US3817585A
Expired / Lapsed
US
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Anti-lock brake system
Assignee: Motors Liquidation Co
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Filing: 1972-10-30
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Granted: 1974-06-18
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Expires: 1992-10-30
Abstract
Abstract An extremal anti-lock brake system utilizes automatic transmission governor pressure as the average rear wheel speed input signal. An accumulator receives fluid from the governor at a flow rate proportional to wheel acceleration and stores fluid proportional in volume and pressure to the wheel speed. Return of fluid from the accumulator to the governor during wheel deceleration is through a deceleration orifice. During wheel deceleration at rates indicative of impending wheel lock, the orifice restricts the discharge flow and provides a pressure differential equivalent to the difference between actual and predetermined maximum wheel velocities during braking under optimum conditions. This pressure differential operates a control valve which exhausts the supporting pressure from a conventional brake pressure modulator to release the brakes. A period of wheel acceleration follows the brake release and during the resulting wheel speed recovery the accumulator is recharged and the control valve shifts to reapply pressure to the modulator. An acceleration valve senses the wheel speed recovery permitted by the brake release and closes a hold valve which isolates the brake pressure modulator from the control valve to maintain the modulator supporting pressure and its then existing magnitude to provide the hold mode of the extremal cycle. When the wheel speed recovery ends the acceleration valve and hold valve are shifted and the support pressure is reapplied to the modulator to initiate the brake apply mode of the extremal cycle.
Inventors
- 👤 L Bowler
- 👤 L Johnston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:39
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/42; B60T8/4208; B60T8/4225
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
132 words
An anti-lock brake system comprising; a brake pressure modulating means, governor means driven at wheel speed and providing fluid at pressure proportional to wheel speed and a flow rate proportional to wheel acceleration and deceleration, accumulator means, valve means communicating wheel speed proportional pressure fluid to the accumulator means during wheel acceleration to charge the accumulator means, orifice means discharging pressure fluid from the accumulator means to the governor during wheel deceleration at a predetermined maximum fluiD flow rate to provide a differential between wheel speed proportional pressure and accumulator pressure during wheel deceleration at a level causing a fluid flow rate exceeding the flow threshold of the orifice means, and control means operably by the differential between wheel speed proportional pressure and accumulator pressure to control the brake pressure modulating means.
Claim 2
Dependent Claim
132 words
An anti-lock brake system comprising; a brake pressure modulating means, governor means driven at wheel speed and providing fluid at pressure proportional to wheel speed and a flow rate proportional to wheel acceleration and deceleration, accumulator means, valve means communicating wheel speed proportional pressure fluid to the accumulator means during wheel acceleration to charge the accumulator means, orifice means discharging pressure fluid from the accumulator means to the governor during wheel deceleration at a predetermined maximum fluiD flow rate to provide a differential between wheel speed proportional pressure and accumulator pressure during wheel deceleration at a level causing a fluid flow rate exceeding the flow threshold of the orifice means, and control means operably by the differential between wheel speed proportional pressure and accumulator pressure to control the brake pressure modulating means.
Claim 3
Dependent Claim
156 words
An anti-lock brake system comprising; brake pressure modulating means, means driven at wheel speed and providing fluid flow in one direction therethrough during wheel acceleration at a flow rate proportional to the rate of acceleration and in the other direction therethrough during wheel deceleration and at a flow rate proportional to the rate of deceleration, accumulator means, valve means communicating fluid from the means driven at wheel speed to the accumulator means during wheel acceleration to charge the accumulator means, orifice means returning fluid from the accumulator means to the means driven at wheel speed during wheel deceleration, and control means operable by a pressure differential across the orifice means to control the brake pressure modulating means, the orifice means restricting flow therethrough to a rate corresponding to a predetermined wheel deceleration rate whereby upon wheel deceleration in excess of the predetermined rate a pressure differential results across the orifice means to operate the control means.
Claim 4
Dependent Claim
156 words
An anti-lock brake system comprising; brake pressure modulating means, means driven at wheel speed and providing fluid flow in one direction therethrough during wheel acceleration at a flow rate proportional to the rate of acceleration and in the other direction therethrough during wheel deceleration and at a flow rate proportional to the rate of deceleration, accumulator means, valve means communicating fluid from the means driven at wheel speed to the accumulator means during wheel acceleration to charge the accumulator means, orifice means returning fluid from the accumulator means to the means driven at wheel speed during wheel deceleration, and control means operable by a pressure differential across the orifice means to control the brake pressure modulating means, the orifice means restricting flow therethrough to a rate corresponding to a predetermined wheel deceleration rate whereby upon wheel deceleration in excess of the predetermined rate a pressure differential results across the orifice means to operate the control means.
Claim 5
Dependent Claim
158 words
An anti-lock brake system comprising; brake pressure modulating means, governor means driven at wheel speed and providing fluid at a pressure proportional to wheel speed and a flow rate proportional to wheel acceleration, accumulator means, check valve means communicating wheel speed proportional fluid to the accumulator means during wheel acceleration to charge the accumulator means, orifice means discharging pressure fluid from the accumulator means to the governor means during wheel deceleration and restricting flow to a predetermined maximum fluid flow rate corresponding to the known maximum rate of permissible wheel deceleration without wheel lock-up, control means operable by the differential between wheel speed proportional pressure and accumulator pressure to control the brake pressure modulating means as a function of the magnitude of said differential, and circuit means effective during wheel acceleration above a predetermined level to isolate the control means from the brake pressure modulating means to maintain the brake pressure modulating means at its then existing condition.
Claim 6
Dependent Claim
158 words
An anti-lock brake system comprising; brake pressure modulating means, governor means driven at wheel speed and providing fluid at a pressure proportional to wheel speed and a flow rate proportional to wheel acceleration, accumulator means, check valve means communicating wheel speed proportional fluid to the accumulator means during wheel acceleration to charge the accumulator means, orifice means discharging pressure fluid from the accumulator means to the governor means during wheel deceleration and restricting flow to a predetermined maximum fluid flow rate corresponding to the known maximum rate of permissible wheel deceleration without wheel lock-up, control means operable by the differential between wheel speed proportional pressure and accumulator pressure to control the brake pressure modulating means as a function of the magnitude of said differential, and circuit means effective during wheel acceleration above a predetermined level to isolate the control means from the brake pressure modulating means to maintain the brake pressure modulating means at its then existing condition.
Claim 7
Dependent Claim
163 words
An anti-lock brake system comprising; brake pressure modulating means, governor means driven at wheel speed and providing fluid at a pressure proportional to wheel speed and a flow rate proportional to wheel acceleration, accumulator means, check valve means communicating wheel speed proportional pressure fluid to the accumulator means during wheel acceleration to charge the accumulator means, orifice means discharging pressure fluid from the accumulator means during wheel deceleration at a rate not exceeding a predetermined fluid flow rate corresponding to the known maximum optimum rate of permissible wheel deceleration without wheel lock-up, control valve means operably by the differential between wheel speed proportional pressure and accumulator pressure to control the brake pressure modulating means, hold valve means effective when actuated to isolate the control valve means from the brake pressure modulating means to maintain the brake pressure modulating means at its then existing condition, and acceleration sensing valve means operable during wheel acceleration above a predetermined level to actuate the hold valve means.
Claim 8
Dependent Claim
163 words
An anti-lock brake system comprising; brake pressure modulating means, governor means driven at wheel speed and providing fluid at a pressure proportional to wheel speed and a flow rate proportional to wheel acceleration, accumulator means, check valve means communicating wheel speed proportional pressure fluid to the accumulator means during wheel acceleration to charge the accumulator means, orifice means discharging pressure fluid from the accumulator means during wheel deceleration at a rate not exceeding a predetermined fluid flow rate corresponding to the known maximum optimum rate of permissible wheel deceleration without wheel lock-up, control valve means operably by the differential between wheel speed proportional pressure and accumulator pressure to control the brake pressure modulating means, hold valve means effective when actuated to isolate the control valve means from the brake pressure modulating means to maintain the brake pressure modulating means at its then existing condition, and acceleration sensing valve means operable during wheel acceleration above a predetermined level to actuate the hold valve means.
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) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |