US3912337A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Antiskid apparatus
Assignee: Toyota Motor Corp
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Filing: 1972-06-30
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Granted: 1975-10-14
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Expires: 1992-06-30
Abstract
Abstract In the antiskid apparatus, a brake modulating apparatus reduce the braking effort of a braking system on a wheel of a vehicle when the wheel is about to skid, and a regulator that operates the modulating apparatus adjusts the operation of the modulating apparatus to the coefficient of friction between the wheel and the road surface. In the regulator, a control apparatus responds to the speed of the wheel and actuates the brake modulating apparatus when the wheel decelerates faster than a control gradient and continues actuating the brake modulating apparatus while the velocity is less than a velocity that decreases according to the gradient. A variable gradient establishing apparatus increase the gradient over a time period toward a given gradient level while the modulating apparatus is unactuated and decrease the gradient over a time period when the control apparatus actuates the modulating apparatus. A time delay circuit coupled to the gradient establishing apparatus delays the decrease of the gradient for a given time after the modulating apparatus is actuated.
Inventors
- 👤 Takeshi Ochiai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:57
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/58; B60T8/17; B60T8/176; B60T8/1763; B60T8/17633
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
205 words
A skid control system for a vehicle having a wheel and a brake system for slowing the vehicle, comprising wheel velocity detecting means coupled to the wheel, control means responsive to said detecting means for initiating a signal when said detecting means indicates that the wheel velocity decreases faster than a given rate of velocity decrease and for maintaining the signal while the wheel velocity is less than the velocity corresponding to the given rate of decrease, brake modulating means coupled to said control means for reducing the braking effect of the system on the wheel in response to the signal and cancelling the reduction of the braking effectiveness in the absence of the signal, variable gradient establishing means coupled to said control means for continuously only steepening the given rate of decrease over a time period toward a maximum rate of decrease in response to the absence of the signal and for continuously lessening the given rate of decrease over a time period during the signal, time delay means coupled to said gradient establishing means for delaying the lessening of the given rate of decrease and continuing the steepening of the given rate of decrease for a given time after onset of the signal.
Claim 2
Dependent Claim
205 words
A skid control system for a vehicle having a wheel and a brake system for slowing the vehicle, comprising wheel velocity detecting means coupled to the wheel, control means responsive to said detecting means for initiating a signal when said detecting means indicates that the wheel velocity decreases faster than a given rate of velocity decrease and for maintaining the signal while the wheel velocity is less than the velocity corresponding to the given rate of decrease, brake modulating means coupled to said control means for reducing the braking effect of the system on the wheel in response to the signal and cancelling the reduction of the braking effectiveness in the absence of the signal, variable gradient establishing means coupled to said control means for continuously only steepening the given rate of decrease over a time period toward a maximum rate of decrease in response to the absence of the signal and for continuously lessening the given rate of decrease over a time period during the signal, time delay means coupled to said gradient establishing means for delaying the lessening of the given rate of decrease and continuing the steepening of the given rate of decrease for a given time after onset of the signal.
Claim 3
Dependent Claim
53 words
A system as in claim 1, further comprising second wheel velocity detecting means coupled to another wheel of the vehicle, said control means being responsive to said second detecting means and initiating a signal when either of said detecting means indicates that a wheel velocity decreases faster than the given rate of decrease.
Claim 4
Dependent Claim
154 words
A system as in claim 1, for a vehicle having another wheel responsive to the brake system, further comprising second wheel velocity detecting means coupled to the wheel, said control means forming an electrical indication corresponding to the given rate of decrease as the given rate of decrease varies, said control means including auxiliary means responsive to the electrical indication and said wheel velocity detecting means for producing a second signal when said second wheel velocity detecting means indicates that the second wheel decelerates faster than the given rate of decrease and for maintaining the signal while the wheel velocity of the second wheel is less than the velocity corresponding to the given rate of decrease, second brake modulating means coupled to said auxiliary means for reducing the braking effectiveness of the system on the second wheel in response to the second signal and cancelling the reduction in the absence of the second signal.
Claim 5
Dependent Claim
133 words
A skid control system as in claim 1 for a vehicle having a second wheel responsive to the brake system, further comprising second wheel velocity detecting means coupled to the second wheel, said control means including auxiliary means responsive to said variable gradient establishing means and responsive to said second detecting means for initiating the signal when the second detecting means indicates that the second wheel velocity decreases faster than a given rate of decrease and for maintaining the signal when the velocity is less than a velocity corresponding to the given rate of decrease, and second brake modulating means coupled to said auxiliary means for reducing the braking effectiveness of the system on the second wheel in response to the second signal and cancelling the reduction in the absence of the signal.
Claim 6
Dependent Claim
34 words
A system as in claim 1, wherein said control means includes gradient setting means responsive to said variable gradient establishing means to set the given rate in response to said variable gradient establishing means.
Claim 7
Dependent Claim
81 words
A system as in claim 5, wherein said variable gradient establishing means includes a gradient setting circuit for varying the given rate of decrease, first correcting means for constraining said gradient setting circuit to steepen the rate of decrease in response to absence of the signal, and second correcting means for lessening the rate of decrease in response to the signal, and signal limiting means resPonsive to said gradient setting circuit for limiting the variation in the given rate of decrease.
Claim 8
Dependent Claim
53 words
A system as in claim 6, further comprising second wheel velocity detecting means coupled to another wheel of the vehicle, said control means being responsive to said second detecting means and initiating a signal when either of said detecting means indicates that a wheel velocity decreases faster than the given rate of decrease.
Claim 9
Dependent Claim
171 words
A system as in claim 6, for a vehicle having another wheel responsive to the brake system, further comprising second wheel velocity detecting means coupled to the wheel, said control means forming an electrical indication corresponding to the given rate of decrease as the given rate of decrease varies, said control means including auxiliary means responsive to the electrical indication and said second wheel velocity detecting means for producing a second signal when said second wheel decelerates faster than the given rate of decrease and for maintaining the signal while the wheel velocity of the second wheel is less than the velocity corresponding to the given rate of decrease, second brake modulating means coupled to said auxiliary means for reducing the braking effectiveness of the system on the second wheel in response to the second signal and cancelling the reduction in the absence of the second signal, said control means including a velocity setting circuit responsive to said signal limiting means, said auxiliary means being responsive to said velocity setting circuit.
Claim 10
Dependent Claim
173 words
A system as in claim 6 for a vehicle having a second wheel responsive to the brake system, further comprising second wheel velocity detecting means coupled to the second wheel, said control means including auxiliary means responsive to said variable gradient establishing means and responsive to said second detecting means for initiating the signal when the second detecting means indicates that the second wheel velocity decreases faster than a given rate of decrease and for maintaining the signal when the velocity is less than a velocity corresponding to the given rate of decrease, and second brake modulating means coupled to said auxiliary means for reducing the braking effectiveness of the system on the second wheel in response to the second signal and cancelling the reduction in the absence of the signal, said control means including a velocity setting circuit responsive to said signal limiting means, said auxiliary means including an auxiliary velocity setting circuit, said auxiliary velocity setting circuit being responsive to said signal limiting means and said second vehicle velocity detecting means.
Claim 11
Dependent Claim
20 words
A system as in claim 1, wherein said brake modulating means includes means for decreasing the braking effectiveness substantially linearly.
Claim 12
Dependent Claim
61 words
A system as in claim 1, wherein said control means includes capacitor means for receiving the output of said detecting means, and comparing means for comparing whether the voltage at said capacitor means follows the output of said detecting means, and for producing the signal when the voltage across said capacitor means fails to follow the output of said detecting means.
Claim 13
Dependent Claim
42 words
A system as in claim 11, wherein said gradient establishing means includes resistive means forming a time constant with said capacitor means for varying the rate at which the voltage across said capacitor means can follow the output of said detecting means.
Claim 14
Dependent Claim
31 words
A system as in claim 12, wherein said gradient establishing means includes time-variable correcting means for urging said resistive means to steepen the given rate of decrease towards the maximum rate.
Claim 15
Dependent Claim
20 words
A system as in claim 13, wherein said time-variable correcting means include a capacitor and means for discharging said capacitor.
Claim 16
Dependent Claim
50 words
A system as in claim 13, wherein said variable gradient establishing means includes second correcting means responsive to said time delay means for reversing the rate of change of the output of said first correcting means so as to constraiN said resistive means to lessen the given rate of decrease.
Claim 17
Dependent Claim
33 words
A system as in claim 15, wherein said first correcting means includes a capacitor which is discharged to steepen the given rate of decrease and wherein said second correcting means charges said capacitor.
Claim 18
Dependent Claim
47 words
A system as in claim 15, wherein said first and second correcting means form a voltage output to said resistive means for controlling said resistive means, and wherein clipping means coupled to the voltage output establish the maximum rate of decrease and a minimum rate of decrease.
Claim 19
Dependent Claim
15 words
An apparatus as in claim 17, wherein said time delay means includes a resistor-capacitor circuit.
Claim 20
Dependent Claim
15 words
A system as in claim 13, wherein said time delay means include a resistor-capacitor circuit.
Claim 21
Dependent Claim
68 words
An apparatus as in claim 1, wherein said variable gradient establishing means continuously steepens and lessens the rate of decrease between the maximum and a minimum, and wherein variable gradient establishing means includes regulating means for regulating the rapidity at which the rate of decrease is varied continuously so that the time between the maximum and minimum rate exceeds the given time of delay in said delay means.
Claim 22
Dependent Claim
92 words
An apparatus as in claim 20, wherein said regulating means includes an energy storage device, and wherein said variable gradient establishing means further includes first switch means responsive to said delay means and the signal for changing the energy stored in said energy storage means in one direction so that said energy storage means produces an output which steepens the rate of decrease and second switch means for changing the energy in said energy storage means in the other direction so that said energy storage means lessens the given rate of decrease.
Claim 23
Dependent Claim
24 words
An apparatus as in claim 21, wherein said energy storage means is a capacitor and said first and second switch means are respective transistors.
Claim 24
Dependent Claim
202 words
For a vehicle having a wheel and a brake system coupled to the wheel for slowing the vehicle, a skid control system, comprising a wheel velocity detector coupled to the wheel, reference velocity establishing means coupled to said detector for establishing a reference velocity descending at a given rate, comparator means coupled to said detector and said establishing means for initiating and maintaining a first signal when the wheel velocity has less than a predetermined relationship with the reference velocity and a second signal at other times, brake modulating means coupled to the comparator for reducing the braking effect in response to the first signal, said comparator means effecting a transition from the first signal to the second signal on the basis of the wheel velocity and the rate in said establishing means, gradient varying means coupled to said establishing means and said comparator means for increasing the rate during the second signal and changing the rate during the first signal always to a rate less at the end of the first signal than the rate at the start of the first signal and changing the time of transition effected by the comparator means from the second signal to the first signal.
Claim 25
Dependent Claim
202 words
For a vehicle having a wheel and a brake system coupled to the wheel for slowing the vehicle, a skid control system, comprising a wheel velocity detector coupled to the wheel, reference velocity establishing means coupled to said detector for establishing a reference velocity descending at a given rate, comparator means coupled to said detector and said establishing means for initiating and maintaining a first signal when the wheel velocity has less than a predetermined relationship with the reference velocity and a second signal at other times, brake modulating means coupled to the comparator for reducing the braking effect in response to the first signal, said comparator means effecting a transition from the first signal to the second signal on the basis of the wheel velocity and the rate in said establishing means, gradient varying means coupled to said establishing means and said comparator means for increasing the rate during the second signal and changing the rate during the first signal always to a rate less at the end of the first signal than the rate at the start of the first signal and changing the time of transition effected by the comparator means from the second signal to the first signal.
Claim 26
Dependent Claim
37 words
An apparatus as in claim 23, wherein said gradient varying means changes the rate during the first signal continuously over an infinite number of rates which can vary only between a maximum rate and a minimum rate.
Claim 27
Dependent Claim
33 words
An apparatus as in claim 23, wherein said gradient varying means includes delay means for delaying the change to the lesser rate for a given time after the onset of the first signal.
Claim 28
Dependent Claim
37 words
An apparatus as in claim 25, wherein said gradient varying means changes the rate during the first signal continuously over an infinite number of rates which can vary only between a maximum rate and a minimum rate.
Claim 29
Dependent Claim
109 words
An apparatus as in claim 23, wherein said gradient varying means includes an energy storage device for producing a physical value controlling the rate, said gradient varying means further including first correcting means responsive tO the first signal and coupled to said energy storage device for changing the energy stored in said energy storage means in one direction so that said energy storage means produces a physical value which lessens the rate and second correcting means and coupled to said energy storage device for changing the energy in said energy storage means in the other direction so energy storage means increases the rate in response to the second signal.
Claim 30
Dependent Claim
37 words
An apparatus as in claim 27, wherein said gradient varying means changes the rate during the first signal continuously over an infinite number of rates which can vary only between a maximum rate and a minimum rate.
Claim 31
Dependent Claim
55 words
An apparatus as in claim 27, wherein said gradient varying means includes delay means for delaying the change to the lesser rate for a given time after the onset of the first signal, said first correcting means being responsive to said delay means so as to change the energy stored only after the delay time.
Claim 32
Dependent Claim
37 words
An apparatus as in claim 29, wherein said gradient varying means changes the rate during the first signal continuously over an infinite number of rates which can vary only between a maximum rate and a minimum rate.
Claim 33
Dependent Claim
102 words
An apparatus as in claim 30, wherein said energy storage means is a capacitor, said first correcting means including a transistor having a path of main current flow for charging the capacitor in response to the first signal and said delay means, said second correcting means including a transistor having a path of main current flow connected across said capacitor and responding to said second signal for discharging said capacitor during said second signal, each of said first and second correcting means including diode means for limiting the operation of said transistors beyond maximum and minimum physical values for changing the rates.
Claim 34
Dependent Claim
72 words
An apparatus as in claim 31, wherein said comparator means includes a two-transistor emitter-coupled differential circuit, each of said transistors in said differential circuit being coupled to said wheel velocity detector, one of said transistors having a base with a reference capacitor connected thereto for establishing the reference velocity, a transistor controlled by said storage means capacitor and coupled across said reference capacitor for varying the discharge rate of the second capacitor.
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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) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |