Rotary angular position sensor with magnet and pole disk assembly mounted on rotatable shaft
US4503391A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 14, 1982 |
| Grant date | Mar 5, 1985 |
| Priority date | — |
| Expiry date | Oct 14, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/4815
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To provide bipolar needle pulses in which oppositely polarized pulses occur close together to form pulse pairs, with long time intervals between pulse pairs, a pair of pole disks (10, 11) are located on a rotor (91, 12) with a permanent magnet (13) interposed. The disks have radially and axially extending claws (15a, 15b, 16) formed thereon, the axial extensions being directed towards each other, but the claws (15a, 15b) projecting from one disk (10) being arranged in claw element pairs with which the claws (16) from the other disk, and magnetically oppositely polarized, are interdigited. The magnetic field, passing through the air gap between the claws, is sensed by a stationary pick-up such as a Hall sensor, a Wiegand sensor, or a magnetic field plate. When used for ignition timing of an internal combustion engine, the number of interdigited claws may correspond to the number of cylinders, and the claw pairs are spaced closely together so that the time (t.sub.b) between oppositely polarized pulse pairs (17, 18) derived from the change in magnetic field upon induction with the sensor, will be large with respect to the timing between oppositely polarized pulses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.