Method and apparatus including a cushion of pulverulent magnetic material for stray field magnetic testing of ferromagnetic parts
US4694247A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1985 |
| Grant date | Sep 15, 1987 |
| Priority date | — |
| Expiry date | Jun 6, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/84
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Elongated ferromagnetic parts of cylindrical or polygonal cross-sectional outline are tested while rotating about their axes and while advancing longitudinally along a cushion of dry pulverulent magnetic material which is supplied by one or more pneumatic conduits into the range of one pole of a first U-shaped electromagnet whose poles extend in the longitudinal direction of but do not contact the parts. The electromagnet establishes a stray magnetic flux in the region of each defect on the ferromagnetic part which is being tested and such flux or fluxes attract pulverulent material which thereby pinpoints the locations of defects. A second electromagnet is placed next to the one pole of the first electromagnet and its poles are spaced apart from each other as considered in the longitudinal direction of the tested part.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.