Cylindrical permanent magnet to produce a transversal and uniform induction field
US4999600A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 1989 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | Apr 14, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/0278
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Industrial problems concerning the production of a field of uniform and traverse induction are solved by providing a cylindrical magnet with magnetic blocks of which the internal magnetization is either radial or tangential to the cylinder. Such an arrangement facilitates the fabrication and the magnetization of the blocks. A radial or tangential magnetization distribution produces a transverses field only if the magnetization modulus varies respectively with the cosine or the sine of the localization angle of the block with respect to the direction of induction to be produced. By combining both structures, it is even possible to obtain a magnet having a zero bipolar moment. The variation of the magnetization modulus is obtained by providing composite magnetic bricks. They comprise plates of magnetic materials which are coupled to non-magnetic plates in a proportion dependeing on the reduction of magnetization to be achieved. Such a magnet applies to imaging by nuclear magnetic resonance in the medical field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.