US3583422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve construction for controlled pressure buildup in fluid-operated brake or clutch
Assignee: ZF Friedrichshafen AG
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Filing: 1968-10-11
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Granted: 1971-06-08
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Expires: 1988-10-11
Abstract
Abstract A hydraulic valve with an inlet port for high-pressure fluid, an outlet port leading to a load such as a hydraulically operated clutch or brake, and a discharge port communicating with a lowpressure region or sump has a slider which, in response to the pressure of incoming fluid at the inlet port, initially establishes a connection between the inlet and outlet ports and, in response to fluid pressure building up in that connection, shifts into a regulating position in which the inlet port is partly cut off and/or the discharge port partly communicates with the outlet port to establish a balance between the inlet pressure and a counteracting pressure from a spring and/or a separate generator of variable fluid pressure. A branch conduit extends from the outlet port to a cylinder of a piston controlling the counteracting pressure, this conduit including a throttle resulting in a gradual or sudden increase of that pressure and, with it, of the load pressure as the piston moves progressively or instantaneously into an alternate position.
Inventors
- 👤 Hansjorg Dach
- 👤 Konrad Sterk
- 👤 Winfried Felder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:18
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/16; B60T13/18; F; F16; F16D; F16D25/00; F16D25/12; F16D25/14; F16D48/00; F16D48/02; F16H; F16H61/00; F16H61/04; F16H61/06; F16H61/061; F16H61/065; F16H61/08; F16D2048/0209; F16D2048/0221; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2574; Y10T137/2605; Y10T137/2607; Y10T137/7722; Y10T137/7781; Y10T137/7793; Y10T137/7797; Y10T137/7798
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
255 words
In a fluid-pressure-operated system for controlling a load, in combination: valve means comprising a housing with an inlet port connectable to a supply of high-pressure operating fluid, an outlet connected to the load and a discharge port terminating at a region of low pressure, said valve means having a starting position interconnecting said inlet port with said outlet to the exclusion of said discharge port, said valve means being provided with a land facing said inlet port for displacement by the supply pressure from said starting position into a regulation position wherein said valve means partly obstructs at least one of said ports for establishing in said outlet an operating pressure lower than said supply pressure; biasing means opposing such displacement of said valve means by said supply pressure for establishing said operating pressure at a level corresponding to the biasing force, said housing forming a cylinder open toward said valve means, said biasing means including a piston in said cylinder and resilient forcetransmitting means linking said piston with said valve means; throttled conduit means extending from said inlet port to a fluid space in said cylinder for progressively building up a pressure differential across said piston to Shift same from a normal position in a direction increasing said biasing force within a predetermined response period following connection of said inlet port to said supply, thereby sharply augmenting said operating pressure; and pressure-control means terminating at said cylinder for preventing the buildup of said pressure differential until said supply pressure has reached a substantial magnitude.
Claim 2
Dependent Claim
255 words
In a fluid-pressure-operated system for controlling a load, in combination: valve means comprising a housing with an inlet port connectable to a supply of high-pressure operating fluid, an outlet connected to the load and a discharge port terminating at a region of low pressure, said valve means having a starting position interconnecting said inlet port with said outlet to the exclusion of said discharge port, said valve means being provided with a land facing said inlet port for displacement by the supply pressure from said starting position into a regulation position wherein said valve means partly obstructs at least one of said ports for establishing in said outlet an operating pressure lower than said supply pressure; biasing means opposing such displacement of said valve means by said supply pressure for establishing said operating pressure at a level corresponding to the biasing force, said housing forming a cylinder open toward said valve means, said biasing means including a piston in said cylinder and resilient forcetransmitting means linking said piston with said valve means; throttled conduit means extending from said inlet port to a fluid space in said cylinder for progressively building up a pressure differential across said piston to Shift same from a normal position in a direction increasing said biasing force within a predetermined response period following connection of said inlet port to said supply, thereby sharply augmenting said operating pressure; and pressure-control means terminating at said cylinder for preventing the buildup of said pressure differential until said supply pressure has reached a substantial magnitude.
Claim 3
Dependent Claim
44 words
The combination defined in claim 1 wherein said pressure-control means comprises a venting channel leading from said fluid space to said region of low pressure, said venting channel being blockable by said valve means upon incipient displacement of the latter from said starting position.
Claim 4
Dependent Claim
28 words
The combination defined in claim 2 wherein said piston has an off-normal position isolating said venting channel from said region of low pressure independently of said valve means.
Claim 5
Dependent Claim
21 words
The combination defined in claim 1 wherein said conduit means is connected with said inlet port by way of said outlet.
Claim 6
Dependent Claim
30 words
The combination defined in claim 1 wherein said valve means comprises a slider coaxial with said piston, said force-transmitting including a compression spring interposed between said piston and said slider.
Claim 7
Dependent Claim
32 words
The combination defined in claim 5 wherein said cylinder is provided with an additional port communicating with a zone of reduced pressure, said piston separating said additional port from said conduit means.
Claim 8
Dependent Claim
34 words
The combination defined in claim 6 wherein said pressure control means includes a source of variable fluid pressure communicating with said additional port for opposing a shaft of said piston from its normal position.
Claim 9
Dependent Claim
35 words
The combination defined in claim 6 wherein said cylinder is provided with unidirectionally effective venting means for rapidly discharging pressure fluid therefrom into said conduit means upon disconnection of said inlet port from said supply.
Claim 10
Dependent Claim
14 words
The combination defined in claim 8 wherein said venting means comprises a check valve.
Claim 11
Dependent Claim
22 words
The combination defined in claim 9 wherein said check valve is provided with an orifice forming part of, said throttled conduit means.
Claim 12
Dependent Claim
48 words
The combination defined in claim 5 wherein said piston and said slider are provided with cooperating formations interengageable in an off-normal limiting position of said piston for shifting said slider toward said starting position to an extent sufficient to apply substantially the full supply pressure to said outlet.
Claim 13
Dependent Claim
55 words
The combination defined in claim 5 wherein said slider is provided with two spaced-apart heads on opposite sides of said inlet port, one of said heads being proximal to said piston, said housing forming a bore for said slider with an equalizing connection from said outlet to a location confronting the other of said heads.
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) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |