Means for developing friction in clock setting shaft
US3930362A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 12, 1975 |
| Grant date | Jan 6, 1976 |
| Priority date | — |
| Expiry date | Mar 12, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04B19/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A clock "friction" for use in clocks having plastic gear wheels which permits manual setting of the hands but in which a reliable level of frictional torque is obtained without requiring use of any auxiliary parts. The centerwheel of the clock has an interference fit with respect to the center, or minute hand, shaft upon which it is telescoped, and the minute hand shaft is formed with an annular groove lying generally in the plane of the centerwheel into which the plastic relaxes and flows for maintaining the centerwheel in a desired axial position. The minute hand shaft has a setting knob, and means are provided for precluding axial shifting of the center shaft, by pushing or pulling, which might result in stripping of the plastic in the groove.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.