Acoustic warning device, in particular a bell
US4097862A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 23, 1976 |
| Grant date | Jun 27, 1978 |
| Priority date | — |
| Expiry date | Dec 23, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10K1/064
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An acoustic warning device of the type comprising a striker member which is also the movable core member of a control solenoid. A radially polarized permanent magnet is disposed at one end of the solenoid, e.g. opposite a gong therefor, and a spring defines with the permanent magnet a rest position of the core/striker member. The end of the core/striker member proximate to the permanent magnet is limited in its outward displacements within the axial extent of the permanent magnet means. The flux through the solenoid is carried mainly by the core member. The alternating polarization of the core/striker member ends is alternately attracted and repelled by the magnetic flux of the permanent magnet which is the equivalent of an imaginary axially polarized magnet in the passage through the solenoid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.