Method and apparatus for detecting the position of a movable object utilizing the magnetostrictive effect to generate ultrasonic waves
US4654590A · kind A · utility
29Cited by
4References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1984 |
| Grant date | Mar 31, 1987 |
| Priority date | — |
| Expiry date | Oct 5, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/247
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A plurality of permanent magnets are disposed on a movable object with predetermined spacings between them, and a fixed permanent magnet or magnets are disposed at positions spaced apart by a predetermined distance from the detection portion of a waveguide disposed along the movable object. Magnetostrictive ultrasonic waves generated on the waveguide are detected at the positions of these permanent magnets, and the position of the movable object is detected from the number of ultrasonic wave signals and the propagation time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.