Sound emitting device for electronic timepiece
US4374624A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 13, 1981 |
| Grant date | Feb 22, 1983 |
| Priority date | — |
| Expiry date | Aug 13, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R9/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sound emitting device for an electronic timepiece comprising a disk-shaped permanent magnet; a first yoke and second yoke introducing magnetic flux produced by the magnet and forming, outside the periphery of the magnet, a magnetic gap having the magnetic flux in the vertical direction of the perimeter of the magnet and in the horizontal direction of the disk surfaces of the magnet; a diaphragm carrying, within the magnetic flux of the magnetic gap, a moving coil wound at right angles to the magnetic flux and adapted to be vibrated in response to sound signal currents sent to the moving coil; and a support member supporting the permanent magnet, the yokes as well as the diaphragm at the diaphragm peripheral portion and removably secured at the support frame peripheral portion to a case. Air openings are provided in a part of the support member except where the permanent magnet, yokes and diaphragm are supported to form an air chamber which opens to the back of the diaphragm when the support member is packaged in the timepiece case.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.