US3848932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle braking systems having height sensing proportioning valve
Assignee: Bendix Corp
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Filing: 1973-07-02
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Granted: 1974-11-19
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Expires: 1993-07-02
Abstract
Abstract A combination valve for a vehicle hydraulic braking system having two separate fluid circuits is disclosed which includes a proportioning valve in one of the circuits and a pressure differential responsive piston for opening the proportioning valve during a pressure differential between the circuits. The proportioning valve and differential pressure responsive piston are both mounted in a single housing, but the pressure differential piston is normally disposed in the normal or neutral position out of engagement with the proportioning valve when equal fluid pressures are available in both of the hydraulic circuits. However, when pressure is available in the circuit in which the proportioning valve is provided during a failure of fluid pressure in the other fluid circuit, the pressure differential responsive piston shifts to a position engaging one of the proportioning valve members to hold the proportioning valve open, thereby permitting unrestricted fluid communication in the corresponding circuit. A hydraulic braking circuit is disclosed which uses a pair of the aforementioned combination valves including a height sensing feature to proportion fluid communication to the rear wheel brakes of the vehicle in accordance with roll of the vehicle body about the longitudinal axis thereof. Another system is disclosed which uses a pair of the aforementioned combination valves to control fluid communication to disc brakes having tandem actuators, so that flow is proportioned in the normal manner when fluid pressure is available to both fluid circuits actuating a tandem actuator, but upon failure of one of the circuits, unrestricted flow is provided through the other circuit thus enhancing the failsafe feature of this type of system.
Inventors
- 👤 R Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:00
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/26; B60T11/00; B60T11/10; B60T11/28; B60T11/34; B60T17/00; B60T17/18; B60T17/22; B60T17/226
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
389 words
In a brake control valve: a housing defining a bore therewithin; means dividing said bore into first and second compartments; one of said compartments having a first inlet port communicated to a first pressure source, an outlet port, and valve means for controlling fluid communication between said first inlet port and said outlet port, said valve means being responsive to a first fluid pressure level at said outlet port to restrict fluid communication between said first inlet port and said outlet port to establish a lower fluid pressure level at said outlet port than at said first inlet port; and pressure differential responsive means mounted in the other compartment and defining a pair of fluid cavitIes between opposite ends of each of the pressure differential responsive means and corresponding ends of said other compartment, means communicating one of said cavities with said first inlet port and the other cavity with a second fluid pressure source, the pressure level generated by said second fluid pressure source normally being substantially equal to the pressure level generated by said first pressure source to hold said pressure differential responsive means in a normal position, said pressure differential responsive means shifting in response to the fluid pressure level at said first inlet port upon failure of fluid pressure at said second inlet port to another position, said pressure differential responsive means carrying means disposed out of engagement with said valve means when the pressure differential responsive means is disposed in the normal position, but engaging said valve means to hold the latter open to permit substantially unrestricted fluid communication between said first inlet port and said outlet port when said pressure differential responsive means is shifted to the another position; said means dividing said bore into said compartments being a wall extending transversely across said bore; said valve means including a pair of valve members cooperating with one another to control fluid communication between said first inlet port and said outlet port; said means carried by said pressure differential responsive means being independent of said valve members disengaged from the latter when the differential pressure responsive means is disposed in said normal position, but moving into engagement with one of said valve members to hold the latter away from the other valve member when said differential pressure responsive means shifts to said another position.
Claim 2
Dependent Claim
389 words
In a brake control valve: a housing defining a bore therewithin; means dividing said bore into first and second compartments; one of said compartments having a first inlet port communicated to a first pressure source, an outlet port, and valve means for controlling fluid communication between said first inlet port and said outlet port, said valve means being responsive to a first fluid pressure level at said outlet port to restrict fluid communication between said first inlet port and said outlet port to establish a lower fluid pressure level at said outlet port than at said first inlet port; and pressure differential responsive means mounted in the other compartment and defining a pair of fluid cavitIes between opposite ends of each of the pressure differential responsive means and corresponding ends of said other compartment, means communicating one of said cavities with said first inlet port and the other cavity with a second fluid pressure source, the pressure level generated by said second fluid pressure source normally being substantially equal to the pressure level generated by said first pressure source to hold said pressure differential responsive means in a normal position, said pressure differential responsive means shifting in response to the fluid pressure level at said first inlet port upon failure of fluid pressure at said second inlet port to another position, said pressure differential responsive means carrying means disposed out of engagement with said valve means when the pressure differential responsive means is disposed in the normal position, but engaging said valve means to hold the latter open to permit substantially unrestricted fluid communication between said first inlet port and said outlet port when said pressure differential responsive means is shifted to the another position; said means dividing said bore into said compartments being a wall extending transversely across said bore; said valve means including a pair of valve members cooperating with one another to control fluid communication between said first inlet port and said outlet port; said means carried by said pressure differential responsive means being independent of said valve members disengaged from the latter when the differential pressure responsive means is disposed in said normal position, but moving into engagement with one of said valve members to hold the latter away from the other valve member when said differential pressure responsive means shifts to said another position.
Claim 3
Dependent Claim
136 words
The invention of claim 1: said one valve member including a stem, the end of said stem engaging said transverse wall to limit movement of said one valve member toward said wall; resilient means yieldably urging one end of the other valve member toward said wall, said other valve member being responsive to the force of fluid pressure at said outlet acting on said one end of said other member sufficient to overcome and resilient means to urge said other member away from said wall relative to the one member until the other member engages the one member to restrict fluid communication to said outlet port; said means carried by said pressure differential responsive means holding said other valve member for movement with said one valve member to thereby prevent sealing engagement of said valve members.
Claim 4
Dependent Claim
58 words
The invention of claim 2; and a washer disposed between said wall and said one end of said other valve member and engaging said stem; said means carried by said pressure differential responsive means urging said washer against said one end of the other valve member when the pressure differential responsive means is shifted to said another position.
Claim 5
Dependent Claim
28 words
The invention of claim 3; and means operably connected to said other valve member to vary the force exerted on said one valve member by said resilient means.
Claim 6
Dependent Claim
217 words
In a vehicle having a body and an axle supporting said body; a pair of wheels rotatable on said axle, a pair of fluid pressure actuated brakes, one brake for each of said wheels, brake pressure generating means for generating substantially equal fluid pressure levels in a pair of separate fluid circuits, each of said circuits being connected to a corresponding brake for actuating the latter, a pair of valve means, one for each of said circuits, permitting uninhibited fluid communication to their corresponding brake until a first fluid pressure level is attained and thereafter restricting fluid communication to their corresponding brake until a first fluid pressure level is attained and thereafter restricting fluid communication to its corresponding brake to produce a proportionally lower fluid pressure level at said corresponding brake thAn the fluid pressure level generated by said pressure generating means, said valve means being mounted on opposite sides of said vehicle, and means operatively connected to each of said valve means, said vehicle, and said axle for varying said first pressure level in accordance with the distance between the vehicle body and said axle on the side of the vehicle upon which valve means is mounted whereby the fluid pressure level is varied to compensate for roll of the vehicle about the longitudinal axis thereof.
Claim 7
Dependent Claim
217 words
In a vehicle having a body and an axle supporting said body; a pair of wheels rotatable on said axle, a pair of fluid pressure actuated brakes, one brake for each of said wheels, brake pressure generating means for generating substantially equal fluid pressure levels in a pair of separate fluid circuits, each of said circuits being connected to a corresponding brake for actuating the latter, a pair of valve means, one for each of said circuits, permitting uninhibited fluid communication to their corresponding brake until a first fluid pressure level is attained and thereafter restricting fluid communication to their corresponding brake until a first fluid pressure level is attained and thereafter restricting fluid communication to its corresponding brake to produce a proportionally lower fluid pressure level at said corresponding brake thAn the fluid pressure level generated by said pressure generating means, said valve means being mounted on opposite sides of said vehicle, and means operatively connected to each of said valve means, said vehicle, and said axle for varying said first pressure level in accordance with the distance between the vehicle body and said axle on the side of the vehicle upon which valve means is mounted whereby the fluid pressure level is varied to compensate for roll of the vehicle about the longitudinal axis thereof.
Claim 8
Dependent Claim
90 words
The invention of claim 5: said valve means including a housing, valve members within said housing for controlling fluid communication in the corresponding circuit communicating with the corresponding brake, pressure differential responsive means for comparing the fluid pressure level in the corresponding circuit and the fluid pressure level in the other circuit and holding said valve members open to permit uninhibited fluid communication to said corresponding brake when the fluid pressure level in the other circuit is less than the fluid pressure in the corresponding circuit, by a predetermined magnitude.
Claim 9
Dependent Claim
127 words
The invention of claim 5: each of said brakes including a pair of fluid responsive actuators, one of said actuators being communicated with a corresponding one of said circuits, the other actuator being communicated with the other circuit, there being two of said valve means for each of said brakes, one valve means for each being communicated to said one circuit and the other valve means being communicated to the other circuit, said valve mean including pressure differential responsive means for comparing the fluid pressure levels in said circuit and holding said valve means open to permit substantially uninhibited fluid communication through the corresponding circuit when the fluid pressure in the other circuit is less than the fluid pressure in the corresponding circuit by a predetermined magnitude.
Claim 10
Dependent Claim
192 words
In a vehicle having a body and an axle supporting said body: a wheel rotatable of said axle, a brake for controlling said wheel having a pair of separate fluid pressure responsive actuators for actuating said brake, brake pressure generating means for generating substantially equal fluid pressure levels in a pair of separate fluid circuits, each of said circuits being connected to a corresponding one of said actuators, valve means in each of said circuits permitting uninhibited fluid communication through their corresponding circuits to their corresponding actuators until a first fluid pressure level is attained and thereafter restricting fluid communication to its corresponding actuator to produce a proportionally lower fluid pressure level at said corresponding actuator than the fluid pressure level generated by said pressure generating means, each of said valve means including pressure differential responsive means for comparing the fluid pressure levels in the corresponding circuit with the fluid pressure in the other circuit and holding said valve means open to permit uninhibited fluid communication to the corresponding actuator when the fluid pressure level in the other circuit exceeds the fluid pressure level in the one circuit by a predetermined magnitude.
Claim 11
Dependent Claim
192 words
In a vehicle having a body and an axle supporting said body: a wheel rotatable of said axle, a brake for controlling said wheel having a pair of separate fluid pressure responsive actuators for actuating said brake, brake pressure generating means for generating substantially equal fluid pressure levels in a pair of separate fluid circuits, each of said circuits being connected to a corresponding one of said actuators, valve means in each of said circuits permitting uninhibited fluid communication through their corresponding circuits to their corresponding actuators until a first fluid pressure level is attained and thereafter restricting fluid communication to its corresponding actuator to produce a proportionally lower fluid pressure level at said corresponding actuator than the fluid pressure level generated by said pressure generating means, each of said valve means including pressure differential responsive means for comparing the fluid pressure levels in the corresponding circuit with the fluid pressure in the other circuit and holding said valve means open to permit uninhibited fluid communication to the corresponding actuator when the fluid pressure level in the other circuit exceeds the fluid pressure level in the one circuit by a predetermined magnitude.
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) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |