US4254623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic control system for brake device
Assignee: Valeo SE
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Filing: 1978-08-25
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Granted: 1981-03-10
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Expires: 1998-08-25
Abstract
Abstract A hydraulic control system for a brake device comprises independent first and second brake circuits, the first circuit communicating with a first chamber pressurized by movement of a master piston actuated by a brake pedal, and the second circuit communicating with a second chamber whose pressure is dependent on that of the first and is developed by an assistance circuit, the second chamber being separated from the assistance circuit by a piston.
Inventors
- 👤 Jean L. R. Dauvergne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:50
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/16; B60T13/161
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
167 words
A hydraulic control system for a brake device, said system comprising independent first and second brake circuits, a brake pedal, a source of assisting hydraulic pressure, a master cylinder having a master piston defining a first chamber, said master piston being actuated by said brake pedal and being insensitive to said assisting hydraulic pressure, said first chamber being in communication with said first brake circuit, a second chamber in communication with said second brake circuit, a third chamber fed by said assisting hydraulic pressure through a valve controlled by the first chamber pressure in such manner that said assisting hydrualic pressure varies as said first chamber pressure, a movable pressure transmitting separator interposed between said second and third chambers in such manner that pressure in said third chamber can be transmitted to said second chamber, and safety thrust means operable between said master piston and said separator in such manner that actuation of said piston can actuate said separator to increase the pressure in said second chamber.
Claim 2
Dependent Claim
167 words
A hydraulic control system for a brake device, said system comprising independent first and second brake circuits, a brake pedal, a source of assisting hydraulic pressure, a master cylinder having a master piston defining a first chamber, said master piston being actuated by said brake pedal and being insensitive to said assisting hydraulic pressure, said first chamber being in communication with said first brake circuit, a second chamber in communication with said second brake circuit, a third chamber fed by said assisting hydraulic pressure through a valve controlled by the first chamber pressure in such manner that said assisting hydrualic pressure varies as said first chamber pressure, a movable pressure transmitting separator interposed between said second and third chambers in such manner that pressure in said third chamber can be transmitted to said second chamber, and safety thrust means operable between said master piston and said separator in such manner that actuation of said piston can actuate said separator to increase the pressure in said second chamber.
Claim 3
Dependent Claim
32 words
A hydraulic control system according to claim 1 wherein said first chamber, said master piston, said second chamber, said separator and said third chamber are axially successively arranged in said master cylinder.
Claim 4
Dependent Claim
51 words
A hydraulic control system according to claim 2, wherein said separator is a sleeve surrounding said master piston, has aperture means and said safety thrust means comprise pin means rigid with said master piston and engaged in said aperture means for limited relative movement between said pin means and said sleeve.
Claim 5
Dependent Claim
34 words
A hydraulic control system according to claim 1, wherein said valve is controlled by said first chamber pressure in such manner that said assisting hydraulic pressure and said first chamber pressure are substantially equal.
Claim 6
Dependent Claim
35 words
A hydraulic control system according to claim 1, wherein said second chamber, said separator, said third chamber, a fixed wall, said first chamber and said master piston are axially successively arranged in said master cylinder.
Claim 7
Dependent Claim
56 words
A hydraulic control system according to claim 5, further comprising safety thrust means operable between said master piston and said separator, wherein said separator is a piston engaged in said master cylinder and said safety thrust means comprise rod means rigid with said master piston and passing through said fixed wall for engaging said separator piston.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |