Patent US3910644A successfully refreshed from Google Patents.
US3910644A
Expired / Lapsed
US
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Anti-skid brake control systems
Assignee: Whitnash PLC
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Filing: 1973-04-24
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Granted: 1975-10-07
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Expires: 1993-04-24
Abstract
Abstract In a fluid pressure vehicle braking system of the kind in which an electrical system associated with wheels of the vehicle is arranged to regulate the braking force applied to each associated wheel and is operable automatically to effect release of a brake acting on each associated wheel when the deceleration thereof exceeds a predetermined amount and to re-apply the released brake when the angular velocity of the respective wheel approaches that at which the periphery of the wheel rolls on the road surface without slipping, there is provided an override control which monitors the speeds of the vehicle wheels, compares them with a reference signal related to the speed of the vehicle, and holds the brakes released from a wheel if the speed of the vehicle exceeds the speed of that wheel by a predetermined amount for a predetermined period of time. The reference signal may be derived by any one of a number of methods. For example, the reference signal may be the speed of the fastest wheel. The brakes applied to the other wheels may be released at the same time or may operate undisturbed.
Inventors
- 👤 Mervyn Brian Packer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:28
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/176; B60T8/1764
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
191 words
An anti-skid brake control system for A vehicle having a plurality of wheels having brakes associated therewith comprising: means for sensing the wheel speed of at least one of a plurality of vehicle wheels and generating wheel speed signals in response thereto, first means responsive to at least one of said wheel speed signals for releasing the brake pressure at the wheel associated with said wheel speed sensing means when wheel deceleration exceeds a predetermined amount, second means responsive to the wheel speed signal of said associated wheel for reapplying the brake pressure at said associated wheel when wheel speed approaches the speed it would have been doing had wheel slippage not occurred, third means responsive to at least one of said wheel speed signals for generating a vehicle speed related reference signal, and comparison means for comparing the wheel speed signal of said associated wheel and the vehicle speed related reference signal and inhibiting reapplication of brake pressure at the associated wheel via said second means when the vehicle speed signal exceeds the wheel speed signal of the associated wheel by a second predetermined amount for a predetermined time interval.
Claim 2
Dependent Claim
191 words
An anti-skid brake control system for A vehicle having a plurality of wheels having brakes associated therewith comprising: means for sensing the wheel speed of at least one of a plurality of vehicle wheels and generating wheel speed signals in response thereto, first means responsive to at least one of said wheel speed signals for releasing the brake pressure at the wheel associated with said wheel speed sensing means when wheel deceleration exceeds a predetermined amount, second means responsive to the wheel speed signal of said associated wheel for reapplying the brake pressure at said associated wheel when wheel speed approaches the speed it would have been doing had wheel slippage not occurred, third means responsive to at least one of said wheel speed signals for generating a vehicle speed related reference signal, and comparison means for comparing the wheel speed signal of said associated wheel and the vehicle speed related reference signal and inhibiting reapplication of brake pressure at the associated wheel via said second means when the vehicle speed signal exceeds the wheel speed signal of the associated wheel by a second predetermined amount for a predetermined time interval.
Claim 3
Dependent Claim
29 words
An anti skid brake control system as claimed in claim 1, wherein the reference signal is computed from the angular velocity of at least one wheel of the vehicle.
Claim 4
Dependent Claim
49 words
An anti skid brake control system as claimed in claim 2, wherein the reference signal with which the signal indicative of the angular velocity of one wheel of the vehicle is compared is computed from the angular velocity of at least one of the other wheels of the vehicle.
Claim 5
Dependent Claim
57 words
An anti skid brake control system as claimed in claim 1, wherein the peaks of each signal indicative of the angular velocities of each wheel from which the reference signal is computed are stored in a respective capacitor, and a constant current generator is associated with each capacitor in order to control the discharge of the capacitor.
Claim 6
Dependent Claim
27 words
An anti skid brake control system as claimed in claim 4, wherein the discharge from each capacitor is determined by the setting of a respective variable resistor.
Claim 7
Dependent Claim
26 words
An anti skid brake control system as claimed in claim 5, wherein the resistance of each variable resistor is set by a common slope control device.
Claim 8
Dependent Claim
37 words
An anti skid brake control system as claimed in claim 6, wherein the resistance of each variable resistor is fixed by the common slope control device so as to correspond to a predetermined deceleration of the vehicle.
Claim 9
Dependent Claim
91 words
An anti skid brake control system as claimed in claim 1, wherein the controlled discharge from each capacitor to which were fed the signals indicative of the angular velocities of each wheel from which the reference signal is computed is fed to a combined summation, amplification and inversion device which adds together the various signals it receives from the capacitors, inverts and amplifies the resultant signal and transmits the inverted amplified signal to a comparator where it is compared with the signal indicative of the angular velocity of said one wheel.
Claim 10
Dependent Claim
47 words
An anti skid brake control system as claimed in claim 8, wherein each capacitor is connected to the combined summation, amplification and inversion device via switching means, the arrangement being such that the shape of the reference signal is dependent upon the setting of the switching means.
Claim 11
Dependent Claim
44 words
An anti skid brake control system as claimed in claim 8, wherein the combined summation, amplification and inversion device includes a feedback circuit and means for changing the resistance of the feedback circuit so as to influence the magnitude of the inverted amplified signal.
Claim 12
Dependent Claim
27 words
An anti skid brake control system as claimed in claim 10, including a potentiometer which has its pointer connected to the comparator to supply said third signal.
Claim 13
Dependent Claim
49 words
An anti skid brake control system as claimed in claim 8, wherein the sum of the inverted amplified signal and the signal indicative of the angular velocity of said one wheel Is compared with a third signal in the comparator, the third signal being representative of said predetermined amount.
Claim 14
Dependent Claim
118 words
An anti skid brake control system as claimed in claim 8, wherein the output of the comparator is connected through a time delay circuit to the means arranged to regulate operation of the brakes applied to said one wheel, the time delay circuit being arranged to transmit an output signal from the comparator to the brake regulating means so as to actuate the brake regulating means for release of the associated brakes, and so that initiation of transmission of a signal to the brake regulating means is delayed for said predetermined interval of time, there being no delay in cessation of the signal transmitted to the brake regulating means after cessation of the output signal from the comparator.
Claim 15
Dependent Claim
220 words
An anti skid brake control system as claimed in claim 13, wherein the time delay circuit includes an input terminal connected in parallel to two inputs of an AND gate, the input terminal being connected to one of the inputs of the AND gate via resistance means, capacitance means having one terminal connected between the resistance means and said one input so as to be charged by current flowing from said input terminal to said one input via said resistance means, and a shunt circuit in parallel with the resistance means providing a shunt connection between the input terminal and said terminal of the capacitance means, the shunt circuit including a diode which permits free discharge of the capacitance means to the input terminal but which prevents current flow from the input terminal via the shunt circuit to charge the capacitance means, the arrangement being such that initiation of an output signal from the AND gate is delayed for a period after initial receipt of a signal at the input terminal until the capacitance means is charged sufficiently for the voltage at said one input of the AND gate to match the voltage at the other input and such that there will be no output signal from the AND gate unless a signal is being received at the input terminal.
Claim 16
Dependent Claim
73 words
An anti skid brake control system as claimed in claim 1, wherein the second predetermined amount by which the magnitude of the reference signal must exceed the magnitude of the signal indicative of the angular velocity of a wheel before operation of the electrical system associated with that wheel is modified is selected so as to allow for the difference between the angular velocities of two coaxial wheels as the vehicle is cornering.
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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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |