US3844513A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for detecting wheel flats on rail vehicles
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1972-10-02
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Granted: 1974-10-29
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Expires: 1992-10-02
Abstract
Abstract A system and method for detecting the presence of wheel flats on rail vehicles. The system includes a voltage source, one side of which is connected to a first rail of a track and the other to a second rail extending parallel with the first rail in a manner whereby the current circuit includes the rim of the wheel being sensed. The connection points are spaced in the longitudinal direction of the track such that the distance between the connection points is shorter than the smallest axle distance occurring in the vehicle. The circuit also includes an impedance and a detecting means connected over a portion of the impedance to sense changes in voltage resulting from a break in the circuit caused by a wheel flat.
Inventors
- 👤 R Bernhardson
- 👤 K Lundfeldt
- 👤 K Ullerfors
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:45
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/28; G01B7/282; B; B61; B61K; B61K9/00; B61K9/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
129 words
A method for detecting wheel flats on rail vehicles having wheels made of electrically conductive material and an axle between oppositely situated wheels, comprising the steps of: passing an alternating current having a relatively high frequency through a current circuit which includes a first and a second wheel to be sensed and the axle between said wheels, said first and second wheels being the only wheels in said current circuit wherein a contact point between the peripheral bearing surface of each wheel and the associated rail together with a portion of a first and a second rail forms part of the circuit, and detecting a change of the current amplitude in the current circuit caused by the presence of a wheel flat on at least one of said wheels.
Claim 2
Independent Claim
129 words
A method for detecting wheel flats on rail vehicles having wheels made of electrically conductive material and an axle between oppositely situated wheels, comprising the steps of: passing an alternating current having a relatively high frequency through a current circuit which includes a first and a second wheel to be sensed and the axle between said wheels, said first and second wheels being the only wheels in said current circuit wherein a contact point between the peripheral bearing surface of each wheel and the associated rail together with a portion of a first and a second rail forms part of the circuit, and detecting a change of the current amplitude in the current circuit caused by the presence of a wheel flat on at least one of said wheels.
Claim 3
Dependent Claim
21 words
A method according to claim 1 wherein the step of detecting comprises detecting the current conditions in the current circuit inductively.
Claim 4
Independent Claim
166 words
A system for detecting wheel flats on rail vehicles having a plurality of pairs of electrically conductive wheels, the wheels of each pair being situated on respective rails of a track and connected by an axle, comprising: a current circuit, having a high frequency alternating voltage source connected to the rails of the track, wherein the circuit includes the peripheral bearing surface of each wheel of the pair of wheels to be sensed and the axle, and wherein one side of the voltage source is connected at one point to a first rail in the track and the other side of the voltage source is connected at a second point to a second rail in the track extending parallel with the first rail and wherein the connection points are spaced apart from each other in a longitudinal direction of the track, said spacing being shorter than the smallest distance between adjacent axles occurring in the vehicle; and means, connected to the circuit, for indicating wheel flats.
Claim 5
Independent Claim
166 words
A system for detecting wheel flats on rail vehicles having a plurality of pairs of electrically conductive wheels, the wheels of each pair being situated on respective rails of a track and connected by an axle, comprising: a current circuit, having a high frequency alternating voltage source connected to the rails of the track, wherein the circuit includes the peripheral bearing surface of each wheel of the pair of wheels to be sensed and the axle, and wherein one side of the voltage source is connected at one point to a first rail in the track and the other side of the voltage source is connected at a second point to a second rail in the track extending parallel with the first rail and wherein the connection points are spaced apart from each other in a longitudinal direction of the track, said spacing being shorter than the smallest distance between adjacent axles occurring in the vehicle; and means, connected to the circuit, for indicating wheel flats.
Claim 6
Dependent Claim
38 words
A system according to claim 3 wherein the distance in the longitudinal direction of the track between the connection points of the voltage source is less than or equal to the circumference of a wheel to be sensed.
Claim 7
Dependent Claim
32 words
A system according to claim 3 wherein the current circuit comprises a resistance, the voltage drop over the resistance being applied to the indicating means for indicating interruptions in the current circuit.
Claim 8
Dependent Claim
36 words
A system according to claim 5 wherein the indicating means comprises two contacts, arranged in spaced relationship with respect to each other, and actuated by a passing wheel for, respectively, connecting and disconnecting, the indicating means.
Claim 9
Independent Claim
189 words
A system for detecting wheel flats on rail vehicles, having a plurality of pairs of electrically conductive wheels, the wheels of each pair being situated on respective rails of a track and connected by an axle, comprising: a current circuit including an AC voltage source connected to the rails of a track, the peripheral surface of each wheel of the pair of wheels to be sensed, the axle and an impedance which is adjusted so that the circuit conTaining the impedance, the rails, the axle and the wheels forms a resonance circuit tuned to the frequency of the voltage source, and wherein one side of the voltage source is connected at one point to a first rail in a track and the other side of the voltage source is connected at a second point to a second rail in the track extending parallel with the first rail and wherein the connection points are spaced apart from each other in a longitudinal direction of the track, said spacing being shorter than the smallest distance between axles occurring in the vehicle; and means connected to the circuit, for indicating wheel flats.
Claim 10
Independent Claim
189 words
A system for detecting wheel flats on rail vehicles, having a plurality of pairs of electrically conductive wheels, the wheels of each pair being situated on respective rails of a track and connected by an axle, comprising: a current circuit including an AC voltage source connected to the rails of a track, the peripheral surface of each wheel of the pair of wheels to be sensed, the axle and an impedance which is adjusted so that the circuit conTaining the impedance, the rails, the axle and the wheels forms a resonance circuit tuned to the frequency of the voltage source, and wherein one side of the voltage source is connected at one point to a first rail in a track and the other side of the voltage source is connected at a second point to a second rail in the track extending parallel with the first rail and wherein the connection points are spaced apart from each other in a longitudinal direction of the track, said spacing being shorter than the smallest distance between axles occurring in the vehicle; and means connected to the circuit, for indicating wheel flats.
Claim 11
Dependent Claim
31 words
A system according to claim 7 wherein the indicating means is connected over a portion of the impedance to sense the voltage changes occurring as a result of a wheel flat.
Claim 12
Independent Claim
166 words
A method for detecting wheel flats on rail vehicles having wheels made of electrically conductive material and an axle between oppositely situated wheels, comprising the steps of: passing an alternating current through a current circuit which includes a first and a second wheel to be sensed and the axle between said wheels, wherein a contact point between the peripheral bearing surface of each wheel and the associated rail together with a portion of a first and a second rail forms part of the circuit, generating a first signal corresponding to a first period of time, detecting, during said first period of time, a change of the current amplitude in the current circuit caused by the presence of a wheel flat on at least one of said wheels and generating a second signal corresponding to the time the wheel flat is detected, comparing said first and second signals, and generating an alarm signal if the comparison indicates the wheel flat is in excess of a predetermined limit.
Claim 13
Independent Claim
166 words
A method for detecting wheel flats on rail vehicles having wheels made of electrically conductive material and an axle between oppositely situated wheels, comprising the steps of: passing an alternating current through a current circuit which includes a first and a second wheel to be sensed and the axle between said wheels, wherein a contact point between the peripheral bearing surface of each wheel and the associated rail together with a portion of a first and a second rail forms part of the circuit, generating a first signal corresponding to a first period of time, detecting, during said first period of time, a change of the current amplitude in the current circuit caused by the presence of a wheel flat on at least one of said wheels and generating a second signal corresponding to the time the wheel flat is detected, comparing said first and second signals, and generating an alarm signal if the comparison indicates the wheel flat is in excess of a predetermined limit.
References Cited (Backward Citations)
US733698A
Cited
US2590603A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |