Single-coil balance wheel for driving a mechanical movement
US4340948A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 24, 1980 |
| Grant date | Jul 20, 1982 |
| Priority date | — |
| Expiry date | Apr 24, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG04C3/069
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A timepiece including a mechanical movement is disclosed and a movable system for driving the movement. The movable system includes a balance wheel formed by a pair of plates and a magnetic member mounted on each plate. The magnetic members include a magnetic north and south pole arranged to provide a magnetic field. A coil is disposed in position so that its winding may be swept with the magnetic field which induces a voltage to which a circuit is responsive to develop a feedback signal to be applied across the winding to add energy to the movable system in replacement of energy losses of friction, and so forth. A feedback signal is developed if the movable system is sweeping the coil briskly. If movement of the movable system is not brisk, or the movable system has stopped, then a start pulse is developed for self-starting. The start pulse is normally prevented by the feedback signal which also serves as a reset signal to reset a start signal counter before completion of a counting operation. The circuit is controlled by an oscillator which opens and closes a gate to prevent creation of a closed loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.