US3727968A - Lumber grabbing apparatus - Google Patents

Lumber grabbing apparatus Download PDF

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Publication number
US3727968A
US3727968A US00146636A US3727968DA US3727968A US 3727968 A US3727968 A US 3727968A US 00146636 A US00146636 A US 00146636A US 3727968D A US3727968D A US 3727968DA US 3727968 A US3727968 A US 3727968A
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United States
Prior art keywords
grabbing
hydraulic cylinder
arms
lumber
port
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00146636A
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English (en)
Inventor
A Tsuchihashi
K Honma
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Hitachi Ltd
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Hitachi Ltd
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Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C3/00—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith and intended primarily for transmitting lifting forces to loose materials; Grabs
    • B66C3/14—Grabs opened or closed by driving motors thereon
    • B66C3/16—Grabs opened or closed by driving motors thereon by fluid motors

Definitions

  • This invention relates to a grabbing apparatus capable of grabbing a large amount of material, e.g., lumbers, at a time by penetrating its grabbing arms deep into the interspace of the lumbers.
  • a prior art grabbing apparatus well-known in the art includes a grab 1 having a pair of cooperating grabbing arms 1a, 1b; a reciprocating cylinder unit 2 for opening and closing said grab 1; a rotary cylinder unit 3 for rotating said grab 1 and another reciprocating cylinder unit 4 for moving the entire assembly of said elements in a vertical direction; said grabbing arms la, lb of said grab 1 being pivotally connected at their middle portions to said cylinder unit 2 by means of rods 5a, 5b respectively and also being pivotally connected at their roots to the lower end extremity ofa piston rod 2a of said cylinder unit 2.
  • the piston rod 2a of the reciprocating cylinder unit 2 is extended or retracted, whereby the grabbing arms 1a, lb are opened or closed to grab the logs T.
  • the object of the present invention is to provide a lumber grabbing apparatus which is small in size and hence enables the weight of the entire loading machine to be reduced, and which is operable with high efficiency even in a narrow space.
  • FIG. 1 is a view showing the construction of a conventional lumber grabbing apparatus
  • FIG. 2 is a view showing the construction of the lumber grabbing apparatus according to the present invention.
  • FIG. 3 is a diagramshowing the hydraulic circuit of the lumber grabbing apparatus of the invention.
  • FIG. 4 is a vertical sectional view of a position command pressure reducing valve used in the present invention.
  • the lumber grabbing apparatus of the invention is shown in FIG. 2.
  • reference numeral 6 designates a grabbing apparatus elevating hydraulic cylinder, in which a piston 7 is slidably disposed.
  • the piston 7 is connected to the lower end of a piston rod 8, the upper end of which is fixed to a machine frame.
  • the fluid pressure in the cylinder varies incident to the vertical movement of the piston rod 8.
  • Reference numeral 9 designates a grabbing apparatus rotating hydraulic cylinder and 10 generally designates a grab.
  • the grab 10 includes grabbing members 11, 11' and arms 12, 12, and said grabbing members and said arms are operable independently.
  • Reference numeral 13 designates a grabbing members opening and closing hydraulic cylinder.
  • the grabbing members 11, 11' are pivotally connected to the lower end of a piston rod of the cylinder 13 at one ends by means of a hinge pin 14.
  • Reference numerals 16, 16' designate rotary cylinders for opening and closing the arms 12, 12', and the arms can be pivotally moved to the left and right by varying the fluid pressure in said cylinders respectively.
  • the hydraulic circuit comprises a manually operable position command pressure reducing valve 17, a servo directional control valve 18, the hydraulic cylinder 16, a position feedback pressure reducing valve 19, the arm 12 and pipes communicating said elements with each other.
  • the servo directional control valve 18 includes a casing 20 which is provided with a port 20a communicating with a first fluid pressure generator P1 of large capacity, a port 20b communicating with the position command pressure reducing valve 17, ports 20c and 20d communicating with ports 16a and 16b of the hydraulic cylinder 16 respectively, a port 20 communicating with the position feedback pressure reducing valve 19 and discharge ports 20f, 20g communicating with a tank (not shown).
  • Reference numeral 21 designates a valve spool slidably disposed in the casing 20, which has a land 21a for establishing orbreaking the communication between the ports 20c and 20g, a land 21b for establishing or breaking the communication between the ports 20a and 20d, and a land 210 for establishing or breaking the communication between the ports 20d and 20f.
  • the position command pressure reducing valve 17 which is operated by the operator at his own will, is constructed as shown in FIG. 4.
  • this pressure reducing valve 17 includes a casing 22 which is provided with a port 22a communicating with a fluid pressure source, a port 2212 communicating with the servo directional control valve 18, and a drain port 22c through which the pressurized fluid flowing into the casing 22 from the port 22a is returned to the tank.
  • a valve spool 23 which has two lands 23a and 23b for establishing or breaking the communication between the ports 22a and 22b.
  • a push rod 24 is inserted into the casing 22 on one side of the valve spool 23 adjacent the land 23a and a spring 25 is provided between said push rod 24 and said land 23a, by which the valve spool 23 is constantly urged downwards.
  • a spring 25 is provided between said push rod 24 and said land 23a, by which the valve spool 23 is constantly urged downwards.
  • annular groove 26 communicating with the port 22a and an annular groove 27 communicating with the port 22b.
  • a passage 29 is formed axially in the land 23b of the valve spool 23, for communicating a chamber 28 formed below the lower end of the valve spool 23, with the annular groove 26 and an orifice 30 is formed in said passage 29 at the central portion thereof.
  • the valve spool 23 is moved down by the spring 25, so that the communication is established between the ports 22a and 22b and the pressurized fluid flows through the pipe to act on the servo directional control valve 18.
  • the pressurized fluid in the annular groove 27 flows into the chamber 28 through the orifice 30 to build up the pressure in said chamber against the biasing force of the spring 25.
  • the valve spool 23 is located in a position to break the communication between the ports 22a and 22b. In other words, the fluid pressure in the port 22a is proportional to the amount of downward movement of the push rod 24.
  • the arm opening and closing rotary cylinder 16 has a port 160 communicating with the port c of the servo directional control valve 18 and a port 16b communicating with the port 20d of said directional control valve 18.
  • the arrangement is such that when the pressurized fluid is supplied into the rotary cylinder 16 from the port 1611, an output shaft is connected directly with the arm is rotated in a clockwise direction, causing the arm in a clockwise direction, whereas when the pressurized fluid is supplied thereinto from the other port 160, the output shaft is rotated in the opposite direction, causing the arm to rotate in a counterclockwise direction.
  • the angle of rotation of the output shaft is limited to not more than 360.
  • the position feedback pressure reducing valve 19 is identical in construction with the position command pressure reducing valve 17 previously described with reference to FIG. 4, and the outer end of a piston rod 19a of the valve 19 is held in contact with the side face of the arm connected to the output shaft of the rotary cylinder 16. The push rod is displaced in proportion to the angle of rotation a of the arm 12. Further, the position feedback pressure reducing valve 19 is in communication with the first fluid pressure generator P1 and also with the servo directional control valve 18 as will be described later.
  • reference numeral 31 designates a pressurized fluid feed pipe extending from a second fluid pressure generator P2 and connected to the port 22b of the position command pressure reducing valve 17, 32 a remote control pipe for feeding the pressurized fluid from the port 22a of the position command pressure reducing valve 17 to the port 20b of the servo directional control valve 18 therethrough, and 33 a pressurized fluid feed pipe extending from the first fluid pressure generator P1 to the port 20a of the servo directional control valve 18.
  • Reference numeral 34 designates a pipe communicating the port 20c of the servo directional control valve 18 with the port 16a of the rotary cylinder 16, 35 a pipe communicating the port 20d of the servo directional control valve 18 with the port 16b of the rotary cylinder 16, 36 a pipe branched from said pressurized fluid feed pipe 33 and connected to the position feedback pressure reducing valve 19, and 37 a pipe communicating the port 20e of the servo directional control valve 18 with the position feedback pressure reducing valve 19.
  • the lumber grabbing apparatus of the invention will operate in the following manner:
  • the rotary cylinder 9 shown in FIG. 2 is actuated to set the arms 12, 12 in positions parallel to the longitudinal direction of the logs and at right angles to the surface of the ground, and then the loading machine is lowered to penetrate the arms 12, 12' into the first layer of logs. Successively thereafter, the arms 12, 12 are penetrated into the second layer of logs.
  • the angular positions of the arms 12, 12 are respectively adjusted by means of the rotary cylinders l6, 16 while holding the hydraulic cylinder 9 and the grab opening and closing cylinder 13 in the fixed state and lowering the grab elevating cylinder 6.
  • the adjustment of the angle of opening a of each arm 12 or 12' can be achieved by projecting or retracting the push rod of the position command pressure reducing valve 17.
  • valve spool 23 when the valve spool 23 is moved down by pushing the push rod 24 in FIG. 4, the ports 22b and 22a are brought into communication with each other and the fluid pressure from the second fluid pressure generator P2 shown in FIG. 3 is supplied through the pipe 32 into the right end chamber of the servo directional control valve 18 from the port 20b, causing the leftward movement of the valve spool 21.
  • the communication is established between the ports 20a and 20d and the fluid pressure from the first fluid pressure generator P1 is supplied into the port 16b of the rotary cylinder 16 through the pipe 35, causing the arms 12, 12 to rotate in a clockwise direction.
  • valve spool 21 moves to the right, the communication between the ports 20a and 20d is gradually broken and the rightward movement of the valve spool 21 stops when the communication is completely broken and the fluid pressure in the left and right end chambers are balanced with each other.
  • the pressurized fluid in the right end chamber of the servo directional control valve 18 is returned to the position command pressure reducing valve 17 through the pipe 32.
  • the pressurized fluid is discharged from the port 22a and flows into the lower end chamber 28 through the orifice 30 of the valve spool 23 in FIG. 4. Consequently, the valve spool 23 is moved upwards and the land 23a opens the port 22c, whereupon the communication is established between the ports 22a and 22c and the pressurized fluid is slowly returned to the tank through the port 22c.
  • the push rod 19a of the position feedback pressure reducing valve 19 is displaced and pressurized fluid supply into the pipe 37 is shut down by the valve spool. Therefore, the fluid pressure in the left end chamber of the servo directional control valve 18 is decreased and that in the right end chamber thereof becomes higher, with the result that the valve spool 21 moves to the left. The leftward movement of the valve spool 21 continues until it reaches a position at which the pressures in the right and left end chambers are equally balanced.
  • valve spool 21 stops its leftward movement.
  • the position of the valve spool 21 of the servo directional control valve 18 is constantly changed by the axial movement of the push rod of the position command pressure reducing valve 17, directing the fluid pressure from the first fluid pressure generator P1 to flow from the port 200 into the port 20c or 20d.
  • the former is slightly smaller in size than the latter but the latter can grab an amount of lumber twice or more times as much as the amount which can be grabbed by the former, at one time.
  • the number of logs which can be grabbed by the subject apparatus are indicated by the hatched lines, and the same number of logs are indicated in FIG. 1 by the solid lines.
  • the logs indicated by the cross-hatched lines are those which can be grabbed by the prior art apparatus but cannot be grabbed by the apparatus of FIG. 2 because the grabbing span is smaller than that of the former. From the comparison between the logs indicated by the solid lines and those indicated by the hatched lines, it will be understood that the apparatus of FIG. 2 can grab a larger amount of lumber at a time than the apparatus of FIG. 1, though it is relatively small in size.
  • the grab is composed of the grabbing members and the arms, and said grabbing members and arms are operable independently. Therefore, the apparatus of the invention can grab a large amount of article at one time as compared with the logs by repeating the operation described above, the 2 cylinder 13 is actuated to close the grabbing members conventional apparatus, even though the former is smaller in grabbing span and in size than the latter.
  • the weight of the entire loading machine can be reduced and the operational efficiency of the machine can be enhanced even in a narrow space.
  • a lumber grabbing apparatus comprising a. a hydraulic cylinder including a piston slidably disposed therein and a piston rod connected to said piston;
  • a pair of grabbing members adapted to be opened and closed by said hydraulic cylinder, each of said grabbing members having one end pivotally connected to the outer end of the piston rod of said hydraulic cylinder, the respective mid portions of said grabbing members being pivotally connected to respective first ends of rods, the other ends of said rods being connected to said hydraulic cylinder;
  • hydraulic cylinders provided on said grabbing members respectively for causing said arms to make a pivotal movement about the other ends of said grabbing members.
  • a lumber grabbing apparatus comprising first hydraulic cylinder means having a piston slidably disposed therein, a piston rod having one end connected to said piston, a pair of grabbing members adapted to be opened and closed by said first hydraulic cylinder means, each of said grabbing members having one end thereof pivotally connected to the other end of said piston rod, a pair of connecting rods, each connecting rod having one end connected to said first hydraulic cylinder means and the other end pivotally connected to the mid portion of a respective one of said grabbing members, a pair of arms means, each of said 3.
  • a lumber grabbing apparatus pivotally connected to the other end of a 2, Whfir in aid nd hydraulic cylinder means inrespective one of said grabbing members, and second cludes a P Of hydraulic Cylinders, each of Said hydraulic cylinder means mounted on said grabbing hydraulic Q'W belng mounted on a respective one members for controlling the pivotal movement of said of Sald grabbmg members f commnlflg the movearm means about the other end of said grabbing memmam of the arm means assoclated therew'thbers

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Load-Engaging Elements For Cranes (AREA)
  • Manipulator (AREA)
  • Ship Loading And Unloading (AREA)
  • Paper (AREA)
US00146636A 1970-06-12 1971-05-25 Lumber grabbing apparatus Expired - Lifetime US3727968A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45050318A JPS4923180B1 (enrdf_load_stackoverflow) 1970-06-12 1970-06-12

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US3727968A true US3727968A (en) 1973-04-17

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US00146636A Expired - Lifetime US3727968A (en) 1970-06-12 1971-05-25 Lumber grabbing apparatus

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US (1) US3727968A (enrdf_load_stackoverflow)
JP (1) JPS4923180B1 (enrdf_load_stackoverflow)
CA (1) CA948672A (enrdf_load_stackoverflow)
DE (1) DE2128712C3 (enrdf_load_stackoverflow)
FR (1) FR2095208B1 (enrdf_load_stackoverflow)
GB (1) GB1342526A (enrdf_load_stackoverflow)
NO (1) NO132471C (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3881263A (en) * 1973-04-18 1975-05-06 Poclain Sa Angular position controller for clam-shell bucket
US4797059A (en) * 1986-11-07 1989-01-10 General Motors Corporation Seat handling fixture
US5066189A (en) * 1990-08-03 1991-11-19 Shell Material Handling Systems, Inc. Method and apparatus for handling discrete cargo units
US6695120B1 (en) * 2000-06-22 2004-02-24 Amkor Technology, Inc. Assembly for transporting material
US6889813B1 (en) 2000-06-22 2005-05-10 Amkor Technology, Inc. Material transport method
US20060202497A1 (en) * 2005-03-11 2006-09-14 Cveykus Gregory A Self-opening tong lifting device
US20100176615A1 (en) * 2006-11-24 2010-07-15 Akinobu Okuda Multi-fingered robot hand
CN104860193A (zh) * 2015-05-20 2015-08-26 中国有色（沈阳）冶金机械有限公司 一种水平捞取的抓斗装置
US20150239713A1 (en) * 2012-09-25 2015-08-27 A Ward Attachments Limited Hydraulic Grapple
CN107381342A (zh) * 2016-05-17 2017-11-24 湖南工业大学 一种实现铝电解捞渣抓斗底部平移的设计方法
CN114104946A (zh) * 2021-09-26 2022-03-01 杭叉集团股份有限公司 一种双驱动电动叉车驱动单元辅助安装装置
US20220065720A1 (en) * 2020-09-03 2022-03-03 GM Global Technology Operations LLC Insertion force measurement system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105986542B (zh) * 2016-07-22 2019-03-01 徐州徐工养护机械有限公司 一种全自动液压抓斗上料系统及其沥青路面养护车

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US247829A (en) * 1881-10-04 And ge
US2743954A (en) * 1951-07-16 1956-05-01 Stora Kopparbergs Bergslags Ab Clutching tong

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US247829A (en) * 1881-10-04 And ge
US2743954A (en) * 1951-07-16 1956-05-01 Stora Kopparbergs Bergslags Ab Clutching tong

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3881263A (en) * 1973-04-18 1975-05-06 Poclain Sa Angular position controller for clam-shell bucket
US4797059A (en) * 1986-11-07 1989-01-10 General Motors Corporation Seat handling fixture
US5066189A (en) * 1990-08-03 1991-11-19 Shell Material Handling Systems, Inc. Method and apparatus for handling discrete cargo units
US6695120B1 (en) * 2000-06-22 2004-02-24 Amkor Technology, Inc. Assembly for transporting material
US6889813B1 (en) 2000-06-22 2005-05-10 Amkor Technology, Inc. Material transport method
US7673918B2 (en) * 2005-03-11 2010-03-09 Kenco Corporation Self-opening tong lifting device
US20060202497A1 (en) * 2005-03-11 2006-09-14 Cveykus Gregory A Self-opening tong lifting device
US20100176615A1 (en) * 2006-11-24 2010-07-15 Akinobu Okuda Multi-fingered robot hand
US8100451B2 (en) * 2006-11-24 2012-01-24 Panasonic Corporation Multi-fingered robot hand
US20150239713A1 (en) * 2012-09-25 2015-08-27 A Ward Attachments Limited Hydraulic Grapple
CN104860193A (zh) * 2015-05-20 2015-08-26 中国有色（沈阳）冶金机械有限公司 一种水平捞取的抓斗装置
CN107381342A (zh) * 2016-05-17 2017-11-24 湖南工业大学 一种实现铝电解捞渣抓斗底部平移的设计方法
US20220065720A1 (en) * 2020-09-03 2022-03-03 GM Global Technology Operations LLC Insertion force measurement system
US11644375B2 (en) * 2020-09-03 2023-05-09 GM Global Technology Operations LLC Insertion force measurement system
CN114104946A (zh) * 2021-09-26 2022-03-01 杭叉集团股份有限公司 一种双驱动电动叉车驱动单元辅助安装装置

Also Published As

Publication number Publication date
DE2128712C3 (de) 1974-04-18
NO132471B (enrdf_load_stackoverflow) 1975-08-11
JPS4923180B1 (enrdf_load_stackoverflow) 1974-06-13
CA948672A (en) 1974-06-04
DE2128712A1 (de) 1971-12-16
FR2095208B1 (enrdf_load_stackoverflow) 1976-03-19
NO132471C (enrdf_load_stackoverflow) 1975-11-19
GB1342526A (en) 1974-01-03
FR2095208A1 (enrdf_load_stackoverflow) 1972-02-11
DE2128712B2 (de) 1973-09-20

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