Patent US3709566A successfully refreshed from Google Patents.
US3709566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the anti-skid braking of vehicles
Assignee: Fiat SpA
•
Filing: 1971-02-24
•
Granted: 1973-01-09
•
Expires: 1991-02-24
Abstract
Abstract A vehicle anti-skid braking system which shortens the time required to reduce an excessive slip of the wheel by ascertaining the instant when the wheel acceleration becomes zero after braking has been released and by keeping constant the braking torque on the wheel at the value it reaches after a predetermined time has elapsed from such instant, braking being resumed when the acceleration of the wheel again begins to decrease.
Inventors
- 👤 G Michellone
- 👤 M Palazzetti
- 👤 G Tabasso
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:21
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/176; B60T8/1761; B60T8/17613
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
111 words
A method of anti-skid braking control of a vehicle wheel comprising the following steps: a. initiating release of braking and allowing the wheel to decelerate under inertia forces; b. surveying a first instant when the wheel begins to accelerate under friction with the road; c. surveying a second instant when the acceleration of the wheel becomes zero; d. keeping the braking torque on the wheel constant at the value it reaches after a predetermined time has elapsed from the said second instant; e. surveying a third instant when the wheel again begins to decelerate; f. re-applying a braking torque on the wheel after a predetermined time from the said third instant.
Claim 2
Independent Claim
111 words
A method of anti-skid braking control of a vehicle wheel comprising the following steps: a. initiating release of braking and allowing the wheel to decelerate under inertia forces; b. surveying a first instant when the wheel begins to accelerate under friction with the road; c. surveying a second instant when the acceleration of the wheel becomes zero; d. keeping the braking torque on the wheel constant at the value it reaches after a predetermined time has elapsed from the said second instant; e. surveying a third instant when the wheel again begins to decelerate; f. re-applying a braking torque on the wheel after a predetermined time from the said third instant.
Claim 3
Dependent Claim
225 words
In an apparatus for the anti-skid braking of a vehicle wheel, including a braking cylinder for actuating a brake of the wheel, a source of pressure for supplying pressure to the brake cylinder through a first normally open solenoid-operated valve, a second normally closed solenoid-operated valve connected between the brake cylinder and exhaust, and means to cause the first valve to close and the second valve to open, the improvement that such means comprise: a. accelerometer means co-operating with the wheel to supply an acceleration signal, b. a first threshold circuit which receives the acceleration signal and, when this signal exceeds a predetermined negative threshold, sends a closing command to a bistable circuit having its output connected to the solenoid of the first valve and an opening command to a bistable circuit having its output connected to the solenoid of the second valve, c. a second threshold circuit receiving the acceleration signal and sending, when this signal passes through zero, a closing command to the bistable circuit having its output connected to the solenoid of the second valve, through a delay circuit having a predetermined delay time, and d. a circuit responsive to change of slope, which receives the acceleration signal and, when the sign of the slope of this signal changes, supplies an opening command to the bistable circuit connected to the first valve.
Claim 4
Dependent Claim
225 words
In an apparatus for the anti-skid braking of a vehicle wheel, including a braking cylinder for actuating a brake of the wheel, a source of pressure for supplying pressure to the brake cylinder through a first normally open solenoid-operated valve, a second normally closed solenoid-operated valve connected between the brake cylinder and exhaust, and means to cause the first valve to close and the second valve to open, the improvement that such means comprise: a. accelerometer means co-operating with the wheel to supply an acceleration signal, b. a first threshold circuit which receives the acceleration signal and, when this signal exceeds a predetermined negative threshold, sends a closing command to a bistable circuit having its output connected to the solenoid of the first valve and an opening command to a bistable circuit having its output connected to the solenoid of the second valve, c. a second threshold circuit receiving the acceleration signal and sending, when this signal passes through zero, a closing command to the bistable circuit having its output connected to the solenoid of the second valve, through a delay circuit having a predetermined delay time, and d. a circuit responsive to change of slope, which receives the acceleration signal and, when the sign of the slope of this signal changes, supplies an opening command to the bistable circuit connected to the first valve.
Claim 5
Dependent Claim
54 words
The apparatus of claim 2, characterized in that the command given by the circuit responsive to change of slope is delivered to the bistable circuit connected to the solenoid of the first valve through a gate circuit which is enabled by the output signals of the first and the second bistable circuits occurring simultaneously.
Claim 6
Dependent Claim
21 words
The apparatus of claim 2, characterized in that the accelerometer means comprises a tachometer means and a differentiator connected in cascade.
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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |