US4039041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid pressure braking systems for vehicles
Assignee: Whitnash PLC
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Filing: 1976-04-12
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Granted: 1977-08-02
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Expires: 1996-04-12
Abstract
Abstract A liquid pressure braking system for a vehicle has a master cylinder which is connected to the brake operating motor cylinder on each front wheel of the vehicle through a respective liquid pressure intensifier. Each intensifier has a differential area piston. The differential liquid pressure on the piston, which tends to close the valve and render the intensifier effective to increase the liquid pressure at its outlet as compared with its liquid pressure inlet, is opposed by a spring which reacts against a stepped plunger. The plunger projects towards a link 18 of a mechanism which interconnects suspension components of the two front wheels. Load transfer from the inboard front wheel during cornering increases the spring load applied to the piston of the intensifier that controls the supply of liquid pressure to that front wheel so that the valve of that intensifier remains open after closure of the valve of the other intensifier and the brake pressure that acts on that inboard front wheel is lower than the brake pressure that acts on the outboard front wheel.
Inventors
- 👤 Robert Michael Farrow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:18
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/24; B60T8/241; B60T8/18; B60T8/1837; B60T8/1856; B60T8/1862; B60T8/246
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
187 words
A fluid pressure braking system for a vehicle which includes a driver controlled source of liquid pressure, a first liquid pressure control device for controlling the pressure that acts in a first liquid pressure motor cylinder to apply a brake to a first wheel which is on one side of the vehicle, a second liquid pressure control device for controlling the pressure that acts in a second liquid pressure motor cylinder to apply a brake to a second wheel which is on the other side of the vehicle, and control means which are responsive to conditions which are indicative of load transfer from one of said wheels to the other and which are operable to modify the performance of one of said liquid pressure control devices in response to such conditions so that any pressure which acts in the other liquid pressure motor cylinder to apply the brake to the other of said wheels is higher than any pressure which acts in said one liquid pressure motor cylinder to apply the brake to said one wheel, wherein each liquid pressure control device is a liquid pressure intensifier.
Claim 2
Dependent Claim
187 words
A fluid pressure braking system for a vehicle which includes a driver controlled source of liquid pressure, a first liquid pressure control device for controlling the pressure that acts in a first liquid pressure motor cylinder to apply a brake to a first wheel which is on one side of the vehicle, a second liquid pressure control device for controlling the pressure that acts in a second liquid pressure motor cylinder to apply a brake to a second wheel which is on the other side of the vehicle, and control means which are responsive to conditions which are indicative of load transfer from one of said wheels to the other and which are operable to modify the performance of one of said liquid pressure control devices in response to such conditions so that any pressure which acts in the other liquid pressure motor cylinder to apply the brake to the other of said wheels is higher than any pressure which acts in said one liquid pressure motor cylinder to apply the brake to said one wheel, wherein each liquid pressure control device is a liquid pressure intensifier.
Claim 3
Dependent Claim
148 words
A fluid pressure braking system as claimed in claim 1, wherein each liquid pressure intensifier comprises a chamber which is in communication with a respective liquid pressure motor cylinder, which is operable to apply the brake to the respective wheel, and which has a movable wall, valve means which operate under certain operating conditions to isolate said chamber from the driver controlled source of liquid pressure and biassing means for exerting a biassing force on said movable wall, the control means being operable to permit operation of said valve means to isolate said chamber from the driver controlled source of liquid pressure and to vary the effect of said biassing force on said movable wall with consequent variation in the liquid pressure that acts in said chamber and in the associated liquid pressure motor cylinder when said chamber is isolated from the driver controlled source of liquid pressure.
Claim 4
Dependent Claim
47 words
A fluid pressure braking system as claimed in claim 2, wherein the chamber of each liquid pressure intensifier is annular, being defined within a larger diameter portion of a stepped bore and around a smaller diameter portion of a stepped piston which slides within the stepped bore.
Claim 5
Dependent Claim
98 words
A fluid pressure braking system as claimed in claim 3, wherein the biassing means of each liquid pressure intensifier include resilient means which act upon the smaller diameter piston portion and react against a movable abutment, the movable abutment being movable by operation of the control means in response to such load transfer to the appropriate wheel, the effect of said biassing force on the piston being varied by movement of the movable abutment and the biassing force acting on the piston to urge the piston in the appropriate direction to maximise the volume of said annular chamber.
Claim 6
Dependent Claim
52 words
A fluid pressure braking system as claimed in claim 4, wherein the movable abutment of each fluid pressure intensifier is a plunger which slides within the respective smaller diameter bore portion and passes through an aperture at the end of the respective smaller diameter bore portion remote from the respective stepped piston.
Claim 7
Dependent Claim
59 words
A fluid pressure braking system as claimed in claim 5, wherein each stepped bore is formed in a valve body which is mounted on a body of the vehicle and the respective plunger is linked to a component of the vehicle suspension system which moves with relative movement between the vehicle body and the appropriate wheel of the vehicle.
Claim 8
Dependent Claim
139 words
A fluid pressure braking system as claimed in claim 6, wherein the resilient means comprise a coil spring and the plunger has a rigid axial projection which extends towards the respective stepped piston, the length of the rigid projection and the loading of the coil spring being such that the stepped piston remains spaced from the rigid axial projection when the brakes are applied and the loading on said first wheel is substantially the same as the loading on the second wheel, whilst the stepped piston can be moved by the liquid pressure loading thereon into abutment with the rigid axial projection when the brakes are applied and the plunger is urged towards the stepped piston by the control means in response to load transfer from the respective one of said first and second wheels to the other wheel.
Claim 9
Dependent Claim
38 words
A fluid pressure braking system as claimed in claim 7, wherein each plunger carries a spring loaded abutment which is adapted to be abutted by the respective stepped piston before the stepped piston abuts the rigid axial projection.
Claim 10
Dependent Claim
71 words
A fluid pressure braking system according to claim 6, wherein the first liquid pressure intensifier has its plunger linked to a component of that part of the suspension system by which the vehicle body is supported upon the second wheel and the second liquid pressure intensifier has its plunger linked to a component of that part of the suspension system by which the vehicle body is supported upon the first wheel.
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) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |