Permanent magnet arrangement
US4998976A · kind A · utility
Inventor
Key dates
| Filing date | Oct 7, 1987 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | Oct 7, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/0278
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A permanent magnet assembly used for creating a uniform magnetic field across a portion of an air gap has a permanent magnet grouping, including a first, principal magnet, a pole piece contacting said principal magnet,and a set of auxiliary magnets extending about the periphery of the pole piece. Two such magnet groupings are positioned within a test chamber, separated by spacers, with the magnet groupings and the chamber defining an air gap across which the magnetic field extends. Apertures formed in selected panels of the test chamber enable an object to be tested to be inserted into the chamber and held within a selected portion of the magnetic field formed therewithin. The strength and uniformity of the magnetic field is adjusted by including a second set of auxiliary permanent magnets or a set of electromagnetic coils positioned within the chamber proximate the respective pole pieces. Further adjustment of the magnetic field is accomplished by shaping the front surfaces of the pole pieces, thus affecting the shape and direciton of the resulting magnetic field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.