty-four hours;
- a date dial advancement transducer activated by a control circuit having received the date dial drive signal;
- and
- a date advancement mechanism having a date dial stabilizing Geneva wheel, and a date dial driving wheel for engagement with a flange of the Geneva wheel and a date wheel gear of the date dial, and being activated with force from said date dial advancement transducer.
An electronic timepiece having a date dial as a rotating indication panel for dates on a calendar, comprising:
- a control device for dates on a calendar, including
- a date advancement transducer for driving a date dial;
- a slow-down gear train for transmitting rotation force of said date advancement transducer to the date dial;
- a date dial intermittent rotation drive device constituting a part of said slow-down gear train, for intermittently driving the date dial;
- and
- a bounding restraint lever, movable by said intermittent rotation drive device, for restraining rotation of the date dial in a non-driven state, and releasing rotation restraint on the date dial in a driven state.
An electronic timepiece having a date dial as a rotating indication panel for dates on a calendar, comprising:
- a control device for dates on a calendar, including
- a date advancement transducer for driving a date dial;
- a slow-down gear train for transmitting rotation force of said date advancement transducer to the date dial;
- a bounding restraint lever for restraining rotation of the date dial in a non-driven state, and releasing rotation restraint on the date dial in a driven state, wherein said bounding restraint lever is engaged with teeth of the date dial in a non-driven state for rotation restraint, and departs from the teeth of the date dial in a driven state for releasing load due to pressing force applied to the date dial;
- and
- a date dial intermittent rotation drive device constituting a part of said slow-down gear train, for intermittently driving the date dial, comprising:
- a date dial driving wheel arranged to continuously engage with the date dial,
- a date intermediate wheel having feed teeth for intermittent engagement with said date dial driving wheel, and
- an eccentric cam for engagement with and rotating said bounding restraint lever,
- wherein said date intermediate wheel and said eccentric cam have a common rotation center.
Dependencies are inferred from the claim text.