Magnetic-based torque/speed sensor
US6959612B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 17, 2001 |
| Grant date | Nov 1, 2005 |
| Priority date | — |
| Expiry date | May 17, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/487
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Torque is measured in the chain wheel (50) of a pedal cycle by a non-contacting magnetic-based transducer. A magnetising source (70), a D.C. type of source such as a permanent magnet is positioned adjacent the chain wheel (50) to induce an arcuate magnetised zone (72) in the wheel (50) as it rotates. The zone emanates a torque-dependent magnetic-field component that is detectable by a sensor (74) that follows the source (70) in the direction of rotation. By having the magnetising source (70) continually in position the arcuate tranducer zone (72) is refreshed on each rotation of the chain wheel. The nature of the pulsating torque in the chain wheel due to the exertion of the rider and its relationship to the angle of the pedal cranks is discussed with a preference for positioning the source (70) and sensor (74) at positions of minimum and maximum exerted torque respectively. If the induced arcuate magnetisation is interrupted (76) pulses for measuring rotational speed are obtainable. The torque measurement is of general application to torque in sprocket wheels or gear wheels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.