Patent US3854779A successfully refreshed from Google Patents.
US3854779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-lock vehicle brake systems
Assignee: US Philips Corp
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Filing: 1973-04-19
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Granted: 1974-12-17
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Expires: 1993-04-19
Abstract
Abstract An electronic control circuit for an anti-lock vehicle brake system including apparatus responsive to an input signal which is a function of wheel speed for producing an output signal for energizing a solenoid valve when wheel acceleration has fallen below a first negative reference rate and wheel speed has changed by an amount which is greater by a given percentage than its amount of change would have been had its change continued at the first reference rate; apparatus for establishing the first reference rate; apparatus for replacing the first reference rate by a second lower reference rate following the production of the output signal; apparatus for replacing the second reference rate by a third positive reference rate after the second reference rate has persisted for a predetermined time; and apparatus responsive to the input signal for terminating the output signal to cause solenoid valve de-energization when the wheel acceleration attains either the second reference rate or the third reference rate, whichever prevails at the time, the prevailing reference rate being replaced by the first reference rate when said output is terminated.
Inventors
- 👤 D Skoyles
- 👤 D Sharp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:54
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/58; B60T8/17; B60T8/176; B60T8/1764; B60T8/34; B60T8/343; Y; Y10; Y10S; Y10S303/00; Y10S303/08
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
240 words
An electronic control circuit for an anti-lock vehicle brake system, said control circuit comprising, means responsive to an input signal having a quantity which is a function of wheel speed to produce an output signal for causing energisation of a solenoid valve when said quantity has changed at a rate in excess of a first reference rate and by an amount which is greater by a given percentage than its amount of change would have been had its change continued at that first reference rate, the latter corresponding to a first value of wheel deceleration, means for establishing said first reference rate within said control circuit, means for replacing said first reference rate by a second reference rate following the production of said output signal, said second reference rate corresponding to a second value of wheel deceleration that is more negative than said first value, means for replacing said second reference rate by a third reference rate after said second reference rate has persisted for a predetermined period of time, said third reference rate corresponding to a first value of wheel acceleration, and means responsive to said input signal for terminating said output signal to cause solenoid value deenergization when the rate of change of said quantity attains either said second reference rate or said third reference rate, whichever prevails at the time, the prevailing reference rate being replaced by said first reference rate when said output signal is terminated.
Claim 2
Dependent Claim
240 words
An electronic control circuit for an anti-lock vehicle brake system, said control circuit comprising, means responsive to an input signal having a quantity which is a function of wheel speed to produce an output signal for causing energisation of a solenoid valve when said quantity has changed at a rate in excess of a first reference rate and by an amount which is greater by a given percentage than its amount of change would have been had its change continued at that first reference rate, the latter corresponding to a first value of wheel deceleration, means for establishing said first reference rate within said control circuit, means for replacing said first reference rate by a second reference rate following the production of said output signal, said second reference rate corresponding to a second value of wheel deceleration that is more negative than said first value, means for replacing said second reference rate by a third reference rate after said second reference rate has persisted for a predetermined period of time, said third reference rate corresponding to a first value of wheel acceleration, and means responsive to said input signal for terminating said output signal to cause solenoid value deenergization when the rate of change of said quantity attains either said second reference rate or said third reference rate, whichever prevails at the time, the prevailing reference rate being replaced by said first reference rate when said output signal is terminated.
Claim 3
Dependent Claim
37 words
A control circuit as claimed in claim 1, wherein the change from said first reference rate to said second reference rate and/or the change from said second reference rate to said third reference rate is substantially instantaneous.
Claim 4
Dependent Claim
41 words
A control circuit as claimed in claim 1, wherein the change from said first reference rate to said second reference rate and/or the change from said second reference rate to said third reference rate is at a predetermined rate of change.
Claim 5
Dependent Claim
187 words
A control circuit as claimed in claim 3, including a control means which is responsive to the same or similar input signal conditions that cause the production of said output signal for solenoid energisation and remains responsive until the input signal quantity has a value corresponding to a certain wheel speed relative to that obtaining when the control means was rendered responsive, the control circuit being so arranged that whilst said control means is responsive, the prevailing reference rate is not replaced by said first reference rate following termination of said output signal to cause solenoid de-energisation, but instead said second reference rate is allowed to persist for the remainder of said predetermined period of time with said third reference rate replacing it as aforesaid, or said third reference rate is maintained, depending on which reference rate was prevailing at the time said output signal was terminated, so that if said input signal quantity subsequently assumes either the second or the third prevailing reference rate whilst this quantity still has a value less than said value, the solenoid is re-energised by the reproduction of said output signal.
Claim 6
Dependent Claim
23 words
A control circuit as claimed in claim 4, wherein said certain wheel speed is the extant speed due to a selected deceleration value.
Claim 7
Dependent Claim
17 words
A control circuit as claimed in claim 5, wherein said selected deceleration value is said first value.
Claim 8
Dependent Claim
20 words
A control circuit as claimed in claim 5, wherein said selected deceleration value is slightly less than said first value.
Claim 9
Dependent Claim
27 words
A control circuit as claimed in claim 4, wherein said certain wheel speed is the speed which the wheel had when the control means was rendered responsive.
Claim 10
Dependent Claim
37 words
A control circuit as claimed in claim 4, wherein said certain wheel speed is changed to the extant speed due to a selected deceleration value which is slightly less than said first value after a pre-set period.
Claim 11
Dependent Claim
83 words
A control circuit as claimed in claim 9, arranged such that if the solenoid valve is still energised when said control means ceases to be responsive, said third reference rate is maintained, with the control circuit further including means responsive to terminate the output signal causing solenoid energisation when the rate of change of said input signal quantity no longer exceeds at least a fourth reference rate that corresponds to a second value of wheel acceleration that is lower than said first value.
Claim 12
Dependent Claim
56 words
A control circuit as claimed in claim 10 wherein said second reference rate is preceded by a further reference rate, which corresponds to a value of wheel deceleration much less negative than said first value of wheel deceleration, for a period just longer than the time taken for the solenoid to pull-in when it is energised.
Claim 13
Dependent Claim
34 words
A control circuit as claimed in claim 11, including means for delaying resetting to said first reference rate for a short period sufficient to allow solenoid release following the termination of said output signal.
Claim 14
Dependent Claim
50 words
A control circuit as claimed in claim 12, including means responsive, when resetting to said first reference rate occurs, to produce for a short period yet a further reference rate corresponding to a much higher value of wheel deceleration than said first deceleration value, before said first rate is reproduced.
Claim 15
Dependent Claim
31 words
A control circuit as claimed in claim 13, including a timer which automatically de-energises the solenoid valve and resets the control circuit to said first reference rate after a preset time.
Claim 16
Dependent Claim
47 words
A control circuit as claimed in claim 14, adapted for response to an input signal derived from a train of pulses the frequency of which is proportional to the speed of rotation of a wheel to be controlled by an anti-lock brake system embodying the control circuit.
Claim 17
Dependent Claim
35 words
A control circuit as claimed in claim 15, including means for producing from such train of pulses an input signal the amplitude of which varies with increase in wheel speed as a natural log. function.
Claim 18
Dependent Claim
43 words
A control circuit as claimed in claim 15, including means for producing from such train of pulses an input signal the amplitude of which is proportional to wheel speed, together with means for producing wheel slip detection in response to such input signal.
References Cited (Backward Citations)
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US3606491A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |