US3847447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adaptive braking system
Assignee: Bendix Corp
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Filing: 1972-06-15
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Granted: 1974-11-12
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Expires: 1992-06-15
Abstract
Abstract An adaptive braking system for an automotive vehicle is disclosed which includes a single comparator which compares a deceleration signal representative of wheel deceleration with a pair of reference levels. When wheel deceleration exceeds the first reference level, the comparator generates an output signal which activates an adaptive braking valve and which also activates a timer which produces an output signal for a predetermined time period after activation of the timer. The output signal from the timer switches the comparator to the second reference level which is lower than the first reference level, maintaining the adaptive braking valve on as long as wheel deceleration exceeds the second reference level. When the timer period expires, the comparator is switched back to the first reference level, to turn off the adaptive braking valve if wheel deceleration is less than the first reference level. A mercury switch which is responsive to vehicle deceleration is provided. When the mercury switch senses vehicle braking on a low coefficient surface both of the comparator reference levels are changed by a predetermined amount, although the difference between the reference levels remains the same.
Inventors
- 👤 J Needham
- 👤 D Elliott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:16
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/176; B60T8/1763; B60T8/17633
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
265 words
In a wheeled vehicle having a brake for braking a corresponding wheel, an adaptive braking system for controlling said brake to prevent skidding of said corresponding wheel comprising: electrically operated valve means for relieving braking pressure in said brake controlling said corresponding wheel to prevent skidding of the latter; and control means for actuating said valve means including first means for generating a speed signal proportional to the anguLar velocity of said corresponding wheel, second means for differentiating said speed signal to generate an acceleration signal proportional to acceleration and deceleration of said corresponding wheel, means for generating first and second bias signals having predetermined values which are independent of fluctuations in said speed signal, said acceleration and deceleration signals, and the rate of deceleration of the vehicle, said means for generating said first and second bias signals being responsive to actuation of said valve means to change the values of said first and second bias signals by predetermined amounts which are independent of fluctuations in said speed and acceleration signals and of deceleration of said vehicle, switching means activating said valve means when said acceleration and deceleration signal drops below the value of the corresponding bias signal and terminating said valve means when said acceleration and deceleration signal exceeds the value of the then corresponding bias signal, bias means switchable from a first state to transmit said first bias signal to said switching means to a second state transmitting said second bias signal to said switching means, and means responsive to vehicle deceleration for switching said bias means between said first and second states.
Claim 2
Dependent Claim
265 words
In a wheeled vehicle having a brake for braking a corresponding wheel, an adaptive braking system for controlling said brake to prevent skidding of said corresponding wheel comprising: electrically operated valve means for relieving braking pressure in said brake controlling said corresponding wheel to prevent skidding of the latter; and control means for actuating said valve means including first means for generating a speed signal proportional to the anguLar velocity of said corresponding wheel, second means for differentiating said speed signal to generate an acceleration signal proportional to acceleration and deceleration of said corresponding wheel, means for generating first and second bias signals having predetermined values which are independent of fluctuations in said speed signal, said acceleration and deceleration signals, and the rate of deceleration of the vehicle, said means for generating said first and second bias signals being responsive to actuation of said valve means to change the values of said first and second bias signals by predetermined amounts which are independent of fluctuations in said speed and acceleration signals and of deceleration of said vehicle, switching means activating said valve means when said acceleration and deceleration signal drops below the value of the corresponding bias signal and terminating said valve means when said acceleration and deceleration signal exceeds the value of the then corresponding bias signal, bias means switchable from a first state to transmit said first bias signal to said switching means to a second state transmitting said second bias signal to said switching means, and means responsive to vehicle deceleration for switching said bias means between said first and second states.
Claim 3
Dependent Claim
53 words
The invention of claim 1: said control means including mechanism generating a timer signal for a predetermined time period after actuation of said valve means, said means for generating said first and second bias signals being responsive to said timer signal for changing the value of said bias signals by said predetermined amounts.
Claim 4
Dependent Claim
42 words
The invention of claim 1: said means responsive to the vehicle deceleration changing the first and second values of the bias signal by an equal predetermined amount which is independent of said speed and acceleration signals and of deceleration of said vehicle.
Claim 5
Dependent Claim
86 words
The invention of claim 1: said means for generating first and second bias signal including a voltage dividing network comprising first resistance means connected in series with second resistance means, said first resistance means including a pair of resistors connected in parallel, said vehicle deceleration responsive switch means switching one of said pair of resistors into said network during vehicle braking on a low coefficient surface and switching said one of said pair of resistors from said circuit during vehicle braking on a high coefficient surface.
Claim 6
Dependent Claim
47 words
The invention of claim 4: said control means including mechanism generating a timer signal for a predetermined time period after actuation of said valve means; said network including switch means controlling the value of said second resistance means, said switch means being responsive to said timer signal.
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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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |