Patent US3574416A successfully refreshed from Google Patents.
US3574416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Antilock brake systems
Assignee: US Philips Corp
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Filing: 1968-10-29
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Granted: 1971-04-13
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Expires: 1988-10-29
Abstract
Abstract An antilock hydraulic brake control system for a wheeled vehicle. A first control valve actuated by a wheel speedreduction sensor in response to wheel locking, operates to relieve the pressure in the brake cylinder by diverting the brake fluid to a reservoir, which fluid closes a second valve controlling the hydraulic flow from the master cylinder. Upon resumption of the wheel rotation a scavenging pump in communication with the reservoir, will be activated and the fluid pressurized by the pump will open the second valve so as to permit hydraulic pressure from the master cylinder to be reapplied to the brake cylinder.
Inventors
- 👤 Derek Robert Skoyles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:19
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/42; B60T8/4275; B60T8/4283; B60T8/341; B60T8/40; B60T8/4018
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
150 words
An antilock brake control system for a wheeled vehicle which system comprises a hydraulic pressure line from a master cylinder to a wheel brake controlled by the system, an antilock control valve adapted for actuation in response to sensor signals from a wheel speed-reduction sensor, a connection from said brake to a reservoir adapted to be opened by said antilock control valve when the latter is actuated, said reservoir being at a lower pressure than the remaining system, first pump means adapted to scavenge fluid back to the brake, means for activating said first pump means in response to an increase in the volume of the fluid in said reservoir beyond a datum value, means for limiting flow of fluid from the master cylinder to the brake during at least part of any period of antilock action, and second pump means adapted to scavenge fluid back to the master cylinder.
Claim 2
Dependent Claim
150 words
An antilock brake control system for a wheeled vehicle which system comprises a hydraulic pressure line from a master cylinder to a wheel brake controlled by the system, an antilock control valve adapted for actuation in response to sensor signals from a wheel speed-reduction sensor, a connection from said brake to a reservoir adapted to be opened by said antilock control valve when the latter is actuated, said reservoir being at a lower pressure than the remaining system, first pump means adapted to scavenge fluid back to the brake, means for activating said first pump means in response to an increase in the volume of the fluid in said reservoir beyond a datum value, means for limiting flow of fluid from the master cylinder to the brake during at least part of any period of antilock action, and second pump means adapted to scavenge fluid back to the master cylinder.
Claim 3
Dependent Claim
36 words
A system as claimed in claim 1 including a volume-limiting valve for the pressure line between the master cylinder and the control valve and controlled by fluid in a reservoir associated with, at least one pump.
Claim 4
Dependent Claim
157 words
An antilock brake system for use with a wheeled vehicle having a master cylinder connected by a hydraulic pressure line to a wheel brake cylinder and comprising at least one reservoir, a pressure relief line connecting the brake cylinder and the reservoir, first valve means interposed between the brake cylinder and the reservoir, wheel speed-reduction sensor means for activating the first valve means to place the brake cylinder in communication with the reservoir in response to wheel locking thereby relieving the pressure in the brake cylinder, second valve means for controlling the fluid flow from the master cylinder to the brake cylinder, said second valve means being activated by the fluid in the reservoir to limit the flow of fluid to the brake cylinder thereby releasing the locked wheel, and pump means activated by the rotation of the wheel for forcing the hydraulic fluid from the reservoir to the master cylinder for reapplication of the braking action.
Claim 5
Dependent Claim
157 words
An antilock brake system for use with a wheeled vehicle having a master cylinder connected by a hydraulic pressure line to a wheel brake cylinder and comprising at least one reservoir, a pressure relief line connecting the brake cylinder and the reservoir, first valve means interposed between the brake cylinder and the reservoir, wheel speed-reduction sensor means for activating the first valve means to place the brake cylinder in communication with the reservoir in response to wheel locking thereby relieving the pressure in the brake cylinder, second valve means for controlling the fluid flow from the master cylinder to the brake cylinder, said second valve means being activated by the fluid in the reservoir to limit the flow of fluid to the brake cylinder thereby releasing the locked wheel, and pump means activated by the rotation of the wheel for forcing the hydraulic fluid from the reservoir to the master cylinder for reapplication of the braking action.
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) | 1974-04-12 | 1974-10-12 | 1975-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-12 | 1978-10-12 | 1979-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-12 | 1982-10-12 | 1983-04-13 | $7700.00 | Window Closed / Lapsed |