US3289546A - Hydraulic actuating mechanism - Google Patents

Hydraulic actuating mechanism Download PDF

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Publication number
US3289546A
US3289546A US388789A US38878964A US3289546A US 3289546 A US3289546 A US 3289546A US 388789 A US388789 A US 388789A US 38878964 A US38878964 A US 38878964A US 3289546 A US3289546 A US 3289546A
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United States
Prior art keywords
valve
fluid
spool
motor
pressure fluid
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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
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US388789A
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English (en)
Inventor
Rodney R Erickson
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.)
Caterpillar Inc
Original Assignee
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 US388789A priority Critical patent/US3289546A/en
Priority to GB33110/65A priority patent/GB1060347A/en
Priority to DE1500345A priority patent/DE1500345C3/de
Priority to ES0316370A priority patent/ES316370A1/es
Priority to FR28058A priority patent/FR1444512A/fr
Application granted granted Critical
Publication of US3289546A publication Critical patent/US3289546A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/34—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with bucket-arms, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms directly pivoted on the frames of tractors or self-propelled machines
    • E02F3/3405—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with bucket-arms, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms directly pivoted on the frames of tractors or self-propelled machines and comprising an additional linkage mechanism
    • E02F3/3411—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets with bucket-arms, i.e. a pair of arms, e.g. manufacturing processes, form, geometry, material of bucket-arms directly pivoted on the frames of tractors or self-propelled machines and comprising an additional linkage mechanism of the Z-type
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
    • E02F3/431—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like
    • E02F3/432—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like for keeping the bucket in a predetermined position or attitude
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
    • E02F3/36—Component parts
    • E02F3/42—Drives for dippers, buckets, dipper-arms or bucket-arms
    • E02F3/43—Control of dipper or bucket position; Control of sequence of drive operations
    • E02F3/431—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like
    • E02F3/434—Control of dipper or bucket position; Control of sequence of drive operations for bucket-arms, front-end loaders, dumpers or the like providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig
    • 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
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/20—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors controlling several interacting or sequentially-operating members
    • 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
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/04—Special measures taken in connection with the properties of the fluid
    • F15B21/044—Removal or measurement of undissolved gas, e.g. de-aeration, venting or bleeding

Definitions

  • This invention relates to a hydraulic control device and more particularly to a device for venting the hydraulic circuit during each cycle of operation and for conditioning the hydraulic circuit to interrupt operation of a hydraulic motor.
  • This invention can be employed to control the flow of actuating pressure fluid to hydraulic motors, particularly linear actuators, in order to interrupt operation of the motor at a desired time, thus positioning an element, whether it be alinkage mechanism, a turntable, or a boom, which is actuated by the motor, at any particular location.
  • Controls of this general type are the subject of Patent No. 3,122,247 and US. application Nos. 208,303 and 286,320, now respectively Patents Nos. 3,211,310 and 3,155,252, all of which are assigned to the assignee of the present invention.
  • This invention provides a hydraulic circuit which includes a cyclically operable valve which is effective, during each cycle of operation of the position ing mechanism, to vent the hydraulic circuit to the atmosphere and thereby maintain the hydraulic circuit free of entrapped air.
  • this invention employs the working pressure fluid to achieve the same result thus giving rise to a simpler and more trouble-free system.
  • Another object of this invention is to provide a hydraulically actuate-d positioning mechanism wherein the hydraulic circuit is cyclically vented to the atmosphere.
  • Another object of this invention is to provide a shiftablehydraulic motor valve to vent a portion of the working fluid to a zone of reduced pressure in order to purge and thus maintain the working fluid free of entrapped air.
  • Another object of this invention is to employ the pressure fluid of the main hydraulic circuit to operate a control device which arrests movement of a positioning mechanism at a desired point.
  • FIG. 1 shows a wheeled vehicle having a bucket positioning mechanism incorporating the control device of this invention.
  • FIG. 2 is a diagrammatic of the hydraulic circuit showing the hydraulic valves in section.
  • a loading apparatus generally indicated by the numeral includes a bucket 12 pivotally connected at 14 to a pair of arms 16.
  • the arms 16 are pivotally connected at 18 to the frame of the loading apparatus with pivotal movement of the arms 16 about the pivot connection 18 being effected by a hydraulic motor 20, preferably a jack.
  • the bucket 12 is interconnected to a tilt motor 22 by a linkage system 24 which 3,289,546 Patented Dec. 6, 1966 operates to hold or retain the bucket 12 in a fixed position relative to the horizontal as it is raised. Retraction of the motor 22 causes the linkage mechanism 24 to eflect pivotal movement of the bucket 12 about the pivot 14 thus dumping the contents from the bucket.
  • the hydraulic circuit for operating the hydraulic motors 20 and 22 includes a lift hick-out mechanism 26 operating to interrupt flow of hydraulic fluid to the motor 20 when the arms 16 have been raised to a predetermined position and a cam kick-out mechanism 28 operating to control the action of ⁇ motor 22 in order to cite-ct tilting of the bucket 12 about the pivot connection 14 when the arms 16 are in their raised position.
  • the portion of the hydraulic circuit for actuating the motor 20 comprises a reservoir 30 which contains hydraulic fluid that is distributed to the circuit by a pump 32 having the discharge port thereof connected to the inlet port of a control valve 34 by a conduit 36.
  • a conventional relief valve 38 located in a branch conduit 40, maintains the pump discharge pressure at a predetermined value by operating to return a portion of the pressure fluid to the reservoir through the conduit 40 and a conduit 42 open to the reservoir 30.
  • Pressure fluid from the conduit 36 is discharged to communicating passageways 44 and 46 formed in the body of the control valve 34.
  • a check valve 48 operates in response to the value of pressure in the passageway 46 to establish communication between the passageway 46 and another passageway 50 which communicates pressure fluid to a bore 54 containing a reciprocable control spool 52.
  • the bore 54 is formed with a plurality of longitudinally spaced annular recesses 56a, 56b, 56c, 56d, which in conjunction with the lands of the spool control the flow of pressure fluid through the valve 34.
  • the passageway 44 distributes pressure fluid to a generally U-shaped cavity 58 and a port 60 to which is connected the conduit 42 to thereby return the pressure fluid to the reservoir 30.
  • a conventional spring centering mechanism 62 is provided for restraining or biasing the spool 52 in a neutral position, which is the position illustrated in the drawing. While in the neutral position, it will be noted that the passageway 44 is in communication with the cavity 58 so that fluid discharged by the pump 32 is immediately returned to reservoir 30 by the conduit 42.
  • the spool 54 is adapted to assume various adjusted positions indicated by the letters R, N, L, and F being respectively, the raise position wherein pressure fluid is communicated to the motor 20 efiecting extension thereof, a neutral position wherein fluid is returned directly to the reservoir 30, the lower position wherein fluid is communicated to the motor 20 in order to effect retraction thereof, and a float position wherein fluid is communicated to the rod end and head end of the fluid motor 20 permitting the bucket to be lowered by gravity and to be able to freely follow the terrain over which it is being moved.
  • the annular recesses 56a and 56d have extending therebetween an internal passageway 64 defining a fluid flow path for returning fluid exhausted from the head end of the hydraulic motor 20 to the recess 56d, through the cavity 58 and to the reservoir 30 by the conduit 42.
  • the recess 56b communicates pressure fluid from the passageway 50 to the head end of the motor 20 by a port 66 and a conduit 68 whereas pressure fluid communicated to the recess 56c by the passageway 50 is communicated, by a port 79 and a conduit 72, to the rod end of the motor 20.
  • the operator positions the spool 52 adjacent the position indicated by the letter R, blocking communication between the passageway 44 and the U- shaped cavity 58 and establishing communication between the passageway 50 and the discharge port 66.
  • the pressure fluid from the pump increases the pressure in the passageway 46 to a sufficient value to cause opening of the check valve 48 and allowing the pressure fluid to flow through the passageway 50 into the annular recess 56b and through the discharge port 66 and the conduit 68 to the head end of the hydraulic motor 20 thus causing extension thereof.
  • Retrac tion of the hydraulic motor 20 is accomplished by moving the spool 52 in the position indicated by the letter L establishing communication between the passageway 50 and the conduit 70 and between the conduit 68 and the passageway 64.
  • the lift kick-out mechanism 26 includes a valve operating in response to the pivotal movement of the arm 16 for communicating pressure fluid derived from the control valve 34 to a slave valve S being effective to release a detent mechanism D thereby conditioning the control valve 34 to interrupt the flow of pressure fluid to the motor 20 and thus halt pivotal movement of the arms 16.
  • the hydraulic system illustrated in FIG. 2 is arranged to employ the high pressure fluid for releasing the detent mechanism D and means are incorporated in the slave valve S for venting the hydraulic circuit in order to purge air which may be entrained in the hydraulic system.
  • the spool 52 has an extension 74 pivotally connected to an actuating lever 76 mounted for rotation with a shaft 78 which is rotatably mounted in a bracket 80 secured to the frame of the machine. Shifting of the spool to any of the indicated positions is accomplished when the operator rotates the shaft 78 in turn rotating the lever 76 thus effecting reciprocation of the spool 52.
  • the detent mechanism D comprises another lever 82 pivotally connected to the frame of the machine at 84 and formed with a laterally projecting support arm 86 on the end of which is rotatably mounted a roller 88.
  • the lever 82 is urged in a clockwise direction by a spring 90 having one end attached to the lower end of the lever 82 and the remaining end attached to a small bracket 92 secured to the body of the valve S.
  • the lower end of the actuating lever 76 is formed with cam surfaces 94, 96, and 98 against which the roller 74 is held in engagement by the spring 90. These cam surfaces are effective in conjunction with the force of the spring 90 to retain the lever 76 and the spool 52 in a desired adjusted position.
  • One of the principal features of this invention pertains to the slave valve S which is constructed and arranged in accordance with the operation of the detent mechanism D to vent the hydraulic circuit when the arms 16 have been raised to their predetermined position.
  • Another important feature of this invention pertains to a high pressure kick-out mechanism operating to communicate pressure fluid discharged through the conduit 68 to the slave valve S in order to rotate the lever 82 of the detent mechanism in a counterclockwise direction thereby returning the spool 52 to its neutral position interrupting prises a base plate 100 rigidly mounted on the arms 16 by plurality of bolts 102.
  • A- bracket 104, secured to the plate 100 has a cam 106 secured thereon in any suitable maner and preferably as shown by means of a bolt 108.
  • a valve 110 is rigidly supported on a boss 111, forming part of the frame of the loading apparatus. This valve includes a spool 112 having an outward extension 114 on the end of which is rotatably mounted a roller 116.
  • the spool 112 is normally held in the illustrated position by a spring 118 located within the bore of the spool.
  • the valve 110 is connected by means of a conduit 120 to the conduit 68 and by means of a conduit 122 to the valve S.
  • the control valve 34 is adjusted to discharge pressure fluid from the pump 32 to the conduit 68 in order to pressurize the head end of the motor 20, the cam 106 engages the roller 116 moving the spool 112 to the right (as viewed in FIG. 2) thereby establishing communication between the conduit 120 and 122 thus communicating presure fluid to the slave valve S.
  • the slave valve S is hydraulically arranged with the valve 110 and mechanically arranged with the detent mechanism D to vent the fluid in the conduit 122 and to permit the spring centering mechanism 62 to return the spool 52 to its neutral position when the arms 16 have reached a predetermined raised position.
  • the valve S comprises a tubular body 124 having a spool 126 reciprocably mounted therein.
  • the spool has a reduced diameter portion 128 extending between inner and outer lands 130 and 132 respectively.
  • An elongated rod portion 134 extending from the land 132 is pivotally connected at 136 to the lower portion of the lever 82.
  • An orifice 138 is provided in the wall of the body 124, located between the lands 130 and 132, and is connected by means of a conduit 140 to the reservoir 30.
  • the conduit 122 establishes communication between the valve 110 and the valve S in order to communicate pressure fluid from the conduit 120 to the valve S when the spool 112 is moved inwardly by the cam 106.
  • a passageway 142 (shown in dotted outline) establishes communication between a chamber 144 and an annular cavity 146.
  • the passageway 142 is provided for communicating pressure fluid, communicated to the cavity 146 by the conduit 122, to the cavity 144 in order to cause shifting of the spool 126 to the right.
  • slave valve S has been shown and described with a loader mechanism or loading apparatus, it is to be appreciated that it may be incorporated in any hydraulic circuit where cyclic automatic purging is desired.
  • a control device for a fluid circuit comprising a moveable support, a fluid motor being arranged to impart movement to said support, a valve mechanism for communicating pressure fluid to said motor to cause operation thereof, means including a pressure operated device connected to the circuit for maintaining said valve mechanism in a position communicating pressure fluid to said motor, and means actuated in response to the position of said support and being operable to communicate pressure fluid to said pressure operated device for disconnecting said motor from a source of pressure fluid in order to arrest movement of said moveable support.
  • a control device for automatically venting a hydraulic control circuit comprising a moveable support, a hydraulic motor being arranged to impart movement to said support, a valve mechanism for communieating pressure fluid to said motor to cause operation thereof, means including a pressure operated device connected to the circuit for maintaining said valve mechanism in a position communicating pressure fluid to said motor, means actuated in response to the position of said support and being operable to communicate line pressure fluid to said pressure operated device for disconnecting said motor from a source of pressure fluid in order to arrest movement of said moveable support, said pressure operated device being formed to define a chambered portion communicating with the source of fluid by a conduit, and means for throttling the flow of the fluid flowing between said chamber and the source of fluid.
  • a control device for automatically venting a hydraulic control circuit comprising a double acting linear actuator; a control valve including a reciprocable spool for controlling the flow of pressure fluid to said actuator to thus effect extension or retraction thereof; a support arranged to be moved by said actuator; means for biasing said spool to a neutral position blocking communication of pressure fluid to said actuator; a detent mechanism for holding said spool in an adjusted position against the bias of said biasing means in order to communicate pressure fluid to said actuator and thereby effect movement of said support; a detent release valve operated by the pressure fluid derived from said control valve and in response to the movement of said support for rendering said biasing means effective to move said spool to the neutral position and thus arrest movement of said support; and means associated with said detent release valve for venting the fluid communicated thereto to a zone of reduced pressure.
  • a control device for venting a hydraulic circuit comprising a fluid control valve having a spool reciprocably mounted therein, a double acting linear actuator connected to said control valve, said spool being adjustable to communicate pressure fluid to said actuator to effect extension and retraction thereof, a detent mechanism rendered operative when said spool is adjusted to effect extension of said actuator and maintain said spool in its adjusted position, a fluid operated detent release mechanism including a housing having a reciprocable valve element formed with land portions and a rod portion, means effective upon the extension of said actuator for communicating pressure fluid from said control valve to an annular chamber of said detent release defined by said rod and land portions, throttling means for exhausting a part of the fluid communicated to said annular chamber to a zone of reduced pressure and thereby purging entrapped air from the circuit, and a passageway in said valve element communicating fluid from said annular chamber to a second chamber defined by one of said lands and said housing in order to effect shifting of said valve element, said valve element being connected to said detent mechanism so that upon
  • a hydraulic motor a selectively operable control valve for controlling the flow of pressure fluid from a source to said motor
  • a reciprocable spool in said control valve formed with an elongated extension located outwardly of the valve body, a first link having one end pivotally connected to said extension and the other end formed to define a cam surface, a second link supporting a cam follower in contact with siliently biased to bring said follower in contact with said cam surface, valve means having a reciprocable spool connected to said second link, said last mentioned spool being moved in one direction by the bias imparted to said second link and in the other direction by pressure fluid communicated to said valve means, a valve operable in response to the operation of said motor communicating pressure fluid to said valve means for moving said spool thereof in said other direction against the bias of said second link to permit disengagement of said cam and follower and allow said first mentioned spool to interrupt flow of pressure fluid to said motor.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)
  • Auxiliary Drives, Propulsion Controls, And Safety Devices (AREA)
  • Motor Or Generator Cooling System (AREA)
  • Lifting Devices For Agricultural Implements (AREA)
  • Mechanically-Actuated Valves (AREA)
US388789A 1964-08-11 1964-08-11 Hydraulic actuating mechanism Expired - Lifetime US3289546A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US388789A US3289546A (en) 1964-08-11 1964-08-11 Hydraulic actuating mechanism
GB33110/65A GB1060347A (en) 1964-08-11 1965-08-03 Hydraulic control circuits
DE1500345A DE1500345C3 (de) 1964-08-11 1965-08-09 Hydraulische Steuervorrichtung für einen durch einen Servomotor verlagerbaren Träger
ES0316370A ES316370A1 (es) 1964-08-11 1965-08-11 Dispositivo de control hidraulico.
FR28058A FR1444512A (fr) 1964-08-11 1965-08-11 Dispositif de commande et de purge de circuit hydraulique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US388789A US3289546A (en) 1964-08-11 1964-08-11 Hydraulic actuating mechanism

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US3289546A true US3289546A (en) 1966-12-06

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US388789A Expired - Lifetime US3289546A (en) 1964-08-11 1964-08-11 Hydraulic actuating mechanism

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US (1) US3289546A (de)
DE (1) DE1500345C3 (de)
ES (1) ES316370A1 (de)
GB (1) GB1060347A (de)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3400634A (en) * 1966-10-21 1968-09-10 Caterpillar Tractor Co Vent means for hydraulic circuit
US3503306A (en) * 1968-07-23 1970-03-31 Caterpillar Tractor Co Positive pressure detent and release apparatus for control valves
US3670628A (en) * 1970-09-02 1972-06-20 Caterpillar Tractor Co Kickout valve and circuit
US3717073A (en) * 1971-06-23 1973-02-20 Caterpillar Tractor Co Proximity switch magnet control for bucket positioner
US3776099A (en) * 1971-12-06 1973-12-04 Applied Power Inc Automatic release and centering device
USB510588I5 (de) * 1974-09-30 1976-01-27
US5046312A (en) * 1988-07-08 1991-09-10 Kubota, Ltd. Swivel speed control circuit for working vehicle
US9714497B2 (en) 2015-10-21 2017-07-25 Caterpillar Inc. Control system and method for operating a machine
US20210095437A1 (en) * 2019-09-27 2021-04-01 Topcon Positioning Systems, Inc. Method and apparatus for mitigating machine operator command delay
US11987949B2 (en) 2017-08-30 2024-05-21 Topcon Positioning Systems, Inc. Method and apparatus for machine operator command attenuation

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102015104761A1 (de) * 2015-03-27 2016-09-29 Claas Selbstfahrende Erntemaschinen Gmbh Hydrauliksystem mit Ölentlüftung

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2159879A (en) * 1936-02-07 1939-05-23 Servo Frein Dewandre Sa Pneumatic control apparatus
GB549134A (en) * 1941-08-19 1942-11-06 David Bro Tractors Ltd Improvements in hydraulic mechanism for the operation of tractor-drawn agricultural implements
US2649076A (en) * 1950-06-20 1953-08-18 Burndy Engineering Co Inc Power-operated tool with automatic control valve system
FR1044005A (fr) * 1951-10-19 1953-11-13 Perfectionnements aux presses à commande hydraulique
US2670713A (en) * 1948-10-06 1954-03-02 Deere Mfg Co Controllable limit means for regulating strokes of fluid pressure apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2159879A (en) * 1936-02-07 1939-05-23 Servo Frein Dewandre Sa Pneumatic control apparatus
GB549134A (en) * 1941-08-19 1942-11-06 David Bro Tractors Ltd Improvements in hydraulic mechanism for the operation of tractor-drawn agricultural implements
US2670713A (en) * 1948-10-06 1954-03-02 Deere Mfg Co Controllable limit means for regulating strokes of fluid pressure apparatus
US2649076A (en) * 1950-06-20 1953-08-18 Burndy Engineering Co Inc Power-operated tool with automatic control valve system
FR1044005A (fr) * 1951-10-19 1953-11-13 Perfectionnements aux presses à commande hydraulique

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3400634A (en) * 1966-10-21 1968-09-10 Caterpillar Tractor Co Vent means for hydraulic circuit
US3503306A (en) * 1968-07-23 1970-03-31 Caterpillar Tractor Co Positive pressure detent and release apparatus for control valves
US3670628A (en) * 1970-09-02 1972-06-20 Caterpillar Tractor Co Kickout valve and circuit
US3717073A (en) * 1971-06-23 1973-02-20 Caterpillar Tractor Co Proximity switch magnet control for bucket positioner
US3776099A (en) * 1971-12-06 1973-12-04 Applied Power Inc Automatic release and centering device
USB510588I5 (de) * 1974-09-30 1976-01-27
US3981539A (en) * 1974-09-30 1976-09-21 Caterpillar Tractor Co. Wagon door control system and dual cam therefor
US5046312A (en) * 1988-07-08 1991-09-10 Kubota, Ltd. Swivel speed control circuit for working vehicle
US9714497B2 (en) 2015-10-21 2017-07-25 Caterpillar Inc. Control system and method for operating a machine
US11987949B2 (en) 2017-08-30 2024-05-21 Topcon Positioning Systems, Inc. Method and apparatus for machine operator command attenuation
US20210095437A1 (en) * 2019-09-27 2021-04-01 Topcon Positioning Systems, Inc. Method and apparatus for mitigating machine operator command delay
US11828040B2 (en) * 2019-09-27 2023-11-28 Topcon Positioning Systems, Inc. Method and apparatus for mitigating machine operator command delay

Also Published As

Publication number Publication date
DE1500345B2 (de) 1973-12-13
ES316370A1 (es) 1966-04-16
DE1500345C3 (de) 1974-07-04
GB1060347A (en) 1967-03-01
DE1500345A1 (de) 1969-05-08

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