US4864822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control device for a hydrostatic drive for at least two actuators
Assignee: Hydromatik GmbH
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Filing: 1988-01-22
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Granted: 1989-09-12
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Expires: 2008-01-22
Abstract
Abstract A control device for a hydrostatic drive for at least two actuators having a variable displacement pump whose adjusting device can be acted on as a function of the displacement and/or of the delivery pressure, wherein a control valve is associated with each actuator in its hydraulic supply line and the delivery flow for each actuator is determined by means of a pressure compensator as a function of the valve preset at the control valve, is simplified while ensuring accurate control. This is achieved by having the adjusting device always set the pump at a displacement which is slightly less than the sum of the actual instantaneous volume flows required by the actuators.
Inventors
- 👤 Ewald Wachs
- 👤 Ludwig Wagenseil
- 👤 Wolfgang Reistle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:05
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/20; E02F9/22; E02F9/2221; E02F9/2225; E02F9/2228; F; F04; F04B; F04B49/00; F04B49/08; F15; F15B; F15B21/00; F15B21/08; G; G05; G05D; G05D16/00; G05D16/20; G05D16/2093; G05D16/2097; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0688
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A control device for a hydrostatic drive for at least two actuators having a variable displacement pump whose adjusting device can be acted on as a function of the displacement or of the delivery pressure, a control valve being associated with each actuator in a hydraulic supply line thereof, pressure compensators for determining the delivery flow for each said actuator as a function of a value preset at the control valve, said pressure compensators being connected in parallel such that the same operating pressure acts thereon, the adjustment device always setting the pump at the displacement which is less than the sum of the actual instantaneous volume flow required by the actuators.
Claim 2
Dependent Claim
112 words
A control device for a hydrostatic drive for at least two actuators having a variable displacement pump whose adjusting device can be acted on as a function of the displacement or of the delivery pressure, a control valve being associated with each actuator in a hydraulic supply line thereof, pressure compensators for determining the delivery flow for each said actuator as a function of a value preset at the control valve, said pressure compensators being connected in parallel such that the same operating pressure acts thereon, the adjustment device always setting the pump at the displacement which is less than the sum of the actual instantaneous volume flow required by the actuators.
Claim 3
Dependent Claim
33 words
A control device according to claim 1, wherein the adjustment device has an adjustment member operating associated therewith and which is controlled as a function of the setting of the control control valves.
Claim 4
Dependent Claim
16 words
A control device according to claim 2, wherein the adjusting member is an electro-hydraulic proportional valve.
Claim 5
Dependent Claim
23 words
A control device according to claim 2, wherein an electronic control device is operatively connected with the control valves and the adjusting member.
Claim 6
Dependent Claim
15 words
A control device according to claim 1, wherein the control valves are electromagnetic proportional valves.
Claim 7
Dependent Claim
20 words
A control device according to claim 1, wherein the control valves are pilot valves acted on by an auxiliary pressure.
Claim 8
Dependent Claim
37 words
A control device according to claim 1, said pump being driven by an internal combustion engine, wherein the maximum load control of the drive is included in the control device as an output control of the drive.
References Cited (Backward Citations)
DE1801137A1
Cited
US3579987A
Cited
US3914939A
Cited
WO1981000742A1
Cited
US4642984A
Cited
US4759183A
Cited
US4712376A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |