US3731979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake anti-skid system
Assignee: United States Department of the Army
•
Filing: 1971-03-19
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Granted: 1973-05-08
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Expires: 1991-03-19
Abstract
Abstract An electromagnetic sensing device on the wheels of a vehicle produces a voltage that is used to keep a relay switch in a central power circuit open. Upon loss of this voltage due to stoppage of a wheel during skidding, the power circuit closes a solenoid valve in the hydraulic brake line, preventing the brake fluid pressure from dropping, and thus keeping the brake disc from rotating. Simultaneously, a square wave generator in the power circuit produces a square wave voltage to activate a solenoid coil operating a piston for automatically cycling the pressure in the brake line, maintaining the brake torque at or near the point of critical slip.
Inventors
- 👤 J Mikaila
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:06
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/42; B60T8/4208; B60T8/321; B60T8/3295; Y; Y10; Y10S; Y10S303/00; Y10S303/02; Y10S303/03; Y10S303/04
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
191 words
In an anti-skid vehicular braking system having an operatoroperable fluid pressure pump to actuate a brake for a vehicle wheel: a fluid conduit connecting the pump with the brake; normally open valve means in the conduit; electrical valve operating means energizeable to close the valve; an electric power circuit for the valve operating means; first switch means in the electric power circuit and having a normally closed position; a switch operating means to hold the switch open in response to rotation of said wheel; a source of fluid at a fluctuating pressure for supplying fluid to said conduit at a pressure which varies from just above the pressure in the conduit at lock-up to a pressure just below the lock-up pressure, said source connected and communicating directly with said conduit and responsive to fluid pressure in said conduit at all times that the valve means is held open by its operating means; said fluid source having electrical actuating means independent of said valve operating means connected to receive power from said power circuit; and other switch means to interrupt said power circuit in response to cessation of operation of said pump.
Claim 2
Dependent Claim
191 words
In an anti-skid vehicular braking system having an operatoroperable fluid pressure pump to actuate a brake for a vehicle wheel: a fluid conduit connecting the pump with the brake; normally open valve means in the conduit; electrical valve operating means energizeable to close the valve; an electric power circuit for the valve operating means; first switch means in the electric power circuit and having a normally closed position; a switch operating means to hold the switch open in response to rotation of said wheel; a source of fluid at a fluctuating pressure for supplying fluid to said conduit at a pressure which varies from just above the pressure in the conduit at lock-up to a pressure just below the lock-up pressure, said source connected and communicating directly with said conduit and responsive to fluid pressure in said conduit at all times that the valve means is held open by its operating means; said fluid source having electrical actuating means independent of said valve operating means connected to receive power from said power circuit; and other switch means to interrupt said power circuit in response to cessation of operation of said pump.
Claim 3
Dependent Claim
23 words
A braking system as in claim 1, said fluid source including electric power generating means of a type which generate an alternating voltage.
Claim 4
Dependent Claim
15 words
A braking system as in claim 2, said fluid source including a solenoid operated pump.
Claim 5
Dependent Claim
30 words
A braking system as in claim 3, the solenoid-operated pump having a piston exposed and responsive to pressure in said conduit, and resilient means biasing the piston against conduit pressure.
Claim 6
Dependent Claim
52 words
A braking system as in claim 4, in which said other switch means includes a normally closed switch and an operator-operable actuator in engagement with the first-named pump, the switch of said other switch means being responsive to the fully retracted position of the operator-operable actuator to open its normally closed contacts.
Claim 7
Dependent Claim
62 words
A braking system as in claim 5, said other switch means including a second normally-closed switch, and pressure sensitive means connected with the fluid conduit on opposite sides of the normally open valve means for opening the second normally closed switch when conduit pressure on the brake side of said valve exceeds conduit pressure on the first-named pump side of said valve.
Claim 8
Dependent Claim
14 words
A braking system as in claim 1, said fluid source including a solenoid-operated pump.
Claim 9
Dependent Claim
30 words
A braking system as in claim 7, the solenoid-operated pump having a piston exposed and responsive to pressure in said conduit, and resilient means biasing the piston against conduit pressure.
Claim 10
Dependent Claim
51 words
A braking system as in claim 8, in which said other switch means includes a normally closed switch and an operator-operable actuator in engagement with the first-named pump, the switch of said other switch means being responsive to the fully retracted position of the operator-operable actuator to open its normally-closed contacts.
Claim 11
Dependent Claim
63 words
A braking system as in claim 9, said other switch means including a second normally closed switch, and pressure sensitive means connected with the fluid conduit on opposite sides of the normally open valve means for opening the second normally closed switch when conduit pressure on the brake side of said valve exceeds conduit pressure on the first-named pump side of said valve.
Claim 12
Dependent Claim
52 words
A braking system as in claim 1, in which said other switch means includes a normally closed switch and an operator-operable actuator in engagement with the first-named pump, the switch of said other switch means being responsive to the fully retracted position of the operator-operable actuator to open its normally closed contacts.
Claim 13
Dependent Claim
63 words
A braking system as in claim 11, said other switch means including a second normally closed switch, and pressure sensitive means connected with the fluid conduit on opposite sides of the normally open valve means for Opening the second normally closed switch when conduit pressure on the brake side of said valve exceeds conduit pressure on the first-named pump side of said valve.
Claim 14
Dependent Claim
60 words
A braking system as in claim 1, said other switch means including a normally closed switch, and pressure sensitive means connected with the fluid conduit on opposite sides of the normally open valve means for opening the normally closed switch when conduit pressure on the brake side of said valve exceeds conduit pressure on the opposite side of said valve.
Claim 15
Dependent Claim
23 words
A braking system as in claim 13, said fluid source including electric power generating means of a type which generate an alternating voltage.
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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) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |