Patent EP0114696A2 successfully refreshed from Google Patents.
US3853357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle pilot pressure controlled brake system with wheel lock control modulating means
Assignee: Motors Liquidation Co
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Filing: 1973-09-04
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Granted: 1974-12-10
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Expires: 1993-09-04
Abstract
Abstract An air brake system of the type used in some trucks includes an air compressor, suitable wet and service tanks, a brake application valve controlled by the brake pedal and actuated by the vehicle operator, and a relay valve receiving pilot pressures from the brake application valve and controlling the admission and release of air pressure from the service tank to the brake chambers at the brakes of the wheels to be braked. The rate of brake release and the rate of brake application are controlled by a valve arrangement which in turn is energized and deenergized in accordance with the needs of the vehicle brake system in order to prevent wheel lock. Under normal conditions of braking operation, the vehicle operator controls the brakes by actuating a brake application valve, which generates the pilot pressure, which in turn controls the action of a relay valve, which in turn admits the necessary amount of air pressure to the vehicle brake actuating chambers to operate the vehicle brakes, and releases the air pressure from those brake chambers when the brakes are released, all in accordance with the pilot pressure supplied to the relay valve. The application of pilot pressures to the relay valve is controlled independently of the brake application valve when wheel lock control signals are being generated to prevent wheel lock, so long as the vehicle operator maintains the brake application valve in a position to brake the vehicle.
Inventors
- 👤 A Hitzelberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:21
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/50; B60T8/5012
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
377 words
In a fluid pressure actuated brake system for a vehicle, said system having: a fluid pressure source, brake means for wheels of the vehicle selectively actuated and released by fluid pressure from said source, brake application valve means receiving fluid pressure from said source and controlled by the vehicle operator to generate pilot pressures in accordance with the amount of braking desired, reLay valve means receiving said pilot pressures and connecting the pressure source and the brake means and controlling the application and release of fluid pressures to and from the brake means in accordance with the pilot pressures received, and wheel acceleration and deceleration sensing and signal generating means sensing brake effectiveness and specifically incipient wheel lock, said sensing and generating means generating wheel lock control signals accordingly, the improvement comprising: a normally open valve fluidly intermediate said brake application valve means and said relay valve means to transmit pilot pressures therebetween, first means receiving signals from said sensing and generating means and closing said normally open valve when the signals indicate incipient wheel lock, an apply flow control valve and a three-way valve connected in fluid series relationship and in parallel fluid relationship with said normally open valve, said three-way valve being also connected to exhaust, and second means receiving signals from said sensing and generating means and acting on said three-way valve closing the fluid connection between said apply flow control valve and said relay valve means concurrently with the initial closing of said normally open valve, and also opening a fluid connection through said three-way valve from said relay valve means to exhaust to cause the pilot pressure acting on said relay valve to decrease independently of said brake application valve means, said second receiving means receiving further signals from said sensing and generating means upon sufficient wheel acceleration and acting to reverse the action of said three-way valve so that said relay valve means receive pilot pressures through said apply flow control valve which controls the rate of pilot pressure increase to the pilot pressure generated by the brake application valve means to increase the fluid pressure to the brake means accordingly, the action of said second receiving means on said three-way valve being repeated as signals again indicate incipient wheel lock.
Claim 2
Dependent Claim
377 words
In a fluid pressure actuated brake system for a vehicle, said system having: a fluid pressure source, brake means for wheels of the vehicle selectively actuated and released by fluid pressure from said source, brake application valve means receiving fluid pressure from said source and controlled by the vehicle operator to generate pilot pressures in accordance with the amount of braking desired, reLay valve means receiving said pilot pressures and connecting the pressure source and the brake means and controlling the application and release of fluid pressures to and from the brake means in accordance with the pilot pressures received, and wheel acceleration and deceleration sensing and signal generating means sensing brake effectiveness and specifically incipient wheel lock, said sensing and generating means generating wheel lock control signals accordingly, the improvement comprising: a normally open valve fluidly intermediate said brake application valve means and said relay valve means to transmit pilot pressures therebetween, first means receiving signals from said sensing and generating means and closing said normally open valve when the signals indicate incipient wheel lock, an apply flow control valve and a three-way valve connected in fluid series relationship and in parallel fluid relationship with said normally open valve, said three-way valve being also connected to exhaust, and second means receiving signals from said sensing and generating means and acting on said three-way valve closing the fluid connection between said apply flow control valve and said relay valve means concurrently with the initial closing of said normally open valve, and also opening a fluid connection through said three-way valve from said relay valve means to exhaust to cause the pilot pressure acting on said relay valve to decrease independently of said brake application valve means, said second receiving means receiving further signals from said sensing and generating means upon sufficient wheel acceleration and acting to reverse the action of said three-way valve so that said relay valve means receive pilot pressures through said apply flow control valve which controls the rate of pilot pressure increase to the pilot pressure generated by the brake application valve means to increase the fluid pressure to the brake means accordingly, the action of said second receiving means on said three-way valve being repeated as signals again indicate incipient wheel lock.
Claim 3
Dependent Claim
50 words
The improved system of claim 1 in which a release flow control valve is connected between said three-way valve and exhaust and acts to meter the rate of release of pilot pressure from said relay valve means when the relay valve means is connected to exhaust through said three-way valve.
Claim 4
Dependent Claim
256 words
A vehicle wheel lock control system for a vehicle air brake system operated by a relay valve in accordance with pilot air pressures provided thereto from a vehicle operator controlled brake application valve, said system comprising: a sensor and logic control signal generator having a first signal outlet energized upon an initial brake release signal being generated and remaining energized until there is a predetermined time delay during which no further brake release signals are generated, and a second signal outlet energized only while the initial and subsequent brake release signals are being generated, said second signal outlet being deenergized otherwise; first valve means fluidly intermediate said brake application valve and said relay valve and responsive to energization of said first signal outlet to interrupt the connection of pilot pressures therethrough; and second valve means continuously fluidly connected to receive pilot pressures from said brake application valve independently of said first valve means and fluidly connected to said relay valve and fluidly connected to exhaust, said second valve means being responsive to energization of said second signal outlet to release to exhaust at a metered rate the pilot pressure at said relay valve to decrease the air pressure supplied to the vehicle brakes at a metered rate, and further responsive to deenergization of said second signal outlet to bypass said first valve means and deliver pilot pressure from said brake application valve to said relay valve at a metered rate of increase to increase the air pressure supplied to the vehicle brakes at a metered rate.
Claim 5
Dependent Claim
256 words
A vehicle wheel lock control system for a vehicle air brake system operated by a relay valve in accordance with pilot air pressures provided thereto from a vehicle operator controlled brake application valve, said system comprising: a sensor and logic control signal generator having a first signal outlet energized upon an initial brake release signal being generated and remaining energized until there is a predetermined time delay during which no further brake release signals are generated, and a second signal outlet energized only while the initial and subsequent brake release signals are being generated, said second signal outlet being deenergized otherwise; first valve means fluidly intermediate said brake application valve and said relay valve and responsive to energization of said first signal outlet to interrupt the connection of pilot pressures therethrough; and second valve means continuously fluidly connected to receive pilot pressures from said brake application valve independently of said first valve means and fluidly connected to said relay valve and fluidly connected to exhaust, said second valve means being responsive to energization of said second signal outlet to release to exhaust at a metered rate the pilot pressure at said relay valve to decrease the air pressure supplied to the vehicle brakes at a metered rate, and further responsive to deenergization of said second signal outlet to bypass said first valve means and deliver pilot pressure from said brake application valve to said relay valve at a metered rate of increase to increase the air pressure supplied to the vehicle brakes at a metered rate.
Claim 6
Dependent Claim
288 words
An air pilot pressure control system for a vehicle air pressure controlled and powered brake system including a source of air pressure, vehicle operator controlled means generating an air pilot pressure in accordance with the braking effort desired, a relay valve receiving said pilot pressure and admitting and releasing power air pressire to and from the vehicle brakes in accordance with the pilot pressures received, said control system comprising: a first normally open solenoid valve fluidly connecting said vehicle operator controlled means and said relay valve so that pilot pressure normally passes therethrough, a flow control valve and a second normally open solenoid valve connected in series, and fluidly connecting said vehicle operator controlled means and said relay valve to provide a flow path for pilot pressure therebetween which is parallel to the flow path through said first normally open solenoid valve, a release control valve controlling pressure decrease therethrough at a metered rate, a third normally closed solenoid valve when open fluidly connecting said relay valve to exhaust through said release control valve, and signal control means responsive to predetermined braking conditions to energize said first normally open solenoid valve to close it and hold it closed, solenoid valves to close said second and open said third solenoid valves, and cyclically deenergize and energize said second and third solenoid valves to cause the vehicle brakes to be applied and released until the predetermined brake conditions cease to exist, and thereafter to deenergize said first normally open solenoid valve, whereby during the cyclic energization and deenergization of said second and third solenoid valves the pilot pressure at said relay valve decreases and increases at metered rates respectively controlled by said release control valve and said flow control valve.
Claim 7
Dependent Claim
288 words
An air pilot pressure control system for a vehicle air pressure controlled and powered brake system including a source of air pressure, vehicle operator controlled means generating an air pilot pressure in accordance with the braking effort desired, a relay valve receiving said pilot pressure and admitting and releasing power air pressire to and from the vehicle brakes in accordance with the pilot pressures received, said control system comprising: a first normally open solenoid valve fluidly connecting said vehicle operator controlled means and said relay valve so that pilot pressure normally passes therethrough, a flow control valve and a second normally open solenoid valve connected in series, and fluidly connecting said vehicle operator controlled means and said relay valve to provide a flow path for pilot pressure therebetween which is parallel to the flow path through said first normally open solenoid valve, a release control valve controlling pressure decrease therethrough at a metered rate, a third normally closed solenoid valve when open fluidly connecting said relay valve to exhaust through said release control valve, and signal control means responsive to predetermined braking conditions to energize said first normally open solenoid valve to close it and hold it closed, solenoid valves to close said second and open said third solenoid valves, and cyclically deenergize and energize said second and third solenoid valves to cause the vehicle brakes to be applied and released until the predetermined brake conditions cease to exist, and thereafter to deenergize said first normally open solenoid valve, whereby during the cyclic energization and deenergization of said second and third solenoid valves the pilot pressure at said relay valve decreases and increases at metered rates respectively controlled by said release control valve and said flow control valve.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |