Patent US4218100A successfully refreshed from Google Patents.
US4218100A
Expired / Lapsed
US
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Antiskid brake system comprising a fluid replenishing device, and a replenishing device for such a system
Assignee: DBA SA
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Filing: 1978-09-11
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Granted: 1980-08-19
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Expires: 1998-09-11
Abstract
Abstract A hydraulic vehicle braking system including an operator-controlled fluid pressure source connected to the actuator of a vehicle wheel brake. An antiskid valve is interposed between the operator-controlled pressure source and the brake actuator and is responsive to wheel skidding to interrupt the fluid connection until the end of the braking phase and to permit a fluid connection between the brake actuator and a low pressure fluid reservoir in response to subsequent wheel skidding. The system includes a second source of pressurized fluid and a device for replenishing the brake actuator having a pressure responsive valve which opens fluid flow connection between the second fluid pressure source and the brake actuator when the pressure difference between the operator-controlled pressure source and the brake actuator exceeds a predetermined value.
Inventors
- 👤 Gilbert Kervogoret
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:02
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/148; B60T8/00; B60T8/32; B60T8/34; B60T8/42
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
244 words
An antiskid brake system comprising at least one brake actuator associated with a wheel brake of a vehicle, a fluid pressure source controlled by an operator and connected to the brake actuator by antiskid valve forming means, said valve forming means being normally open to connect the said pressure source to the brake actuator and being responsive, during a braking phase, to the detection of a risk of skidding of the wheel so as to interrupt the fluid connection between the pressure source and brake actuator until the end of the braking phase, and so as to permit subsequently during the braking phase a fluid connection between the brake actuator and a low pressure source in response to the detection of any risk of skidding, the antiskid brake system being characterized in that it includes a device for replenishing said actuator which comprises a pressure fluid reserve source and a connection to connect the reserve source to the brake actuator, means for controlling the flow of fluid through the connection, said control means comprising a valve forming element situated in the connection and normally urged on to a seat under the influence of the pressure from the reserve source, operating means responsive to a pressure difference between the pressure supplied by the pressure source controlled by an operator and the pressure prevailing downstream of the valve forming element, so as to effect opening of this valve when the pressure difference exceeds a predetermined value.
Claim 2
Dependent Claim
244 words
An antiskid brake system comprising at least one brake actuator associated with a wheel brake of a vehicle, a fluid pressure source controlled by an operator and connected to the brake actuator by antiskid valve forming means, said valve forming means being normally open to connect the said pressure source to the brake actuator and being responsive, during a braking phase, to the detection of a risk of skidding of the wheel so as to interrupt the fluid connection between the pressure source and brake actuator until the end of the braking phase, and so as to permit subsequently during the braking phase a fluid connection between the brake actuator and a low pressure source in response to the detection of any risk of skidding, the antiskid brake system being characterized in that it includes a device for replenishing said actuator which comprises a pressure fluid reserve source and a connection to connect the reserve source to the brake actuator, means for controlling the flow of fluid through the connection, said control means comprising a valve forming element situated in the connection and normally urged on to a seat under the influence of the pressure from the reserve source, operating means responsive to a pressure difference between the pressure supplied by the pressure source controlled by an operator and the pressure prevailing downstream of the valve forming element, so as to effect opening of this valve when the pressure difference exceeds a predetermined value.
Claim 3
Dependent Claim
95 words
An antiskid brake system as claimed in claim 1, characterized in that the operating means comprise a housing containing a bore in which a first piston is slidable so as to separate the bore into a first chamber connected to the pressure source controlled by an operator and into a second chamber situated in the fluid flow path downstream of the control means, the piston being capable of operating a tappet to lift the valve forming element away from its seat when the pressure difference between the first and second chambers exceeds a predetermined value.
Claim 4
Dependent Claim
25 words
An antiskid brake system as claimed in claim 2, characterized in that a constriction is provided in the said connection, downstream of the second chamber.
Claim 5
Dependent Claim
22 words
An antiskid brake system as claimed in any of the preceding claims, characterized in that the pressure reserve source comprises an accumulator.
Claim 6
Dependent Claim
126 words
An antiskid brake system as claimed in claim 4, in which the pressure source controlled by the operator comprises a fluid reservoir, characterized in that the replenishing device comprises a device for recharging the accumulator, the recharging device having a housing defining a variable-volume chamber controlled by a second piston of which the movements depend on the deflection of a suspension of said vehicle, a first non-return valve situated between the variable-volume chamber and the accumulator and designated to prevent the accumulator from discharging to the said chamber, the latter being also connected to the fluid reservoir by way of a second non-return valve permitting the variable-volume chamber to be filled with hydraulic fluid following a depression caused by an increase in volume of the chamber.
Claim 7
Dependent Claim
34 words
An antiskid brake system as claimed in claim 5, characterized in that the recharging device comprises an excess pressure valve designed to limit to a predetermined value the pressure prevailing in the variable-volume chamber.
Claim 8
Dependent Claim
23 words
An antiskid brake system as claimed in claim 5 characterized in that the replenishing device comprises a single housing incorporating the recharging device.
Claim 9
Dependent Claim
78 words
An antiskid brake system as claimed in claim 7, characterized in that the closure element of the valve forming means and the closure element of the first non-return valve are situated in a common bore in the single housing forming an intermediate chamber communicating with the accumulator, the respective closure elements normally resting on their seats, a spring being provided in the intermediate chamber and urging the closure elements away from each other towards their respective valve seats.
Claim 10
Dependent Claim
157 words
A replenishing device for an antiskid brake system comprising, a housing defining a first and a second compartment, the first compartment being connectible to a pressure accumulator, and communicating with the second compartment, by way of a first passage, a valve forming element being provided in the first compartment and cooperating with a seat defined at the end of the first passage to control the fluid connection between the first and second compartments in such a way as normally to prevent such a connection, piston forming means being slidably mounted in the second compartment to separate the second compartment into a first and a second chamber connectible respectively to a braking pressure source and to at least one brake actuator controlled by the antiskid brake system, the valve forming element being capable of being urged off its seat in response to movement of the piston resulting from a predetermined pressure difference between the first and second chambers.
Claim 11
Dependent Claim
157 words
A replenishing device for an antiskid brake system comprising, a housing defining a first and a second compartment, the first compartment being connectible to a pressure accumulator, and communicating with the second compartment, by way of a first passage, a valve forming element being provided in the first compartment and cooperating with a seat defined at the end of the first passage to control the fluid connection between the first and second compartments in such a way as normally to prevent such a connection, piston forming means being slidably mounted in the second compartment to separate the second compartment into a first and a second chamber connectible respectively to a braking pressure source and to at least one brake actuator controlled by the antiskid brake system, the valve forming element being capable of being urged off its seat in response to movement of the piston resulting from a predetermined pressure difference between the first and second chambers.
Claim 12
Dependent Claim
56 words
A replenishing device as claimed in claim 9, characterized in that the piston includes a rod projecting into the second chamber in the second compartment and penetrating into the passage to lift off said valve forming element from its seat, whereby fluid pressure supplied by the accumulator is counteracted in response to movement of said piston.
Claim 13
Dependent Claim
97 words
A replenishing device as claimed in claim 9 or 10, characterized in that it comprises a third compartment defined in the housing, the third compartment communicating with the first compartment by a passage and a non-return valve and having a variable volume controlled by the movement of a second piston as a function of the deflection of the suspension of the vehicle, in order to draw liquid into the third compartment from a low pressure source or expel liquid from the third compartment to the first compartment, depending on the direction of movement of the second piston.
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) | 1983-08-19 | 1984-02-18 | 1984-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-19 | 1988-02-18 | 1988-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-19 | 1992-02-18 | 1992-08-19 | $7700.00 | Window Closed / Lapsed |