Patent US2285310A successfully refreshed from Google Patents.
US3753598A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic antiskid vehicle braking system, having two modes of operation
Assignee: Fiat SpA
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Filing: 1971-07-27
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Granted: 1973-08-21
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Expires: 1991-07-27
Abstract
Abstract An hydraulic anti-skid braking system for vehicles, having two different modes of operation depending on the braking pressure required to cause the wheels to slip or for wheel locking to become imminent. If the surface is slippery the braking pressure required to cause sliding is not high and a rapid, substantially complete release of braking pressure takes place when the antiskid device operates. If the surface has a good grip a high braking pressure is required to cause the wheels to slip and in this case a partial rapid release of pressure followed by a gradual release of pressure takes place when the antiskid device operates, to prevent excessive lurching during operation of the anti-skid device and to assist in a satisfactory anti-skid operation despite changing surface conditions.
Inventors
- 👤 G Michellone
- 👤 L Doano
- 👤 M Peruglia
- 👤 Ambri D De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:23
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/50; B60T8/5087; B60T8/341; B60T8/342; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7793; Y10T137/7805
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
293 words
An anti-skid braking system for at least one wheel of a vehicle, comprising a hydraulic fluid reservoir, a hydraulic pressure pump having an inlet and an outlet, said inlet communicating with said reservoir, a pressure operated brake, first conduit means connecting the outlet of said hydraulic pressure pump to said pressure operated brake, second conduit means communicating the outlet of said hydraulic pressure pump with said reservoir, normally open throttle valve disposed in said second conduit means, said normally open throttle valve being operatively connected with a brake pedal for selectively controlling said throttle valve to control the flow of fluid through said second conduit means, pressure discharge means connected in said first conduit means, said pressure discharge means including, means defining a first discharge path from said brake, a throttle in said first discharge path, an expansion chamber in said first discharge path, means defining a second discharge path in parallel with said first discharge path, a pressure controlled valve in said second discharge path, said pressure controlled valve having a control gate communicating with said pressure operated brake and responsive to the braking pressure to close said valve and block said second discharge path when the braking pressure exceeds a predetermined threshold value so that the only available discharge path to said reservoir is said first discharge path through said throttle, and an electronic anti-skid control device sensitive to the dynamic state of said wheel, said electronic anti-skid control device being operatively connected with said pRessure discharge means to actuate said pressure discharge means during a wheel braking operation in response to the dynamic state of the wheel being braked to selectively release the braking pressure being applied to said pressure operated brake to prevent a vehicle skidding condition from arising.
Claim 2
Dependent Claim
293 words
An anti-skid braking system for at least one wheel of a vehicle, comprising a hydraulic fluid reservoir, a hydraulic pressure pump having an inlet and an outlet, said inlet communicating with said reservoir, a pressure operated brake, first conduit means connecting the outlet of said hydraulic pressure pump to said pressure operated brake, second conduit means communicating the outlet of said hydraulic pressure pump with said reservoir, normally open throttle valve disposed in said second conduit means, said normally open throttle valve being operatively connected with a brake pedal for selectively controlling said throttle valve to control the flow of fluid through said second conduit means, pressure discharge means connected in said first conduit means, said pressure discharge means including, means defining a first discharge path from said brake, a throttle in said first discharge path, an expansion chamber in said first discharge path, means defining a second discharge path in parallel with said first discharge path, a pressure controlled valve in said second discharge path, said pressure controlled valve having a control gate communicating with said pressure operated brake and responsive to the braking pressure to close said valve and block said second discharge path when the braking pressure exceeds a predetermined threshold value so that the only available discharge path to said reservoir is said first discharge path through said throttle, and an electronic anti-skid control device sensitive to the dynamic state of said wheel, said electronic anti-skid control device being operatively connected with said pRessure discharge means to actuate said pressure discharge means during a wheel braking operation in response to the dynamic state of the wheel being braked to selectively release the braking pressure being applied to said pressure operated brake to prevent a vehicle skidding condition from arising.
Claim 3
Dependent Claim
45 words
The anti-skid braking system of claim 1, a normally open reset valve in parallel with said throttle between said expansion chamber and said reservoir, said reset valve being controlled by said anti-skid control device to close simultaneously with the actuation of said pressure discharge means.
Claim 4
Dependent Claim
22 words
The anti-skid braking system of claim 1 wherein there is provided an expansion chamber between said brake and said pressure discharge means.
Claim 5
Dependent Claim
121 words
The anti-skid braking system of claim 1 wherein said pressure discharge means include a valve comprising a piston slidable in a bore, means resiliently biasing said piston in one direction along said bore to a first position, a control port through which pressure is applied to move said piston in the other direction to a second position, an intermediate annular relieved portion on said piston, a pressure inlet to said bore, a pressure outlet from said bore, said intermediate annular relieved portion of said piston allowing communication between said inlet and said outlet when said piston is in said first positon, said piston moving to said second position to block said communication when the control pressure exceeds a predetermined threshold value.
Claim 6
Dependent Claim
114 words
The anti-skid braking system of claim 1 wherein said pressure discharge means include a valve comprising a piston slidable in a bore, means resiliently biasing said piston in one direction along said bore to a first position, a control port through which pressure is applied to move said piston in the other direction to a second position, a plunger on said piston, an outlet in the end of said bore, an inlet to said bore, said plunger cooperating with said outlet when said piston is in said second position, to block communication between said outlet port and said inlet to said bore, and allowing said communication when said piston is in said first position.
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |