Patent US3947711A successfully refreshed from Google Patents.
US3947711A
Expired / Lapsed
US
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Magnetic speed sensor
Assignee: Bendix Corp
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Filing: 1974-06-13
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Granted: 1976-03-30
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Expires: 1994-06-13
Abstract
Abstract A speed sensor for a vehicle wheel has a rotating tone wheel and a stationary E-shaped magnetic sensor having a sensing pole of square loop magnetic material positioned between two switching poles. A coil is wound on the sensing pole and the poles are magnetized to periodically reverse the flux in the sensing pole as the teeth on the tone wheel alternately pass the switching poles to induce a signal voltage in the coil corresponding to wheel speed and substantially free of noise components due to misalignment and vibrations of the tone wheel upon relative rotation of the tone wheel and magnetic sensor.
Inventors
- 👤 Rex Wallace Presley
- 👤 Jack Richardson Lorraine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:03
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/488; B; B60; B60T; B60T8/00; B60T8/32; B60T8/321; B60T8/329
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
120 words
A speed sensor for a vehicle wheel comprising a tone wheel driven by the vehicle and subject to misalignment and vibration, the tone wheel being made of magnetic material and having a plurality of teeth, and sensing means having a pair of switching poles of magnetic material and a sensing pole of square loop magnetic material positioned between the switching poles, the poles being positioned proximate the tone wheel teeth, coil means on the sensing pole, and means for magnetizing the poles to induce a signal voltage in the coil means corresponding to wheel speed and substantially free of noise components due to misalignment and vibration of the tone wheel upon relative rotation of the tone wheel and sensing means.
Claim 2
Dependent Claim
120 words
A speed sensor for a vehicle wheel comprising a tone wheel driven by the vehicle and subject to misalignment and vibration, the tone wheel being made of magnetic material and having a plurality of teeth, and sensing means having a pair of switching poles of magnetic material and a sensing pole of square loop magnetic material positioned between the switching poles, the poles being positioned proximate the tone wheel teeth, coil means on the sensing pole, and means for magnetizing the poles to induce a signal voltage in the coil means corresponding to wheel speed and substantially free of noise components due to misalignment and vibration of the tone wheel upon relative rotation of the tone wheel and sensing means.
Claim 3
Dependent Claim
44 words
A speed sensor as described in claim 1 in which the teeth on the tone wheel are arranged to alternately pass the switching poles to periodically reverse the direction of flux in the sensing pole to induce the signal voltage in the coil means.
Claim 4
Dependent Claim
20 words
A speed sensor as described in claim 1 in which the means for magnetizing the poles is a permanent magnet.
Claim 5
Dependent Claim
38 words
A speed sensor as described in claim 3 in which the switching poles are secured to the ends of the permanent magnet and the sensing pole is secured to the permanent magnet at its center in E-shaped configuration.
Claim 6
Dependent Claim
34 words
A speed sensor as described in claim 1 in which the switching poles are formed by permanent magnets and are secured with the sensing pole in E-shaped configuration to a member of magnetic material.
Claim 7
Dependent Claim
21 words
A speed sensor as described in claim 5 in which the north and south poles of the magnets are oppositely disposed.
Claim 8
Dependent Claim
44 words
A speed sensor as described in claim 1 in which the teeth on the tone wheel and the spaces therebetween are the same size and the distance between the sensing pole and each of the switching poles is substantially the length of one tooth.
Claim 9
Dependent Claim
54 words
A speed sensor as described in claim 1 in which the tone wheel comprises a pair of toothed members separated by a disk-like member therebetween and the magnetic sensor is positioned adjacent the circumference of the tone wheel with the switching poles adjacent the toothed wheels and the sensing pole adjacent the disk-like member.
Claim 10
Dependent Claim
106 words
A speed sensor as described in claim 1 in which the teeth on the tone wheel are formed near the circumference of the tone wheel by two concentric rows of slots separated by a continuous portion therebetween, the slots in one row being staggered relative to the slots in the other row with a slot in one row adjacent the bridge between the slots in the other row, and the magnetic sensor being positioned radially at the side of the tone wheel with each switching pole aligned with a row of slots and the sensing pole aligned with the continuous portion between the rows of slots.
Claim 11
Dependent Claim
36 words
A speed sensor as described in claim 1 in which the switching poles are formed of magnetic material attached to permanent magnets secured with the sensing pole in E-shaped configuration to a member of magnetic material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |