US3712340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic and air operated relay valve
Assignee: Bendix Westinghouse Automotive Air Brake Co
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Filing: 1971-03-19
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Granted: 1973-01-23
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Expires: 1991-03-19
Abstract
Abstract In a braking arrangement especially adapted for tractor-trailer vehicle brakes wherein the tractor includes hydraulically operated brakes and the trailer is equipped with compressed air operated brakes, the provision of a relay valve on the tractor for controlling the trailer brakes, the relay valve being selectively operable by hydraulic pressure when the tractor brakes are applied or by a separate source of compressed air carried by the tractor.
Inventors
- 👤 B Deem
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:27
CPC Classifications
F; F16; F16K; F16K17/00; B; B60; B60T; B60T13/00; B60T13/10; B60T13/58; B60T13/581; B60T15/00; B60T15/02; B60T15/18; B60T15/20; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86919
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
166 words
In a relay valve comprising a casing having an outlet port, an inlet port and a cavity, a pressure responsive member positioned in said cavity and dividing the latter into an outlet chamber and a control chamber, said outlet port being in constant communication with said outlet chamber, a normally closed valve for preventing communication between said inlet port and said outlet chamber while connecting the latter to the atmosphere, a spring acting on said pressure responsive member to normally move the latter in one direction so that said valve occupies its normally closed position, the improvement which comprises means for selectively moving said pressure responsive member in the opposite direction to operate said valve for closing communication between the outlet chamber and atmosphere and for opening communication between the outlet chamber and said inlet port, said last named means including a hydraulically operated piston, resilient graduating means operatively connecting said piston and pressure responsive member and means for admitting compressed air to said control chamber.
Claim 2
Dependent Claim
166 words
In a relay valve comprising a casing having an outlet port, an inlet port and a cavity, a pressure responsive member positioned in said cavity and dividing the latter into an outlet chamber and a control chamber, said outlet port being in constant communication with said outlet chamber, a normally closed valve for preventing communication between said inlet port and said outlet chamber while connecting the latter to the atmosphere, a spring acting on said pressure responsive member to normally move the latter in one direction so that said valve occupies its normally closed position, the improvement which comprises means for selectively moving said pressure responsive member in the opposite direction to operate said valve for closing communication between the outlet chamber and atmosphere and for opening communication between the outlet chamber and said inlet port, said last named means including a hydraulically operated piston, resilient graduating means operatively connecting said piston and pressure responsive member and means for admitting compressed air to said control chamber.
Claim 3
Dependent Claim
39 words
A relay valve as set forth in claim 1 which comprises in addition, a cylinder in which the hydraulic piston is mounted for reciprocal movement and a check valve for sealing communication between the control chamber and the cylinder.
Claim 4
Dependent Claim
28 words
A relay valve as set forth in claim 2 wherein the check valve and graduating means constitute a unitary member positioned between the piston and pressure responsive member.
Claim 5
Dependent Claim
31 words
A relay valve as set forth in claim 3 wherein the check valve is provided with a peripheral sealing lip in constant engagement with a peripheral seat formed in the casing.
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) | 1976-01-23 | 1976-07-24 | 1977-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-23 | 1980-07-24 | 1981-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-23 | 1984-07-24 | 1985-01-23 | $7700.00 | Window Closed / Lapsed |