US3927781A - Excavator - Google Patents

Excavator Download PDF

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Publication number
US3927781A
US3927781A US384299A US38429973A US3927781A US 3927781 A US3927781 A US 3927781A US 384299 A US384299 A US 384299A US 38429973 A US38429973 A US 38429973A US 3927781 A US3927781 A US 3927781A
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US
United States
Prior art keywords
hydraulic cylinder
boom
bucket
arm
excavator
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
US384299A
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English (en)
Inventor
Nobuya Okabe
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.)
Hitachi Construction Machinery Co Ltd
Original Assignee
Hitachi Construction Machinery Co Ltd
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 Hitachi Construction Machinery Co Ltd filed Critical Hitachi Construction Machinery Co Ltd
Application granted granted Critical
Publication of US3927781A publication Critical patent/US3927781A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • E02F3/435—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like
    • E02F3/436—Control of dipper or bucket position; Control of sequence of drive operations for dipper-arms, backhoes or the like for keeping the dipper in the horizontal position, e.g. self-levelling
    • 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
    • E02F3/30—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 a dipper-arm pivoted on a cantilever beam, i.e. boom
    • E02F3/308—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 a dipper-arm pivoted on a cantilever beam, i.e. boom working outwardly
    • 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
    • E02F3/425—Drive systems for dipper-arms, backhoes or the like

Definitions

  • a levelling hydraulic cylinder is connected between 1 the underside of a boom and the intermediate portion of an arm in addition to a hydraulic cylinder for operating the arm.
  • a fluid chamber on the piston rod pushout side of the levelling cylinder is maintained in communication through a tube with fluid chambers on the piston rod push-out side of a pair of hydraulic cylinders for operating the boom while a fluid chamber on the piston rod pull-in side of the levelling cylinder is maintained in communication through another tube with fluid chambers on the piston rod pull-in side of the pair of hydraulic cylinders for operating the boom.
  • a bucket supported at the forward end of the arm can be thrust horizontally forwardly to dig out soil as the arm is oscillated when a piston rod sliding into and out of the hydraulic cylinder for operating the arm.
  • FIG. 3 PRIOR ART US. Patent Dec. 23, 1975 FIG. 3
  • FIG. 5 PRIOR ART FIG. 5
  • This invention relates to an excavator of the type which is provided with a bucket for digging out soil supported at one end of an arm in turn is supported by a boom connected to an excavator proper so that the bucket can be pushed out horizontally forwardly by means of the boom and the arm to dig out soil.
  • the horizontal forward movement of the bucket 3 for scooping up soil and dumping the soil in the bucket into the truck can be performed adequately only if the boom 2, arm 1 and bucket 3 are simultaneously operated so that each of them moves a proper distance in a proper direction.
  • conventional excavators have the disadvantage of their operators having to be highly skilled in the art of operating their machines. An added disadvantage is that even skilled operators get greatly tired when they operate their machines to push out the bucket 3 horizontally forwardly.
  • This invention obviates the aforementioned disadvantages of conventional excavators of the bucket type in which the bucket is pushed out horizontally forwardly. Accordingly, the invention has as its object the provision of an excavator of the bucket type which can be operated with greater ease and which permits an excavating operation to be performed with a higher degree of efficiency.
  • an excavator of the bucket type comprising an excavator proper including a movable body, a rotary body and a swivel body, a boom pivotally supported at a forward end portion of the swivel body of the excavator proper for movement between a lying position and an upright position, a pair of hydraulic cylinders for moving the boom between the lying position and upright position, an arm pivotally supported through a pin at a forward end of the boom for oscillating motion, a hydraulic cylinder for operating the arm and causing the same to move in oscillating motion, a bucket pivotally supported at a forward end of the arm, a hydraulic cylinder for operating the bucket pivotally connected through a pair of rigid links to a forward end portion of the arm for moving the bucket horizontally forwardly away from the excavator proper in oscillating motion, and a levelling hydraulic cylinder connected at one end to the boom at its underside and at the other end to the arm at its substantially intermediate portion, said levelling hydraulic cylinder connected at one end to the
  • One of the features of the invention is that the bucket can be pushed out horizontally forwardly merely by manipulating the hydraulic cylinder for operating the arm.
  • FIG. 1 schematically shows a conventional excavator of the bucket type in which the bucket is pushed out horizontally forwardly;
  • FIG. 2 is a schematic view of the excavator of the bucket type comprising one embodiment of the invention
  • FIG. 3 is a view in explanation of the operation of excavator according to the invention.
  • FIG. 4 shows the relation between the digging force and the reaction at work when soil digging is carried out by the conventional excavator shown in FIG. 1;
  • FIG. 5 shows the relation between the digging force and the reaction at work when soil digging is carried out by the excavator according to the invention.
  • 8 generally designates an excavator proper according to the invention including a movable body 8a having a caterpillar, a rotary body 8b mounted on the movable body 8a, and a swivel body mounted on the rotary body 8b.
  • the swivel body 8c is provided with an operators cab 8d.
  • a boom 9 is pivotally connected to the swivel body 8c for movement in one vertical plane between a lying position and an upright position by the action of a pair of hydraulic cylinders 10, 10 for operating the boom 9.
  • the hydraulic cylinders 10, 10 are each disposed on one of opposite sides of the boom 9 and connected at its base to the swivel body 80 through a pin 11.
  • Piston rods 12, 12 each received in one of the pair of hydraulic cylinders 10, are connected to the boom 9 through a pin 13. 7
  • An arm 15 is pivotally connected through a pin 14 to a forward end of the boom 9 for movement in one vertical plane, like the boom 9, by the action of a hydraulic cylinder 16 for operating the arm 15.
  • the hydraulic cylinder 16 is connected at its base through a pin 17 to a bracket 18 projecting downwardly from the underside of a forward end portion of the boom 9.
  • the hydraulic cylinder 16 receives therein a piston rod 19 connected at its forward end to a forward end portion of the arm 15 through a pin 20.
  • a bucket 21 is connected through a pin 22 to the forward end of the arm 15 and moves in what is referred to as a wrist motion by the action of a hydraulic cylinder 23 for operating the bucket 21.
  • the hydraulic cylinder 23, which is connected at its base through a pin 24 to the forward end portion of the boom 9, receives therein a piston rod 25 connected at its forward end through a pin 26 to one end of each of rigid links 27 28.
  • the rigid links 27, 28 are connected at the other end to the forward end of the piston rod 19 received the hydraulic cylinder 16 respectively.
  • a levelling hydraulic cylinder 29 operatively associated with the hydraulic cylinder 16 for operating the arm 15 is connected between the boom 9 and the arm 15 and disposed nearer to them than the hydraulic cylinder 16, so that the levelling hydraulic cylinder 29 can move into the arm 15. More specifically, the levelling hydraulic cylinder 29 is .connected at its base through a pin 30 to the bracket 18 projecting downwardly from the underside of the forward end portion of the boom 9 and receives therein a piston rod 31 connected through a pin 32 to the underside of the substantially intermediate portion of the arm 15.
  • the levelling hydraulic cylinder 29 has a fluid chamber on the piston rod push-out side thereof which is maintained through a tube 33 in communication with fluid chambers on the piston rod push-out side of the hydraulic cylinders 10, 10, and another fluid chamber on the piston rod pull-in side thereof which is maintained through another tube 34 in communication with fluid chambers on the piston rod pull-in side of the hydraulic cylinders'10, 10.
  • the connections between the levelling hydraulic cylinder 29 and the hydraulic cylinders 10, 10 perform an important function in pushing out the bucket 21 horizontally outwardly. More specifically, when the arm 15 is pivoted in the direction of an arrow A in FIG. 2 by the action of the hydraulic cylinder 16, the piston rod 31 is forced to slide out of the levelling hydraulic cylinder 29. This results in the fluid under pressure in the fluid chamber on the piston rod pull-in side of the levelling hydraulic cylinder 29 being forced to flow out of the fluid chamber and moving through tube 34 into the fluid chambers on the piston rod pull-in side of the hydraulic cylinders 10, 10.
  • the hydraulic cylinders 10, 10 and 29 are constructed such that they are equal to each other in the diameter of their piston and piston rod or in the pressure receiving area ratio in order to prevent the occurrence of a vacuum due to the oversupply or the lack of fluid when the aforementioned operation is performed.
  • the position in which the base of the hydraulic cylinder 23 is connected to the boom 9 through pin 24 is selected such that a quadrilateral is formed by the pins 14, 20, 26 and 24 in the plane of FIG. 2, so that a toothed portion 21a of the bucket 21 can be maintained at a predetermined angle with respect to the horizontal when the arm 15 is oscillated and the boom 9 is moved between the lying and upright positions.
  • the hydraulic cylinders l0, l6 and 23 can be actuated independently of one another by manipulating control levers provided in the operators cab 8d.
  • fluid under pressure is supplied to a fluid chamber on the piston rod push-out side of the hydraulic cylinder 16 for operating the arm 15 when the bucket 21 is disposed in a position designated V in which it is near the excavator proper 8 as shown in FIG. 2.
  • the piston rod 31 is forced to slide out of the levelling hydraulic cylinder 29, and the fluid under pressure in the fluid chamber on the piston rod pull-in side of the levelling hydraulic cylinder 29 flows into the fluid chamber on the piston rod pull-in side of each hydraulic cylinder 10 through tube 34 to operate the boom 9.
  • fluid under pressure is caused to act on the fluid chambers on the piston rod push-out side of the hydraulic cylinders l0, 10.
  • the fluid under pressure caused to act on the fluid chambers on the piston rod push-out side of the hydraulic cylinders 10, 10 in this way may act on the fluid chamber on the piston rod push-out side of the hydraulic cylinder 29 through tube 33. This causes no trouble because the hydraulic cylinder 16 for operating the arm 15 is locked at this time.
  • the excavator according to the invention is constructed such that the force with which the bucket is 'rushed out horizontally forwardly away from the excavator proper in digging out soil is greater than the force with which the bucket of a conventional excavator is pushed out in the same direction, so that soil digging can be carried out with a higher degree of efficiency.
  • a reaction to the force with which digging is carried out is produced at the toothed portion of the bucket when the bucket is pushed out horizontally forwardly and its front end is raised to a higher level than its rear end when an earth digging operation is performed.
  • a reaction F1 to the force with which earth digging is carried out is produced at the toothed portion of the bucket 3 of a conventional excavator as shown in FIG. 4, the reaction F1 and a force P produced by the hydraulic cylinder 6 for operating the arm will balance as follows.
  • reaction F2 is greater than the reaction F1 in the prior art by (n'/m') Q.
  • the force exerted by the levelling hydraulic cylinder 29 may be either positive or negative.
  • the force Q is positive when the working angle 0 of the reaction F2 produced at the toothed portion 21a of the bucket 21 is such that the reaction F2 acts from above on the surface of the toothed portion 21a; the force Q is negative when the working angle 0 of the reaction F2 produced at the toothed portion 210 of the bucket 21 is such that the reaction acts from below on the surface of the toothed portion 21a. If the working angle 0 of the reaction F2 is positive, the hydraulic cylinders 10, 10 for operating the boom 9 will be subjected to a force which will tend to cause the piston rods 12, 12 to slide into the respective cylinders 10, 10.
  • the working angle 0 of the reaction F2 is positive in most cases and the excavator according to the invention exerts a greater digging force than a conventional excavator by (n'lm') Q.
  • the working angle 0 is negative, however, the digging force exerted by the excavator according to the invention is reduced as much. This offers an advantage in that the excavator proper is kept from slipping because at this time it is subjected to an upwardly oriented force and its ground gripping force is reduced in magnitude.
  • the invention is characterized by the provision, in addition to the hydraulic cylinder for operating the arm, of the levelling,hydraulic cylinder between the boom and the arm.
  • Such levelling hydraulic cylinder being constructed such that its fluid chambers are maintained in communication with corresponding fluid chambers in the hydraulic cylinders for operating the boom, so that the bucket supported at the forward end of the arm can be pushed out horizontally outwardly away from the excavator proper merely by manipulating the hydraulic cylinder for operating the arm.
  • the invention permits the bucket to be pushed out horizontally outwardly with a greater force in digging out soil, so that the ability of the excavator to dig out soil can be greatly enhanced.
  • the embodiment shown and described herein has a link ratio such that the capacity of the excavator can be increased by 30 percent.
  • An excavator of the bucket type comprising an excavator proper including movable body means, rotary body means and swivel body means, boom means pivotally supported at a forward end portion of said swivel body means of the excavator proper for movement between a lying position and an upright position, boom hydraulic cylinder means for moving the boom means, arm means pivotally supported at a forward end of said boom means for oscillating motion, arm hydraulic cylinder means for operating said arm means, bucket means pivotally supported at a forward end of said arm means, bucket hydraulic cylinder means for operating said bucket means pivotally connected through linking means to an end portion of said arm means for moving the bucket means horizontally forwardly away from the excavator proper in oscillating motion, and levelling hydraulic cylinder means connected at one end to the boom-means and at another end to the arm means, said levelling hydraulic cylinder means having a first fluid chamber on a piston rod push-out side thereof maintained in fluid communication with a fluid chamber on a piston rod push-out side of the boom hydraulic cylinder means
  • levelling hydraulic cylinder means and said boom hydraulic cylinder means are constructed such that they are equal to each other in the diameter of their piston and piston rod or in the pressure receiving area ratio in order to prevent the occurrence of a vacuum due to the oversupply or the lack of fluid when the bucket means is pushed horizontally outwardly from the excavator proper.
  • said linking means includes a pair of rigid links, and wherein said pair of rigid links are pivotally connected at one end through a pin to a forward end of a piston rod received in said bucket hydraulic cylinder means and another end of one of said pair of rigid links is pivotally connected through another pin to a forward end portion of said arm means while the other end of the other rigid link is pivotally connected to the bucket means.
  • boom hydraulic cylinder means comprises a pair of hydraulic cylinders, and wherein the arm means is pivotally supported to the boom means through a pin.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Operation Control Of Excavators (AREA)
US384299A 1972-08-28 1973-07-31 Excavator Expired - Lifetime US3927781A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47085352A JPS5233883B2 (enrdf_load_stackoverflow) 1972-08-28 1972-08-28

Publications (1)

Publication Number Publication Date
US3927781A true US3927781A (en) 1975-12-23

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US384299A Expired - Lifetime US3927781A (en) 1972-08-28 1973-07-31 Excavator

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US (1) US3927781A (enrdf_load_stackoverflow)
JP (1) JPS5233883B2 (enrdf_load_stackoverflow)
DE (1) DE2342399C3 (enrdf_load_stackoverflow)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2454484A1 (fr) * 1979-04-18 1980-11-14 Komatsu Mfg Co Ltd Perfectionnements apportes aux commandes hydrauliques d'excavateurs
FR2472633A1 (fr) * 1979-05-31 1981-07-03 Hitachi Construction Machinery Excavateur a commande hydraulique monte sur un organe de deplacement
EP0072539A3 (en) * 1981-08-18 1983-09-28 Hitachi Construction Machinery Co., Ltd. Hydraulic circuit of hydraulic power shovel
US4775288A (en) * 1986-10-03 1988-10-04 Dynamic Industries, Inc. High-lift loader
US4986010A (en) * 1989-03-13 1991-01-22 Cartner Jack O Sloper apparatus
US20040194355A1 (en) * 2001-05-22 2004-10-07 Josef Stock Wheel loader
US20060180563A1 (en) * 2004-07-22 2006-08-17 J.C. Bamford Excavators Limited Method of operating a machine
US20130034419A1 (en) * 2010-04-20 2013-02-07 Koichiro Tsukane Construction machine
US10676893B1 (en) * 2019-09-10 2020-06-09 Larry Irby Williams Self-leveling front-end loader having a double boom with a dogleg bend of 105 to 135 degrees including an extension powered by hydraulic cylinders
CN113338367A (zh) * 2021-06-28 2021-09-03 徐工集团工程机械股份有限公司科技分公司 一种四连杆两油缸的滑移装载机单边动臂结构及提升方法
US11555292B2 (en) * 2018-06-28 2023-01-17 Tigercat Industries Inc. Heavy equipment boom system and method and hydraulic circuit therefor

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5230819A (en) * 1975-09-04 1977-03-08 Tatsuo Ookohara Production of porous* lighttweight concrete board
JPS52145002U (enrdf_load_stackoverflow) * 1976-04-28 1977-11-02
JPS52145905U (enrdf_load_stackoverflow) * 1976-04-30 1977-11-05
JPS5849268Y2 (ja) * 1976-07-13 1983-11-10 株式会社神戸製鋼所 水平押出し可能な油圧式フエイスシヨベル
JPS53113103A (en) * 1977-03-14 1978-10-03 Mitsubishi Heavy Ind Ltd Device for correcting tilt angle of bucket of excavator
JPS5736702Y2 (enrdf_load_stackoverflow) * 1977-04-13 1982-08-13

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3220581A (en) * 1964-12-14 1965-11-30 Case Co J I Material handling equipment
US3230717A (en) * 1964-05-08 1966-01-25 Alden Lars Anders Gustaf Loading gear
US3339763A (en) * 1966-10-14 1967-09-05 Univ Oklahoma State Automatic back hoe control system
US3465903A (en) * 1967-08-11 1969-09-09 Bucyrus Erie Co Excavator shovel apparatus
US3586182A (en) * 1968-04-18 1971-06-22 Friedrich Schwing Bucket mounting for trench hoe

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3230717A (en) * 1964-05-08 1966-01-25 Alden Lars Anders Gustaf Loading gear
US3220581A (en) * 1964-12-14 1965-11-30 Case Co J I Material handling equipment
US3339763A (en) * 1966-10-14 1967-09-05 Univ Oklahoma State Automatic back hoe control system
US3465903A (en) * 1967-08-11 1969-09-09 Bucyrus Erie Co Excavator shovel apparatus
US3586182A (en) * 1968-04-18 1971-06-22 Friedrich Schwing Bucket mounting for trench hoe

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4301607A (en) * 1979-04-18 1981-11-24 Kabushiki Kaisha Komatsu Seisakusho Hydraulic excavator
FR2454484A1 (fr) * 1979-04-18 1980-11-14 Komatsu Mfg Co Ltd Perfectionnements apportes aux commandes hydrauliques d'excavateurs
FR2472633A1 (fr) * 1979-05-31 1981-07-03 Hitachi Construction Machinery Excavateur a commande hydraulique monte sur un organe de deplacement
EP0072539A3 (en) * 1981-08-18 1983-09-28 Hitachi Construction Machinery Co., Ltd. Hydraulic circuit of hydraulic power shovel
US4504185A (en) * 1981-08-18 1985-03-12 Hitachi Construction Machinery Co., Inc. Hydraulic circuit of hydraulic power shovel
US4775288A (en) * 1986-10-03 1988-10-04 Dynamic Industries, Inc. High-lift loader
US4986010A (en) * 1989-03-13 1991-01-22 Cartner Jack O Sloper apparatus
US7162817B2 (en) * 2001-05-22 2007-01-16 Liebherr-Werk Bischofshofen Gmbh Wheel loader
US20040194355A1 (en) * 2001-05-22 2004-10-07 Josef Stock Wheel loader
US20060180563A1 (en) * 2004-07-22 2006-08-17 J.C. Bamford Excavators Limited Method of operating a machine
US20130034419A1 (en) * 2010-04-20 2013-02-07 Koichiro Tsukane Construction machine
US8939699B2 (en) * 2010-04-20 2015-01-27 Sumitomo Heavy Industries, Ltd. Construction machine with hydraulic pipes
US11555292B2 (en) * 2018-06-28 2023-01-17 Tigercat Industries Inc. Heavy equipment boom system and method and hydraulic circuit therefor
US10676893B1 (en) * 2019-09-10 2020-06-09 Larry Irby Williams Self-leveling front-end loader having a double boom with a dogleg bend of 105 to 135 degrees including an extension powered by hydraulic cylinders
CN113338367A (zh) * 2021-06-28 2021-09-03 徐工集团工程机械股份有限公司科技分公司 一种四连杆两油缸的滑移装载机单边动臂结构及提升方法
CN113338367B (zh) * 2021-06-28 2022-01-11 徐工集团工程机械股份有限公司科技分公司 一种四连杆两油缸的滑移装载机单边动臂结构及提升方法

Also Published As

Publication number Publication date
JPS5233883B2 (enrdf_load_stackoverflow) 1977-08-31
DE2342399A1 (de) 1974-03-14
DE2342399B2 (de) 1975-03-20
DE2342399C3 (de) 1975-10-30
JPS4939905A (enrdf_load_stackoverflow) 1974-04-15

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