Patent US3881780A successfully refreshed from Google Patents.
US3881780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake hydraulic pressure control system for vehicles
Assignee: Aisin Corp
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Filing: 1973-04-30
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Granted: 1975-05-06
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Expires: 1993-04-30
Abstract
Abstract A brake actuating hydraulic pressure control system for a vehicle comprising a pressure control valve device arranged within a brake hydraulic circuit to reduce the pressure of the brake actuating fluid relative to the master cylinder pressure after the master cylinder pressure exceeds a predetermined value, the pressure control valve device including a valve member cooperating a piston for on-off controlling the circuit, and a skid control device for relieving the pressure of the brake fluid upon the occurrence of a substantial wheel skidding condition; the skid control device including a plunger normally holding the valve member of the pressure control valve device into a given position and a control piston effecting the movement of the plunger to displace the valve member into its close position upon the occurrence of the skidding condition.
Inventors
- 👤 Mizuo Nyunoya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:04
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T17/00; B60T17/18; B60T17/22; B60T8/00; B60T8/26; B60T8/32; B60T8/34; B60T8/42; B60T8/4208
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
362 words
A brake actuating hydraulic pressure control system for a vehicle comprising; a master cylinder, a wheel cylinder of at least one wheel of the vehicle, a hydraulic circuit communicating said cylinders, a pressure control valve device disposed within said circuit for controlling the relative hydraulic pressure supplied to said wheel cylinder after the master cylinder pressure exceeds a predetermined value, said pressure control valve device including a housing having a bore, a stepped piston slidably mounted within said bore and having a first effective area portion exposed to the master cylinder pressure to urge said piston in one direction and said piston having a second portion of a greater effective area than that of said first portion, said second portion being exposed to the hydraulic pressure in said wheel cylinder to move said piston in opposition to the master cylinder pressure, a spring means for biasing said piston in said one direction, and a valve member for on-off controlling said hydraulic circuit in response to the movement of said piston, means for sensing a substantial wheel skidding condition and delivering an instructive signal as a result of the sensing, a change-over valve means movable in response to said instructive signal, a skid control device for relieving the hydraulic pressure of the brake in said wheel cylinder through said change-over valve means, and said skid control device including a plunger movable within said hydraulic circuit and operatively contacted with said valve member of said pressure control valve device and said plunger has a portion which normally holds said valve member of said pressure control valve device in the open position, whereby under skid condition said valve member is closed and said stepped piston is contacted with said housing in response to the movement of said plunger so as to interrupt the hydraulic communication between said master cylinder and said wheel cylinder, and the effective volume of said hydraulic circuit between said valve member and said wheel cylinder is varied in response to the movement of said plunger and a control piston operatively connected with said plunger for effecting the movement of said plunger through said change-over valve means to reduce the brake pressure.
Claim 2
Dependent Claim
362 words
A brake actuating hydraulic pressure control system for a vehicle comprising; a master cylinder, a wheel cylinder of at least one wheel of the vehicle, a hydraulic circuit communicating said cylinders, a pressure control valve device disposed within said circuit for controlling the relative hydraulic pressure supplied to said wheel cylinder after the master cylinder pressure exceeds a predetermined value, said pressure control valve device including a housing having a bore, a stepped piston slidably mounted within said bore and having a first effective area portion exposed to the master cylinder pressure to urge said piston in one direction and said piston having a second portion of a greater effective area than that of said first portion, said second portion being exposed to the hydraulic pressure in said wheel cylinder to move said piston in opposition to the master cylinder pressure, a spring means for biasing said piston in said one direction, and a valve member for on-off controlling said hydraulic circuit in response to the movement of said piston, means for sensing a substantial wheel skidding condition and delivering an instructive signal as a result of the sensing, a change-over valve means movable in response to said instructive signal, a skid control device for relieving the hydraulic pressure of the brake in said wheel cylinder through said change-over valve means, and said skid control device including a plunger movable within said hydraulic circuit and operatively contacted with said valve member of said pressure control valve device and said plunger has a portion which normally holds said valve member of said pressure control valve device in the open position, whereby under skid condition said valve member is closed and said stepped piston is contacted with said housing in response to the movement of said plunger so as to interrupt the hydraulic communication between said master cylinder and said wheel cylinder, and the effective volume of said hydraulic circuit between said valve member and said wheel cylinder is varied in response to the movement of said plunger and a control piston operatively connected with said plunger for effecting the movement of said plunger through said change-over valve means to reduce the brake pressure.
Claim 3
Dependent Claim
35 words
A system as set forth in claim 1, wherein said stepped piston comprises a large diameter portion having said second portion at its one end and a small diameter portion exposed to the atmospheric pressure.
Claim 4
Dependent Claim
79 words
A system as set forth in claim 1, wherein said stepped piston is formed with a passage means which is formed as a part of said hydraulic circuit and said valve member is Interposed within said passage means, said valve member comprising a valve head which cooperates with a seat portion of said stepped piston and a stem portion which normally contact with said plunger, and said valve head being urged by a further spring in its closing direction.
Claim 5
Dependent Claim
70 words
A system as set forth in claim 1, further comprising a vehicle engine operated pump means for providing a source means of pressurized hydraulic fluid, and said skid control device includes a cylinder fixed to a main body so as to slidably accommodate said control piston therein and a hydraulic chamber defined by said control piston within said cylinder and communicable with said source means through said change-over valve means.
Claim 6
Dependent Claim
72 words
A system as set forth in claim 4 further comprising an emergency piston normally urged into its rest position by the pressurized hydraulic fluid, a supplementary piston arranged between said control piston and said plunger and a spring biasing said emergency and supplementary pistons toward said plunger upon failure of said source means of pressure so that said valve member of said pressure control valve device is urged to its open position.
Claim 7
Dependent Claim
72 words
A system as set forth in claim 1, wherein said control piston is a spring biased diaphragm piston thereby defining first and second chambers within a main body, said first chamber being connected to said change-over valve means and said second chamber being connected to a vacuum source, and said change-over valve means is associated with the atmosphere and the vacuum source for controlling the flow of the atmospheric air and vacuum.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |