WO2011003139A1

WO2011003139A1 - An arrangement of the crowd cylinder crank arm and linkage mechanism for giving freedom of movement for loading and tilting implements and buckets.

Info

Publication number: WO2011003139A1
Application number: PCT/AU2010/000865
Authority: WO
Inventors: Daniel Webb; John Healey; Craig Healey
Original assignee: Challenge Implements Holdings Pty Limited
Priority date: 2009-07-07
Filing date: 2010-07-06
Publication date: 2011-01-13
Also published as: AU2010269121A1

Abstract

A crowd cylinder axle or crank arm (9.006) is offset from its rotational axis and includes a crowd cylinder pivot support 9.044 which is unobstructed in the direction of rotational operation of the cylinder about pivot point 9.010. The axle is attached to a pair of booms (1.002,1.004), and a cross-bar (1.008) joins the booms. The cross-bar (1.008) is curved to permit greater freedom of rotational movement for the crowd cylinder. As a result of the freedom of rotational movement, the bucket can be joined to each boom by a single pivot, avoiding the need for additional linkages between the boom and bucket.

Description

AN ARRANGEMENT OF THE CROWD CYLINDER CRANK ARM AND

LINKAGE MECHANISM FOR GIVING FREEDOM OF MOVEMENT FOR

LOADING AND TILTING EARTH MOVING BUCKETS

Field of the invention

[001] This invention relates to loaders such as front end loaders.

[002] The invention is particularly applicable to the crowd cylinder pivot points, crank arms or axles, and operating mechanisms.

Background of the invention.

[003] The co-pending PCT patent application PCT/AU2009/000116 describes a boom arm arrangement for a front end loader in which components of a boom arm 10 can be supplied in a flat-pack and assembled from the components by welding, riveting, etc.

[004] In that arrangement, one end of the crowd cylinder is connected to a cylindrical axle member with transverse flanges providing a pivot attachment for the crowd cylinder. The implement, such as a bucket, is operated by the crowd cylinder's piston through a linkage system attached to a lower cross bar and bucket. The bottom linkage system includes a bottom link to which a slave link is pivotally attached.

[005] We have found that the lower linkage system adds complexity and can increase susceptibility to damage or malfunctioning as well as adding to the weight and the cost of the loader assembly. In addition, when a bucket linkage system is absent, then the crowd cylinder pivot arrangement and/or the lower cross bar can be subject to mutual interference which can limit the range of pivoting movement of the crowd cylinder or lift mechanism.

[006] The range of movement can also be limited by potential interference between the cross-beam and the tractor bonnet.

[007] It is desirable to provide a crowd cylinder operating arrangement which mitigates one or more of these problems.

[008] Any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates, at the priority date of this application.

Summary of the invention

[009] The invention replaces the straight axle of the prior art with a crank arm in which the crowd cylinder pivot point is off set in relation to the rotational axis of the crank arm, the configuration of the crank arm being such as to increase the rotational freedom of the crowd cylinder.

[010] The present invention provides a crowd cylinder crank arm having a crowd cylinder pivot support which is open over the range of rotational movement of the crowd cylinder

[011] The crank arm cross-beam can be shaped so that, in operation, the range of movement of the crowd cylinder is not inhibited by the axle member.

[012] The crowd cylinder pivot can include a crowd cylinder pivot member having a cross-beam which is at least partly off-axis in relation to the cylinder pivot axis.

[013] The crowd cylinder cross-beam pivot can include a pair of substantially transverse side cranks.

[014] The cross-beam can include crowd cylinder pivot attachment which is shaped and located to permit the crowd cylinder to pivot about a first axis through a working angle without interference from the cross-beam.

[015] The cross-beam can include first and second side pivot arms aligned on a second axis, the first and second pivot arms extending transverse to the second axis, the cross-beam including a yoke member connecting the first and second pivot arms and being non-intersecting with the second axis.

[016] The first axis can be above the second axis in the down or dump position.

[017] The first axis can be forward of the second axis in the down position.

[018] The first and second axes are located so that, in use, the crowd cylinder longitudinal axis does not cross the over-the-centre (toggle) point in relation to an imaginary line between the crowd cylinder pivot and the bucket/boom pivot.

[019] The crowd cylinder longitudinal axis and the imaginary line are located so that, in use, the crowd cylinder longitudinal axis is at least a minimum angle above the imaginary line.

[020] The yoke can include a crowd cylinder pivot arrangement.

[021] The cross-beam can be arced in one or more directions.

[022] The cross-beam can be arced in two directions.

[023] The cross-beam can be adapted to be curved upward when at or near the down position.

[024] The cross-beam can be adapted to be curved outward in the crowd position. [025] The cross-beam can be formed as a one-piece casting.

[026] The cross-beam can be formed of cut and welded sections.

[027] The crowd cylinder pivot arrangement can include an open box section having a lower side and a forward side open.

[028] The present invention also provides a crowd cylinder operating arrangement having such a cross-beam.

[029] The present invention further provides a boom arrangement for a front end loader having such a crowd cylinder cross-beam rotatably attached to a pair of booms.

[030] The boom arrangement can include a lower cross-bar.

[031] The lower cross-bar can be curved downward.

[032] The lower cross-bar can be curved inward.

[033] The loader can be a level lift loader.

[034] "Inward" and "outward" refer to the relation between the curvature of the lower cross-bar and the tractor.

[035] The present invention also provides a boom operating lever arrangement including: a boom; a link arm; a crank arm; a top mount; a boom pivot; a link pivot; a boom crank pivot; a link crank pivot; wherein the boom is connected to the boom pivot and the boom crank pivot; the link arm is connected to the link pivot and the link crank pivot; the crank arm is connected between boom crank pivot and the link crank pivot; the boom pivot is connected to the top mount; the link pivot is connected to a second location on the top mount.

[036] The boom, the link arm, the crank arm and the top mount together form a quadrilateral linkage system with pivoting connections.

[037] The link crank pivot can be located within the boom and is able to be displaced relative to the boom as the arrangement rotates.

[038] The lever quadrilateral can include a displacement opening in the boom in which link crank pivot can be displaced.

[039] The link crank pivot can be displaced in the displacement opening.

[040] The boom can include a bracket to mount and provide the boom crank pivot.

[041] The bracket can include therein a second displacement opening for the link crank pivot to also be displaced in. [042] One or both of the displacement openings can limit the displacement of the link crank pivot relative to the boom.

[043] The displacement opening can be in the form of a slot, which is preferably arcuate.

[044] The present invention further provides a boom arm having a generally V or

Chevron-shape, the boom arm being formed of a pair of V or Chevron -shaped plates separated by spacing means to define an interior space, the boom including a cable duct within the interior space which terminates short of the cusp of the V or Chevron -shaped boom, the boom including a second duct adapted to conduct cables and or conduits from one side of the interior space proximate the cusp to interior space on the other side of the cusp.

[045] The invention also provides a boom arm operating arrangement including a mount, boom arm, a link arm, a crank arm, a boom pivot, a link pivot, a boom crank pivot, and a link crank pivot, wherein the crank arm has a cantilever mounted boom pivot.

[046] The invention further provides a crowd cylinder arrangement including a crank arm with a single sided cantilever mounted crowd cylinder pivot.

[047] The cylinder can be mounted in the plane of the boom.

[048] The crank boom pivot can be located proximate a bend in the boom arm.

Brief description of the drawings

[049] An embodiment or embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[050] Figure 1 illustrates a loader boom arrangement;

[051] Figure 2 schematically illustrates a section through the cross-beam and crossbar of a boom arrangement;

[052] Figure 3 illustrates a loader in the raised crowd position;

[053] Figure 4 illustrates a loader in the lowered crowd position;

[054] Figure 5 illustrates a loader in the lowered dump position;

[055] Figure 6 illustrates a loader in the raised crowd position;

[056] Figure 7 illustrates a loader in the raised down or dump position;

[057] Figure 8 is a rear view of a cross-beam axle or crank arm;

[058] Figure 9 is a front view of the cross-beam axle or crank arm of Figure 8; [059] Figure 10 is a side view of the cross-beam of Figure 8;

[060] Figure 11 is a top view of the cross-beam;

[061] Figure 12 is an underside view of the cross-beam;

[062] Figure 13 shows an alternate cross-beam axle;

[063] Figure 14 is a side view of another loader arm arrangement;

[064] Figure 15 shows a half front view of the boom arrangement of Figure 14;

[065] Figure 16 illustrates detail of the crowd cylinder with the boom raised;

[066] Figure 17 is a lever diagram schematically illustrating the operation of the loader arm of Figure 14;

[067] Figure 18 is a side illustration of another boom lifting arrangement;

[068] Figure 19 is a partial view illustrating features of the arrangement of Figure 18;

[069] Figure 20 is an illustration of a crank adapted for use in the arrangement of

Figure 18;

[070] Figure 21 illustrates a double crowd cylinder arrangement; and

[071] Figure 22 illustrates a two sided crank, similar to that of figure 20.

[072] The numbering convention used in the drawings is that the digits in front of the full stop indicate the drawing number, and the digits after the full stop are the element reference numbers. Where possible, the same element reference number is used in different drawings to indicate corresponding elements.

[073] Unless indicated otherwise, the drawings are intended to be illustrative rather than exact representations, and are not necessarily drawn to scale. The orientation of the drawings is chosen to illustrate the features of the objects shown, and does not necessarily represent the orientation of the objects in use.

Detailed description of the embodiment or embodiments

[074] The invention will be described with reference to the accompanying drawings.

In the description, the terms "crowd cylinder axle" and "crowd cylinder crank arm" are used interchangeably to refer to the off-centre operating arm which carries the off-set crowd cylinder pivot.

[075] While various implements can be attached to the boom arrangement, in the embodiment described herein, the implement will be a bucket. The bucket can be controlled to assume positions between a down or dump position and an up or crowd position. Similarly, the boom can be controlled to assume a position between a raised position and a lowered position. The boom arrangement can also be of the type which provides a generally level lift system, to within the tolerances acceptable to the loader manufacturing industry.

[076] Figure 1 illustrates a boom arrangement having a pair of booms 1.002, 1.004 which are connected by a lower cross-bar 1.008. A rotatably mounted crank arm 1.006 is mounted on the booms via a pair of off-centre or displaced pivot points, only one of which, 1.012 is visible. The crank arm 1 ,006 has a crowd cylinder pivot mount 1.010 which is centrally located on the crank arm. The booms are hollow and contain operating mechanisms for manipulating the implement to be attached to the boom arrangement. A rotation limit stop 1.046 will be further described below in a level lift condition as described in detail in

PCT/AU2009/000116, which is incorporated herein by reference.

[077] Details of the crank arm axis are shown in Figures 8 to 12, and will be described below.

[078] Figure 2 is a schematic section view of the crank arm 2.006 and the lower cross-bar 2.008. While both are open section members, they are shown as such in Figure 2 with solid cross-hatched members to indicate the section. Figure 2 illustrates the relative location of the crowd cylinder axis between pivot 2.010 and bucket lower pivot 2.014 and the imaginary line between crank arm axis of rotation 2.012 and the bucket lower pivot 2.014 when the crank arm 2.006 is in a substantially upright orientation, at which orientation the crowd cylinder is partially retracted. While the crank arm is in the position shown, the crowd cylinder pivot 2.010 is above and forward of the crank arm pivot 2.012.

[079] Figure 3 illustrates the bucket 3.038 in the crowd position (crowd cylinder fully retracted with the boom raised. The lift cylinder 3.024 connects to lift cylinder pivot 3.030 on the boom. Lift piston rod 3.026 connects to lift piston pivot 3.028 on top mount 3.020. Top mount 3.020 is fixed in relation to the tractor, so that the booms and lift cylinder move relative to the top mount 3,020, and the boom pivots in relation to the vehicle around pivot 3.018 under the action of lift cylinder 3.024. The boom is pivoted to top mount 3.020 at link arm top mount pivot 3.018, and level lift link 3.022 is pivoted at pivot 3.023 to the distal end of top mount 3.020. The pivot 3.023 at the distal end of top mount 3.020 passes through the slot 3.016 on the boom. The level lift link 3.022 is pivotally connected at 3.027 to lift crank 3.025. The lift crank 3.025 is operatively connected to turn the crank arm 3.006 about pivot 3.010. The lift crank can be affixed to the crank arm axle by use of a keyway, splines, or other suitable means so that the crank arm 3.006 rotates with the crank 3.025. Thus, the lift cylinder 3.024 can move the crank arm axle 3.006 to maintain a level orientation of the bucket 3.028 during raising or lowering of the booms. [080] As shown in Figure 3, the lift piston 3.026 is extended, the boom is rotated so that the top mount 3.020 remains stationary relative to the tractor and pivot 3.023 is located to the right hand end (full forward) in the slot 3.016 as boom 3.004 is rotated to the fully raised condition and rotated fully anti-clockwise relative to the top mount 3.020. In this position, the crank arm axle 3.006 is rotated in a clockwise direction. The crowd cylinder pivot is not visible, but its location is indicated at 3.040.

[081] The crank 3.025, the link 3.022, the section of top mount 3.020 between pivots 3.018 and 3.023 and the section of the boom between pivots 3.018 and 3.010 form a quadrilateral linkage arrangement with pivoting corners or connections. While the slot 3.016 may be able to limit the movement of this arrangement, it is preferable to limit this movement by the range of extension and contraction of the lift cylinder 3.026.

[082] Generally, when the lift cylinder piston 3.026 is contracted, the pivot 3.023 is at the left of the slot 3.016, while, when the lift piston is extended, the pivot 3.023 is at the right end of the slot 3.016.

[083] The bucket 3.038 includes a projecting bracket 3.042 extending towards the boom, and the boom has a stop 3.046 which engages the bucket to limit the rearward or counter clockwise rotation of the bucket as discussed with reference to Figure 4. Similarly stop edge 3.043 engages the bucket to limit clockwise rotation (see, eg, Figure 7).

[084] A link 3.022 and crank 3.025 can be located within the walls of each boom.

There can be a lift cylinder assembly associated with each boom.

[085] Figure 4 illustrates the bucket 4.038 in the crowd position with the boom fully lowered. In this configuration, the lift piston 4.026 is withdrawn into the cylinder 4.024, the boom is rotated so the distal end of lever 4.020 is located to the left end of the slot 4.016, and the crank 4.025 and crank arm axle or crank arm 4.006 are rotated anticlockwise.

[086] The stop surface 4.046 on the boom and a rear edge of the bracket 4.042 on the bucket 4.038 are in contact in this configuration, preventing further counter-clockwise rotation of the bucket 4.038 relative to the boom.

[087] In the configuration shown in Figure 4, the relative movement of the crowd cylinder 4.032 and the crank arm axle 4.006 would be limited by mutual interference if the crank arm axle were straight rather than curved. Similarly, the lower cross-bar is curved inward and downward to avoid interference with the crowd cylinder.

[088] As illustrated in Figure 4, the position of the imaginary line 4.048

corresponding to the axis of the crowd cylinder and the imaginary line 4.050 between the crowd cylinder pivot 4.010 and the lower bucket main pivot 4.044 is an important factor in the satisfactory operation of the equipment. If line 4.048 were to cross over line 4.050, this could result in jamming the mechanism because this is an over-the-centre position, so any restoring force would instead tend to cause the bucket to rotate in a counter-clockwise direction. However, as discussed above, the abutting of the stop surface 4.046 and the edge of bracket 4.042 prevents the over-the-centre condition. Preferably the stop action occurs while there is at least a minimum angle between lines 4.048 and 4.050 to provide some mechanical leverage for the crowd cylinder to rotate the bucket clockwise. The minimum angle can be of the order of 3.8°.

[089] Figures 5, 6, and 7 illustrate various additional configurations of the loader which can be attained using the present invention.

[090] Figure 5 illustrates the bucket in the crowded down position and the boom fully lowered. The crank arm axle or crank arm 5.006 is rotated counter-clockwise in relation to the boom arm, the lift piston 5.026 is contracted into the cylinder 5.024 and the crowd piston 5.034 is fully extended.

[091] Figure 6 illustrates the boom raised and the bucket in the crowded state. The lift piston 6.026 is extended, the crowd cylinder 6.034 is contracted and the crank arm 6.006 is rotated clockwise.

[092] Figure 7 illustrates boom raised and the bucket down. The lift piston 7.026 is extended, the crowd cylinder 7.032 is extended, and the crank arm 7.006 is rotated clockwise.

[093] With respect to Figure 6, it can be seen that because the crank 25 is part of the quadrilateral linkage system, the boom can implement a level lift to maintain the orientation of the bucket relative to level ground during raising or lowering of the boom by controlling the operation of the lift cylinder 3.026.

[094] The lower cross-bar 1.008 is raked back or curved backward in the centre to provide additional room for the crowd cylinder 7.032 to move. In addition, the lower cross-bar can be curved downward in the centre. Because of the open box configuration of the crowd cylinder pivot arrangement 1.010 on the crank arm 1.006 the shape of the crank arm axle does not interfere with the operation of the crowd cylinder within its designed working range. Thus the arrangement of the present invention provides sufficient freedom of movement for the crowd cylinder to operate the bucket without the need for the lower bucket linkage arrangement of the prior art.

[095] Figure 8 is a rear view of a crank arm 8.006 showing the pivot apertures 8.012 off centre with respect to the pivot 8.010, the forward curve 8.056 of the rear edges of the crank arm., the side cranks 8.052, the crowd cylinder pivot retaining section 8.044, the crowd cylinder pivot 8.010, and the curved front edge 8.054. The open box 8.044 provides a strengthened support for the crowd cylinder pivot.

[096] Figure 9 is a front view of the crank arm 9.006 illustrating the same features as Figure 8. In this view the upward curve of the crank arm is better illustrated.

[097] Figure 10 is a side view of the crank arm 10.006. This view illustrates the relative location of the crowd cylinder pivot 10.010 (shown in dotted outline) in relation to the beam pivot 10.012. As can be seen the crowd cylinder pivot 10.010 is forward of and above the beam pivot 10.012, forward being referenced to the front face 10.054.

[098] Figure 11 is a top view of the crank arm axle illustrating the forward curve of the front face 11.054.

[099] Figure 12 is an underside view of the crank arm axle in which the dot-dash lines illustrate the forward displacement of the crowd cylinder pivot 12.010 in relation to the beam pivot 12.012.

[0100] Figure 13 illustrates an alternative crank arm axle. In this case, the crank arm

13.006 is of a cylindrical shape with a central crowd cylinder pivot 13.010. The side cranks 13.052 include the axle pivot apertures 13.012. The crowd cylinder pivot 13.010 is displaced from the axle or crank arm pivots, and can be located in the desired forward and upward relation to the axle pivot during installation.

[0101] Figures 14 to 17 illustrate another boom arrangement.

[0102] Figure 14 is a side view with the near side boom wall removed to show the interior mechanism.

[0103] The boom 14.002 is pivoted to the top mount at boom pivot 14.018. The link arm 14.022 is pivoted to the top mount at 14.023. The lift cylinder 14.024 is pivoted to the top mount at 14.028.

[0104] The boom 14.002 has a generally boomerang or V or chevron shape with an upper straight section which is pivotally attached to the top mount at 14.018, and a lower straight section, the free end of which carries the bucket attachment for bucket 14.038.

[0105] In the arrangement of Figure 14 to 17, a bracket 14.066 fits in the "elbow" or cusp of the boom, and tapers as it extends towards its end, with the boom lift pivot 14.030 being located at the deeper end of the bracket. The bracket 14.066 can be made of cast or moulded metal. The bracket 14.066 can have a "U" shaped cross-section so as to be also able to function as a duct or conduit for cables and or conduits, as will be described below. The bracket 14.066 has the boom lift pivot 14.030 at one end and extends to at least partially overlap with a crank support bracket 14.062. The bracket 14.062 is attached to the boom 14.002, and is provided so as to reinforce the inboard side wall of the boom 14.002. This is done because the slot 15.060 in the inboard side wall of the boom would otherwise weaken the boom 14.002. To compensate for this potential weakness the bracket 14.062 is welded to the boom 14.002.

[0106] As compared with the earlier described arrangements, eg, in Figure 3, the slot

3.016 in the boom at the top mount end of the link arm 3.022 in Figure 3 has been removed, and, in this arrangement, a new displacement opening or slot 14.360 has been placed to cooperate with the crank end of the link arm 14.022. The slot 14.360 is in the crank support bracket 14.362, which also carries the crank pivot 14.012. the inboard side of the booms 14.002 also incudes a displacement opening or slot which corresponds with the slot 14.360.

[0107] The link arm 14.022 can be constructed with top, bottom, walls and side walls.

The link arm can be reinforced by a suitable bracing arrangement to increase the rigidity of the link arm 14.022, such as the cast or moulded triangular array 14.029 shown at the slot end of the link arm.

[0108] The lift cylinder 14.024 is pivotally connected to the bottom of the top mount at

14.028 and to the boom 14.002 via the bracket 14.066 shown in the fully crowded position with the back of the bucket adjacent the boom.

[0109] The slot 14.360, and the corresponding displacement opening or slot through the inboard side of the boom 14.002, provides the lift crank pivot 14.027 with a degree of freedom in relation to the pivot points 14.023, 14.018, and 14.012. These slots provide freedom or ability of the lift crank pivot 14.027 to displace, either rotationally or

translationally, with respect to the boom 14.002 ( and bracket 14.062) in which it is located. By this means the quadrilateral formed by the pivot points 14.023, 14.018, 14.012 and 14.027 is able to maintain a quadrilateral configuration, even though they do not form a regular parallelogram or rhombus.

[0110] Figure 15 shows a half front view of the boom arrangement of Figure 14 without the bucket. In this view, the crank arm 15.006 and the second boom have an inner wall 15.070 and a top cover wall 15.074. The outboard and lower walls of the second boom arm are not visible in this figure. The outboard wall of the first boom is removed to show the interior mechanism. The crank arm 15.006 is pivoted to the respective booms via a pair of crank pivots such as 15.012.

[0111] The crowd cylinder 15.032 is pivoted to the crank arm at 15.010 and its bucket attachment is shown at 15.036 adapted to pivotally engage an upper, centrally located attachment arrangement on the bucket. The bucket upper attachment includes a pair of downward facing hooks adapted to be engaged by the crowd cylinder bucket attachment 15.036.

[0112] A pair of opposed lower bucket engagement means, such as axle 15.064, are provided proximate the end of the boom to engage a further downward facing pair of saddles, hooks or slots (not illustrated) on the bucket.

[0113] The duct 15.080 can carry pneumatic and or hydraulic hoses or electrical cables, and terminates close to the bracket 15.066 located at the elbow of the boom. As the link arm 15.022 is close to the elbow, there is a possibility of the cables and hoses being damaged by the movement of the link arm. Accordingly, the bracket 15.066 includes a plate 15.082 provided across the bracket "U" section at the elbow to perform a duct or conduit function to retain the cables and hoses within the bracket 15.066 and to provide them passage from one side of the elbow or cusp to the other side.

[0114] The link arm 15.022 is contained within the interior of the boom defined by the boom walls. The slot 15.360 formed in the slot bracket 15.062 is shown adjacent to or attached to the inner wall of the boom, which has a matching slot therein through which the crank arm can be connected to the crank arm pivot on the lifting arm. The slot 15.360 can provide a means to mechanically limit the displacement of the link crank pivot 15.027 relative to the boom 15.002 and bracket 15.062, but this is preferably done by means of the limits of extension and retraction of the lift cylinder. The slots 15.062 and the corresponding slots in the inboard sides of the booms are provided as arcuate slots, but it will be readily understood that other shaped openings can be provided which will allow for the displacement of the link crank pivot 15.027 with respect to the boom and the bracket 15.062, whether or not travel limiting is provided.

[0115] Figure 16 is a partial detail view illustrating the booms in a raised condition, with the near boom having its walls removed to illustrate the mechanism. In the limit position, the crowd cylinder is prevented from further rotation by the cross-bar 16.008. Accordingly, cross-bar 16.008 is curved rearwards, or, in the fully lifted position, downwards, to increase the allowable range of movement of the crowd cylinder. The triangular array link arm reinforcing 16.029 is an extension of an insert attached between the ends of the wall plates of the link arm 16.022, and connected to the link arm pivot 16.012.

[0116] Figure 17 is a lever diagram illustrating the operation of the loader arm of

Figure 14. The positions illustrated represent the lowered condition, POSITION A, and a partially raised condition, POSITION B. [0117] The link arm 17.022, the boom 17.002, the crank arm 17.006, and the top mount between pivots 17.018 and 17.023 form the sides of a quadrilateral, the corresponding pivots defining the corners thereof. The levers do not form a parallelogram or a rhombus. The link crank pivot 17.027 can move in displacement opening or slot 17.360.

[0118] The link arm 17.022 is shorter than the lever section of the boom 17.002 between the boom pivot 17.018 and the boom crank pivot 17.012, so the link arm arc 17.084 has a smaller radius than the boom arm arc 17.086. As can be seen, the line between the pivots 17.018 and 17.023 and the line between the pivots 17.012 and 17.027 are not parallel when the boom is in the lowered position and the bucket fully crowded (POSITION A).

[0119] The boom pivot 17.018 and the link arm pivot 17.023 are considered to be

"fixed" for the purposes of this analysis. The slot 17.060/17.360 is located in relation to crank arm pivot 17.012 so as to provide space or room for displacement of pivot 17.027 as it moves along arc 17.086 of the boom. The link arm crank pivot 17.027 is free to move within slot 17.060/17.360 and is constrained to move along arc 17.084 of the link arm. The crank arm 17.006 is shown in the upright orientation in the lowered condition (POSITION A), and retains this orientation in the raised condition (POSITION B).

[0120] The arrangement is such that the orientation of the crank can be retained with a resulting tolerance value at the bucket 6.038, of the order of, for example, +/- 10°, over the working range of the boom.

[0121] In the arrangements shown in the foregoing description, a single, centrally mounted crowd cylinder is attached to a single crank arm which is mounted on mirror image pivot arrangements in each boom. The crank extends between the two booms.

[0122] In the arrangement shown in Figures 18 to 20, two cranks and two crowd cylinders are employed.

[0123] Figure 18 is a side view of a boom 18.002 with a crowd cylinder 18.102 mounted adjacent the boom and generally forward thereof and pivotally connected to a bucket 18.038 by a crowd cylinder mounting bracket 18.101. A cantilever mounted crank 18.120 is pivotally connected to the crowd cylinder at 18.006, as shown in more detail in Figure 19.

[0124] In Figure 19, crank 19.120 is pivoted to the boom by pivot 19.012. The link pivot 19.027 is connected to the link inside the boom through a slot 19.360 which is visible through the matching slot 19.060 in the boom inboard wall. The crowd cylinder is pivoted to the crank at 19.012. Preferably the slot 19.060 in the boom inboard side wall is larger in dimension than the slot 19.060 in the bracket 19.062, firstly to allow for welding of the two components together, by the overlap of the two slots allowing a fillet weld around the periphery of the slots 19.060/19.360 to be placed therein. Secondly so that as the pivot 19.027 moves from one end of the slot 19.027 to the other, no contact will be made with the slot 19.060 in the inboard side wall of the boom. This allows the bracket 19.062 to be made of more durable and consequently more expensive steel that the inboard side wall of the boom.

[0125] It will be understood that if the inboard side wall of the boom were of appropriate strength and durability the portion of the bracket 19.062 which contains the slot 19.360 can be removed to allow unobstructed movement of the pivot 19.027.

[0126] In one embodiment, the crank arrangement of Figures 18 & 19 can take advantage of the curved cusp section 19.122 of the boom arm by mounting the crank boom pivot 19.012 close to the curved section 19.122 which permits the crowd cylinder crank pivot a greater arc of movement without interference from the boom.

[0127] The crank 19.120 can be of a linear or curved shape and the three pivots can be mounted in a linear or triangular layout on the crank.

[0128] The boom arrangement can have a bucket, part of which is shown at 19.038, affixed to the ends of the boom and operatively connected to the crowd cylinder.

Alternatively, a quick attachment arrangement can be mounted to the end of the boom and operatively connected to the crowd cylinder.

[0129] Figure 20 illustrates a crank adapted for use with a cantilever pivot crowd cylinder arrangement of Figure 19. The crank 20.120 includes a cantilever crank boom pivot 20.012 which can be mounted to the boom. The crank link pivot 20.027 can be restrained in the slot 19.060. The cantilever crank crowd cylinder pivot 20.006 is connected to the crowd cylinder.

[0130] Figure 21 is a partial view illustrating a double crowd cylinder arrangement. A crowd cylinder 21.102, 21.104 is connected to each boom by a crank such as that shown in Figure 20 carrying the crank boom pivot 21.012, the crank link pivot 21.027, and the crank crowd cylinder pivot 21.006. The crowd cylinder piston rod is attached to a quick

engagement member or bucket shown in part view at 21.038 by mounting bracket 21.106 at pivot 21.108. The boom is pivotally connected to a second pivoted attachment (not shown).

[0131] A second crowd cylinder 21.104 is connected in a similar manner to the opposite boom arm.

[0132] If desired, as is illustrated in Figure 22, a crank 22.120 similar to that of Figure

20, can be utilised. This crank 22.120 has a first and second side links 22.121 and 22.123, which are held together by means of the pivots 22.012, 22.027 and 22.006, or by means of the bridge 22.124 and reinforced by the pivots 22.012, 22.027 and 22.006. In this crank 22.120, the length of the pivots 22.012, 22.027 and 22.006, between the inboards sides of side links 22.121 and 22.123, is greater than the thickness of the boom in the region of the cusp or elbow 19.122, so that the crank 22.120 can be able to pass through the boom, which will have two corresponding slots 19.060 on both the inboard and outboard sides of the boom.

[0133] Both the cranks of figures 20 and 22 allow cleaner lines on the boom arrangement so that the operator has clean line of sight, as the cranks are close to the side peripheries of the booms, locating the crowd cylinder in alignment with the booms thereby increasing vision through the loader.

[0134] In this specification, reference to a document, disclosure, or other publication or use is not an admission that the document, disclosure, publication or use forms part of the common general knowledge of the skilled worker in the field of this invention at the priority date of this specification, unless otherwise stated.

[0135] In this specification, terms indicating orientation or direction, such as "up",

"down", "forward", "backward", "vertical", "horizontal", "left", "right" "upright", "transverse", "clockwise" etc. are not intended to be absolute terms unless the context requires or indicates otherwise. These terms will normally refer to orientations shown in the drawings.

[0136] Where ever it is used, the word "comprising" is to be understood in its "open- sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of. A corresponding meaning is to be attributed to the

corresponding words "comprise", "comprised" and "comprises" where they appear.

[0137] It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text. All of these different combinations constitute various alternative aspects of the invention.

[0138] While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, and all modifications which would be obvious to those skilled in the art are therefore intended to be embraced therein.

Claims

1. A crowd cylinder crank arm for rotatably mounting one end of a crowd cylinder having a crowd cylinder pivot support which is open over the range of rotational movement of the crowd cylinder

2. A crowd cylinder crank arm as claimed in claim 1 , wherein the cross-beam is shaped so that, in operation, the range of movement of the crowd cylinder is not inhibited by the axle member.

3. A crowd cylinder crank arm as claimed in claim 1 or claim 2, including a cross-beam which is at least partly off-axis.

4. A crowd cylinder crank arm as claimed in any one of claims 1 to 3, wherein the crowd cylinder cross-beam axle includes a pair of substantially transverse side cranks.

5. A crowd cylinder crank arm as claimed in any one of the preceding claims, wherein the cross-beam includes crowd cylinder pivot attachment means which is shaped and located to permit the crowd cylinder to pivot about a first axis through a working angle without interference from the cross-beam.

6. A crowd cylinder crank arm as claimed in any one of the preceding claims, wherein the cross-beam includes first and second of side pivot arms aligned on a second axis, the first and second pivot arms extending transverse to the second axis, the cross-beam including a yoke member connecting the first and second pivot arms and being non- intersecting with the second axis.

7. A crowd cylinder crank arm as claimed in claim 6, wherein the first axis is above the second axis in the down or dump position.

8. A crowd cylinder crank arm as claimed in claim 6 or clam 7, wherein the first axis is forward of the second axis in the down position.

9. A crowd cylinder crank arm as claimed in any one of claims 6 to 8, wherein the crowd cylinder axis and the imaginary line between the crowd cylinder pivot and the bucket boom pivots are located so that, in use, the crowd cylinder axis does not cross the over-the-centre (toggle) point in relation to the imaginary line.

10. A crowd cylinder crank arm as claimed in any one of claims 6 to 9, wherein the axis of the crowd cylinder and the bucket boom pivot are located so that, in use, the crowd cylinder axis is at least a minimum angle above the imaginary line.

11. A crowd cylinder crank arm as claimed in any one of the preceding claims, wherein the cross-beam is displaced in one or more directions from the cross-beam axle axis of rotation.

12. A crowd cylinder crank arm as claimed in claim 11 , wherein the cross-beam is curved in two directions.

13. A crowd cylinder crank arm as claimed in any one of the preceding claims, wherein the cross-beam is adapted to be curved upward when at or near the down position.

14. A crowd cylinder crank arm as claimed in any one of the preceding claims, wherein the crowd cylinder pivot arrangement includes an open box section having a open lower side and an open forward side.

15. A crowd cylinder crank arm as claimed in any one of the preceding claims, wherein the cross-beam is formed of cut and welded sections.

16. A crowd cylinder crank arm as claimed in any one of claims 1 to 14, wherein the cross-beam is formed as a one-piece casting.

17. A crowd cylinder crank arm substantially as herein described with reference to the accompanying drawings.

18. A crowd cylinder operating arrangement having a crank arm as claimed in any one of the preceding claims, the arrangement including a pair of side booms to which the crank arm axle is rotatably connected, each boom having a corresponding second cylinder operatively attached to each boom controlling the lifting or lowering of the booms.

19. A crowd cylinder operating arrangement as claimed in claim 18, wherein at least one of the second cylinders controls the rotation of the crank arm.

20. A crowd cylinder operating arrangement as claimed in claim 18 or 19, wherein the crank arm is adapted to be curved outward in the crowd position.

21. A crowd cylinder operating arrangement as claimed in any one of claim 18, 19, or 20, including a lower cross-bar between the booms.

22. A crowd cylinder operating arrangement as claimed in claim 20, wherein the lower cross-bar is curved downward.

23. A crowd cylinder operating arrangement as claimed in claim 21 or claim 22, wherein the lower cross-bar is curved inward.

24. A crowd cylinder operating arrangement as claimed in any one of claims 18 to 23, wherein the arrangement is a level lift arrangement.

25. A cross-bar for connecting a pair of booms of a front end loader, the cross-bar being shaped to curve backward when installed.

26. A cross-bar as claimed in claim 25, wherein the cross-bar is shaped to curve downward when installed.

27. A boom operating arrangement including:

a boom;

a link arm;

a crank arm;

a top mount;

a boom pivot,

a link pivot;

a boom crank pivot;

a link crank pivot;

wherein the boom is connected to the boom pivot and the boom crank pivot;

the link arm is connected to the link pivot and the link crank pivot;

the crank arm is connected between boom crank pivot and the link crank pivot;

the boom pivot is connected to the top mount.

the link pivot is connected to a second location on the top mount.

28. A boom arrangement as claimed in claim 27, wherein the boom, the link arm, the crank arm and the top mount form a quadrilateral linkage system with pivoting connections.

29. A boom arrangement as claimed in any one of claims 27 or 28, wherein said link crank pivot is located within said boom and is able to be displaced relative to said boom as said arrangement rotates.

30. A boom arrangement as claimed in claim 28 or 29 in which the lever quadrilateral includes a displacement opening in said boom in which link crank pivot can be displaced.

31. A boom arrangement as claimed in claim 29 or 30, wherein the link crank pivot is displaced in the displacement opening.

32. A boom arrangement as claimed in any one of claims 27 to 31 , wherein said boom includes a bracket to mount and provide said boom crank pivot.

33. A boom arrangement as claimed in claim 32 when appended to claim 30 or claim 31 when appended to claim 30, wherein said bracket includes therein a second displacement opening for said link crank pivot to be displaced in.

34. A boom arrangement as claimed in claim 33, wherein one of said displacement openings limits the displacement of said link crank pivot relative to said boom.

35. A boom arrangement as claimed in any one of claims 30 to 35, wherein said displacement opening is in the form of a slot, which is preferably arcuate.

36. A boom arm having a generally V or Chevron-shape, the boom arm being formed of a pair of V or Chevron -shaped plates separated by spacing means to define an interior space, the boom including a cable duct within the interior space which terminates short of the cusp of the V or Chevron -shaped boom, the boom including a second duct adapted to conduct cables and or conduits from one side of the interior space proximate the cusp to interior space on the other side of the cusp.

37. A boom arm operating arrangement including a mount, boom arm, a link arm, a crank arm, a boom pivot, a link pivot, a boom crank pivot, and a link crank pivot, wherein the crank arm has a cantilever mounted boom pivot.

38. A crowd cylinder arrangement including a crank arm with a single sided cantilever mounted crowd cylinder pivot.

39. A crowd cylinder arrangement as claimed in claim 38, wherein the cylinder is mounted in the plane of the boom.

40. A crowd cylinder arrangement as claimed in any one of claims 38 to 40, wherein the crank boom pivot is located proximate a bend in the boom arm.