US4560208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brake pressure control unit of deceleration-responsive type
Assignee: Nissan Motor Co Ltd
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Filing: 1983-07-26
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Granted: 1985-12-24
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Expires: 2003-07-26
Abstract
Abstract A brake pressure control unit of the deceleration-responsive type comprises a control valve operable to restrict the transfer of fluid pressure therethrough from an inlet port to an outlet port and biased by a spring to a position of opening, a storing chamber operatively connected to the control valve in a manner to assist the bias of the control valve spring with an increasing force as the fluid pressure in the storing chamber increases, a deceleration-responsive valve operable to sealingly close the storing chamber in response to a vehicle deceleration at a rate exceeding a predetermined value, and a differential pressure valve disposed between the deceleration-responsive valve and the storing chamber to restrict the transfer of fluid pressure therethrough. The differential pressure valve is adapted to open in response to a varying fluid pressure that varies with the variation of the rate of fluid pressure at the inlet port.
Inventors
- 👤 Hitoshi Kubota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:05
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/26; B60T8/28; B60T8/282; B60T11/00; B60T11/10; B60T11/28; B60T11/34; B60T8/17; B60T8/176; B60T8/1766
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
234 words
A brake pressure control unit of the deceleration-responsive type comprising: a housing having an inlet port and an outlet port; a control valve disposed in said housing between said inlet and outlet ports and operable to restrict the transfer of fluid pressure therethrough, said control valve having a spring by which it is biased to a position of opening; a storing chamber disposed in said housing and communicable with said inlet port, said storing chamber being variable in volume depending upon the variation of the fluid pressure supplied thereto and operatively connected to said control valve in a manner to urge the control valve in the direction to assist the bias of said control valve spring with an increasing force as the fluid pressure in the storing chamber increases; a deceleration-responsive valve disposed in said housing between said inlet port and said storing chamber and operable to sealingly close said storing chamber in response to a vehicle deceleration at a rate exceeding a predetermined value; and a differential pressure valve disposed in said housing between said deceleration-responsive valve and said storing chamber and operable to restrict the transfer of fluid pressure therethrough, said differential pressure valve having means for varying its valve opening pressure at which it opens to allow the transfer of fluid pressure therethrough in accordance with the variation of the rate of increase of the fluid pressure at said inlet port.
Claim 2
Dependent Claim
234 words
A brake pressure control unit of the deceleration-responsive type comprising: a housing having an inlet port and an outlet port; a control valve disposed in said housing between said inlet and outlet ports and operable to restrict the transfer of fluid pressure therethrough, said control valve having a spring by which it is biased to a position of opening; a storing chamber disposed in said housing and communicable with said inlet port, said storing chamber being variable in volume depending upon the variation of the fluid pressure supplied thereto and operatively connected to said control valve in a manner to urge the control valve in the direction to assist the bias of said control valve spring with an increasing force as the fluid pressure in the storing chamber increases; a deceleration-responsive valve disposed in said housing between said inlet port and said storing chamber and operable to sealingly close said storing chamber in response to a vehicle deceleration at a rate exceeding a predetermined value; and a differential pressure valve disposed in said housing between said deceleration-responsive valve and said storing chamber and operable to restrict the transfer of fluid pressure therethrough, said differential pressure valve having means for varying its valve opening pressure at which it opens to allow the transfer of fluid pressure therethrough in accordance with the variation of the rate of increase of the fluid pressure at said inlet port.
Claim 3
Dependent Claim
181 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 1, in which said differential pressure valve comprises a valve chamber constantly communicating with said storing chamber and communicable with said inlet port through said deceleration-responsive valve and a valve member having an end extending into said valve chamber and axially movable toward said valve chamber to a position of opening where it provides communication between said deceleration-responsive valve and said storing chamber and also axially movable away from said valve chamber to a position of closure where it obstructs communication between same, and said means comprises an actuator in the form of a stepped piston, axially movable toward and away from said valve member and having an end extending into said valve chamber, and a spring disposed within said valve chamber and interposed between said valve member and said actuator to urge same in opposite directions, said actuator being adapted to move increasingly toward said valve member, compressing said differential pressure spring, as the rate of increase of the fluid pressure at said inlet port increases.
Claim 4
Dependent Claim
119 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 2, in which said actuator comprises a larger diameter section and in which said differential pressure valve further comprises first and second actuator chambers on the respective sides of said larger diameter section, said first actuator chamber being communicated with said control valve while said second actuator chamber being communicated with said inlet port, said larger diameter section being formed with an orifice providing communication between said first and second actuator chambers, said orifice being adapted to cause such a pressure difference between said first and second actuator chambers that increases as the rate of increase of the fluid pressure at said inlet port increases.
Claim 5
Dependent Claim
51 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 3, in which said differential pressure valve further comprises a bimetal member which is mounted on said actuator in a manner to restrict the fluid flow through said orifice increasingly as the temperature of the fluid increases.
Claim 6
Dependent Claim
37 words
A brake pressure control valve of the deceleration-responsive type as set forth in claim 3, in which said actuator is adapted to be acted upon at the opposed axial ends thereof by such pressures that are counterbalanced.
Claim 7
Dependent Claim
76 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 5, in which said differential pressure valve further comprises a balancing chamber into which the other end of said actuator extends, said actuator having an axial hole extending throughout the length thereof to provide communication between said valve chamber and said balancing chamber, said valve chamber being in constant communication with said storing chamber through said axial hole and said balancing chamber.
Claim 8
Dependent Claim
28 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 6, in which the opposed ends of said actuator have the same sectional area.
Claim 9
Dependent Claim
163 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 3, in which said differential pressure valve further comprises a partition member separating said valve chamber into a pressure chamber section and an air chamber section, said one end of said valve member passing through said pressure chamber section to extend into said air chamber section while being sealingly and axially movably carried by said partition member, said pressure chamber section being an annular chamber around said valve member and constantly communicating with said inlet port through said deceleration-responsive valve, said one end of said actuator extending into said air chamber section, and in which said differential pressure valve further comprises an air balancing chamber which is in communication with the open air and into which said other end of said actuator extends, said actuator being formed with an axial hole extending throughout the length thereof to provide communication betwen said air chamber section and said air balancing chamber.
Claim 10
Dependent Claim
28 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 8, in which the opposed ends of said actuator have the same sectional area.
Claim 11
Dependent Claim
131 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 1, in which said control valve further comprises poppet valve means, a plunger axially movable to selectively open and close said poppet valve means and a piston axially aligned with said plunger and axially movable toward and away from said plunger, said control valve spring being interposed between said plunger and said piston to urge same in opposite directions, said piston having an end extending into said storing chamber and axially movable in response to the fluid pressure in the storing so that said plunger is biased by said control valve spring to its position of opening where it opens said poppet valve means with an increasing force as the increase of the storing chamber pressure increases.
Claim 12
Dependent Claim
101 words
A brake pressure control unit of the deceleration-responsive type as set forth in claim 1, in which said control valve further comprises poppet valve means, a plunger axially movable to selectively open and close said poppet valve means, said spring biasing said plunger to its position of opening, and a control valve chamber defined by said plunger, said control valve chamber being in constant communication with said storing chamber and adapted so that the fluid pressure therein urges said plunger to its position of opening where it opens said poppet valve means with increasing force as the storing chamber pressure increases.
References Cited (Backward Citations)
US3825303A
Cited
US3944292A
Cited
US4141596A
Cited
US4325582A
Cited
US4284307A
Cited
US4254996A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |