US3866623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tractor protection valve
Assignee: Berg Manufacturing Co
•
Filing: 1973-12-10
•
Granted: 1975-02-18
•
Expires: 1993-12-10
Abstract
Abstract A tractor protection valve for use in the air brake system of a tractor-trailer vehicle combination to protect and maintain the braking system of the tractor in case of failure of the emergency braking system. The valve has a shuttle which normally closes communication between the emergency inlet and outlet and a piston which normally closes communication between the service inlet and outlet. A small shuttle valve gives the shuttle in which it is mounted a dual action characteristic. The application of fluid pressure at the emergency inlet causes the shuttle to move through a fixed distance thereby closing communication between the emergency outlet and an exhaust port. Further movement of the shuttle unseats the small shuttle valve and opens communication between the emergency inlet and outlet. Pressure at the emergency outlet causes the piston to move thereby opening communication between the service inlet and outlet.
Inventors
- 👤 Boleslaw Klimek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:01
CPC Classifications
B; B60; B60T; B60T11/00; B60T11/10; B60T11/28; B60T11/32; B60T11/326; B60T15/00; B60T15/02; B60T15/36; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2544; Y10T137/2559; Y10T137/2564
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
237 words
A tractor protection valve including a housing having a first and second chamber, an emergency inlet and outlet and a first exhaust port in communication with said first chamber, a service inlet and outlet and a second exhaust port in communication with said second chamber and a passage in said housing opening communication between said emergency outlet and said second chamber; a shuttle in said first chamber between said emergency inlet and outlet including a second small shuttle valve therein, spring means urging said shuttle toward a first position and said small shuttle valve toward its closed position, closing communication between said emergency inlet and outlet, said emergency outlet being in open communication with said first exhaust port when said shuttle is in said first position; a piston in said second chamber and means yielding urging it toward a position in which a piston seal engaged thereon closes communication between said service inlet and outlet; fluid pressure entering said emergency inlet causing said shuttle to move initially toward a second position in which the small shuttle valve closes the first exhaust port and then toward a third position in which the small shuttle valve is forced open, completely opening communication between the emergency inlet and outlet; the resultant fluid pressure at the emergency outlet causing said piston to travel within said second chamber unseating said piston seal and thus opening communication between said service inlet and outlet.
Claim 2
Dependent Claim
237 words
A tractor protection valve including a housing having a first and second chamber, an emergency inlet and outlet and a first exhaust port in communication with said first chamber, a service inlet and outlet and a second exhaust port in communication with said second chamber and a passage in said housing opening communication between said emergency outlet and said second chamber; a shuttle in said first chamber between said emergency inlet and outlet including a second small shuttle valve therein, spring means urging said shuttle toward a first position and said small shuttle valve toward its closed position, closing communication between said emergency inlet and outlet, said emergency outlet being in open communication with said first exhaust port when said shuttle is in said first position; a piston in said second chamber and means yielding urging it toward a position in which a piston seal engaged thereon closes communication between said service inlet and outlet; fluid pressure entering said emergency inlet causing said shuttle to move initially toward a second position in which the small shuttle valve closes the first exhaust port and then toward a third position in which the small shuttle valve is forced open, completely opening communication between the emergency inlet and outlet; the resultant fluid pressure at the emergency outlet causing said piston to travel within said second chamber unseating said piston seal and thus opening communication between said service inlet and outlet.
Claim 3
Dependent Claim
43 words
The structure of claim 1 wherein the small shuttle valve consists of first and second valve heads connected to the ends of a short resilient stem which passes through an aperture in the shuttle having a greater cross-section area than the valve stem.
Claim 4
Dependent Claim
78 words
The structure of claim 2 wherein the first valve head is disposed on the emergency inlet side of the shuttle and is yieldingly urged to seal against a circumferencial area around said shuttle aperture, said second valve head being disposed on the emergency outlet and first exhaust port side of the shuttle and being yieldingly urged downward and away from the shuttle surface surrounding the aperture as far as permitted by the limited length of the valve stem.
Claim 5
Dependent Claim
62 words
The structure of claim 3 further characterized by and including seals on said first and second valve heads, the seal on the first valve head being positioned to seal against a circumferencial area around said shuttle aperture and the seal on the second valve head being positioned To seal against a circumferencial area of the second chamber around the first exhaust port.
Claim 6
Dependent Claim
122 words
The structure of claim 2 further characterized in that the entire shuttle unit which includes the small shuttle valve is disposed within the first chamber such that the application of fluid pressure at the emergency inlet causes the entire shuttle unit to move through the distance between said second valve head and first exhaust port opening, said second valve head closing communication between the first exhaust port and the emergency outlet and preventing further travel of the small shuttle valve; the fluid pressure causing the shuttle to move through an additional limited distance unseating the first valve head from the shuttle surface surrounding the shuttle aperture annd allowing said fluid pressure to be communicated through said shuttle aperture into said emergency outlet.
Claim 7
Dependent Claim
71 words
The structure of claim 1 further characterized in that said piston includes at least one seal engaging said second chamber between said passage to the emergency outlet and the service outlet to prevent communication therebetween at all positions of said piston; and at least one other seal engaging said second chamber between said second exhaust port and said service inlet, likewise to prevent communication therebetween in all positions of said piston.
Claim 8
Dependent Claim
142 words
The structure of claim 6 further characterized in that said piston includes a large surface which carries a seal engaging said second chamber between said passage to the emergency outlet and the service outlet, said surface and its seal being presented to fluid pressure entering said second chamber through the passage to the emergency outlet; and said piston seal positioned to close communication between the service inlet and outlet, as the piston is yieldingly urged toward one end of the chamber, said piston thus being moveably in response to fluid pressure entering said second chamber thereby unseating the piston seal and opening communication between the service inlet and outlet, the air trapped in the end of the second chamber toward which the piston moves being forced out through the second exhaust port allowing for motion of the piston within the second chamber.
Claim 9
Dependent Claim
24 words
The structure of claim 7 further characterized in that said piston seal is an annular member engaged in a circumferencial groove in said piston.
Claim 10
Dependent Claim
53 words
The structure of claim 8 further characterized in that said second chamber includes an enlarged portion between said service inlet and outlet of greater diameter than the remainder of the chamber, said piston seal adapted to travel within said portion being yieldingly urged against the inner annular end surface of said widened portion.
Claim 11
Dependent Claim
32 words
The structure of claim 1 further characterized by and including a spring which urges said piston toward a position in which said piston seal closes communication between said service inlet and outlet.
References Cited (Backward Citations)
US2850330A
Cited
US2859763A
Cited
US2979069A
Cited
US3109442A
Cited
US3240223A
Cited
US3304131A
Cited
US3413040A
Cited
US3510172A
Cited
US3653721A
Cited
US3654948A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |