US3937527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid pressure relay valve
Assignee: KNORR-BREMSE GmbH
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Filing: 1974-09-16
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Granted: 1976-02-10
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Expires: 1994-09-16
Abstract
Abstract A fluid pressure relay valve particularly for the electro-pneumatic control of vehicle brakes has a piston displaceable within a valve housing to define a control chamber on one side of the piston and on the other side of the piston there is a second chamber which is connected to the braking device. The pressure within the control chamber is controlled by inlet and outlet solenoid valves. The piston actuates valve means for controlling the pressure in the second chamber by venting the chamber or by connecting the chamber to a source of fluid pressure. An additional volume of pressure medium is connected to the control chamber for the purpose of increasing the pressure in the control chamber subsequently to the release of the signal "hold the pressure." The increase in pressure is to a predetermined level which is a function of a controlled lowering of pressure in the additional volume.
Inventors
- 👤 Alfred Eckhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:39
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/50; B60T8/5018
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
139 words
A fluid pressure relay valve for the electro-pneumatic control of vehicle brakes comprising a housing having a control chamber therein, inlet and outlet solenoid valve means connected to said control chamber for controlling the control pressure therein, a piston displaceable within said control chamber and defining one wall of said control chamber, there being a second chamber on the other side of said piston connected to a braking device, first and second valve means actuable by said piston for venting said second chamber and for connecting said second chamber to a source of pressure medium, and means defining an additional volume of pressure medium connected to said control chamber for increasing the pressure in said control chamber to a predetermined level by a lowering of the pressure in said additional volume means subsequently to a "hold the pressure" signal.
Claim 2
Dependent Claim
139 words
A fluid pressure relay valve for the electro-pneumatic control of vehicle brakes comprising a housing having a control chamber therein, inlet and outlet solenoid valve means connected to said control chamber for controlling the control pressure therein, a piston displaceable within said control chamber and defining one wall of said control chamber, there being a second chamber on the other side of said piston connected to a braking device, first and second valve means actuable by said piston for venting said second chamber and for connecting said second chamber to a source of pressure medium, and means defining an additional volume of pressure medium connected to said control chamber for increasing the pressure in said control chamber to a predetermined level by a lowering of the pressure in said additional volume means subsequently to a "hold the pressure" signal.
Claim 3
Dependent Claim
35 words
A fluid pressure relay valve as claimed in claim 1 and means in the connection of said additional volume means to said control chamber for regulating the decrease of pressure in said additional volume means.
Claim 4
Dependent Claim
30 words
A fluid pressure relay valve as claimed in claim 1 and means for regulating the drop of pressure in said additional volume means by the pressure in said control chamber.
Claim 5
Dependent Claim
18 words
A fluid pressure relay valve as claimed in claim 2 wherein said regulating means comprises a throttle valve.
Claim 6
Dependent Claim
49 words
A fluid pressure relay valve as claimed in claim 2 wherein said regulating means comprises a check valve which is opened at a predetermined reduced pressure in said control chamber, and unthrottled connection between said additional volume means and said control chamber and controlled by said solenoid outlet valve.
Claim 7
Dependent Claim
40 words
A fluid pressure relay valve as claimed in claim 5 wherein the cross-sectional area of said solenoid outlet valve is dependent upon the characteristic curve between the volume of said control chamber and the volume of said additional volume means.
Claim 8
Dependent Claim
19 words
A fluid pressure relay valve as claimed in claim 5 wherein said check valve comprises a throttle check valve.
Claim 9
Dependent Claim
27 words
A fluid pressure relay valve as claimed in claim 5 wherein the closing force of said check valve is overcome by the pressure in said control chamber.
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) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |