US3805678A - Hydraulic control system for load supporting hydraulic motors - Google Patents

Hydraulic control system for load supporting hydraulic motors Download PDF

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Publication number
US3805678A
US3805678A US00244822A US24482272A US3805678A US 3805678 A US3805678 A US 3805678A US 00244822 A US00244822 A US 00244822A US 24482272 A US24482272 A US 24482272A US 3805678 A US3805678 A US 3805678A
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United States
Prior art keywords
valve
fluid
pilot
motor
control
Prior art date
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
US00244822A
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English (en)
Inventor
S Rhodes
D Bianchetta
K Lohbauer
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Caterpillar Inc
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Caterpillar Tractor 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 Caterpillar Tractor Co filed Critical Caterpillar Tractor Co
Priority to US00244822A priority Critical patent/US3805678A/en
Priority to CA168,016A priority patent/CA985600A/en
Priority to BE130015A priority patent/BE798216A/xx
Priority to FR7313764A priority patent/FR2180870B1/fr
Priority to US05/409,869 priority patent/US3943825A/en
Priority to US05437383 priority patent/US3906840A/en
Application granted granted Critical
Publication of US3805678A publication Critical patent/US3805678A/en
Priority to FR7501337A priority patent/FR2259264B2/fr
Priority to US05/574,229 priority patent/US4006667A/en
Priority to JP1980064558U priority patent/JPS55171703U/ja
Assigned to CATERPILLAR INC., A CORP. OF DE. reassignment CATERPILLAR INC., A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: CATERPILLAR TRACTOR CO., A CORP. OF CALIF.
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
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/003—Systems with load-holding valves
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20538—Type of pump constant capacity
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/3157—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line
    • F15B2211/31576—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source, an output member and a return line having a single pressure source and a single output member
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/86—Control during or prevention of abnormal conditions
    • F15B2211/8609—Control during or prevention of abnormal conditions the abnormal condition being cavitation
    • 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
    • Y10T137/87233—Biased exhaust valve
    • Y10T137/87241—Biased closed

Definitions

  • lt is also necessary to permit opening of the load check valve when it is necessary to lower the load inthe absence of fluid pressure in the system due to a stalled engine or a failure in the control circuit.
  • the Hein, et al system has this capability with a manually actuated control spool as depicted therein, such system would not be operative in a control system utilizing a pilot actuated control spool.
  • pilot actuated control systems when pilot pressure fails it is necessary to bypass the main control spool for returning fluid from the load supporting end of the motor to the reservoir, since pilot pressure will not be available for shifting the control spool to the load lowering position.
  • FIG. l there is schematically illustrated a fluid control system embodying the principles of the present invention, generally indicated by the reference numeral 1, operatively connected to control a load supporting fluid motor 2.
  • the motor includes a cylinder 3 having a piston 4 reciprocally mounted therein to define a i head end chamber 5 and a rod end chamber 6.
  • a rod 7 has its inner end secured to the piston and extends outwardly of the cylinder.
  • the head end of the motor is pivotally supported as indicated at 8 to a base or vehicle 9 with the outer end of the rod connected intermediate theends of a load supporting arm 10.
  • the control system includes a pump 12 which draws fluid from a reservoir 13 for supply through a line 14 to a pilot operated main control valve l5 which is selectively positionable between a neutral or hold position A and either one of two operative positionsl B and C.
  • the control valve 15 communicates with the reservoir 13 by way of a line 17 and a main return line 19.
  • the control valve further communicates with a load supporting or head end of the motor 2 by way of a line 20 and with an opposite or rod end of the motor by way of a line 2l.
  • a relief valve 23 selectively controls communication between the pump output line 14 and return line 19 to limit the maximum pressure in the control system.
  • a pilot control system indicated generally at 3l for operation of valve 15 includes a pump 32 which draws fluid from reservoir 13 for supply through a line 33 to a pilot control valve indicated generally at 34.
  • the pilot control valve communicates with the reservoir by way of a line 35 and further communicates with the opposite ends of the main control valve by way of the pilot lines 36 and 37.
  • control valves such as that schematically depicted at I5 are of the sliding spool type which necessarily include an annular clearance between the valve spool and the body to permit relatively free movement of the spool. This annular clearance permits leakage which is unacceptable in load supporting situations of this type, in that it permits downward drifting of the load as such leakage occurs.
  • a load check valve indicated generally at 42 is disposed in line 20 intermediate the head end of the mo'tor and the main control valve l5.
  • the load c home valve includes a body 43 having a port 44 which communicates with a valve bore 45.
  • the port 44 terminates at its inner end with a chamfered seat 46.
  • An annular groove 47 is interposed the inner ends of the port 44 and the bore 45 for communication therewith and communicates through a ⁇ passage 48 with a port 49.
  • the port44 is in communication with the main control valve l5, whereas port 49 communicates directly to the load supporting end of the motor 2.
  • the valve body 43 further includes a return port 57 and a valve bore 58 disposed in coaxial relation to the return port.
  • An annular groove 59 is formed in the body in encircling relation to the valve bore and is further disposed in communicating relation between the passage 47 and the port 49.
  • a threaded plug 60 threadably engages the outer end of the bore 58 and includes an inwardly facing recess 61. Since the motor 2 is subject to external forces acting thereon which may result in excessive pressure in the head end of the motor, a relief valve indicated generally at 62 is disposed in the body 43 between the load check valve 50 and the load supporting end of the motor.
  • the relief valve 62 includes a cartridge 63 having an inner end 64 threadably secured to the body.
  • the cartridge includes'a passage 65 communicating between the return port 57 and a valve bore 66 with the intersection therebetween being defined by a conical seat 67.
  • the valve bore 66 terminates at the opposite end of the cartridge with a counterbore 68, which is cornmunicated by an orifice 69 with the annular groove 59 by way of an annular relief 70 in the bore 58.
  • a relief dump spool 7l is slidably mounted in bore 66 and includes a seating end 72 for selective sealing engagement with seat 67.
  • An outer biasing end of the spool 71 forms, with the recess 61 in the plug, a control chamber 75.
  • a spring 76 is disposed in the control chamber in biasing relation to the biasing end 74 of the spool to urge the spool into sealing contact with the seat 67 normally to block communication between the return port and the annular groove 59.
  • the seating end 72 of the spool 71 is of relatively smaller diameter than the body of the spool, thus forming a shoulder 78 exposed to fluid pressure in the annular groove 59.
  • the spool 71 further includes a central chamber 79 which communicates through a passage 80 with the control chamber 75.
  • the chamber 79 also communicates through a passage 8l with the return port 57 by way ofthe passage 65.
  • the passages 80 and 8l are relatively larger than the orifice 69 so that fluid flow therethrough will result in a differential pressure across the orifice.
  • a spring biased poppet 83 is disposed in the chamber 79 and is urged into closing relation with the passage 80 normally to block communication between the chamber and the return port.
  • avent line 89 provides'communication between the control chamber 54 and a normally closed vent valve
  • An anti-cavitation valve 94 is disposed in fluid communication controlling relation between the motor line and the return line 19.
  • a line 95 communicates between the valve 94 and the motor line 20 with a line 96 communicating between the anti-cavitaton valve and the return line.
  • the anti-cavitation valve includes a body 97 with means defining an outlet port 98 and an inlet port 99 which are interconnected by an annular groove 100.
  • the valve body further defines a valve bore 102 coaxially aligned with port 99 and separated therefrom by the annular groove.
  • the valve bore has an open outer end which is closed by a threaded plug 103 which includes a vent port 104.
  • a check valve member 106 is reciprocally disposed in the valve bore and includes a body portion 107 and a valving portion 108 of relatively smaller diameter which is adapted to seat in the end of an inlet port 99.
  • the check valve, plug 103, and valve bore 102 cooperate to define a control chamber 109 opposite the valving portion 108.
  • An orifce 110 in the check valve p rovides restricted communication between the groove 100 and the control chamber.
  • a spring 111 is disposed in the control chamber in biasing relation to the check valve to urge it into sealing engagement with the inner end of the inlet port to block communication between the inlet port and the outlet port.
  • Control chamber 109 is communicated through a line 112, a line 113, a line 114, and return line 35 to reservoir 13.
  • a manually actuated normally closed valve 116 is disposed in the line 112 and may be selectively opened to vent the control chamber to the reservoir.
  • the line 89 communicating with control Chamber 54 of valve 42 is communicable with the reservoir 13 by way of a line 117 and lines 113, 114 and 35.
  • a manually controlled normally closed valve 119 is disposed in the line 117 for selectively controlling communication between ccntrol chamber 54 and the reservoir.
  • the safety valve When it is desired to disable the pilot system, such as when the operator is dismounting the machine, the safety valve is actuated to a position H. This is effective to establish communication between the lines 122 and 123 to vent the relief valve and permit it to open at a relatively low pressure and direct the output of pump 32 to the reservoir by way of the line 40. The pressure required to open the relief valve under these conditions is not sufficient to actuate the valve element of main control valve 15 and the pilot system is rendered inoperative. Inadvertent operation of the motor 2 and resultant movement of load l1 is thus prevented.
  • line 113 communicates with safety valve 121 such that the safety valve controls communication between the lines 113 and 114.
  • safety valve 121 When the safety valve 121 is in the position shown, the line 113 is communicated to the line 114 whereas movement of the safety valve to position I-I blocks communication between the lines.
  • Line 114 is further connected to pilot valve 34 and is blocked from communication with return line 35 and the reservoir when the pilot valve is in the neutral D position shown.
  • FIG. 2 Identical elements in the FIG. 2 embodiment are identified by the same reference numerals, as in the previous embodiment.
  • a comparison of the embodiments of FIG. 1 and FIG. 2 will disclose that the pilot supply line 33 (FIG. 1) is now controlled by new safety valve 125 (FIG. 2) and becomes new supply lines 126 and 127.
  • the safety valve 125 operates in the G position to provide communication of pilot fluid by way of lines 126 and 127 to the pilot control valve 34. Communication is also established between lines 113 and 114 in this position (G) as in the previous embodiment.
  • the structure of the present invention provides an improved fluid control system for load supporting fluid motors having positive leakage control. This is accomplished while still retaining safe functional control of the load under both operative and inoperative conditions of the control circuit. This functional desiderata is further achieved with a minimum of cost and without undue complication of the relatively large main control valve.
  • a load supporting fluid system comprising: load supporting means including a fluid motor for raising and supporting a load, said motor having a load supporting end including a fluid chamber; a source of pressurized fluid for operating said motor;
  • means including a pilot operated directional control valvefor selectively communicating pressurized fluid between said source and motor for raising, lowering and positioning said load support means;
  • check valve means having a control chamber including restriction means communicating with said load supporting chamber, and said check valve means being responsive to fluid pressure in said 2.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
US00244822A 1972-04-17 1972-04-17 Hydraulic control system for load supporting hydraulic motors Expired - Lifetime US3805678A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
US00244822A US3805678A (en) 1972-04-17 1972-04-17 Hydraulic control system for load supporting hydraulic motors
CA168,016A CA985600A (en) 1972-04-17 1973-04-05 Hydraulic control system for load supporting hydraulic motors
BE130015A BE798216A (fr) 1972-04-17 1973-04-13 Systeme de commande hydraulique pour moteurs hydrauliques soutenant une charge
FR7313764A FR2180870B1 (enrdf_load_stackoverflow) 1972-04-17 1973-04-16
US05/409,869 US3943825A (en) 1972-04-17 1973-10-26 Hydraulic control system for load supporting hydraulic motors
US05437383 US3906840A (en) 1972-04-17 1974-01-28 Hydraulic control system for load supporting hydraulic motors
FR7501337A FR2259264B2 (enrdf_load_stackoverflow) 1972-04-17 1975-01-16
US05/574,229 US4006667A (en) 1972-04-17 1975-05-02 Hydraulic control system for load supporting hydraulic motors
JP1980064558U JPS55171703U (enrdf_load_stackoverflow) 1972-04-17 1980-05-13

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00244822A US3805678A (en) 1972-04-17 1972-04-17 Hydraulic control system for load supporting hydraulic motors

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US05/409,869 Division US3943825A (en) 1972-04-17 1973-10-26 Hydraulic control system for load supporting hydraulic motors
US05437383 Continuation-In-Part US3906840A (en) 1972-04-17 1974-01-28 Hydraulic control system for load supporting hydraulic motors

Publications (1)

Publication Number Publication Date
US3805678A true US3805678A (en) 1974-04-23

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Family Applications (1)

Application Number Title Priority Date Filing Date
US00244822A Expired - Lifetime US3805678A (en) 1972-04-17 1972-04-17 Hydraulic control system for load supporting hydraulic motors

Country Status (5)

Country Link
US (1) US3805678A (enrdf_load_stackoverflow)
JP (1) JPS55171703U (enrdf_load_stackoverflow)
BE (1) BE798216A (enrdf_load_stackoverflow)
CA (1) CA985600A (enrdf_load_stackoverflow)
FR (1) FR2180870B1 (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3960059A (en) * 1974-12-09 1976-06-01 Caterpillar Tractor Co. Fast exhaust circuit for hydraulic jacks
DE2624272A1 (de) * 1975-05-29 1976-12-09 Bennes Marrel Sa Anordnung bei einem hydraulisch betaetigbaren 5/3-wegeventil in schieberbauart
FR2312676A1 (fr) * 1975-05-27 1976-12-24 Caterpillar Tractor Co Systeme d'elevation de charge hydraulique
US4148248A (en) * 1975-03-11 1979-04-10 Maxton Manufacturing Company Hydraulic valve control system
WO1982002229A1 (en) * 1980-12-19 1982-07-08 Melocik Kurt B Control for dead engine lower
US4392415A (en) * 1980-12-19 1983-07-12 Caterpillar Tractor Co. Control for dead engine lower
US4955283A (en) * 1988-03-03 1990-09-11 Kabushiki Kaisha Kobe Seiko Sho Hydraulic circuit for cylinder
US5251705A (en) * 1992-03-19 1993-10-12 Deere & Company Electrical trigger for quick drop valve
US8925439B2 (en) 2011-01-13 2015-01-06 Husco International, Inc. Valve control valve circuit for operating a single acting hydraulic cylinder
US20180087479A1 (en) * 2016-09-27 2018-03-29 Caterpillar Inc. Protection device for limiting pump cavitation in common rail system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE419021B (sv) * 1979-02-22 1981-07-06 Ellemtel Utvecklings Ab Festanordning elektrisk komponent med tva cylindriska i forhallande till varandra vridbara delar

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Publication number Priority date Publication date Assignee Title
US2373167A (en) * 1943-03-31 1945-04-10 Western Electric Co Extrusion apparatus
US2618121A (en) * 1949-11-07 1952-11-18 Hpm Dev Corp Locking control circuit for fluid-actuated motors
US2750743A (en) * 1952-03-12 1956-06-19 Bosch Gmbh Robert Control devices for hydraulic motors
US3068596A (en) * 1961-11-24 1962-12-18 Caterpillar Tractor Co Hydraulic circuit for actuation of an earthmoving scraper bowl
US3272085A (en) * 1963-11-19 1966-09-13 Parker Hannifin Corp Fluid system and valve assembly therefor
US3433131A (en) * 1967-08-22 1969-03-18 Ingebret Soyland Control systems for hydraulic power units
US3620129A (en) * 1970-07-15 1971-11-16 Gen Signal Corp Hydraulic power circuit with emergency lowering provisions

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR995278A (fr) * 1948-09-17 1951-11-29 Ford Mécanisme de commande pour instruments agricoles et instruments agricoles munis de ce mécanisme
GB1185261A (en) * 1968-01-12 1970-03-25 Pkm Hydraulik Karl Marx Stadt Hydraulic Control Means for an Assembling and Welding Apparatus
FR2032054A5 (en) * 1969-02-17 1970-11-20 Ind Werke K Marx Hydraulic control device for forge rolling - mills

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2373167A (en) * 1943-03-31 1945-04-10 Western Electric Co Extrusion apparatus
US2618121A (en) * 1949-11-07 1952-11-18 Hpm Dev Corp Locking control circuit for fluid-actuated motors
US2750743A (en) * 1952-03-12 1956-06-19 Bosch Gmbh Robert Control devices for hydraulic motors
US3068596A (en) * 1961-11-24 1962-12-18 Caterpillar Tractor Co Hydraulic circuit for actuation of an earthmoving scraper bowl
US3272085A (en) * 1963-11-19 1966-09-13 Parker Hannifin Corp Fluid system and valve assembly therefor
US3433131A (en) * 1967-08-22 1969-03-18 Ingebret Soyland Control systems for hydraulic power units
US3620129A (en) * 1970-07-15 1971-11-16 Gen Signal Corp Hydraulic power circuit with emergency lowering provisions

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3960059A (en) * 1974-12-09 1976-06-01 Caterpillar Tractor Co. Fast exhaust circuit for hydraulic jacks
US4148248A (en) * 1975-03-11 1979-04-10 Maxton Manufacturing Company Hydraulic valve control system
FR2312676A1 (fr) * 1975-05-27 1976-12-24 Caterpillar Tractor Co Systeme d'elevation de charge hydraulique
US4000683A (en) * 1975-05-27 1977-01-04 Caterpillar Tractor Co. Hydraulic load lifting system
DE2624272A1 (de) * 1975-05-29 1976-12-09 Bennes Marrel Sa Anordnung bei einem hydraulisch betaetigbaren 5/3-wegeventil in schieberbauart
US4093002A (en) * 1975-05-29 1978-06-06 Bennes Marrel Control device of a large hydraulic distributor, in particular for public works appliances
WO1982002229A1 (en) * 1980-12-19 1982-07-08 Melocik Kurt B Control for dead engine lower
US4392415A (en) * 1980-12-19 1983-07-12 Caterpillar Tractor Co. Control for dead engine lower
US4955283A (en) * 1988-03-03 1990-09-11 Kabushiki Kaisha Kobe Seiko Sho Hydraulic circuit for cylinder
US5251705A (en) * 1992-03-19 1993-10-12 Deere & Company Electrical trigger for quick drop valve
US8925439B2 (en) 2011-01-13 2015-01-06 Husco International, Inc. Valve control valve circuit for operating a single acting hydraulic cylinder
US20180087479A1 (en) * 2016-09-27 2018-03-29 Caterpillar Inc. Protection device for limiting pump cavitation in common rail system
US10378500B2 (en) * 2016-09-27 2019-08-13 Caterpillar Inc. Protection device for limiting pump cavitation in common rail system

Also Published As

Publication number Publication date
JPS55171703U (enrdf_load_stackoverflow) 1980-12-09
FR2180870B1 (enrdf_load_stackoverflow) 1978-12-01
FR2180870A1 (enrdf_load_stackoverflow) 1973-11-30
CA985600A (en) 1976-03-16
BE798216A (fr) 1973-10-15

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Owner name: CATERPILLAR INC., 100 N.E. ADAMS STREET, PEORIA, I

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CATERPILLAR TRACTOR CO., A CORP. OF CALIF.;REEL/FRAME:004669/0905

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Effective date: 19860515