US3768875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adaptive control for fluid pressure braking system
Assignee: Bendix Corp
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Filing: 1972-05-08
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Granted: 1973-10-30
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Expires: 1992-05-08
Abstract
Abstract An adaptive fluid pressure braking system responsive to wheel deceleration and acceleration for cyclicly decreasing and increasing braking effort at optimum levels to prevent wheel lock-up and provide maximum deceleration. The system includes band control means responsive to a pair of pre-selected wheel acceleration levels whereby, instead of taking corrective action as soon as sensed, whenever wheel acceleration during a preceding cycle is less than the lower level or greater than the upper level, a signal is generated whereby corrective action is taken during the next cycle. Where maximum wheel acceleration falls between the pre-selected levels no corrective action signal is generated for the next cycle. The corrective action may comprise a greater rate of decrease in braking pressure during the next cycle or a lesser rate of decrease in pressure.
Inventors
- 👤 D Davis
- 👤 D Sudnick
- 👤 J Juhasz
- 👤 S Kurichh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:08
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/50; B60T8/5081; B60T8/17; B60T8/176; B60T8/1761; B60T8/17613; B60T8/1763; B60T8/17633; B60T8/36; B60T8/5018; B60T8/58; Y; Y10; Y10S; Y10S188/00; Y10S188/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
269 words
For use in an adaptive braking system, the combination of a fluid pressure operated brake actuator having an exhaust port, and a supply port adapted to be connected to a source of fluid pressure, modulating valve means for controlling the fluid pressure in said actuator in the event of an incipient skid, said modulating valve means comprising a supply valve and exhaust valve for the respective supply and exhaust ports, each of said valves including a valve member for closing its port in opposition to pressure at said port tending to open said valve, a fluid pressure cavity for each of said valve members, a fluid pressure responsive element in each cavity and operatively connected to a valve member to move it to closed position in response to fluid pressure of a pre-determined value in said cavity applying a force acting on said elements in excess of the fluid pressure force at said port tending to open said valve member, a pair of valve seats surrounding ports connecting said cavity to the interior of the actuator and to exhaust, respectively, a double acting valve element movable between said seats to connect said cavity to one of said ports while disconnecting it from the other and vice versa, and signal actuated means responsive to signals established by wheel deceleration and acceleration and operatively connected to each of said valve elements to move said element out of engagement with one seat and into engagement with the other to effect opening and closing of said valve members in response to the presence or absence of actuator pressure in each of said cavities.
Claim 2
Dependent Claim
269 words
For use in an adaptive braking system, the combination of a fluid pressure operated brake actuator having an exhaust port, and a supply port adapted to be connected to a source of fluid pressure, modulating valve means for controlling the fluid pressure in said actuator in the event of an incipient skid, said modulating valve means comprising a supply valve and exhaust valve for the respective supply and exhaust ports, each of said valves including a valve member for closing its port in opposition to pressure at said port tending to open said valve, a fluid pressure cavity for each of said valve members, a fluid pressure responsive element in each cavity and operatively connected to a valve member to move it to closed position in response to fluid pressure of a pre-determined value in said cavity applying a force acting on said elements in excess of the fluid pressure force at said port tending to open said valve member, a pair of valve seats surrounding ports connecting said cavity to the interior of the actuator and to exhaust, respectively, a double acting valve element movable between said seats to connect said cavity to one of said ports while disconnecting it from the other and vice versa, and signal actuated means responsive to signals established by wheel deceleration and acceleration and operatively connected to each of said valve elements to move said element out of engagement with one seat and into engagement with the other to effect opening and closing of said valve members in response to the presence or absence of actuator pressure in each of said cavities.
Claim 3
Dependent Claim
63 words
The combination of claim 1 including a bleed port providing continuous open communication between the interior of said actuator and said supply port upstream of the valve member controlling said port whereby fluid pressure continuously bleeds at a controlled rate from said source of fluid pressure into said actuator whenever the pressure in the latter is less than the pressure from said source.
Claim 4
Dependent Claim
137 words
The combination of claim 2 wherein said exhaust port has a cross-sectional area of a pre-determined size so that when said exhaust valve member is open pressure fluid is exhausted from said actuator at a restricted rate determined by the area of said exhaust port, and a second exhaust port of a pre-determined cross-sectional area different from the area of said first exhaust port, a normally closed valve member controlling said second port and including wheel deceleration responsive valve control means therefore, said exhaust valve members being openable in response to wheel deceleration signals either singly or concertedly to afford a first exhaust area when the valve for the smaller port is opened, a second exhaust area when the valve for the larger port is opened and a third exhaust area when both valves are concertedly opened.
Claim 5
Dependent Claim
37 words
The combination of claim 1 wherein the motive area of the fluid pressure responsive element in each cavity is greater than the motive area of the respective valve members exposed to the pressure at their respective ports.
Claim 6
Dependent Claim
22 words
The combination of claim 4 including spring means acting on each of said valve members to bias it towards its closed position.
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 |