Patent US3768876A successfully refreshed from Google Patents.
US3768876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Proportioning valve with load sensing blend back
Assignee: Bendix Corp
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Filing: 1971-06-11
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Granted: 1973-10-30
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Expires: 1991-06-11
Abstract
Abstract A control device is disclosed for use in a vehicle hydraulic braking system which proportions the braking effort between the front wheels of the vehicle and the rear wheels. The control device includes a housing defining a bore therewithin, and a pair of valve members within the bore dividing the latter into an inlet chamber which is communicated to one side of the vehicle''s split system master cylinder and an outlet chamber which is communicated to either the front or the rear brakes of the vehicle. The valve members permit substantially uninhibited fluid communication between the inlet and the outlet chambers until a relatively low predetermined pressure level is attained in the inlet chamber, whereupon the valve members begin proportioning flow of fluid between the inlet and outlet chambers to establish a lower fluid pressure level in the outlet chamber than the fluid pressure level established in the inlet chamber. A piston is provided within the bore so that when a predetermined pressure level in the inlet chamber is attained, the piston overcomes the force of a spring to move into operative engagement with the one valve member. After this occurs, the pressure level in the outlet chamber will increase more rapidly than the pressure level in the inlet chamber is increased, until the pressure level in the outlet chamber is again substantially equal to the pressure level in the inlet chamber whereupon substantially uninhibited fluid communication is again permitted between the inlet and outlet chambers. The piston is also operably connected to sensing means which reflects the relative position between the axle of the vehicle and the body of the vehicle, so that the piston is moved away from the valve member as the load carried by the vehicle increases. Therefore, a proportionally greater fluid pressure level in the inlet chamber will be required for a heavy loaded vehicle before the piston engages the one valve member.
Inventors
- 👤 R Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:04
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/26
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
202 words
In a control device for use in a vehicle braking system: a housing having an inlet, an outlet, and a bore communicating the inlet with the outlet; valve means within said bore dividing the latter into an inlet chamber and an outlet chamber; said valve means restricting fluid communication between the inlet and outlet chambers to permit the fluid pressure level in the inlet chamber to increase more rapidly than does the fluid pressure level in the outlet chamber until a predetermined fluid pressure level is attained in said inlet chamber; other means in said bore cooperating with said valve means after said predetermined level is attained to increase the fluid pressure level in the outlet chamber more rapidly than the fluid pressure level in the inlet chamber is increased until the fluid pressure level in the outlet chamber becomes equal to the fluid pressure level in the inlet chamber; and sensing means operably connecting said other means to the body of the vehicle; said sensing means being responsive to the load carried by the vehicle to increase said predetermined pressure level at which said other means initially cooperates with said valve means as the load carried by the vehicle is increased.
Claim 2
Dependent Claim
202 words
In a control device for use in a vehicle braking system: a housing having an inlet, an outlet, and a bore communicating the inlet with the outlet; valve means within said bore dividing the latter into an inlet chamber and an outlet chamber; said valve means restricting fluid communication between the inlet and outlet chambers to permit the fluid pressure level in the inlet chamber to increase more rapidly than does the fluid pressure level in the outlet chamber until a predetermined fluid pressure level is attained in said inlet chamber; other means in said bore cooperating with said valve means after said predetermined level is attained to increase the fluid pressure level in the outlet chamber more rapidly than the fluid pressure level in the inlet chamber is increased until the fluid pressure level in the outlet chamber becomes equal to the fluid pressure level in the inlet chamber; and sensing means operably connecting said other means to the body of the vehicle; said sensing means being responsive to the load carried by the vehicle to increase said predetermined pressure level at which said other means initially cooperates with said valve means as the load carried by the vehicle is increased.
Claim 3
Dependent Claim
102 words
The invention of claim 1: said valve means including a pair of valve members; said other means including a first piston slidable within said housing from a first position in which said first piston is spaced from one of said valve members to a second position in which said first piston engages said one valve member when the fluid pressure level in said inlet chamber attains the predetermined level; said first piston being responsive to the fluid pressure level in said inlet chamber to engage said one valve member when the fluid pressure level in said inlet chamber attains said predetermined level.
Claim 4
Dependent Claim
48 words
The invention of claim 2: said sensing means permitting said first piston to move away from said one valve member as the load carried by the vehicle is increased to thereby increase the stroke required of said first piston to move into engagement with said one valve member.
Claim 5
Dependent Claim
71 words
The invention of claim 3: said other means including a second piston slidable within said housing; and resilient means engaging one end of said second piston yieldably urging the other end of said second piston into engagement with said sensing means, whereby said second piston is moved away from said one valve member as the sensing means moves away from said housing; said first piston being carried by said second piston.
Claim 6
Dependent Claim
65 words
The invention of claim 4: said second piston defining a blind bore therewithin extending from said one end of said second piston; said first piston being slidably received within said blind bore and cooperating with the closed end of the latter to define a variable volume chamber therebetween; and means communicating said variable volume chamber with the fluid pressure level communicated to said inlet chamber.
Claim 7
Dependent Claim
99 words
The invention of claim 5: said one valve member having a larger effective area defined on one end of the latter exposed to the fluid pressure level in said outlet chamber and a smaller effective area defined on the other end of said one valve member exposed to the fluid pressure level in said inlet chamber; the sum of the smaller effective area on said one valve member and the effective area of said first piston exposed to the fluid pressure level coMmunicated to said inlet chamber being greater than the larger effective area on said one valve member.
Claim 8
Dependent Claim
117 words
The invention of claim 2: said one valve member having a larger effective area defined on one end of the latter exposed to the fluid pressure level in said outlet chamber and a smaller effective area defined on the other end of said one valve member exposed to the fluid pressure level in said inlet chamber; said first piston having an effective area exposed to the fluid pressure level communicated to said inlet chamber; the sum of the smaller effective area on said one valve member and the effective area of said one piston exposed to the fluid pressure level communicated to said inlet chamber being greater than the larger effective area on said one valve member.
Claim 9
Dependent Claim
26 words
The invention of claim 6; and resilient means carried by said second piston yieldably urging said first piston toward the closed end of said blind bore.
Claim 10
Dependent Claim
180 words
The invention of claim 1: said valve means including a pair of valve members; said other means including first and second pistons slidably mounted in said bore, said second piston defining a blind bore therewithin slidably receiving said first piston, resilient means yieldably urging said one piston toward the closed end of the blind bore, and means communicating the fluid pressure level in said inlet chamber to the variable-volume chamber defined between the end of said first piston and the closed end of said blind bore; said first piston moving into engagement with one of said valve members when the fluid pressure level in said variable-volume chamber attains a value sufficient to overcome the force of said resilient means, said value being equal to said predetermined level; said second piston being responsive to said sensing means to carry said first piston away from said one valve member as the load carried by the vehicle is increased, whereby a greater fluid pressure level in said variable-volume chamber is required to drive said first piston into engagement with said one valve member.
Claim 11
Dependent Claim
74 words
The invention of claim 9: one end of said second piston extending from said bore; said sensing means being a bar reflecting the relative position of the body of the vehicle to the axle of the vehicle, one end of said bar engaging said one end of the second piston; and resilient means engaging the other end of said second piston to urge the one end of the latter into engagement with said bar.
Claim 12
Dependent Claim
258 words
In a control device for use in a vehicle braking system: a housing having an inlet, an outlet, and a bore communicating the inlet with the outlet; valve means in said bore dividing the latter into an inlet chamber and an outlet chamber; one of said valve means having a larger effective area exposed to the fluid pressure level in said outlet chamber and a smaller effective area exposed to the fluid pressure level in said inlet chamber, and resilient means urging said valve members apart, said one valve member cooperating with the other valve member to meter fluid communication between said chambers when the force differential across said one valve member due to said difference in areas attains a first predetermined level sufficient to overcome said resilient means to thereafter increase the fluid pressure level in said inlet chamber more rapidly than the fluid pressure in the outlet chamber is increased; said valve means including other means responsive to a second pre-determined level of the fluid pressure in said inlet chamber to increase the effective area of the valve means exposed to the fluid pressure level in said inlet chamber to a value greater than the area exposed to the fluid pressure level in the outlet chamber to thereafter permit the fluid pressure level in said outlet chamber to increase more rapidly than the fluid pressure level in said inlet chamber is increased; and sensing means responsive to the load carried by said vehicle for varying said second predetermined pressure level in accordance with the vehicle load.
Claim 13
Dependent Claim
258 words
In a control device for use in a vehicle braking system: a housing having an inlet, an outlet, and a bore communicating the inlet with the outlet; valve means in said bore dividing the latter into an inlet chamber and an outlet chamber; one of said valve means having a larger effective area exposed to the fluid pressure level in said outlet chamber and a smaller effective area exposed to the fluid pressure level in said inlet chamber, and resilient means urging said valve members apart, said one valve member cooperating with the other valve member to meter fluid communication between said chambers when the force differential across said one valve member due to said difference in areas attains a first predetermined level sufficient to overcome said resilient means to thereafter increase the fluid pressure level in said inlet chamber more rapidly than the fluid pressure in the outlet chamber is increased; said valve means including other means responsive to a second pre-determined level of the fluid pressure in said inlet chamber to increase the effective area of the valve means exposed to the fluid pressure level in said inlet chamber to a value greater than the area exposed to the fluid pressure level in the outlet chamber to thereafter permit the fluid pressure level in said outlet chamber to increase more rapidly than the fluid pressure level in said inlet chamber is increased; and sensing means responsive to the load carried by said vehicle for varying said second predetermined pressure level in accordance with the vehicle load.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |