US3909069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air control valve for a pneumatic brake system
Assignee: MIDBRAKE Corp
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Filing: 1974-12-11
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Granted: 1975-09-30
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Expires: 1994-12-11
Abstract
Abstract A failsafe, foolproof control valve for a tractor-trailer air brake system which, among its other features, permits the tractor brakes to remain in a parked position while the trailer system is being pressurized. The control valve includes four ports, two of which communicate with a first valve chamber and the other two communicate with a second valve chamber. A spring biased first plunger is disposed within the first chamber and a manually operable second plunger extends within the second chamber. Movement of the second plunger establishes several operating modes of the valve to provide various fluid flow paths between the ports in a predetermined manner. At least one of these modes automatically repositions the second plunger to its normal operating mode after the trailer system has been optionally pressurized by actuation of a conventional park valve.
Inventors
- 👤 Harold Durling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:02
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/24; B60T13/26; B60T13/268; B60T13/261; B60T13/263; B60T15/00; B60T15/02; B60T15/04; B60T15/041; B60T15/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
226 words
A control valve for use in a brake system comprising: a valve body having a first chamber in a first portion thereof and a second chamber in a second portion thereof, said second chamber open at one end and in communication with said first chamber at its opposite end; a first and second port in communication with said second chamber and a third and fourth port in communication with said first chamber; a first pressure responsive plunger slidably disposed within said first chamber, first sealing means associated with said first plunger preventing fluid communication between said third port and said second chamber when said first plunger is in a first position and preventing communication between said fourth port and said second chamber when said plunger is in a second position; and a second plunger within said second chamber movable between a first and second position, second sealing means associated with said second plunger to isolate said first port from fluid communication with said second port and said first chamber and provide fluid communication between said second port and said first chamber when said second plunger is in a first position, third sealing means associated with said second plunger to prevent fluid communication between said first and second chambers and provide fluid communication between said first and second ports when said plunger is in said second position.
Claim 2
Dependent Claim
226 words
A control valve for use in a brake system comprising: a valve body having a first chamber in a first portion thereof and a second chamber in a second portion thereof, said second chamber open at one end and in communication with said first chamber at its opposite end; a first and second port in communication with said second chamber and a third and fourth port in communication with said first chamber; a first pressure responsive plunger slidably disposed within said first chamber, first sealing means associated with said first plunger preventing fluid communication between said third port and said second chamber when said first plunger is in a first position and preventing communication between said fourth port and said second chamber when said plunger is in a second position; and a second plunger within said second chamber movable between a first and second position, second sealing means associated with said second plunger to isolate said first port from fluid communication with said second port and said first chamber and provide fluid communication between said second port and said first chamber when said second plunger is in a first position, third sealing means associated with said second plunger to prevent fluid communication between said first and second chambers and provide fluid communication between said first and second ports when said plunger is in said second position.
Claim 3
Dependent Claim
60 words
The control valve of claim 1 further including spring means associated with said first plunger normally biasing said first plunger to said first position; and pressure responsive means formed as part of said second plunger and operable to automatically move said second plunger from its second position to its first position when said bias of said spring means is neutralized.
Claim 4
Dependent Claim
104 words
The control valve of claim 2 wherein said second chamber is further defined by a first cavity adjacent said first chamber, and a second cavity adjacent said open end of said second chamber and contiguous with said first cavity, said first cavity greater in cross section than said second cavity; said second plunger is further defined by a first portion similar in configuration to said first cavity and a second portion similar in configuration to said second portion, said first portion having a base surface adjacent said second chamber; and said pressure responsive means including said base surface, and an actuating lever associated therewith.
Claim 5
Dependent Claim
46 words
The control valve of claim 3 wherein said first plunger includes a first slider-piston adjacent said third port, a second slider-piston adjacent said fourth port and a member interconnecting said first and second slider-pistons and defining a gap therebetween, said actuating lever extending within said gap.
Claim 6
Dependent Claim
111 words
The control valve of claim 4 wherein each slider-piston includes a cylindrical slider portion adjacent said member and a cylindrical piston portion extending from said slider portion, said first slider portion sealingly slidably supported by a first seal in said first chamber when said first plunger is in its first position, said second slider portion sealingly and slidably supported in said first chamber by a second seal when said first plunger is in its second position; and said second slider portion having a groove formed adjacent said second piston portion to provide fluid communication between said fourth port and said second chamber when said first plunger is in its first position.
Claim 7
Dependent Claim
94 words
The control valve of claim 5 wherein an annular shoulder extending from said second chamber adjacent said second port defines a line of demarcation between said first and second cavities, said second plunger abutting said shoulder when said second plunger is in its second position; and said first cavity further having a plurality of circumferentiAlly spaced flutes communicating with said second port, said flutes extending a predetermined axial distance within said first cavity to provide fluid communication between said first cavity and said second port when said second plunger is in its first position.
Claim 8
Dependent Claim
56 words
The control valve of claim 6 further including said first and second cavities, and said first and second portions of said second plunger being generally cylindrical in configuration; and eccentric means associated with said base surface operable when said second plunger in its first position is rotated to lock said first plunger in its first position.
Claim 9
Dependent Claim
104 words
The control valve of claim 7 wherein said cavity includes a shelf protruding therefrom adjacent said first chamber, said shelf recessed to define a central opening therein; and said eccentric means includes a boss depending from said base surface and extending on one side of the center of said first cavity and an actuating lever depending from said boss, said actuating lever received within said central opening and said boss resting on said shelf when said second plunger is rotated, said boss preventing rotation when said second plunger is in second position while permitting rotation when said second plunger is in its first position.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |