Patent US3583285A successfully refreshed from Google Patents.
US3583285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure responsive direction control valve
Assignee: Deere and Co
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Filing: 1969-07-17
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Granted: 1971-06-08
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Expires: 1989-07-17
Abstract
Abstract A hydraulic control system for a remote, double-acting piston motor in which a normally hydraulically balanced, springcentered, spool-type direction control valve is shifted from the centered position in which the opposite work ports of the motor are simultaneously pressurized to first and second positions in which fluid under pressure is selectively admitted to one or the other ends of the motor while the opposite end is exhausted. The opposite ends of the direction control valve are connected to the inlet pressures of a respective one of a pair of variable flow resistance valves and the control valve is shifted from the centered position to a selected one of the other positions by changing the resistance, hence the inlet pressure, of one of the flow valves and the control valve is returned to the centered position as a result of a feedback from the motor which shifts the other flow resistance valve until the forces on the opposite ends of the control valve are again equal.
Inventors
- 👤 Bruce Leland Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:52
CPC Classifications
F; F15; F15B; F15B9/00; F15B9/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
303 words
A hydraulic system comprising: a control conduit means including variable flow resistance means for establishing control pressures at first and second series connected locations, a valve bore means, conduit means for connecting a source of fluid under pressure to said control conduit means upstream from said first location and to said valve bore means, return fluid passage means intersecting said valve bore means, a reversible hydraulic motor having a pair of work passages connected to said valve bore means, a control valve means axially shiftable in said valve bore means between a neutral position wherein fluid is blocked to the work passages of the hydraulic motor and active positions wherein one or the other of the work passages is connected to fluid pressure while the opposite work passage is connected to the return passage means, bias means normally holding said control valve means in said neutral position, said control valve means including means for sensing the control pressures at said first and second locations and for directing forces represented by the pressures in opposite axial directions, means for adjusting said variable flow resistance means to a preselected position for causing a ratio of control pressures which will result in equal and opposite forces being applied to said control valve whereby said bias means will hold said control valve in said neutral position, said flow resistance means being adapted for connection to an input signal for disturbing the preselected ratio of control pressures so that the control valve means will shift to one of said active positions to cause actuation of said hydraulic motor, and feedback means interconnecting the output of said motor with said flow resistance means for adjusting the latter for reestablishing the preselected control pressure ratio whereby the bias means will again return the control valve means to its neutral position.
Claim 2
Dependent Claim
303 words
A hydraulic system comprising: a control conduit means including variable flow resistance means for establishing control pressures at first and second series connected locations, a valve bore means, conduit means for connecting a source of fluid under pressure to said control conduit means upstream from said first location and to said valve bore means, return fluid passage means intersecting said valve bore means, a reversible hydraulic motor having a pair of work passages connected to said valve bore means, a control valve means axially shiftable in said valve bore means between a neutral position wherein fluid is blocked to the work passages of the hydraulic motor and active positions wherein one or the other of the work passages is connected to fluid pressure while the opposite work passage is connected to the return passage means, bias means normally holding said control valve means in said neutral position, said control valve means including means for sensing the control pressures at said first and second locations and for directing forces represented by the pressures in opposite axial directions, means for adjusting said variable flow resistance means to a preselected position for causing a ratio of control pressures which will result in equal and opposite forces being applied to said control valve whereby said bias means will hold said control valve in said neutral position, said flow resistance means being adapted for connection to an input signal for disturbing the preselected ratio of control pressures so that the control valve means will shift to one of said active positions to cause actuation of said hydraulic motor, and feedback means interconnecting the output of said motor with said flow resistance means for adjusting the latter for reestablishing the preselected control pressure ratio whereby the bias means will again return the control valve means to its neutral position.
Claim 3
Dependent Claim
131 words
The invention defined in claim 1 wherein the variable flow resistance means comprises first and second valve bores respectively at said first and second series connected locations, each of said valve bores having an inlet and an outlet, the series connection between the locations being between the outlet of the firsT bore and the inlet of the second bore, first and second pistons being of lesser diameters than said first and second bores, respectively, and being positioned for axial movement in at least the portions of the bores between the respective inlets and outlets for causing a variable pressure drop between the respective inlets and outlets, and one of said pistons being adapted for connection to said input signal and the other of said pistons being connected to said feedback means.
Claim 4
Dependent Claim
36 words
The invention defined in claim 1, said control conduit means further including adjustable means for bypassing selected amounts of fluid around said first and second locations for aiding in establishing said preselected ratio of pressure drops.
