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
  • E02F3/3618—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat with two separating hooks
• • 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
  • E02F3/3622—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 locking element acting on a pin
• • 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
  • E02F3/365—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat with redundant latching means, e.g. for safety purposes
• • 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 quick coupler for bucket excavators.
• Hydraulically operated mechanical excavators have a dipper arm on the end of which are two mounting points by means of which an excavating bucket is pivotally attached to the end of the arm, and pivoted relative to the arm, respectively.
• an excavating bucket is pivotally attached to the end of the arm, and pivoted relative to the arm, respectively.
• the couplers can either be of the hydraulic type or of the mechanical type and are effectively permanently fitted to the two pivot apertures of the dipper arm and the bucket pivoting link, respectively.
• These couplers incorporate a generally horizontally and rearwardly extending hook-like aperture or jaw adapted to engage with one of the pivot pins on the bucket (both of which are left fitted to the bucket), and a generally downwardly extending aperture or jaw adapted to locate over the other pivot pin on the bucket, with which downwardly extending aperture a moveable latching hook is associated.
• this latching hook is biased by a coil spring to its latching position, and is moved away from its latching position by a release handle or lever rod which is removably locatable in an aperture in the nose of the latching hook.
• a double acting hydraulic piston and cylinder device moves the latching hook between its respective positions, and check valves are located within the piston and cylinder device to prevent inadvertent movement of the piston in the event of hydraulic failure.
• a safety pin has to be provided which must be located by the excavator operator in specially provided apertures in the coupler, to lock the latching hook in its latching position. This means that in both of these versions, the digger operator still has to leave his cab to secure in position the safety pin; this is inconvenient and time consuming.
• a coupler to enable an excavator operator to couple an excavator bucket to a dipper arm of an excavator without leaving his cab, the coupler comprising two spaced side plates each having four fixed pin location points, the coupler being mountable in use between the bucket and the dipper arm and comprising a first aperture and a second aperture defining two of said points and connectable respectively, in use, to the dipper arm of the excavator and a bucket piston and cylinder device, by suitable pins, a first open-ended hook-like aperture defining a third of said points and for engagement with a first pivot pin provided on an excavator bucket, and a pivoting latching hook co-operating with a second open-ended aperture defining said fourth point and for latching engagement with a second pivot pin provided on the bucket once the first hook-like aperture has been engaged with the first pivot pin, in use, power operated means for moving the latching hook between latching and unlatched positions and operable by the operator from the cab
• the blocking means is moveable under its own weight by the force of gravity into a latch blocking position in which it prevents the latching hook from being disengaged from the second pivot pin on the bucket, and resiliently deformable means is provided on the blocking means which, in use, will engage an abutment when the coupler is inverted by rotation in one sense (with the result that the blocking means will tend under its own weight to move away from its blocking position) such engagement resulting in the resiliently deformable means biasing the blocking means into its latch blocking position.
• the blocking means will move, under its own weight, to a fully crowded position in which it no longer blocks the latching hook.
• a spring may be provided permanently to bias the blocking means into its blocking position, and means is provided to move the blocking means against the bias of the spring, so that it no longer blocks the latching hook.
• said means is provided by a wire and pulley arrangement, the wire of which will tighten when the coupler is inverted, i.e. on full curl of the bucket, to move the blocking means out of its blocking position.
• a small hydraulic cylinder could be provided to move the blocking means out of its blocking position, against the bias of the spring.
• the latching hook is operated by means of a double acting piston and cylinder device, one end of which is pivotally connected about a first pivot axis to the coupler, and the other end of which is pivotally connected to the latching hook.
• the blocking means comprises a bifurcated blocking bar, the two limbs of which are pivotally supported on the coupler, preferably on the said first pivot axis, and the opposite end of which bears against a face on the rear of the latching hook.
• the blocking means may comprise a single blocking bar pivotally supported at one end region on the coupler, preferably on the first pivot axis and adapted to bear at its opposite end against a face on the rear of the hook.
• the face is stepped so that the coupler can be used with different sized bucket pivot pin distances (known as pin spread).
• the resiliently deformable means comprises an upstanding resiliently deformable arm on the blocking bar which will bear against an abutment on the dipper arm when the coupler is inverted, e.g. when a bucket operating cylinder is retracted to pivot the bucket.
• a protection plate is fitted over the latching hook and blocking means, through which plate the resiliently deformable arm projects, the plate being provided to ensure that excavated material does not interfere with the operation of the blocking means.
• the plate may be welded or bolted in position.
• Hydraulic hoses for the double acting piston and cylinder device for operating the latching hook preferably pass through one or more apertures in the plate, but alternatively that the plate may carry two hydraulic hose couplings and on the inner side of the plate, the couplings are permanently connected by suitable hoses to the said piston and cylinder device. This allows further hoses leading from the main pressure system on the excavator to be connected and disconnected easily to the coupler.
• the spring for biasing the blocking means into its blocking position may be located between the protection plate and the blocking means.
• the piston and cylinder device for the latching hook is provided with a check valve and the blocking means is provided, it is important that maximum provision is made to ensure that a bucket cannot accidentally become disconnected from the coupler, and preferably therefore, the latching hook is designed so that it will not rotate to a release position when under load, or when there is a hydraulic failure in the piston and cylinder device controlling the hook, and when the blocking means has failed.
• the hook has a profile which is such that, under the above conditions, and the hook is carrying the weight of the bucket, the forces acting on the pin are such that there is a moment about the pivot supporting the hook which will cause the hook to rotate to its unlatched position, thus releasing the bucket.
• a hook which has a profile such that under the above conditions, and when the hook is carrying the weight of the bucket, and there would otherwise be a tendency for the hook to rotate to a release position, the pin will move along the internal concave surface of the hook, from a first position tending to unlatch the hook to one putting no unlatching force on the hook and thereafter to one tending to move the hook to a latching position.
• the free end of the hook preferably has an upturned, extended nose, the inner face of which is concave and which is preferably connected to the normal concave internal surface of the hook by an internal planar portion.
• FIGURES 1 to 3 are schematic side elevations showing how a coupler is used to connect an excavator bucket to a dipper arm of an excavator
• FIGURE 4 is a partly schematic side elevation with parts broken away, showing details of a manual prior art coupler
• FIGURE 5 is a view similar to Figure 4 of a hydraulically operated prior art coupler
• FIGURE 6 is a perspective view with parts broken away showing a first embodiment of coupler according to the invention
• FIGURE 7 is a view similar to Figure 6 showing a second embodiment of coupler according to the invention
• FIGURE 8 is a further perspective view with parts cut away showing two further preferred features of the invention
• FIGURE 9 is a scrap view showing a coupler latching hook according to a preferred feature of the invention
• FIGURE 10 is a view similar to Figure 9, but showing the hook with the bucket pin in a slightly different position
• FIGURE 11 is an enlarged view showing the hook and pin in its Figure 10 position
• FIGURE 12 shows schematically six different relative orientations of an excavator dipper arm, coupler and excavator bucket, and
• FIGURE 13 is a view similar to Figures 6-8, but showing the coupler in a different position, and showing two possible alternative constructions.
• an excavator bucket is shown at 1, and the distal end of an excavator dipper arm is shown at 3.
• the dipper arm 3 supports a bucket piston and cylinder device 4 for controlling the bucket 1 via two pivot links 6, the bucket 1 normally being connected directly to the dipper arm 3 by means of a first pivot pin 7 carried by the bucket and engaging directly within a mounting point or pivot aperture in an end region of the dipper arm 3 and a second pivot pin 9 engaging directly within a mounting point or pivot aperture 5' in an end region of one of the links 6 (this arrangement is not shown).
• a coupler 11 has been used to enable the semi-automatic connection of the bucket 1 to the dipper arm 3 and as illustrated, the coupler has two mounting points thereon by means of which it is connected to the mounting points 5 and 5' on the dipper arm 3 and on the link 6 respectively, by suitable connecting pins 12.
• the coupler 11 is provided in a lower region thereof with a first generally horizontally and rearwardly extending aperture or jaw 13 and a second generally downwardly extending aperture or jaw 15.
• rearwardly extending we mean opening outwardly, in use, from the coupler towards the operator of an excavator on which the dipper arm and coupler are fitted and by downwardly extending we mean, in use, extending or opening outwards generally downwards towards the ground.
• the excavator operator manoeuvres the dipper arm to the position shown in Figure 1 and then moves the dipper arm downwardly and rearwardly so as to engage the first aperture or jaw 13 with the first pivot pin 7, which is virtually permanently fitted to the bucket 1 ; he then operates the bucket-controlling piston and cylinder device 4 so as to swing the pivot links 6 downwardly, as represented by the arrow A in Figure 2, so as to move the second aperture or jaw 15 into engagement with the second pivot pin 9, which is also virtually permanently secured to the bucket 1.
• the coupler is then latched in position so that the jaw 15 is clamped around the pin 9 and the bucket can be used for digging as illustrated in Figure 3.
• a manual prior art coupler which is provided with a latching hook 17, pivotally supported on the body of the coupler about a pivot 18 and biased to a latching position (in which it maintains the pivot pin 9 in the aperture 15) by means of a coil spring 16.
• a bar or release handle 14 In order to move the hook 17 against the bias of the spring 16, e.g. to release the pivot pin 9 from the aperture 15 and thus to drop a bucket 1, a bar or release handle 14 has to be inserted into an aperture 10 in a nose portion of the hook 17 so that when downward pressure is applied to the end of the bar, the hook 17 will pivot about its pivot 18 accordingly.
• the latching hook 17 is moved between its illustrated latching position and a release position by means of a double-acting hydraulic piston and cylinder device 19, the piston of which is pivotally connected to the hook at 20 and the cylinder of which is pivotally connected to the body of the coupler at 22.
• a suitable check valve (not shown) is provided within the piston and cylinder device 19 in case there should be a failure in the hydraulic supply to the piston and cylinder device 12.
• this check valve should fail, or in the case of the manual coupler shown in Figure 4, in case the spring 16 should fail, a safety pin 23 is always provided.
• This safety pin 23 bridges between the body or two side plates of the coupler 1 and a rear face of the latching hook 17 so as to hold the latching hook 17 in a latching position and prevent the bucket pivot 9 from being released from the aperture 15.
• the disadvantage with this arrangement is that every time the safety pin 23 has to be inserted or removed, the excavator operator has to dismount from the cab of the excavator. This is time consuming and inconvenient for the excavator operator and as a result, the operator often never fits the safety pin 23.
• the safety pin of the prior art construction shown in Figure 5 is dispensed with and replaced with a blocking means shown generally at 25.
• the blocking means is in the form of a bifurcated blocking bar with two rearwardly extending limbs 26 which are pivotally supported on the pivot 22 by means of which the piston and cylinder device 19 is connected to the coupler 11 , and a forward end 24 of which engages within a recess on a rear face of the latching hook 17.
• the blocking means 25 moves into blocking engagement with the roller of the latching hook 17 under its own weight due to the force of gravity, causing it to pivot anticlockwise about the pivotal connection 22 under normal operating conditions of the coupler and excavator bucket.
• the blocking means 25 is provided on its rearmost end with resiliently deformable means 27 which is then activated to bias the forward end 24 of the blocking means into engagement with the rear face of the latching hook 17.
• the resiliently deformable means 27 is in the form of an upstanding leaf-spring 28, a free end portion of which will abut against an abutment on the dipper arm 3, thus producing a suitable reaction force to hold the blocking means 25 in engagement with the rear face of the hook 17.
• the bifurcated blocking bar with its two limbs 26 is replaced by a single blocking bar 37, which is pivotally connected to the pivot connection 22, as in the previous embodiment.
• this single blocking bar 37 has an upstanding leaf-spring 28 connected thereto which operates as previously described.
• a forward end portion 35 of the blocking bar engages within a recess 33 in a rear face of the latching hook 17 to hold the latching hook 17 in its latching position but in other respects, the single blocking bar 37 acts in the same way, under its own weight, as in the previous embodiment.
• a series of steps or recesses 41 are provided on a rear face of the latching hook 17 with which a modified forward end portion 31 of the blocking means 25 engage.
• the bucket pivot pin 9 shown therein is of a normal size, but by providing the series of steps on the rear face of the latching hook 17, larger sizes of bucket pin 9, or different-sized bucket pin pivot centres (known as pin spread) can be accommodated.
• the gravity operated blocking means 25 whether it be the embodiment shown in Figure 6 or the embodiment shown in Figure 7, or that shown in Figure 8, allows an excavator operator to change buckets without leaving his cab.
• the latching hook 17 is hydraulically actuated by means of the piston and cylinder device 19, which itself is provided with check valves to prevent movement of the piston therein in the event of hydraulic failure.
• the blocking means 25 will still prevent the latching hook 17 moving to an unlatched position.
• a protection plate 47 between the two side plates of the coupler 11, which completely overlies the blocking means 25 and the double acting hydraulic piston and cylinder device 19, as shown in Figure 8.
• This plate 47 is preferably welded in position and accordingly, has an aperture therein through which the resiliently deformable leaf-spring 28 projects.
• two hydraulic hose connectors are fitted to the plate, as shown at 55, to which hydraulic hoses 49 for the piston and cylinder device 19 are connected.
• the connectors 55 are provided with fittings to receive connectors from further hydraulic hoses (not shown), which are secured to the dipper arm 3 and lead to the main pressure system on the excavator.
• the protection plate 47 prevents the ingress of excavated material to the interior of the coupler, the provision of the hydraulic connectors 55 still allows the coupling 11 to be disconnected from the dipper arm if required and when various parts of the coupler become worn, these can all simply be removed by dropping them downwardly from the coupler as shown in Figure 8, since all the various pivot connections are easily removable from the coupler.
• the weight of the bucket on the hook which is transferred to the hook through the bucket pin 9, will cause the hook to swing anticlockwise, due to the reaction force Rl, acting on the inner concave face of the hook, causing an anticlockwise moment represented by the arrow M, shown in Figure 9.
• the preferred hook of the invention instead of simply having an internal profile such as shown schematically in Figures 4 and 5, is provided not only with a first concave portion 56 and a planar portion 57, both of which are generally of known construction, but also with a second concave portion 61, by virtue of the presence of a nose portion 63 on the free end portion of the hook 17.
• Figure 12(4) shows the position taken by the coupler 11 when the bucket (not shown) is in the fully crowded position, i.e. the coupler is inverted. In this position, the blocking bar will swing under gravity to an open position to allow the hook 17 to be retracted by operation of the piston and cylinder device 19.
• Figure 12(5) shows the coupler 11 after it has been rolled to a position to allow the bucket pin 9 to swing clear of the coupler, whereas Figure 12(6) shows how the bucket can then be removed by rolling the coupler 11 clockwise relative to its Figure 12(5) position.
• the coupler is principally for coupling excavating buckets to the dipper arm
• other attachments such as concrete breakers, rippers and clamshells can be coupled to the dipper arm using the coupler, and the terms "bucket' and Tjuckets 1 should be interpreted accordingly.
• the coupler allows attachments from various different manufacturers in the same size excavator range to be used on a particular excavator.
• a spring 71 may be provided permanently to bias the blocking bar 37 into its blocking position (see Figure 13).
• This spring 71 is a coil spring extending between the protection plate 47 and the blocking bar 37.
• a wire and pulley arrangement 73 is provided, the wire of which would tighten when the coupler is inverted, i.e. on full curl of the bucket, to move the blocking means 37 out of its blocking position.
• a small hydraulic cylinder 75 could be provided to move the blocking bar 37 out of its blocking position, and against the bias of the spring 37. Only then, could the piston and cylinder device 19 be operated to move the latching hook 17 to its bucket release position as shown in Figure 13.

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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)
• Earth Drilling (AREA)
• Agricultural Machines (AREA)
• Quick-Acting Or Multi-Walled Pipe Joints (AREA)
• Paper (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10838543

Family Applications (1)

Country Status (11)

Cited By (4)

Families Citing this family (99)

Citations (8)

Family Cites Families (31)

• 1998
  • 1998-09-08 GB GB9819598A patent/GB2330570B/en not_active Expired - Lifetime
• 1999
  • 1999-06-21 US US09/337,447 patent/US6422805B1/en not_active Expired - Lifetime
  • 1999-07-01 PT PT99928158T patent/PT1112413E/pt unknown
  • 1999-07-01 WO PCT/GB1999/002091 patent/WO2000014342A1/en not_active Ceased
  • 1999-07-01 AT AT99928158T patent/ATE259450T1/de active
  • 1999-07-01 JP JP2000569069A patent/JP3962213B2/ja not_active Expired - Fee Related
  • 1999-07-01 DE DE69914774T patent/DE69914774T2/de not_active Expired - Lifetime
  • 1999-07-01 DK DK99928158T patent/DK1112413T3/da active
  • 1999-07-01 EP EP99928158A patent/EP1112413B1/en not_active Expired - Lifetime
  • 1999-07-01 ES ES99928158T patent/ES2216524T3/es not_active Expired - Lifetime
  • 1999-07-01 US US09/786,804 patent/US6481124B1/en not_active Expired - Lifetime
  • 1999-07-01 AU AU45271/99A patent/AU4527199A/en not_active Abandoned

Patent Citations (8)

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