Patent US3791701A successfully refreshed from Google Patents.
US3791701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Skid control system
Assignee: ZF Active Safety US Inc
•
Filing: 1972-07-07
•
Granted: 1974-02-12
•
Expires: 1992-07-07
Abstract
Abstract A braking system including a skid control system, in which the brakes are actuated from a source of hydraulic power with the magnitude of pressure to the brakes being varied generally as a function of the input force from the vehicle operator and; during controlled operation, as a function of the magnitude of an error signal indicative of an incipient skid or excessive slip condition.
Inventors
- 👤 H Riordan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:56
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/58; B60T8/17; B60T8/176; B60T8/1761; B60T8/17613; B60T8/34; B60T8/44; B60T8/447
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
258 words
In a skid control system for a hydraulic brake system for at least one wheel of a wheeled vehicle, the combination comprising: speed sensing means for sensing the speed of a skid controlled wheel and for supplying a wheel speed signal representing the speed of the wheel and skid control means for skid controlling the wheel comprising skid control circuit means for developing a skid control signal and brake modulating means responsive to said skid control signal for modulating brake pressure to the wheel, said skid control circuit means comprising differentiating circuit means for differentiating the wheel speed signal to develop a wheel acceleration signal, reference circuit means for developing a reference acceleration signal, subtracting circuit means for subtracting one acceleration siGnal from the other acceleration signal to develop a subtracting circuit output signal representing the difference between the two acceleration signals, integrating circuit means for integrating the subtracting circuit output signal to develop an integrating circuit output signal representing the integral of the difference between the two acceleration signals and means for supplying said integrating circuit output signal to said brake modulating means so that said integral constitutes a component of said skid control signal, said skid control circuit means including means for developing a modified wheel speed signal from the wheel speed signal and summing circuit means for summing the modified wheel speed signal with the integrating circuit output signal so that said integral and the modified value of wheel speed as represented by said modified wheel speed signal constitute components of said skid control signal.
Claim 2
Dependent Claim
258 words
In a skid control system for a hydraulic brake system for at least one wheel of a wheeled vehicle, the combination comprising: speed sensing means for sensing the speed of a skid controlled wheel and for supplying a wheel speed signal representing the speed of the wheel and skid control means for skid controlling the wheel comprising skid control circuit means for developing a skid control signal and brake modulating means responsive to said skid control signal for modulating brake pressure to the wheel, said skid control circuit means comprising differentiating circuit means for differentiating the wheel speed signal to develop a wheel acceleration signal, reference circuit means for developing a reference acceleration signal, subtracting circuit means for subtracting one acceleration siGnal from the other acceleration signal to develop a subtracting circuit output signal representing the difference between the two acceleration signals, integrating circuit means for integrating the subtracting circuit output signal to develop an integrating circuit output signal representing the integral of the difference between the two acceleration signals and means for supplying said integrating circuit output signal to said brake modulating means so that said integral constitutes a component of said skid control signal, said skid control circuit means including means for developing a modified wheel speed signal from the wheel speed signal and summing circuit means for summing the modified wheel speed signal with the integrating circuit output signal so that said integral and the modified value of wheel speed as represented by said modified wheel speed signal constitute components of said skid control signal.
Claim 3
Dependent Claim
22 words
The combination of claim 1 wherein said modified wheel speed signal varies in proportion with the derivative of said wheel speed signal.
Claim 4
Dependent Claim
26 words
The combination of claim 1 wherein said modified wheel speed signal is equal to the derivative of said wheel speed signal multiplied by a scaling factor.
Claim 5
Dependent Claim
18 words
The combination of claim 1 wherein said modified wheel speed signal is formed from said wheel acceleration signal.
Claim 6
Dependent Claim
23 words
The combination of claim 4 wherein said modified wheel speed signal is equal to said wheel acceleration signal multiplied by a scaling factor.
Claim 7
Dependent Claim
226 words
In a skid control system for a hydraulic brake system for at least one wheel of a wheeled vehicle, the combination comprising: sensing means for sensing actual acceleration and velocity of a skid controlled wheel and for supplying wheel acceleration and wheel velocity signals representing the values thereof, and skid control means for skid controlling the wheel comprising skid control circuit means for developing a skid control signal and brake modulating means responsive to said skid control signal for modulating brake pressure to the wheel, said skid control circuit means comprising reference circuit means for establishing reference signals representing preselected reference values of wheel acceleration and vehicle velocity, substracting circuit means for subtracting the actual wheel acceleration signal from the reference wheel acceleration signal to develop a subtracting circuit signal when the actual wheel velocity signal differs from the reference vehicle velocity signal by a predetermined value representative of a certain wheel slip, integrating circuit means for integrating the subtracting circuit signal to develop an integrating circuit signal, means for supplying said integrating circuit signal to said brake modulating means, and means responsive to said actual wheel velocity signal departing from said reference vehicle velocity signal by an amount greater than said predetermined value representative of said certain wheel slip for supplying a supplemental signal to said integrating circuit means to supplement said subtracting circuit signal.
Claim 8
Dependent Claim
226 words
In a skid control system for a hydraulic brake system for at least one wheel of a wheeled vehicle, the combination comprising: sensing means for sensing actual acceleration and velocity of a skid controlled wheel and for supplying wheel acceleration and wheel velocity signals representing the values thereof, and skid control means for skid controlling the wheel comprising skid control circuit means for developing a skid control signal and brake modulating means responsive to said skid control signal for modulating brake pressure to the wheel, said skid control circuit means comprising reference circuit means for establishing reference signals representing preselected reference values of wheel acceleration and vehicle velocity, substracting circuit means for subtracting the actual wheel acceleration signal from the reference wheel acceleration signal to develop a subtracting circuit signal when the actual wheel velocity signal differs from the reference vehicle velocity signal by a predetermined value representative of a certain wheel slip, integrating circuit means for integrating the subtracting circuit signal to develop an integrating circuit signal, means for supplying said integrating circuit signal to said brake modulating means, and means responsive to said actual wheel velocity signal departing from said reference vehicle velocity signal by an amount greater than said predetermined value representative of said certain wheel slip for supplying a supplemental signal to said integrating circuit means to supplement said subtracting circuit signal.
Claim 9
Dependent Claim
31 words
The combination of claim 6 including means for supplying said supplemental signal to said brake modulator means so that said supplemental signal also constitutes a component of said skid control signal.
Claim 10
Dependent Claim
33 words
The combination of claim 7 including means for supplying said subtracting circuit signal to said brake modulating means so that said subtracting circuit signal also constitutes a component of said skid control signal.
References Cited (Backward Citations)
US3469662A
Cited
US3401984A
Cited
US3556610A
Cited
US3554612A
Cited
DE1810163A1
Cited
US3614174A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |