US3908515A - Hydraulic circuit with selectively actuatable float control - Google Patents

Hydraulic circuit with selectively actuatable float control Download PDF

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Publication number
US3908515A
US3908515A US395647A US39564773A US3908515A US 3908515 A US3908515 A US 3908515A US 395647 A US395647 A US 395647A US 39564773 A US39564773 A US 39564773A US 3908515 A US3908515 A US 3908515A
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motor
valve
control valve
fluid
valve means
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US395647A
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Howard L Johnson
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Caterpillar Inc
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Caterpillar Tractor Co
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Priority to US395647A priority Critical patent/US3908515A/en
Priority to JP2728974A priority patent/JPS5535563B2/ja
Priority to CA204,191A priority patent/CA1025326A/en
Priority to ZA00744408A priority patent/ZA744408B/en
Priority to AU71750/74A priority patent/AU482064B2/en
Priority to BR6750/74A priority patent/BR7406750D0/en
Priority to BE148361A priority patent/BE819721A/en
Application granted granted Critical
Publication of US3908515A publication Critical patent/US3908515A/en
Priority to BE164820A priority patent/BE839147R/en
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.
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    • 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
    • F15B13/01—Locking-valves or other detent i.e. load-holding devices

Definitions

  • the present invention relates to hydraulic circuits and pertains particularly to a circuit having a lock valve selectively actuatablc to provide a floating-condition for a hydraulicjack.
  • FIG. 1 is a schematic layout of a Circuit in accordance with the present invention.
  • FIG. 2 is a schematic of a modification of an auxiliary valve for the circuit of FIG. 1.
  • a hydraulic circuit in accordance with the present invention generally comprises a source of pressurized fluid including a pump 11 which draws fluid from a sump or reservoir 12.
  • the pump supplies pressurized fluid by way of a supply conduit 13 to a main control valve 14 with fluid exhausted from the control valve being returned to the reservoir through a return line or conduit 15.
  • a relief valve 16 interconnects the supply conduit 13 and the return conduit to relieve excessive pressure in the hydraulic circuit.
  • the control valve 14 is of the type that has three positions attainable by actuation of a control lever 17 to one of the three positions indicated by the letters R, N, and L.
  • the control valve is operative in selecting one of the R or L positions to direct fluid via supply lines 21 and 22 to either the head or rod end of a double act- ,ing..hydr aulic motor orjac k 23.
  • both of a pair of control eonduits 18 and 19 are in communication with the return conduit 15 to: reservoir 12.
  • the conduits l8 and 19 communicate fluid'from the control valve 14 to a pilot operable lock valve 20, where the fluid is communicated by way of motor supply lines 21 and 22 to jack 23.
  • the hydraulic jac k 23 is controlled by the lock valve through conduits 21 and 22.
  • the lock valve 20 includes a valve body'24 having a bore 2 5-extending longitudinally therethrough.
  • a first pair of axially'spa ced radial ports 26 and 27 are formed in. the body and. communicate the conduits l8 and 19, respectively, with the bore 25.
  • a second pair of axially spaced radial ports 28 and 29 are formed in the body and communicate the conduits 21 and 22, respectively, with the bore.
  • the valve body has a third radial port 30 formed therein intermediate the ports 26 and 27.
  • a pair of solenoid control valves 48 and 4) are in communicationwith the port 30 and Chamber 45v of the valve body through a conduit 50.
  • the valve 48 is normally open and in communication with reservoir 12 through a return conduit 51.
  • the solenoid valve 49 is normally closed and communicates with the lluid supply conduit 13 through a branch or by-pass conduit 52.
  • a suitable conductor 53 electically connects the solenoid valves to a normally open toggle switch 54 which is connected to a suitable electrical source such as a battery 55.
  • the solenoid operated valves 48 and 49 of FIG. 1 may be replaced with a single 2-position, 3-way solenoid control valve 56 which normally communicates the conduit 50 with the return conduit 51. (losing the toggle switch 54 energizes the solenoid control valve causing it to shift to a position to communicate the branch conduit 52 with the conduit 50. This communicates pressufrized fluid to chamber 45 which forces pistons 41 and 42 to unseat ball check valves 35 and 36 to thereby disable the lock valve 20. i
  • the toggle switch 54 is open so that the chamber 45 is vented to the reservoir 12 through the conduit 50, the normally open solenoid valve 48, and the return conduit 51.
  • the lock valve 20 functions as a Conventional lock valve whereby fluid from both ends of the hydrostatic jack 23 is blocked by the respective check valve assemblies 31 and 32 of the lock valve.
  • the control valve 14 is shifted to direct pressurized fluid through conduit 18 to the lock valve, the ball 35 of the check valve assembly 31 is unseated by the pressurized fluid which is then transmitted to the hydraulic jack through conduit 21. Simultaneously, the pressurized fluid entering the lock valve through the conduit 18 acts upon the actuator piston 41 shifting it and the actuator piston 42 to the right.
  • the toggle switch 54 is closed to direct electrical energy to the solenoid control valves 48 and 49.
  • the valve 48 is shifted to a closed position blocking communication therethrough while valve 49 is shifted to an open position to direct pressurized fluid from the pump 11 through conduits 13, 52 and 50 into the chamber 45 of the lock valve 20.
  • the pressurized fluid in chamber 45 urges the actuator pistons 41 and 42 in opposite directions to unseat the balls 35 and 36 of both check valve assemblies 31 and 32. This communicates both the head end and the rod end of the hydraulic jack 23 with the reservoir 12 through the various conduits and provides the float condition.
  • a linear double-acting hydraulic motor connected to a work member, a source of fluid pressure including a sump and a pump for supplying fluid for operating said motor, a three position directional control valve in a valve housing and having a neutral position, and raise and lower positions for selectively directing fluid from said source to either end of said motor for operation of said motor for positioning said work member, a single control lever for operating said control valve, lock valve means including first and second passage means communicating said fluid respectively with alternate ends of said motor, check valve means disposed in each said passage means to normally block flow of said fluid from said motor and including pressure-responsive piston and plunger means in each said passage means for unseating said check valve means to provide communication between both ends of said motor and sump by way of said directional control valve, said check valve means disposed between said control valve means and said hydraulic motor for normally locking said motor in a selected position; solenoid operated auxiliary valve means separate spaced from and independent of said directional control valve and valve housing disposed between said source of fluid pressure and said lock valve means for bypassing said directional
  • control means for said solenoid operated auxiliary valve means comprising a source of electrical power and switch means for selectively activating said solenoids.

Abstract

A hydraulic system having the combination of a source of pressurized fluid, a linear hydraulic motor, a main control valve to selectively direct hydraulic fluid to the motor, and a lock valve disposed between the control valve and motor is provided with an auxiliary valve to by-pass the main control valve to disable the lock valve to provide a float condition for the motor.

Description

United States Patent Johnson 1 Sept. 30, 1975 [54] HYDRAULIC CIRCUIT WITH 3.274.902 9/1966 Klcckncr 91/420 SELECTIVELY ACTUATABLE FLOAT 3.381.587 5/1968 Parquet 91/420 CONTROL 3.543.647 12/1970 -Hall et a1. 91/420 3.558 102 1/1971 Cruse 91/447 X [75] Inventor: Howard L. Johnson, Jolict. 111. 3.583.438 6/1971 Ru hs 37/596 3.608.431 9/1971 Pczlse 91/454 X 1 Asslgneel CaterPIllar Tractor y. 3,730207 5 1973 Christensen 91 437 x Peoria, 111.
[22] Filed: Sept 10, 1973 Primary E.\aminerlrwin C. Cohen Attorney, Agent, 0" Firm-Phillips Moore, PP 395.647 Wcissenberger Lempio & Strabala 52 us. Cl. 91/420; 91/437; 91/445; 1 ABSTRACT 91/447; 91/453; 91/464 A hydraulic system having the combination of a [51 1 Int. Cl.'- F1513 11/08; F1513 13/042; source of pressurized fluid, a linear hydraulic motor, a FlSB 13/043 main control valve to selectively direct hydraulic fluid [58] Field of Search 91/420, 445, 437, 447, to the motor, and a lock valve disposed between the.
91/453, 464; 137/596.l2, 596.13 control valve and motor is provided with an auxiliary valve to by-pass the main control valve to disable the [56] References Cited lock valve to provide a float condition for the motor.
UNITED STATES PATENTS 2.517.164 8/1950 Arps 91/420 X' 3 Claims, 2 Drawing Figures f -1T1 'E' IIIJ -25 L .LL
Z4- Z0 +5 Z5 3 0 3 1 28 1'2 BACKGROUND OF THE INVENTION The present invention relates to hydraulic circuits and pertains particularly to a circuit having a lock valve selectively actuatablc to provide a floating-condition for a hydraulicjack.
It is common practice to utilize anearthmoving vehi cle for ancillary operations. by attaching an auxiliary implement thereto. For example, motor graders are'frequently employed for snow removal by attaching a snow plow to the forward end thereof. In many cases, the auxiliary implement, suchtas the snow plow, operates more efficiently if it is free to ride or float on the surface so it can follow the surface contour. However, many of the hydraulic control systems of such vehicles employ a lock valve which would prevent free floating of the blade. Thus, one of the difficulties encountered in using a vehicle for ancillary operations is that of providing an attachment type control circuit which provides a float position-without employing a sophisticated and expensive control valve, and which is compatible with. the basic hydraulic circuit of the vehicle.
SUMMARY OF THE INVENTION A BRIEF-DESCRIPTION OF THE DRAWINGS Other objects and advantages of the present invention will become apparent from the following description when read in conjunction with the accompanying drawings wherein:
FIG. 1 is a schematic layout of a Circuit in accordance with the present invention; and
FIG. 2 is a schematic of a modification of an auxiliary valve for the circuit of FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring more particularly to FIG. 1 of the drawing, a hydraulic circuit in accordance with the present invention generally comprises a source of pressurized fluid including a pump 11 which draws fluid from a sump or reservoir 12. The pump supplies pressurized fluid by way of a supply conduit 13 to a main control valve 14 with fluid exhausted from the control valve being returned to the reservoir through a return line or conduit 15. A relief valve 16 interconnects the supply conduit 13 and the return conduit to relieve excessive pressure in the hydraulic circuit.
The control valve 14 is of the type that has three positions attainable by actuation of a control lever 17 to one of the three positions indicated by the letters R, N, and L. The control valve is operative in selecting one of the R or L positions to direct fluid via supply lines 21 and 22 to either the head or rod end of a double act- ,ing..hydr aulic motor orjac k 23. when the control valve is in theneutral position, both of a pair of control eonduits 18 and 19 are in communication with the return conduit 15 to: reservoir 12. The conduits l8 and 19 communicate fluid'from the control valve 14 to a pilot operable lock valve 20, where the fluid is communicated by way of motor supply lines 21 and 22 to jack 23. The hydraulic jac k 23is controlled by the lock valve through conduits 21 and 22.
The lock valve 20 includes a valve body'24 having a bore 2 5-extending longitudinally therethrough. A first pair of axially'spa ced radial ports 26 and 27 are formed in. the body and. communicate the conduits l8 and 19, respectively, with the bore 25. A second pair of axially spaced radial ports 28 and 29 are formed in the body and communicate the conduits 21 and 22, respectively, with the bore. The valve body has a third radial port 30 formed therein intermediate the ports 26 and 27.
' A pair of identical check valve assemblies 31 and 32 are individually disposed in opposite ends of the bore and secured in place by a respective one of a pair of plugs 33 and 34 individually threadably secured in the open end of the bore. Check valve assembly 31 normally blocks port 2 8 from port 26 while check valve assembly 32 normally blocks port 29 from port 27. Each check valve assembly includes a ball 35 and 36 resiliently urged against a seat 37 and 38 by a compression .check valve assembly.
A pair of solenoid control valves 48 and 4) are in communicationwith the port 30 and Chamber 45v of the valve body through a conduit 50. The valve 48 is normally open and in communication with reservoir 12 through a return conduit 51. The solenoid valve 49 is normally closed and communicates with the lluid supply conduit 13 through a branch or by-pass conduit 52. A suitable conductor 53 electically connects the solenoid valves to a normally open toggle switch 54 which is connected to a suitable electrical source such as a battery 55.
In an alternate embodiment as shown in FIG. 2, the solenoid operated valves 48 and 49 of FIG. 1 may be replaced with a single 2-position, 3-way solenoid control valve 56 which normally communicates the conduit 50 with the return conduit 51. (losing the toggle switch 54 energizes the solenoid control valve causing it to shift to a position to communicate the branch conduit 52 with the conduit 50. This communicates pressufrized fluid to chamber 45 which forces pistons 41 and 42 to unseat ball check valves 35 and 36 to thereby disable the lock valve 20. i
OPERATION During normal vehicular operation, the toggle switch 54 is open so that the chamber 45 is vented to the reservoir 12 through the conduit 50, the normally open solenoid valve 48, and the return conduit 51. With ehanv ber 45 vented, the lock valve 20 functions as a Conventional lock valve whereby fluid from both ends of the hydrostatic jack 23 is blocked by the respective check valve assemblies 31 and 32 of the lock valve. When the control valve 14 is shifted to direct pressurized fluid through conduit 18 to the lock valve, the ball 35 of the check valve assembly 31 is unseated by the pressurized fluid which is then transmitted to the hydraulic jack through conduit 21. Simultaneously, the pressurized fluid entering the lock valve through the conduit 18 acts upon the actuator piston 41 shifting it and the actuator piston 42 to the right. The plunger 47 of the piston 42 engages and unseats the ball 36 of the check valve assembly 32 permitting fluid exhausted from the hydraulic jack through the conduit 22 to be exhausted through conduit 19, the control valve 14 and the return conduit to the reservoir 12. Conversely, pressurized fluid directed through conduit 19 passes through the lock valve in a similar manner and to the head end of the hydraulic jack through conduit 22. The fluid exhausted through conduit 21 passes through the lock valve 20, conduit 18, control valve 14, and return conduit 15 to the reservoir. 1
To obtain a float position of the hydraulic jack 23, the toggle switch 54 is closed to direct electrical energy to the solenoid control valves 48 and 49. Simultaneously, the valve 48 is shifted to a closed position blocking communication therethrough while valve 49 is shifted to an open position to direct pressurized fluid from the pump 11 through conduits 13, 52 and 50 into the chamber 45 of the lock valve 20. The pressurized fluid in chamber 45 urges the actuator pistons 41 and 42 in opposite directions to unseat the balls 35 and 36 of both check valve assemblies 31 and 32. This communicates both the head end and the rod end of the hydraulic jack 23 with the reservoir 12 through the various conduits and provides the float condition.
What is claimed is:
1. In a hydraulic system for selectively positioning a work member in selected fixed positions the combination comprising:
a linear double-acting hydraulic motor connected to a work member, a source of fluid pressure including a sump and a pump for supplying fluid for operating said motor, a three position directional control valve in a valve housing and having a neutral position, and raise and lower positions for selectively directing fluid from said source to either end of said motor for operation of said motor for positioning said work member, a single control lever for operating said control valve, lock valve means including first and second passage means communicating said fluid respectively with alternate ends of said motor, check valve means disposed in each said passage means to normally block flow of said fluid from said motor and including pressure-responsive piston and plunger means in each said passage means for unseating said check valve means to provide communication between both ends of said motor and sump by way of said directional control valve, said check valve means disposed between said control valve means and said hydraulic motor for normally locking said motor in a selected position; solenoid operated auxiliary valve means separate spaced from and independent of said directional control valve and valve housing disposed between said source of fluid pressure and said lock valve means for bypassing said directional control valve for directing fluid solely to each said piston and plunger means solely for unseating each said check valve means for communicating both ends of said motor with said sump by way of said directional control valve for enabling free floating movement of said hydraulic motor when said main control valve is in a neutral position between said raise and said lower positions. 2. The hydraulic system of claim 1 wherein said solenoid operated auxiliary valve means comprises a pair of solenoid operated two-position valves.
3. The hydraulic system of claim 2 including control means for said solenoid operated auxiliary valve means comprising a source of electrical power and switch means for selectively activating said solenoids.

Claims (3)

1. In a hydraulic system for selectively positioning a work member in selected fixed positions the combination comprising: a linear double-acting hydraulic motor connected to a work member, a source of fluid pressure including a sump and a pump for supplying fluid for operating said motor, a three position directional control valve in a valve housing and having a neutral position, and raise and lower positions for selectively directing fluid from said source to either end of said motor for operation of said motor for positioning said work member, a single control lever for operating said control valve, lock valve means including first and second passage means communicating said fluid respectively with alternate ends of said motor, check valve means disposed in each said passage means to normally block flow of said fluid from said motor and including pressure-responsive piston and plunger means in each said passage means for unseating said check valve means to provide communication between both ends of said motor and sump by way of said directional control valve, said check valve means disposed between said control valve means and said hydraulic motor for normally locking said motor in a selected position; solenoid operated auxiliary valve means separate spaced from and independent of said directional control valve and valve housing disposed between said source of fluid pressure and said lock valve means for bypassing said directional control valve for directing fluid solely to each said piston and plunger means solely for unseating each said check valve means for communicating both ends of said motor with said sump by way of said directional control valve for enabling free floating movement of said hydraulic motor when said main control valve is in a neutral position between said raise and said lower positions.
2. The hydraulic system of claim 1 wherein said solenoid operated auxiliary valve means comprises a pair of solenoid operated two-position valves.
3. The hydraulic system of claim 2 including control means for said solenoid operated auxiliary valve means comprising a source of electrical power and switch means for selectively activating said solenoids.
US395647A 1973-09-10 1973-09-10 Hydraulic circuit with selectively actuatable float control Expired - Lifetime US3908515A (en)

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Application Number Priority Date Filing Date Title
US395647A US3908515A (en) 1973-09-10 1973-09-10 Hydraulic circuit with selectively actuatable float control
JP2728974A JPS5535563B2 (en) 1973-09-10 1974-03-11
CA204,191A CA1025326A (en) 1973-09-10 1974-07-05 Hydraulic circuit with selectively actuatable float control
ZA00744408A ZA744408B (en) 1973-09-10 1974-07-09 Hydraulic circuit with selectively actuatable float control
AU71750/74A AU482064B2 (en) 1973-09-10 1974-07-29 Hydraulic circuit with selectively actuatable float control
BR6750/74A BR7406750D0 (en) 1973-09-10 1974-08-15 HYDRAULIC SYSTEM TO SELECTIVELY POSITION A WORK ACCESSORY
BE148361A BE819721A (en) 1973-09-10 1974-09-10 HYDRAULIC CIRCUIT WITH FLOATING CONTROL SELECTIVELY ACTIONABLE
BE164820A BE839147R (en) 1973-09-10 1976-03-03 HYDRAULIC CIRCUIT WITH FLOATING CONTROL SELECTIVELY ACTIONABLE

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JP (1) JPS5535563B2 (en)
BE (1) BE819721A (en)
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ZA (1) ZA744408B (en)

Cited By (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4018350A (en) * 1975-03-17 1977-04-19 Pettibone Corporation Hydraulic cyliner systems with safeguarded float action
US4039085A (en) * 1976-06-10 1977-08-02 Koehring Company Crane with a pivoted boom and a float valve therefor
US4128047A (en) * 1975-08-14 1978-12-05 Textron Inc. Actuator with locking valves
US4130049A (en) * 1977-04-07 1978-12-19 Caterpillar Tractor Co. Vent control for cylinder mounted load check valves
US4165675A (en) * 1977-04-07 1979-08-28 Caterpillar Tractor Co. Load check valve cylinder mounted
US4167892A (en) * 1977-04-07 1979-09-18 Caterpillar Tractor Co. Load check with mechanical venting means
US4170279A (en) * 1976-04-30 1979-10-09 Societe Anonyme Potain Pioclain Materiel (P.P.M.) Fluid flow control devices
US4170246A (en) * 1977-05-23 1979-10-09 Sta-Rite Industries, Inc. Pilot operator valve
WO1981000600A1 (en) * 1979-08-30 1981-03-05 Caterpillar Tractor Co Lock valve with variable length piston and hydraulic system for a work implement using the same
US4367673A (en) * 1981-01-09 1983-01-11 Dresser Industries, Inc. System and method for controlling the elevation of a boom hoist device
US4417502A (en) * 1980-11-17 1983-11-29 Dresser Industries, Inc. Load supporting hydraulic circuit with emergency automatic load restraint
US4523513A (en) * 1982-07-08 1985-06-18 Wabco Westinghouse Fahrzeugbremsen Gmbh Pneumatic door-operating arrangement
US4558630A (en) * 1980-06-05 1985-12-17 Oy Tampella Ab Hydraulic mechanism with elastically backed piston parts and cooperating valve means
US4619187A (en) * 1982-10-25 1986-10-28 Caterpillar Inc. Fluid control for two independent actuators
US4754693A (en) * 1986-04-23 1988-07-05 Concordia Fluidtechnik Gmbh Valve
US4761954A (en) * 1987-03-16 1988-08-09 Dynamic Hydraulic Systems, Inc. Fork-lift system
US4761953A (en) * 1984-04-18 1988-08-09 Dynamic Hydraulic Systems, Inc. Hydraulic elevator mechanism
US4768420A (en) * 1986-04-04 1988-09-06 Ernst Korthaus Control arrangement for controlling a hydraulic drive for driving a piston pump
US4852660A (en) * 1987-11-21 1989-08-01 O & K Orenstein & Koppel Aktiengesellschaft Grader blade having a pressurized float position
FR2629304A1 (en) * 1988-03-30 1989-10-06 Steyr Daimler Puch Ag LIFT BAR CONNECTING A LIFT ARM TO A LOWER HITCH LEVER IN A LIFT DEVICE FOR A TRACTOR
US5036750A (en) * 1989-08-29 1991-08-06 Nippon Air Brake Kabushiki Kaisha Pilot-operated dual check valve assembly with cross-line flow valving pilot pistons
WO1991019108A1 (en) * 1990-05-26 1991-12-12 Robert Bosch Gmbh Piston-cylinder control device
US5235896A (en) * 1991-03-20 1993-08-17 Hoerbiger Fluidtechnik Gmbh Hydraulic cylinder/piston mechanism
US5284083A (en) * 1991-11-26 1994-02-08 Messier-Bugatti System for powering the driving actuator of an aircraft undercarriage
US5934176A (en) * 1995-02-01 1999-08-10 Applied Power Inc. Hydraulic operating system
US5988028A (en) * 1993-02-02 1999-11-23 Putzmeister Aktiengesellschaft Process for conveying thick matter containing preshredded scrap metal or similar solids
US6131610A (en) * 1996-11-22 2000-10-17 Smc Kabushiki Kaisha Speed controller with pilot check valve
DE19919014A1 (en) * 1999-04-27 2000-11-09 Danfoss Fluid Power As Hydraulic valve with locking and floating function has housing bore, in which switch channel optionally providable with pressure and with connecting channels on both sides is connectable by control valve with pressure source and tank
US6293181B1 (en) 1998-04-16 2001-09-25 Caterpillar Inc. Control system providing a float condition for a hydraulic cylinder
US20030111117A1 (en) * 1999-12-13 2003-06-19 Horn Edward R. Valve arrangement including release valve
EP1310680A3 (en) * 2001-11-08 2005-08-10 Botschafter-Knopff, IIse Stop valve arrangement and control valve with such a stop valve arrangement
US20060027092A1 (en) * 1999-09-28 2006-02-09 Caterpillar Inc. Hydraulic system with an actuator having independent meter-in meter-out control
US20080121101A1 (en) * 2006-11-29 2008-05-29 Volvo Construction Equipment Holding Sweden Ab Double check valve having floating function
US20090014074A1 (en) * 2007-07-12 2009-01-15 Sauer-Danfoss Aps Hydraulic valve arrangement
US20090078111A1 (en) * 2007-09-20 2009-03-26 Volvo Construction Equipment Holding Sweden Ab. Double check valve having floating function
US20100218746A1 (en) * 2008-07-03 2010-09-02 Vianney Rabhi Ball-lift electrohydraulic valve for a hydraulic power unit of a variable compression ratio engine
CN102135196A (en) * 2010-01-27 2011-07-27 马克阀门公司 Proportional pressure controller
WO2012082355A2 (en) * 2010-12-15 2012-06-21 Caterpillar Inc. Hydraulic system having load lock valve
US20130055886A1 (en) * 2010-05-18 2013-03-07 Volvo Construction Equipment Ab Double check valve for construction equipment
US9429174B1 (en) * 2013-03-15 2016-08-30 Clark Equipment Company Enabling valve having separate float and lift down positions
IT201900005056A1 (en) * 2019-04-04 2020-10-04 Nem S R L HYDRAULIC DRIVE CIRCUIT FOR OPERATING MACHINE WITH MECHANICAL ARTICULATION EQUIPPED WITH FLOATING FUNCTION.

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2517164A (en) * 1947-02-19 1950-08-01 Bruno F Arps Two-speed hydraulic ram
US3274902A (en) * 1965-10-22 1966-09-27 Deere & Co Hydraulic control system
US3381587A (en) * 1965-09-10 1968-05-07 Deere & Co Hydraulic control system
US3543647A (en) * 1969-05-02 1970-12-01 Deere & Co Control valve means for a two-way hydraulic cylinder
US3558102A (en) * 1969-01-10 1971-01-26 William M Cruse Theater stage set control system
US3583438A (en) * 1968-08-17 1971-06-08 Herion Werke Dg Fa Safety arrangements in servo operated systems
US3608431A (en) * 1969-07-14 1971-09-28 Lummus Industries Control system for the ram of vertically disposed fluid pressure cylinders
US3730207A (en) * 1970-10-02 1973-05-01 Danfoss As Valve arrangement for hydraulic steering systems

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4423873Y1 (en) * 1965-05-12 1969-10-08

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2517164A (en) * 1947-02-19 1950-08-01 Bruno F Arps Two-speed hydraulic ram
US3381587A (en) * 1965-09-10 1968-05-07 Deere & Co Hydraulic control system
US3274902A (en) * 1965-10-22 1966-09-27 Deere & Co Hydraulic control system
US3583438A (en) * 1968-08-17 1971-06-08 Herion Werke Dg Fa Safety arrangements in servo operated systems
US3558102A (en) * 1969-01-10 1971-01-26 William M Cruse Theater stage set control system
US3543647A (en) * 1969-05-02 1970-12-01 Deere & Co Control valve means for a two-way hydraulic cylinder
US3608431A (en) * 1969-07-14 1971-09-28 Lummus Industries Control system for the ram of vertically disposed fluid pressure cylinders
US3730207A (en) * 1970-10-02 1973-05-01 Danfoss As Valve arrangement for hydraulic steering systems

Cited By (59)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4018350A (en) * 1975-03-17 1977-04-19 Pettibone Corporation Hydraulic cyliner systems with safeguarded float action
US4128047A (en) * 1975-08-14 1978-12-05 Textron Inc. Actuator with locking valves
US4170279A (en) * 1976-04-30 1979-10-09 Societe Anonyme Potain Pioclain Materiel (P.P.M.) Fluid flow control devices
US4039085A (en) * 1976-06-10 1977-08-02 Koehring Company Crane with a pivoted boom and a float valve therefor
US4130049A (en) * 1977-04-07 1978-12-19 Caterpillar Tractor Co. Vent control for cylinder mounted load check valves
US4165675A (en) * 1977-04-07 1979-08-28 Caterpillar Tractor Co. Load check valve cylinder mounted
US4167892A (en) * 1977-04-07 1979-09-18 Caterpillar Tractor Co. Load check with mechanical venting means
US4170246A (en) * 1977-05-23 1979-10-09 Sta-Rite Industries, Inc. Pilot operator valve
WO1981000600A1 (en) * 1979-08-30 1981-03-05 Caterpillar Tractor Co Lock valve with variable length piston and hydraulic system for a work implement using the same
EP0025107A1 (en) * 1979-08-30 1981-03-18 Caterpillar Tractor Co. Lock valve with variable length piston and hydraulic system for a work implement using the same
US4286432A (en) * 1979-08-30 1981-09-01 Caterpillar Tractor Co. Lock valve with variable length piston and hydraulic system for a work implement using the same
US4558630A (en) * 1980-06-05 1985-12-17 Oy Tampella Ab Hydraulic mechanism with elastically backed piston parts and cooperating valve means
US4417502A (en) * 1980-11-17 1983-11-29 Dresser Industries, Inc. Load supporting hydraulic circuit with emergency automatic load restraint
US4367673A (en) * 1981-01-09 1983-01-11 Dresser Industries, Inc. System and method for controlling the elevation of a boom hoist device
US4523513A (en) * 1982-07-08 1985-06-18 Wabco Westinghouse Fahrzeugbremsen Gmbh Pneumatic door-operating arrangement
US4619187A (en) * 1982-10-25 1986-10-28 Caterpillar Inc. Fluid control for two independent actuators
WO1993013319A1 (en) * 1982-10-25 1993-07-08 Blake William W Fluid control for two independent actuators
US4761953A (en) * 1984-04-18 1988-08-09 Dynamic Hydraulic Systems, Inc. Hydraulic elevator mechanism
US4768420A (en) * 1986-04-04 1988-09-06 Ernst Korthaus Control arrangement for controlling a hydraulic drive for driving a piston pump
US4754693A (en) * 1986-04-23 1988-07-05 Concordia Fluidtechnik Gmbh Valve
US4761954A (en) * 1987-03-16 1988-08-09 Dynamic Hydraulic Systems, Inc. Fork-lift system
US4852660A (en) * 1987-11-21 1989-08-01 O & K Orenstein & Koppel Aktiengesellschaft Grader blade having a pressurized float position
FR2629304A1 (en) * 1988-03-30 1989-10-06 Steyr Daimler Puch Ag LIFT BAR CONNECTING A LIFT ARM TO A LOWER HITCH LEVER IN A LIFT DEVICE FOR A TRACTOR
US5036750A (en) * 1989-08-29 1991-08-06 Nippon Air Brake Kabushiki Kaisha Pilot-operated dual check valve assembly with cross-line flow valving pilot pistons
WO1991019108A1 (en) * 1990-05-26 1991-12-12 Robert Bosch Gmbh Piston-cylinder control device
US5235896A (en) * 1991-03-20 1993-08-17 Hoerbiger Fluidtechnik Gmbh Hydraulic cylinder/piston mechanism
US5284083A (en) * 1991-11-26 1994-02-08 Messier-Bugatti System for powering the driving actuator of an aircraft undercarriage
US6158313A (en) * 1993-02-02 2000-12-12 Putzmeister Aktiengesellschaft Process for conveying thick matter containing preshredded scrap metal or similar solids
US5988028A (en) * 1993-02-02 1999-11-23 Putzmeister Aktiengesellschaft Process for conveying thick matter containing preshredded scrap metal or similar solids
US5934176A (en) * 1995-02-01 1999-08-10 Applied Power Inc. Hydraulic operating system
US6131610A (en) * 1996-11-22 2000-10-17 Smc Kabushiki Kaisha Speed controller with pilot check valve
US6293180B1 (en) 1996-11-22 2001-09-25 Smc Kabushiki Kaisha Speed controller with pilot check valve
US6296015B1 (en) 1996-11-22 2001-10-02 Smc Kabushiki Kaisha Speed controller with pilot check valve
US6293181B1 (en) 1998-04-16 2001-09-25 Caterpillar Inc. Control system providing a float condition for a hydraulic cylinder
DE19919014A1 (en) * 1999-04-27 2000-11-09 Danfoss Fluid Power As Hydraulic valve with locking and floating function has housing bore, in which switch channel optionally providable with pressure and with connecting channels on both sides is connectable by control valve with pressure source and tank
DE19919014C2 (en) * 1999-04-27 2001-03-01 Danfoss Fluid Power As Nordbor Hydraulic valve with a locking and a floating function
US20060027092A1 (en) * 1999-09-28 2006-02-09 Caterpillar Inc. Hydraulic system with an actuator having independent meter-in meter-out control
US7472638B2 (en) * 1999-09-28 2009-01-06 Caterpillar Inc. Hydraulic system with an actuator having independent meter-in meter-out control
US6997210B2 (en) * 1999-12-13 2006-02-14 Aladdin Engineering & Manufacturing, Inc. Valve arrangement including release valve
US20030111117A1 (en) * 1999-12-13 2003-06-19 Horn Edward R. Valve arrangement including release valve
EP1310680A3 (en) * 2001-11-08 2005-08-10 Botschafter-Knopff, IIse Stop valve arrangement and control valve with such a stop valve arrangement
US20080121101A1 (en) * 2006-11-29 2008-05-29 Volvo Construction Equipment Holding Sweden Ab Double check valve having floating function
EP1927759A1 (en) * 2006-11-29 2008-06-04 Volvo Construction Equipment Holding Sweden AB Double check valve having floating function
US7954420B2 (en) 2007-07-12 2011-06-07 Sauer-Danfoss Aps Hydraulic valve arrangement
US20090014074A1 (en) * 2007-07-12 2009-01-15 Sauer-Danfoss Aps Hydraulic valve arrangement
DE102007032415B3 (en) * 2007-07-12 2009-04-02 Sauer-Danfoss Aps Hydraulic valve arrangement
US20090078111A1 (en) * 2007-09-20 2009-03-26 Volvo Construction Equipment Holding Sweden Ab. Double check valve having floating function
EP2048372A2 (en) * 2007-09-20 2009-04-15 Volvo Construction Equipment Holding Sweden AB Double check valve having floating function
US8001882B2 (en) * 2007-09-20 2011-08-23 Volvo Construction Equipment Holding Sweden Ab Double check valve having floating function
EP2048372A3 (en) * 2007-09-20 2012-05-30 Volvo Construction Equipment Holding Sweden AB Double check valve having floating function
US20100218746A1 (en) * 2008-07-03 2010-09-02 Vianney Rabhi Ball-lift electrohydraulic valve for a hydraulic power unit of a variable compression ratio engine
CN102135196A (en) * 2010-01-27 2011-07-27 马克阀门公司 Proportional pressure controller
CN102135196B (en) * 2010-01-27 2014-10-29 马克阀门公司 proportional pressure controller
US20130055886A1 (en) * 2010-05-18 2013-03-07 Volvo Construction Equipment Ab Double check valve for construction equipment
US9068322B2 (en) * 2010-05-18 2015-06-30 Volvo Construction Equipment Ab Double check valve for construction equipment
WO2012082355A2 (en) * 2010-12-15 2012-06-21 Caterpillar Inc. Hydraulic system having load lock valve
WO2012082355A3 (en) * 2010-12-15 2012-09-07 Caterpillar Inc. Hydraulic system having load lock valve
US9429174B1 (en) * 2013-03-15 2016-08-30 Clark Equipment Company Enabling valve having separate float and lift down positions
IT201900005056A1 (en) * 2019-04-04 2020-10-04 Nem S R L HYDRAULIC DRIVE CIRCUIT FOR OPERATING MACHINE WITH MECHANICAL ARTICULATION EQUIPPED WITH FLOATING FUNCTION.

Also Published As

Publication number Publication date
JPS5535563B2 (en) 1980-09-16
ZA744408B (en) 1975-08-27
BE819721A (en) 1975-03-10
BR7406750D0 (en) 1975-09-09
AU7175074A (en) 1976-01-29
CA1025326A (en) 1978-01-31
JPS5054778A (en) 1975-05-14

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AS Assignment

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

Effective date: 19860515

Owner name: CATERPILLAR INC., A CORP. OF DE.,ILLINOIS

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

Effective date: 19860515