Motor for electronic watch
US4277704A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1978 |
| Grant date | Jul 7, 1981 |
| Priority date | — |
| Expiry date | Dec 4, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K37/16
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A stepping motor particularly intended for electronic watches comprises two poles connected to a core bearing an elongated coil. The poles are joined at nose portions thereof by interposed elements of a material having a magnetic permeability as close as possible to 1. The one-piece stator may be formed by blanking from a composite band, thus considerably simplifying the problem of positioning the poles of the stator relative to the plate of the watch movement and to the rotor. A method of fabricating the one-piece stators efficiently consists in rolling together two strips of ferromagnetic metal and an interposed fillet of non-magnetic metal, these elements being joined at their edges to form a composite band from which the stators are blanked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.