Plunger type electromagnet
US5268662A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1992 |
| Grant date | Dec 7, 1993 |
| Priority date | — |
| Expiry date | Jul 24, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/13
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A plunger type electromagnet is provided with an attractive plate connected to the plunger, with an improved configuration of plunger and stationary element, or with a flanged tubular member of magnetic material affixed to the axial end of a coiling bobbin, in order to increase the rate of change in the permeance of the magnetic circuit at the time of attractive operation and to enhance the sensitivity of the electromagnet. Furthermore, the surface area of the abutment faces of the stationary and movable elements is calibrated so as to control the attractive and retaining force thereof. In some embodiments, a permanent magnet is provided which is shaped in the form of an annulus and is magnetized in the direction of thickness of the annulus, so as to facilitate magnetization of the permanent magnet, to reduce the number of component parts, and to provide an electromagnet which is compact in size, light in weight, and suitable for mass production.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.