US3730541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid pressure brake system
Assignee: Borg Warner Corp
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Filing: 1972-06-02
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Granted: 1973-05-01
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Expires: 1992-06-02
Abstract
Abstract A fluid pressure brake system includes wheel slip control means which provides for reducing the braking pressure in steps in order to conserve fluid while alleviating a locked wheel condition.
Inventors
- 👤 J Bush
- 👤 A Cunningham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:21
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
201 words
A fluid pressure braking system for a vehicle including a source of fluid pressure, a brake actuator circuit including a pressure responsive brake actuator, and means for selectively connecting said pressure source to said actuator circuit including an operator control valve and wheel slip control apparatus for applying a braking force to said vehicle, said wheel slip control apparatus comprising: a shuttle valve movable for isolating said pressure source from said actuator circuit and for connecting said actuator circuit to a pressure regulated exhaust valve in response to a control signal indicating excessive braking force, said pressure regulated exhaust valve being connected to a pilot circuit and being constructed and arranged for reducing pressure in said actuator circuit by a preselected magnitude below a reference pressure in said pilot circuit, a charging valve connecting said actuator circuit to said pilot circuit providing a reference pressure in said pilot circuit reLated to pressure in said actuator circuit, and a time delay pressure relief valve connected to said pilot circuit arranged for holding said reference pressure in said pilot circuit for a predetermined time interval during which said exhaust valve is operable to effect a step of pressure reduction in said actuator circuit.
Claim 2
Dependent Claim
201 words
A fluid pressure braking system for a vehicle including a source of fluid pressure, a brake actuator circuit including a pressure responsive brake actuator, and means for selectively connecting said pressure source to said actuator circuit including an operator control valve and wheel slip control apparatus for applying a braking force to said vehicle, said wheel slip control apparatus comprising: a shuttle valve movable for isolating said pressure source from said actuator circuit and for connecting said actuator circuit to a pressure regulated exhaust valve in response to a control signal indicating excessive braking force, said pressure regulated exhaust valve being connected to a pilot circuit and being constructed and arranged for reducing pressure in said actuator circuit by a preselected magnitude below a reference pressure in said pilot circuit, a charging valve connecting said actuator circuit to said pilot circuit providing a reference pressure in said pilot circuit reLated to pressure in said actuator circuit, and a time delay pressure relief valve connected to said pilot circuit arranged for holding said reference pressure in said pilot circuit for a predetermined time interval during which said exhaust valve is operable to effect a step of pressure reduction in said actuator circuit.
Claim 3
Dependent Claim
126 words
A fluid pressure braking system according to claim 1 in which said pressure relief valve includes a pair of balance chambers and a member movable toward and from a pressure relieving position in response to pressure differences in said chambers, one of said chambers being connected for receiving pressure from said actuator circuit, and the other of said chambers being connected for receiving pressure from said pilot circuit through a restrictor providing a fluid impedance, said member being urged toward said pressure relieving position for reducing said reference pressure in said pilot circuit in response to excess pressure in said other chamber, and being movable from said pressure relieving position for terminating reduction of said reference pressure in response to excess pressure in said one chamber.
Claim 4
Dependent Claim
47 words
A fluid pressure braking system according to claim 2, in which said relief valve has a one-way valve connected in flow parallel with said fluid restrictor for resetting said relief valve when the instantaneous pressure in said actuator circuit exceeds the pressure in said pilot control circuit.
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) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |