Patent US3937526A successfully refreshed from Google Patents.
US3937526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single valve braking system having anti-skid control
Assignee: Goodyear Aerospace Corp
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Filing: 1974-12-16
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Granted: 1976-02-10
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Expires: 1994-12-16
Abstract
Abstract An anti-skid and brake control system for use on an aircraft wherein the output signals from standard anti-skid circuitry are combined with the signals from a brake pedal transducer to create braking signals. The braking signals are applied to current controlled hydraulic valves for regulation of the application and release of brake pressure. The brakes utilized are dual cavity brakes with corresponding cavities of all brakes being interconnected to the same hydraulic line. Shut-off valves are interposed in the hydraulic lines and are operative to enable the brake valves to regulate brake pressure when either brake pedal of the aircraft has been depressed a fixed amount. Biasing circuitry is presented to affect the brake signal in such a manner as to overcome a dead band within the response characteristics of the brake valves utilized.
Inventors
- 👤 Edgar J. Ruof
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:51
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/321; B60T8/325; B60T8/17; B60T8/1701; B60T8/1703; B64; B64C; B64C25/00; B64C25/32; B64C25/42; B64C25/44; B64C25/46
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
243 words
An anti-skid system and brake control device for use on a vehicle having at least two wheels and having anti-skid circuitry connected to brakes on each of said wheels for producing anti-skid signals indicative of skidding activity and further having brake pedals connected to brake pedal transducers for producing pedal force signals indicative of the degree of brake pedal depression, comprising: rectifiers connected to the transducers for producing a DC signal from the associated pedal signals; differencing circuits connected to the rectifiers and anti-skid circuits for producing brake signals indicative of the difference between the pedal force and anti-skid signals; current controlled brake valve means connected to brakes on each of said wheels; valve driver circuit means interconnected between said differencing circuit and said brake valve means for regulating the application and release of brake pressure according to said brake signals; and wherein said brakes are dual cavity brakes, having first and second cavities, and a first hydraulic line interconnecting the first cavity of all brakes with a hydraulic pressure source, and a second hydraulic line interconnecting the second cavity of all brakes with said hydraulic pressure source, each hydraulic line having a shut-off valve positioned between said hydraulic pressure source and the respective cavities, and further including threshold detection circuit means interconnected between said rectifiers and the shut-off valves for effecting the application of hydraulic pressure to the brake cavities when either of the brake pedals is depressed beyond a particular amount.
Claim 2
Dependent Claim
243 words
An anti-skid system and brake control device for use on a vehicle having at least two wheels and having anti-skid circuitry connected to brakes on each of said wheels for producing anti-skid signals indicative of skidding activity and further having brake pedals connected to brake pedal transducers for producing pedal force signals indicative of the degree of brake pedal depression, comprising: rectifiers connected to the transducers for producing a DC signal from the associated pedal signals; differencing circuits connected to the rectifiers and anti-skid circuits for producing brake signals indicative of the difference between the pedal force and anti-skid signals; current controlled brake valve means connected to brakes on each of said wheels; valve driver circuit means interconnected between said differencing circuit and said brake valve means for regulating the application and release of brake pressure according to said brake signals; and wherein said brakes are dual cavity brakes, having first and second cavities, and a first hydraulic line interconnecting the first cavity of all brakes with a hydraulic pressure source, and a second hydraulic line interconnecting the second cavity of all brakes with said hydraulic pressure source, each hydraulic line having a shut-off valve positioned between said hydraulic pressure source and the respective cavities, and further including threshold detection circuit means interconnected between said rectifiers and the shut-off valves for effecting the application of hydraulic pressure to the brake cavities when either of the brake pedals is depressed beyond a particular amount.
Claim 3
Dependent Claim
34 words
The anti-skid system and brake control device as recited in claim 1 wherein each said rectifiers is a precision rectifier comprising an isolation transformer receiving a pedal force signal and driving a half-wave rectifier.
Claim 4
Dependent Claim
59 words
The anti-skid system and brake control device as recited in claim 1 wherein said brakes have a dead band in which increases of current to the valve means results in no increase of brake pressure and wherein said differencing circuit includes biasing means to present a quiescent output to the valve driving circuit means to overcome said dead band.
Claim 5
Dependent Claim
219 words
A brake control system for use on an aircraft having at least two wheels, one on each side of the aircraft, each wheel having an electrically controlled hydraulic valve connected to a brake for such wheel, all wheels on the same side of the aircraft being controllable by the same brake pedal and each wheel having anti-skid circuitry associated therewith to produce anti-skid signals indicative of skidding activity of the wheel comprising: a brake pedal transducer connected to each pedal and producing a pedal signal corresponding to the degree of depression of said pedal; first circuit means, including a differencing circuit, connected to said brake pedal transducers for receiving said pedal and anti-skid signals and producing a brake signal as a function thereof; valve driver means connected to said first circuit means and to said hydraulic valves for controlling application and release of brake pressure to the brakes; second circuit means connected to said transducers for opening shut-off valves in hydraulic lines between hydraulic pressure sources and the hydraulic valves to enable such hydraulic valves to regulate brake pressure when either brake pedal has been depressed a fixed amount; and wherein a level shift circuit is provided for biasing the differencing circuit to superimpose the anti-skid signal on a DC level before the application thereof to the differencing circuit.
Claim 6
Dependent Claim
219 words
A brake control system for use on an aircraft having at least two wheels, one on each side of the aircraft, each wheel having an electrically controlled hydraulic valve connected to a brake for such wheel, all wheels on the same side of the aircraft being controllable by the same brake pedal and each wheel having anti-skid circuitry associated therewith to produce anti-skid signals indicative of skidding activity of the wheel comprising: a brake pedal transducer connected to each pedal and producing a pedal signal corresponding to the degree of depression of said pedal; first circuit means, including a differencing circuit, connected to said brake pedal transducers for receiving said pedal and anti-skid signals and producing a brake signal as a function thereof; valve driver means connected to said first circuit means and to said hydraulic valves for controlling application and release of brake pressure to the brakes; second circuit means connected to said transducers for opening shut-off valves in hydraulic lines between hydraulic pressure sources and the hydraulic valves to enable such hydraulic valves to regulate brake pressure when either brake pedal has been depressed a fixed amount; and wherein a level shift circuit is provided for biasing the differencing circuit to superimpose the anti-skid signal on a DC level before the application thereof to the differencing circuit.
Claim 7
Dependent Claim
55 words
The brake control system as recited in claim 4 wherein said first circuit means comprises a precision rectifier and a differencing circuit, the rectifier receiving the pedal signals and creating a corresponding DC signal and the differencing circuit creating said brake signal as a function of the difference between the pedal and anti-skid signal levels.
Claim 8
Dependent Claim
29 words
The brake control system as recited in claim 4 when said first circuit means further includes a precision rectifier receiving the pedal signals and creating a corresponding DC signal.
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) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |