Three hand movement for a timepiece with improved timesetting gear train
US4932011A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 1989 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Nov 6, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04B27/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A three hand movement of the type having a frame, a stepping motor mounted in the frame, a manually actutable timesetting stem disposed in the frame and a gear train driven by the stepping motor to rotate coaxial members carrying "seconds", "minutes", and "hours" hands. An improved dual reduction gear assembly comprises a first rotatable member with a toothed wheel and a second rotatable member having first and second pinions driving the "hours" and "minutes" wheels. A timesetting gear is adapted to be clutched to the "minute wheel". A friction coupling connects the first and second rotatable members during timekeeping. During timesetting, the friction coupling slips to disengage the toothed wheel from the first and second pinions, so that the second rotatable member separately functions as a reduction gear during timesetting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.