US3906980A - Direction control valve embodying a sleeve-like pressure equalizing valve element - Google Patents

Direction control valve embodying a sleeve-like pressure equalizing valve element Download PDF

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Publication number
US3906980A
US3906980A US457961A US45796174A US3906980A US 3906980 A US3906980 A US 3906980A US 457961 A US457961 A US 457961A US 45796174 A US45796174 A US 45796174A US 3906980 A US3906980 A US 3906980A
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United States
Prior art keywords
valve
fluid
bore
pressure
port
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US457961A
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English (en)
Inventor
Paul Edmund Hanser
William Lee Snyder
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deere and Co
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Deere and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Deere and Co filed Critical Deere and Co
Priority to US457961A priority Critical patent/US3906980A/en
Priority to CA204,456A priority patent/CA1025324A/en
Priority to JP50008583A priority patent/JPS5833433B2/ja
Priority to DE2513013A priority patent/DE2513013C3/de
Priority to SE7503580A priority patent/SE408816B/xx
Priority to FR7509612A priority patent/FR2266812B1/fr
Priority to AR258224A priority patent/AR209095A1/es
Priority to GB1397075A priority patent/GB1457492A/en
Application granted granted Critical
Publication of US3906980A publication Critical patent/US3906980A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0401—Valve members; Fluid interconnections therefor
    • F15B13/0402—Valve members; Fluid interconnections therefor for linearly sliding valves, e.g. spool valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/2496—Self-proportioning or correlating systems
    • Y10T137/2544—Supply and exhaust type
    • Y10T137/2554—Reversing or 4-way valve systems
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust
    • Y10T137/87193—Pilot-actuated

Definitions

  • ABSTRACT A directional control valve is provided for controlling the extension and retraction of a two-way hydraulic motor of the type including a piston rod having a piston secured to one end thereof and reciprocably received within. a cylinder.
  • the control valve includes a sleeve-like pressure-equalizing valve element having its opposite ends respectively subjected to system pressure and to the pressure at that port which is to be exhausted by actuation of the valve, the valve element being responsive to these pressures to prevent pressure oil from being transmitted to the cylinder at one side of the piston unless the pressure exhausting from the cylinder at the other side of the piston is at or below the system pressure.
  • the present invention relates to a direction control. valve for controlling the flow of fluid toandfrom the opposite work ports of a double-acting hydraulic moto'r. a
  • a novel direction control valve for controlling the flow of fluid to and from a two-way, extensible and retractable hydraulic motor.
  • a broad object of the invention is to provide a control valve which includes means for preventing the connection of system pressure to one end of such a hydrauv lic motor until the pressure at the other end of the cylinder is at or below system pressure.
  • a more specific object is to provide a direction control valve which includes a sleeve-like valve element having its opposite ends exposed to system pressure and the pressure at a first work port of the hydraulic motor when the control valve is being actuated tosupply system pressure to a second work port of the motor, the sleeve-like valve el ement being responsive to a pressure differential at its opposite ends to block the flow of fluid to the second work port of the motor when the pressure at the first work port is above the system pressure.
  • Still a more specific object is to provide a sleeve-like valve element as described abovewhich is shaped and mounted such that it cooperates with the valve bore to define means for dampening the movement of the sleevelike valve element caused by different pressures acting on the opposite ends thereof.
  • FIG. I is a mixed sectional and schematic view showing the control valve of the present invention in longitudinal cross section and schematically representing the connection of the control valve with a source of fluid pressure and a fluid motor.
  • FIG. 2 is a partial top plan view of the sealing ring carried by the pressure equalizing sleeve-like element.
  • FIG. 1 therein is shown a fluid system embodying a direction control valve constructed according to the principles of the present invention
  • the fluid system 10 includes a direction control valve 12'comprising a valve body 14 having a cavity in its upper portion which defines a: reservoir I6. Extending vertically in the valve body and having upper ends opening into the reservoir 16 are substantially identical right and left bores 18 and 20, respectively.
  • the bores 18 and 20 respectively include top, intermediate and bottom annular recesses 22 and 24,26 and 28 and'30 and 32, respectively.
  • the top annular recess 22 of the right bore and the intermediate annular recess 28 of the left bore are interconnected by a cross-passage 34, the annular recess 22 further being connected to an upper control port 36 which extends to the outer surface of the valve body 14.
  • the top annular recess 24 of the left bore 20 is connected to the intermediate recess 26 of the right bore 18 through means of a cross-passage 38, the intermediate recess 26 also being connected to' a lower control port 40 which extends to the outer surface of the valve body 14'.
  • the bottom annular recesses 30 and 32 of the right and left bores 18 and 20 are interconnected by a passage 42, the annular recess 18 also being connected to a pres sure inlet port shown schematically at 44.
  • the upper and lower control ports 36 and 40 are connected to first and second work ports 48 and 50 respectively located adjacent the opposite ends of a cylinder 52 forming a part of an extensible and retractable hydraulic motor 54.
  • a hydraulic pump 58 has' inlet and outlet ports respectively connected to a reservoir 60 and the pressure inlet port 44.
  • Respectively tightly fitted in end-to-end relationship in the right and left bores 18 and 20 are top sleeves 62 and 64, intermediate sleeves 66 and 68 and bottom sleeves 70 and 72, respectively.
  • the sleeves 62, 66 and 70 provided in the right bore 18 respectively have sets of ports 74, 76 and 78 which establish fluid communication between the interiors of the respective sleeves and the top intermediate and bottom annular recesses 22, 26 and 30, respectively.
  • top, intermediate and bottom sleeves 64, 68 and 72, respectively provided in the left bore 20 have respective sets of ports 80, 82 and 84 extending through the'walls thereof which establish fluid communication between the interiors thereof and the top, intermediate and bottom annular recesses 24, 28 and 32.
  • the right and left bores 18 and 20 and the respective sleeves located therein thus cooperate to define respective right and left valve bore means.
  • valve assemblies 86 and 88 respectively axially disposed in the right and left bores 18 and 20 are identical right and left valve assemblies 86 and 88, respectively. Since the valve assemblies 86 and 88 are identical, much of the detailed description of the "left valve assembly is omitted for the sakeof brevity. Resuming then with the description of the right valve assembly 86, it includes a valve stem 90 having a cylindrical portion disposed axially within the bore 18. Carried adjacent the lower end of the valve stem is a snap ring 92 which serves to prevent a retaining collar 94 from slipping off the bottom of the valve stem.
  • shims 96 Supported by the upper surface of the retaining collar 94 are a plurality of shims 96 which serve to time the opening and closing of valve elements carried by the valve stem in a manner to be described below.
  • Slidably mounted on the valve stem 90 above the shims 96 is a piston-like poppet valve element 98.
  • the valve element 98 is dimensioned for slidably engaging the inner wall surface of the bottom sleeve 70 and, for the purpose of preventing leakage across the valve ele ment 98, it is provided with an annular groove 100 in which is located a sealing ring 102 which is of a split type having a small gap 104 located between ends thereof.
  • valve element 98 Only that peripheral portion of the valve element 98 which is above the sealing ring is in sliding engagement with the bottom sleeve 70, and it is provided with an opening 106 leading to the annular groove 100.
  • the peripheral portion of the valve element 98 which is below the sealing ring 102 is spaced slightly from the inner wall, as indicated at 108, the radial space thus defined being less than the radial thickness of the sealing ring 102.
  • a restricted fluid passage is provided across the valve element 98 and is defined by the opening 106, the annular groove 100, the gap between the ends of the sealing ring 102 and the clearance space 108.
  • a load check valve element 116 Slidably mounted on the valve stem 90 at the opposite end of the opening 114 from the valve element 98 is a load check valve element 116 which has a downwardly facing conical seating surface 118 biased into engagement with the upper end of the opening 114 through means of a coil compression spring 119 compressed between the check valve element 116 and a seal arrangement fixed to the valve stem.
  • the seal arrangement 120 includes a resilient O-ring 122 which is loosely fitted about the valve stem 90 and located between upper and lower washer-like elements 124 and 126 which are respectively held in place by upper and lower collars 128 and 130, respectively, the collars in turn being held in place by upper and lower snap rings 132 and 134, respectively.
  • the outer surface defined by the seal arrangement is cylindrical and is spaced radially inwardly from the inner wall of the intermediate sleeve 66.
  • Mounted for reciprocation in the space thus defined between the seal arrangement and the intermediate sleeve 66 is a sleeve-like pressure equalizing valve element 136.
  • the inside diameter of the upper portion of the intermediate sleeve 66 is larger than the inside diameter of the lower portion of the sleeve and the valve element 126 has an enlarged upper end 138 sized for engaging the upper portion of the sleeve.
  • annular space 140 is present beneath the enlarged upper end 138 of the valve element. While not discernible from the drawing, the upper end 138 of the valve element 136 is dimensioned such that there is sufficient clearance between it and the inner wall of the sleeve 66 to permit the flow of fluid to and from the space 140.
  • the enlarged upper end 138 of the valve element 136 is provided with an annular groove in which is located a sealing ring 142 which is similar to the above-described sealing ring 102 in that it is split and has a gap between opposite ends thereof. The gap thus serves to meter fluid to and from the annular space 140 which expands and retracts during upward and downward movement of the pressure equalizing valve element 136.
  • a fluid tight seal means 144 is mounted in the sleeve 66 below the space 140 and engages the lower portion of the valve element 136.
  • the pressure equalizing valve element 136 is dimensioned such relative to the ports 76 of the intermediate sleeve 66 that when the pressure acting on the top end of thesleeve is greater than that acting upon the bottom end, the sleeve will shift downwardly and block the ports 76. It is to be noted that the respective effective areas of the top and bottom of the pressure equalizing valve element 136 which are exposed to fluid pressure are the same and that the valve element will shift downwardly only when pressure acting on the top thereof is greater than system pressure.
  • the valve element 146 includes an upwardly facing conical seating 148 disposed for engagement with a valve seat 150 defined by a shoulder at the open upper end of the top sleeve 62.
  • a coil compression spring 152 which acts between the lower end of the valve element 146 and the upper collar 128 of the seal arrangement 120. So that the poppet valve element 126 will be unseated by downward movement of the valve stem 90, a snap ring 154 is carried by the valve stem and is disposed for engaging the valve element 146.
  • valve stem 90 Downward shifting movement of the valve stem 90 is accomplished by imposing a pressure drop across the piston-like poppet valve element 98 which results in downward shifting movement of the valve element 98 and hence downward movement of the valve stem.
  • the valve stem 90 is provided with a central passage 156 having its lower end in fluid communication with the space beneath the valve element 98 and having cross ports 158, at its upper end, which extend through the outer surface of the valve stem 90.
  • a collar 160 which is shiftably mounted on the upper end of the valve stem 90 is held in blocking relationship to the cross ports 158 by means of a coil compression spring 161 which acts between a shoulder on the collar and a shoulder on an element 162 located below the collar and forming part of the valve stem. Leakage between the collar 160 and stem 90 is prevented by a poppet surface 163 formed on the upper portion of the stem which is normally seated against the top inner portion of the collar 160.
  • a control rod 164 which extends into the reservoir 16 and is rotatably mounted in the walls of the ilar to that of the operation of the right valve assembly 86, which operation is to be set forth below.
  • the speed that the piston and piston rod assembly 56 of the motor 54 will be moved during actuation is controlled by' controlling the downward displacement of the valve stem 90 to thus control the amount ofseparation of the respective seating surfaces 112 and 148 of the piston-like poppet valve element 98 and the poppet valve element 146 from their respective seats.
  • This control is accomplished through means of an axially adjustable stop 168 in the form of a special screw threaded in an end plug 170 which is in turn threaded in the bottom of the bottom sleeve 70.
  • the upper end of the stop 168 is provided with a conical surface 172 which-is disposed for moving closely adjacent to a conically shaped surface 176 forming the lower end of the central passage 156.
  • the conically shaped surface 176 is such that when the conical end 172 of the stop 168 is in close proximity thereto, flow between the conical end and the conical surface is restricted to such an ex tent that forces acting axially on the valve stem 90 are brought into equilibrium.
  • the left valve assembly 88 is similar to the right valve assembly 86 and controls the flow of pressure fluid to the first work port 48 of the motor 54, that the speed of flow of fluid to opposite ends of the motor 54 may be regulated so as to be at different speeds.
  • control valve 12 The operation of the control valve 12 is briefly summarized as follows. Assuming that the control valve 12 is in its neutral-condition, as illustrated in FIG. 1, the
  • the high pressure fluid supplied by the pump 58 flows through the piston-like poppet valve element 98 by way of the opening 106, the annular groove 100, the gap 104 between the ends of the sealing ring 102 and the clearance 108 between the valve element 98 and the wall of the bottom sleeve 70. It is here noted that the movement of the sealing ring 102 against the wall of the bottom sleeve will act to keep contaminants in the hydraulic fluid from accumulating in the gap. The flow of fluid across the piston-like poppet valve element 98 will immediately result in a pressure drop across the valve element which results in the latter being moved downwardly.
  • valve stem will move downwardly until the conical surface 116 at its lower end moves towards the upper end of the stop 168 until the flow between the stop and surface is restricted to such an extent that the axial forces acting on the stern become equalized. 1f the control rod 154 has been moved to some intermediate position commanding less than maximum flow to the motor 54, the stem 90 will shift downwardly until the poppet surface 163, adjacent the upper end thereof, restricts the flow occuring through the top of the collar to the extent that the axial forces acting on the stem 90 become balanced. Downward movement of the poppet valve element 98 will of course result in the same becoming un seated and will effect the unseating of the poppet valve element 146.
  • the opening of the poppet valve element 146 is timed relative to the opening of the piston-like poppet valve element 98 so as to open just after the valve element has opened. This timing is accomplished through means of the shims .96, the numbers of which can be increased or decreased so as to accomplish the timing desired.
  • the greater pressure acting on the top of the pressure equalizing valve element 136 will cause it to shift downwardly to block the ports 76 and thus acts to block the system pressure from the motor 54.
  • the poppet valve element 146 will be unseated to thus permit fluid to exhaust from the first work port 48 of the motor 54 to the reservoir 60.
  • the pressure equalizing valve element 136 will be returned to its upper, open position, as shown, to thus permit system pressure to once again enter the second work port 50 of the motor 54.
  • the movement of the pressure equalizing valve element 136 in either the upward or downward direction is damped due to the fact that the space 140 below the enlarged upper end 138 of the valve element is connected in fluid communication with the first work port 48 of the motor 54 by a restricted passage comprising the clearance space between the enlarged upper end 138 and the inside wall surface of the intermediate sleeve 66 and the end gap (not shown) between the opposite ends of the sealing ring 142.
  • Actuation of the motor 44 to cause it to retract is affected in a manner similar to that just described by actuating the left valve assembly 88 and for the sake of brevity no discussion is given of this operation. Suffice it to say that the maximum flow of fluid to whichever end of the motor that which is being pressurized is controlled through means of the adjustable stop 168 and the cor-responding stop of the left valve assembly 88 which stops limit the distance that the poppet valves may be separated from their seats.
  • a hydraulic direction control valve for controlling the flow of fluid to and away from an extensible and retractable hydraulic motor, comprising: a valve bore means; serially arranged first, second, third and fourth fluid passage means connected to said valve bore means at axially spaced locations and being respectively adapted for connection to a reservoir, to a first motor work port, to a second motor work port and to a source of fluid pressure; said bore means including first and second valve engageable surface means respectively located between the first and second passage means and between the third and fourth passage means; a valve stem axially shiftably mounted in said valve bore means and having first and second valve means mounted thereon for movement therewith between a neutral position wherein the first and second valve means are in sealing engagement with said first and second valve engageable surface means to respectively present the flow of fluid between the first and second passage means and between the third and fourth passage means, and an operative position wherein the first and second valve means are respectively unseated from the first and second valve engageable surface means for respectively establishing fluid communication between the first and second passage means and between the third and fourth passage means;

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Multiple-Way Valves (AREA)
  • Electrically Driven Valve-Operating Means (AREA)
  • Safety Valves (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Check Valves (AREA)
  • Measuring Fluid Pressure (AREA)
  • Sliding Valves (AREA)
  • Mechanically-Actuated Valves (AREA)
US457961A 1974-04-04 1974-04-04 Direction control valve embodying a sleeve-like pressure equalizing valve element Expired - Lifetime US3906980A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US457961A US3906980A (en) 1974-04-04 1974-04-04 Direction control valve embodying a sleeve-like pressure equalizing valve element
CA204,456A CA1025324A (en) 1974-04-04 1974-07-09 Direction control valve embodying a sleeve-like pressure equalizing valve element
JP50008583A JPS5833433B2 (ja) 1974-04-04 1975-01-20 エキアツホウコウセイギヨベン
DE2513013A DE2513013C3 (de) 1974-04-04 1975-03-25 Hydraulisches Wegeventil
SE7503580A SE408816B (sv) 1974-04-04 1975-03-26 Hydraulventil for reglering av tryckmedelsflodet till eller bort fran en dubbelverkande hydraulisk cylinder
FR7509612A FR2266812B1 (de) 1974-04-04 1975-03-27
AR258224A AR209095A1 (es) 1974-04-04 1975-04-02 Una valvula hidraulica de control de direccion
GB1397075A GB1457492A (en) 1974-04-04 1975-04-04 Hydraulic control vavle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US457961A US3906980A (en) 1974-04-04 1974-04-04 Direction control valve embodying a sleeve-like pressure equalizing valve element

Publications (1)

Publication Number Publication Date
US3906980A true US3906980A (en) 1975-09-23

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Application Number Title Priority Date Filing Date
US457961A Expired - Lifetime US3906980A (en) 1974-04-04 1974-04-04 Direction control valve embodying a sleeve-like pressure equalizing valve element

Country Status (8)

Country Link
US (1) US3906980A (de)
JP (1) JPS5833433B2 (de)
AR (1) AR209095A1 (de)
CA (1) CA1025324A (de)
DE (1) DE2513013C3 (de)
FR (1) FR2266812B1 (de)
GB (1) GB1457492A (de)
SE (1) SE408816B (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4096784A (en) * 1976-09-07 1978-06-27 Theodore Ongaro Hydraulic power system
US4878418A (en) * 1986-12-26 1989-11-07 Hiab Foco Ab Distributor for hydraulic cylinders
US5038670A (en) * 1990-04-09 1991-08-13 Dynamic Valves, Inc. Pneumatic control valve apparatus
US5799485A (en) * 1995-06-22 1998-09-01 Robert Bosch Gmbh Electrohydraulic control device for double-acting consumer
USRE38355E1 (en) * 1995-06-22 2003-12-23 Robert Bosch Gmbh Electrohydraulic control device for double-acting consumer
WO2003106872A1 (de) * 2002-06-12 2003-12-24 Fsp-Holding Ag Einschraubventil
CN103352887A (zh) * 2013-07-18 2013-10-16 武汉科技大学 一种单叶片水压自伺服转阀
US20170051841A1 (en) * 2014-05-01 2017-02-23 Eaton Corporation Manual override assembly
CN111473007A (zh) * 2020-04-26 2020-07-31 长江三峡通航管理局 船闸应急操作的输水阀门液压系统及应急关阀操作方法
CN113685387A (zh) * 2021-07-19 2021-11-23 北京天地玛珂电液控制系统有限公司 压力平衡式水基比例换向阀
CN114484062A (zh) * 2022-03-17 2022-05-13 浙江成达特种阀门厂 一种可避免误操作的四通球阀操作机构

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9512368D0 (en) * 1995-06-17 1995-08-16 Knorr Bremse Systeme Fluid pressure responsive governor valves
CN105042119A (zh) * 2015-06-26 2015-11-11 合肥工业大学 一种分片式手动多路换向阀

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3587640A (en) * 1969-11-13 1971-06-28 Deere & Co Directional control valve
US3631761A (en) * 1967-09-18 1972-01-04 Houdaille Industries Inc Hydraulic action devices with inertia insensitive snubbing circuit

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE905702C (de) * 1951-04-18 1954-03-04 Rotenburger Metallwerke Rudolf Steuervorrichtung fuer hydraulische Stellmotoren

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3631761A (en) * 1967-09-18 1972-01-04 Houdaille Industries Inc Hydraulic action devices with inertia insensitive snubbing circuit
US3587640A (en) * 1969-11-13 1971-06-28 Deere & Co Directional control valve

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4096784A (en) * 1976-09-07 1978-06-27 Theodore Ongaro Hydraulic power system
US4878418A (en) * 1986-12-26 1989-11-07 Hiab Foco Ab Distributor for hydraulic cylinders
US5038670A (en) * 1990-04-09 1991-08-13 Dynamic Valves, Inc. Pneumatic control valve apparatus
US5799485A (en) * 1995-06-22 1998-09-01 Robert Bosch Gmbh Electrohydraulic control device for double-acting consumer
USRE38355E1 (en) * 1995-06-22 2003-12-23 Robert Bosch Gmbh Electrohydraulic control device for double-acting consumer
WO2003106872A1 (de) * 2002-06-12 2003-12-24 Fsp-Holding Ag Einschraubventil
US20050139275A1 (en) * 2002-06-12 2005-06-30 Fsp-Holding Ag Screw-in valve
US7000891B2 (en) 2002-06-12 2006-02-21 Fsp-Holding Ag Screw-in valve
CN103352887A (zh) * 2013-07-18 2013-10-16 武汉科技大学 一种单叶片水压自伺服转阀
CN103352887B (zh) * 2013-07-18 2015-08-19 武汉科技大学 一种单叶片水压自伺服转阀
US20170051841A1 (en) * 2014-05-01 2017-02-23 Eaton Corporation Manual override assembly
US10371276B2 (en) * 2014-05-01 2019-08-06 Eaton Intelligent Power Limited Manual override assembly
US11441693B2 (en) 2014-05-01 2022-09-13 Danfoss Power Solutions Ii Technology A/S Manual override assembly
CN111473007A (zh) * 2020-04-26 2020-07-31 长江三峡通航管理局 船闸应急操作的输水阀门液压系统及应急关阀操作方法
CN113685387A (zh) * 2021-07-19 2021-11-23 北京天地玛珂电液控制系统有限公司 压力平衡式水基比例换向阀
CN113685387B (zh) * 2021-07-19 2023-10-27 北京天玛智控科技股份有限公司 压力平衡式水基比例换向阀
CN114484062A (zh) * 2022-03-17 2022-05-13 浙江成达特种阀门厂 一种可避免误操作的四通球阀操作机构
CN114484062B (zh) * 2022-03-17 2024-02-27 浙江成达特种阀门有限公司 一种可避免误操作的四通球阀操作机构

Also Published As

Publication number Publication date
DE2513013A1 (de) 1975-10-16
FR2266812A1 (de) 1975-10-31
JPS5833433B2 (ja) 1983-07-19
FR2266812B1 (de) 1977-04-15
AR209095A1 (es) 1977-03-31
GB1457492A (en) 1976-12-01
CA1025324A (en) 1978-01-31
DE2513013B2 (de) 1980-10-02
JPS50131127A (de) 1975-10-17
SE408816B (sv) 1979-07-09
DE2513013C3 (de) 1981-07-16
SE7503580L (sv) 1975-10-06

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