Claim 5
Dependent Claim
36 words
The invention defined in claim 2, said control conduit means further including adjustable means for bypassing selected amounts of fluid around said first and second pistons for aiding in establishing said preselected ratio of pressure drops.
Claim 6
Dependent Claim
17 words
The invention defined in claim 1 wherein the means for sensing the pressure drops includes piston means.
Claim 7
Dependent Claim
101 words
The invention defined in claim 5 wherein the valve bore means includes first and second portions, the first portion being of a smaller diameter than the second, said piston means comprising first and second pistons positioned respectively in and being of diameter sufficient to span said first and second bore portions, said control conduit means connecting the inlet of said first bore to one side of the smaller piston for exerting a force in one axial direction and connecting the inlet of said second bore to one side of the larger piston for exerting a force in the other axial direction.
Claim 8
Dependent Claim
293 words
A hydraulic system comprising: a valve bore, supply and return conduit means intersecting said valve bore, a reversible hydraulic motor having a pair of work passages, a pressure responsive control valve means positioned in said valve bore for axial shifting movement from a normally maintained neutral position wherein said work passages of the motor are blocked to either of two active positions wherein said supply conduit means is connected with one or the other of said work passages of said motor while simultaneously interconnecting the opposite work passage with said return conduit means, bias means tending to maintain said control valve means in said neutral position, control conduit means being adapted for connection to a source of fluid under pressure and including first and second series connected flow resistance valve means, each having an inlet connected to said control valve means so as to normally apply equal and opposite acting forces on the control valve whereby said bias means maintains said control valve means in said first position, one of said flow resistance valve means being adapted for connection to and being responsive to an input signal for selectively causing changes in pressure at its inlet for causing an unbalance of said oppositely acting forces on said control valve thereby causing the control valve to shift axially to one of said active positions for operating said hydraulic motor and a feedback means interconnecting the output of said hydraulic motor and the other of said flow resistance valve means for causing adjustment of said other flow resistance valve means for creating a pressure at its inlet for again producing an equal and opposite force on said control valve means whereby the bias means will again restore said control valve means to said neutral position.
Claim 9
Dependent Claim
293 words
A hydraulic system comprising: a valve bore, supply and return conduit means intersecting said valve bore, a reversible hydraulic motor having a pair of work passages, a pressure responsive control valve means positioned in said valve bore for axial shifting movement from a normally maintained neutral position wherein said work passages of the motor are blocked to either of two active positions wherein said supply conduit means is connected with one or the other of said work passages of said motor while simultaneously interconnecting the opposite work passage with said return conduit means, bias means tending to maintain said control valve means in said neutral position, control conduit means being adapted for connection to a source of fluid under pressure and including first and second series connected flow resistance valve means, each having an inlet connected to said control valve means so as to normally apply equal and opposite acting forces on the control valve whereby said bias means maintains said control valve means in said first position, one of said flow resistance valve means being adapted for connection to and being responsive to an input signal for selectively causing changes in pressure at its inlet for causing an unbalance of said oppositely acting forces on said control valve thereby causing the control valve to shift axially to one of said active positions for operating said hydraulic motor and a feedback means interconnecting the output of said hydraulic motor and the other of said flow resistance valve means for causing adjustment of said other flow resistance valve means for creating a pressure at its inlet for again producing an equal and opposite force on said control valve means whereby the bias means will again restore said control valve means to said neutral position.
Claim 10
Dependent Claim
177 words
The invention defined in claim 7 wherein said flow resistance valve means includes first and second bores each being intersected by an inlet and an outlet port, conduit means interconnecting the outlet port of said first bore with the inlet port of said second bore, said control valve means including pistons at its opposite ends, said control conduit means further including first and second conduits respectively interconnecting the inlet ports of said first and second bores with one of the opposed faces of said pistons, sAid pair of flow resistance valve means each being positioned in a respective one of said bores and including an axially shiftable piston portion of lesser diameter than the bore bridging the outlet port and having one end positioned between the inlet and outlet ports and a fluidtight seal annularly disposed about the other end and means for connecting the piston portion of one of said flow resistance valves to said input signal means and said feedback means being connected to the piston portion of the other of said flow resistance valves.
Claim 11
Dependent Claim
76 words
The invention defined in claim 8 and further including a normally closed adjustable restrictor valve interconnecting said first and second conduits, and said conduit means connecting the outlet port of said first bore with the inlet port of said second bore also including an adjustable normally closed restrictor valve joining the conduit means with the sump, whereby said restrictor valves may be opened to bypass fluid for adjusting the pressure in the first and second conduits.
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 |