US3566749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic flow amplifier valve
Assignee: Caterpillar Inc
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Filing: 1968-03-13
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Granted: 1971-03-02
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Expires: 1988-03-13
Abstract
Abstract A hydraulic flow amplifier valve assembly for regulating fluid flow to steering jacks. A steering control valve receives fluid directly from a pump and is pilot operated by fluid from a conventional metering unit to provide amplified flow of pump fluid to the jacks. A blocker valve passes fluid from the steering valve during steering motion of the jacks and otherwise isolates the jacks to prevent fluid loss. A lock valve protects against steering wheel slippage during overpressure conditions and also permits pilot fluid provided by the metering unit to operate the steering jacks in the event of pressure failure.
Inventors
- 👤 Thomas E Allen
- 👤 Gordon W Johnson
- 👤 Richard L M Sears
- 👤 Chester L Strantz
- 👤 John B Waggoner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:27
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/022; B; B62; B62D; B62D12/00; B62D5/00; B62D5/06; B62D5/061; B62D5/08; F15B11/00; F15B11/16; F15B11/161; F15B11/162; F15B13/04; F15B13/0416; F15B13/0417; F15B2211/00; F15B2211/30; F15B2211/305; F15B2211/30505; F15B2211/30525; F15B2211/3053; F15B2211/30535; F15B2211/3056; F15B2211/30565; F15B2211/32; F15B2211/329; F15B2211/50; F15B2211/57; F15B2211/60; F15B2211/605; F15B2211/6051; F15B2211/6054; F15B2211/6055; F15B2211/635; F15B2211/6355; F15B2211/70; F15B2211/71; F15B2211/7114; F15B2211/7128; F15B2211/75
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
304 words
A flow amplifier valve assembly for regulating fluid flow including a single pump providing a source of hydraulic fluid under pressure and hydraulic motor means operable in response to fluid metering means which are operable to deliver fluid from said source to said valve assembly at a rate proportional to a desired rate of operation for the motor means comprising: passage means connecting said source to said motor means, a control valve in said passage means for regulating fluid flow from said source to the motor means; lock valve means interconnected by conduit means between said metering means and the ends of said control valve; said lock valve including means to bias said lock valve to a first position preventing fluid communication between said metering means and said control valve and further including means connected to and responsive to fluid pressure from said source biasing said valve to a second position permitting fluid communication between said metering means and the ends of said control valve; said control valve including end face means responsive to fluid pressure from said metering means to regulate delivery of fluid from said source to said motor means at an amplified and proportional rate in relation to the delivery of fluid from the metering means to the control valve; pressure compensating valve means having a first pressure responsive portion in said passage means on the source side of said control valve and a second pressure responsive portion interconnected through shuttle valve means on the hydraulic motor side of said control valve to adjust fluid pressure at said control valve; and said lock valve means including bypass means for communicating fluid when said lock valve is in said first position from said metering means directly to said hydraulic motor in the event of pressure loss from said source of hydraulic fluid.
Claim 2
Dependent Claim
304 words
A flow amplifier valve assembly for regulating fluid flow including a single pump providing a source of hydraulic fluid under pressure and hydraulic motor means operable in response to fluid metering means which are operable to deliver fluid from said source to said valve assembly at a rate proportional to a desired rate of operation for the motor means comprising: passage means connecting said source to said motor means, a control valve in said passage means for regulating fluid flow from said source to the motor means; lock valve means interconnected by conduit means between said metering means and the ends of said control valve; said lock valve including means to bias said lock valve to a first position preventing fluid communication between said metering means and said control valve and further including means connected to and responsive to fluid pressure from said source biasing said valve to a second position permitting fluid communication between said metering means and the ends of said control valve; said control valve including end face means responsive to fluid pressure from said metering means to regulate delivery of fluid from said source to said motor means at an amplified and proportional rate in relation to the delivery of fluid from the metering means to the control valve; pressure compensating valve means having a first pressure responsive portion in said passage means on the source side of said control valve and a second pressure responsive portion interconnected through shuttle valve means on the hydraulic motor side of said control valve to adjust fluid pressure at said control valve; and said lock valve means including bypass means for communicating fluid when said lock valve is in said first position from said metering means directly to said hydraulic motor in the event of pressure loss from said source of hydraulic fluid.
Claim 3
Dependent Claim
32 words
The combination of claim 1 including variable bias means acting on said pressure compensating valve means, said variable bias means being selectively operable to vary the actuating ratio for the motor means.
Claim 4
Dependent Claim
17 words
The combination of claim 2 wherein the hydraulic motor means is the steering means of a vehicle.
Claim 5
Dependent Claim
52 words
The combination of claim 1 further comprising blocker means to normally block fluid communication from said control valve to the motor means and thus maintain the motor means in an established condition, said blocker means having means thereon responsive to said amplified flow to permit fluid passage for operating the motor means.
Claim 6
Dependent Claim
29 words
The combination of claim 4 wherein said blocker means includes relief means for communicating the motor to drain in response to overpressure above a preselected level in the motor.
Claim 7
Dependent Claim
50 words
The combination of claim 1 wherein said pressure compensating means permits variable bypass flow of excess inlet fluid to drain and includes spring means acting on the second pressure responsive portion of said pressure compensating means to limit bypass flow of fluid from the inlet across said pressure compensating means.
Claim 8
Dependent Claim
112 words
The combination of claim 6 wherein said motor means is a double acting hydraulic type including opposed jacks and wherein two chambers are provided between said control valve and said motor means, each chamber being in communication with opposite ends of the pair of jacks, said control valve communicating amplified fluid flow through one of said two chambers, said shuttle valve means being between said chambers and said pressure compensating means and being effective to selectively communicate both of the downstream chambers with said pressure compensating means so that fluid pressure in one of the downstream chambers is communicated to said pressure compensating means and is blocked from the other downstream chamber.
Claim 9
Dependent Claim
95 words
The combination of claim 7 wherein each downstream chambeR is associated with a separate end of the jack by means defining a separate fluid flow path, a slidable blocker spool normally blocking each downstream chamber from its respective flow path, said blocker spool including means responsive to pressure in either one of said downstream chambers to communicate said one downstream chamber to its associated flow path, said blocker spool also including means responsive to overpressure in either one of the flow paths to communicate the one flow path to drain through its associated downstream chamber.
Claim 10
Dependent Claim
42 words
The combination of claim 8 wherein said lock valve includes means responsive to excessive pressure in the flow amplifier valve assembly to block said flow amplifier valve assembly and said flow pass from the metering means in an additional lock valve position.
Claim 11
Dependent Claim
83 words
The combination of claim 6 wherein said control valve is a slidable spool having at least one axial notch and at least one land means for simultaneously and respectively controlling fluid flow from said metering means to drain and fluid from said inlet to the fluid motor, said control valve spool having centering spring means for regulating the pressure drop of flow across said notch, the pressure drop of fluid across said land means from said inlet being regulated by said compensating means.
Claim 12
Dependent Claim
44 words
The combination of claim 10 wherein solenoid means for selectively varying the actuating ratio for the flow amplifier valve assembly is included with said pressure compensating means, said solenoid means being operable to vary action of said spring means on said pressure compensating means.
Claim 13
Dependent Claim
35 words
The combination of claim 1 wherein said bypass means comprises means operable in an additional lock valve position to block excessive pressures in the flow amplifier valve assembly from communication back to the metering means.
Claim 14
Dependent Claim
42 words
The combination of claim 1 wherein the flow amplifier valve assembly further comprises means to block excessive pressures therein from communication back to the metering means and supplemental relief means for venting excessive fluid pressure arising in the flow amplifier valve assembly.
Claim 15
Dependent Claim
58 words
The combination of claim 1 further comprising limit means associated with the fluid motor means and operable to prevent operation of the motor means beyond selected limits by the flow amplifier valve assembly, said limit means being effective to block fluid flow from the metering means to the flow amplifier valve assembly while permitting reverse fluid flow therebetween.
References Cited (Backward Citations)
US2020951A
Cited
US2917125A
Cited
US2936037A
Cited
US3198088A
Cited
US3260325A
Cited
US3249173A
Cited
US3320745A
Cited
US3326317A
Cited
US3347041A
Cited
US3410306A
Cited
US3403512A
Cited
US3394545A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |