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
  • E02F3/36—Component parts
  • E02F3/3604—Devices to connect tools to arms, booms or the like
  • E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
  • E02F3/364—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat using wedges
• • 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
  • E02F3/3604—Devices to connect tools to arms, booms or the like
  • E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
  • E02F3/3627—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat with a hook and a longitudinal locking element
• • 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
  • E02F3/3604—Devices to connect tools to arms, booms or the like
  • E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
  • E02F3/3645—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat with auto-engagement means for automatic snap-on of the tool coupler part
• • 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
  • E02F3/3604—Devices to connect tools to arms, booms or the like
  • E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
  • E02F3/3663—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat hydraulically-operated

Definitions

• This invention relates to a locking device for a quick coupler.
• Quick couplers for mounting an attachment e.g. a bucket, to an earth working machine, such as an excavator
• a potential danger with a quick coupler is that the coupler can fail to hold the attachment at one or both of the mounting points at which the attachment is mounted to the quick coupler. As a result the attachment can either fall off the coupler (if the coupling at each of the mounting points fails) or swing down from the coupler (i.e. swing about one of the mounting points).
• the mounting points on the attachment are typically formed by so called pins and these fit into recesses of docking points of the quick coupler and then locked therein.
• the coupler When the coupler is mounted to the earth working machine such as an excavator, the end that is closest to the operator is referred to herein as the "front end”. As a consequence the pin of the attachment that fits into the recess/docking point at the front end is referred to herein as the "front pin”. Likewise the other end of the coupler is referred to as the “rear end” and the pin of the attachment that fits therein is referred to as the "rear pin”.
• the failure to correctly hold the attachment in place can be due to a variety of reasons.
• the quick coupler is of a type where the rear pin is retained by a sliding wedge component which is hydraulically operated an hydraulic failure can result in the quick coupler failing to retain the attachment in a working position. This will typically result from the rear pin applying a loading on the sloping leading surface of the wedge component which will drive the wedge "backward" to a position where the pin is no longer locked in the quick coupler. Consequently the attachment will swing down from the coupler about the axis of the front pin.
• An object of the present invention is thus to provide a wedge locking element for a locking device of a quick coupler, the wedge locking element being such that it at least reduces the tendency of a pin retained by the wedge driving the wedge (in the event of hydraulic failure) to a position where the pin will no longer be retained by the coupler or to at least provide the public with a useful choice.
• the inventive concept which achieves this object broadly resides in the leading end of the wedge having an orientation relative to a pin with which the wedge will engage in a locking relationship being such that the possibility of the pin applying a loading on the wedge to drive the wedge to a release position is at least reduced.
• a wedge locking element for a locking device of a quick coupler for coupling the pin of an attachment to earth working machinery, the wedge locking element including a sloping wedge surface, characterised in that projecting from the wedge surface is an engagement surface with which the attachment pin can engage but not apply any substantial driving force to the wedge locking element in the event of failure of a force maintaining the wedge locking element in a position whereby the pin is wedge coupled by the wedge surface to the coupler.
• the locking device further includes a clamp device operable to retain the pin with the pin engagement surface in the event of said failure of the driving force.
• the pin engagement surface is located at and forms the distal leading part of the wedge.
• the pin engagement surface is substantially planar.
• the pin engagement surface lies in a plane that is substantially in line with the direction in which the locking element is, in use, moved by the driving force.
• the driving force is hydraulic.
• the wedge locking element is adapted to couple to an hydraulic linear actuator, and more preferably the wedge locking element forms part of the hydraulic actuator.
• the clamp device is mounted to the wedge locking element.
• the clamp device includes an arm mounted to be pivotable about a pivot axis, the arm incorporating a pin engagement portion distal from the pivot axis.
• the arm is biased by biasing means.
• the biasing means is a spring.
• a quick coupler for coupling the pin of an attachment to earth working machinery, the coupler including a the combination of the wedge locking element and a clamp device as stated in the above second broad aspect of the invention.
• the wedge locking element is slidingly retained in the quick coupler and the clamp device is mounted for movement with the wedge locking element.
• Fig . 1 is a sectioned side elevation view of a prior art hydraulic quick coupler with a wedge form of pin engagement means, the drawing showing the front and rear pins of an attachment engaged in the front and rear recesses of the coupler,
• Fig . 2 is a further side elevation view similar to Fig. 1 of the prior art coupler but showing the coupler in a "failed mode" in which the rear pin is able to move out of the rear recess,
• Fig . 3 is a sectioned side elevation view of a coupler with which front and rear pins of an attachment are engaged and in which the leading part of the movable element (for locking the rear pin in the rear recess) has a profile according to the present invention, the movable element being shown in the fully retracted position,
• Figs . 4 to 8 are a succession of sectioned side elevation views of the coupler shown in Fig. 3 showing the rear pin in the rear recess and the progression of the movable element moving into the rear recess until it reaches a fully engaged position where the rear pin is retained in the rear recess by the movable element ( Fig. 8),
• Fig . 9 is a view similar to Fig. 8 but showing the coupler in a failed mode where the movable element has moved into a partially retracted position yet with the rear pin retained in engagement with the movable element by the clamp arm according to the present invention
• Fig . 1 0 is a view similar to Fig. 9 but showing the coupler in a failed mode where the movable element has moved into a partially retracted position yet with the rear pin retained not in engagement with the movable element yet still prevented by the clamp arm from moving from the recess,
• Fig . 1 1 is a view similar to Figs. 9 and 1 0 showing the coupler in a failed mode where the movable element has moved into a partially retracted position yet with the rear pin prevented from moving out of the rear recess by the clamp arm and the front pin prevented from moving from the front recess by the front recess retaining element,
• Fig . 1 2 is an isometric view of an example of the movable element according to the invention with a mount on which the clamp arm is located,
• Fig . 1 3 is a further isometric view of the movable element as shown in Fig. 1 2 but with the clamp arm coupled to the mount,
• Fig . 1 4 is a further isometric view of the movable element as shown in of Fig. 1 3,
• Fig . 1 5 is an isometric view of the movable element as shown in Figs. 1 4 and 1 5 coupled to an hydraulic cylinder,
• Fig . 1 6 is a graphical illustration of two different diameter pins retained with the wedge by the clamp arm mechanism
• Fig . 1 7 is a view similar to Fig. 1 6 illustrating where the smaller sized rear pin would sit if it where not for the shaped end of the clamp arm.
• the quick coupler as shown in Figures 1 and 2 of the drawings is a known form of quick coupler A made by our company.
• the quick coupler A is operated hydraulically by the hydraulics of the machine (usually an earth working machine) to which the coupler is attached.
• the body B of the coupler has mounting points C whereby the coupler can be attached to say the arm of an excavator (not shown).
• the coupler body B has a hook shaped front recess D into which the front mounting pin PI of an attachment engages.
• the hook shaped recess end of the quick coupler is typically referred to as the "front" of the coupler as this is the end of the coupler that will face toward the operator of the machine (e.g. excavator).
• the rear mounting pin P2 of the attachment locates in the rear recess E.
• the movable locking element F which in this form of coupler is a wedge component, (hereinafter for simplicity “wedge F") is extendible to capture the rear mounting pin P2 of the attachment in the rear recess E.
• the wedge F is hydraulically powered.
• the excavator operator will position recess D of the coupler onto the front pin PI of the attachment and then crowd the coupler such that the rear pin P2 engages in the recess E.
• the wedge F is then extended to engage with and lock the rear pin P2 in the rear recess E.
• the pins PI and P2 engaged by the coupler A are shown in Fig. 1 .
• the attachment is thereby coupled to the coupler A in the working position.
• the attachment can fall from the coupler and hence fall from the excavator arm. However, if the front pin PI is retained (by say our l-Lock device L as described and claimed in our New Zealand patent specification 552294/546893) then the attachment will not fall completely off the coupler A but will swing down on the pin PI .
• the wedge F is part of an operating means formed by hydraulic cylinder G which applies a driving force to control the extension and retraction of the wedge F via the piston rod R of the cylinder G.
• hydraulic cylinder G which applies a driving force to control the extension and retraction of the wedge F via the piston rod R of the cylinder G.
• the leading or distal end of the wedge F includes an inclined or sloping surface M.
• the pin P2 will cause the pin P2 to drive the wedge F backward (as indicated by arrow Y in Fig. 1 ). This is due to the sloped face M (and the applied normal forces indicated by the arrow X in Fig. 1 ). Consequently, the rear pin P2 moves down the wedge face to a point where it is no longer retained in the rear recess by the wedge F (Fig. 2) and the attachment will be free to swing about the front pin PI as described above.
• the distance between pins PI and P2 is rigidly fixed, as is the diameter of the pins.
• the quick coupler caters to attachments which have pin diameters and pin centres which fall within the range provided by the rear recess E, relative to the front recess D.
• the wedge locking element of the invention thus suits multiple attachment pin centres, but could equally be applied to a single pin centre design.
• a wedge 1 0 (an example of which is shown in Figs. 1 2 to 1 5) that includes at the leading end a projecting part 1 1 that provides a substantially flat (planar) pin engagement surface 1 2.
• This flat surface 1 2 extends beyond the lower extremity of the sloping wedge surface 1 3.
• the angle between the sloping surface 1 3 and the flat surface 1 2 is obtuse.
• the surface of the pin engagement surface 1 2 is substantially normal to the direction of forces (indicated by arrow "X") that will be applied by the pin P2 to the wedge 1 0 in a failed state of the coupler.
• arrow "X" the direction of forces
• the presence of the clamp device 1 4 will ensure that after the wedge 1 0 has moved back by the above mentioned amount it is then pulled back again as the pin P2 moves in a direction opposite to direction Y. This clamp device 1 4 will thus prevent the pin P2 from passing beyond the distal end 21 of the pin engagement surface 1 2 of the wedge 1 0 and become disengaged with the coupler.
• the clamp device 1 4 does not require additional hydraulic actuators to operate the clamp device. This not only reduces costs but improves reliability.
• the clamp device 1 4 is coupled to the wedge 1 0 via a suitable mount 1 5 so as to be moveable with the wedge 1 0.
• the coupling of the clamp 1 4 to the wedge 1 0 thereby ensures that the clamp 1 4 may retain the appropriate relationship with the pin P2 in any wedging position of the wedge 1 0 with pin P2.
• the clamp includes a solid clamp arm 1 6.
• the clamp arm 1 6 is substantially in the shape of an arc and is pivotally coupled at one end at 1 7 to the mount 1 5.
• the clamp arm 1 6 is biased, preferably sprung biased, and thus in one form the clamp arm 1 6 is biased by a compression spring 1 8 (as shown) or other biasing means such as a torsional spring. As illustrated the spring 1 8 is engaged with the clamp arm 1 6 at a point spaced from but adjacent to the axis of pivot 1 7. The other end of the spring 1 8 is coupled to a cross piece 1 9 of the mount 1 5.
• the mount 1 5 is, as described above, carried by the wedge 1 0. In the illustrated form the mount 1 5 is located in a suitably shaped recess 1 5a provided in the wedge 1 0.
• the clamp arm 1 6 is of a design and configuration such that the pin P2 can force the clamp arm 1 6 to move against the bias effect of spring 1 8 during movement of the pin P2 into the recess E. This provides the necessary clearance to enable the pin P2 to move into the recess.
• the leading and pin contacting portion 20 of the clamp arm 1 6 is suitably profiled so that it smoothly and positively engages with and rides over the pin P2 during both the engagement of the pin P2 into recess E (when the coupler A is engaging with the attachment) and disengagement from the coupler (when the attachment is being released from the coupler A).
• Figure 3 of the drawings shows the profiled end 20 of the clamp arm 1 6 approaching the pin P2 as the wedge 1 0 starts to extend under the action of the cylinder G while Fig. 4 shows end 20 of the clamp arm 1 6 having come into contact with the pin P2 as the wedge 1 0 continues to extend. Further advancement of the wedge 1 0 causes the end 20 of the clamp arm 1 6 to ride over the pin P2 (see Figs 5 and 6).
• the force available from the hydraulic cylinder C is very large in comparison to the clamp force of the clamp arm 1 6 provided by the biasing means (e.g. spring 1 8). Hence the movement of the wedge 1 0 will result in the clamp arm 1 6 easily moving against the bias of the spring 1 8 when engaging and disengaging with the pin P2 during normal function. Thus no additional hydraulic actuators are required to drive or operate the clamp device 1 4.
• the biasing means e.g. spring 1 8
• Fig. 8 of the drawings shows the coupler A in the engaged position with pins PI and P2 and hence the attachment locked onto the coupler.
• the pin P2 is in the rear recess E and the wedge 1 0 is extended by cylinder G so that the pin P2 is held between the wedge 1 0 (in this case sloping surface 1 3) and the surface of the recess E.
• the retention of the attachment pins PI and P2 relies on the front pin PI being retained by a retention means such as our l-Lock safety locking device mentioned previously.
• the front pin PI can only move between its normal position and the locking feature (i.e. the l-Lock) as illustrated in Fig. 1 1 .
• the rear pin P2 may only move by the same amount as the front pin PI .
• Fig.1 6 of the drawings provides an illustration of two different pin diameters e.g. small and large diameter pins.
• Fig 1 7 of the drawings illustrates where the smaller pin P2 would sit if not for the shaped end 20 of the clamp arm 1 6.
• the shape and configuration of the inside surface of the distal end of the clamp arm 1 6 is, preferably, shaped so that it will retain the smaller diameter pin as far as possible from the distal end 21 of the flat section 1 2.
• This is shown graphically in Figs. 1 6 and 1 7 where the large and small diameters of pin P2 are shown and the smaller diameter pin is shown to be retained closer to the distal edge 21 .
• the smaller pin P2 thus must move further, which in-turn causes the load applied by the clamp device 14 to be higher (i.e. more spring compression).
• the arm 1 6 is referred to as a clamp arm 1 6.
• the form and function of the arm 1 6 is, as will be appreciated by the skilled addressee, such that the arm 1 6 can be described as a "safety" arm.
• the sprung clamp arm 1 6 can be formed by a spring member.

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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)
• Shovels (AREA)
• Quick-Acting Or Multi-Walled Pipe Joints (AREA)
• Details Of Connecting Devices For Male And Female Coupling (AREA)
• Mutual Connection Of Rods And Tubes (AREA)
• Connection Of Plates (AREA)
• Snaps, Bayonet Connections, Set Pins, And Snap Rings (AREA)

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Applications Claiming Priority (2)

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Family Applications (1)

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Cited By (3)

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Citations (5)

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• 2016
  • 2016-12-01 JP JP2018529159A patent/JP7041059B2/ja active Active
  • 2016-12-01 AU AU2016365527A patent/AU2016365527B2/en active Active
  • 2016-12-01 WO PCT/NZ2016/050189 patent/WO2017099610A1/en not_active Ceased
  • 2016-12-01 CN CN201680071542.5A patent/CN108431334B/zh active Active
  • 2016-12-01 CA CA3007341A patent/CA3007341A1/en active Pending
  • 2016-12-01 US US15/782,010 patent/US11846083B2/en active Active
  • 2016-12-01 GB GB1810260.8A patent/GB2560847B/en active Active
• 2023
  • 2023-11-06 US US18/502,915 patent/US12428799B2/en active Active

Patent Citations (5)

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