Dragline bucket

Abstract

Abstract A dragline bucket including: a floor having a ground engaging leading edge at the front and two spaced apart side walls extending upward from said floor and rearward from said leading edge, and a rear wall also extending upward from said floor rearward from said leading edge and contiguous with said two spaced apart side walls, said side walls and said rear wall including a cap rail defining an open top, said cap rail of said rear wall extending inwards towards the front and a rear portion of said cap rails of said respective side walls extending inwards towards the opposite side wall and a front portion of said cap rails of said respective side walls extending outwards away from the opposite side wall. 1 / 8 FIG1 SE 11 El LH 21 86 O 14'by 10 TE OF VEL LI 7 21 Er the EeFe A / X 1ts 8H tre 81 +11 1+1 4 IEl. 91 vtry 01 of gre 20 26 20 20 80 18 M ar 2 02 6 2 0 2 6 2 0 2 0 8 0 1 8 M a r 2 0 2 6 2 71 41 82 4 2 1 4 1 4 6 2 0 2 6 2 0 2 0 8 0 1 8 M a r 2 0 2 6 2 7 2 1 4 1 4 6

Description

Field of the Invention This invention relates to dragline buckets. 5 Background of the Invention Dragline buckets typically comprise a floor having a ground engaging leading edge or lip and a continuous wall extending upwards from the floor to form opposing side walls extending 10 rearwards from the opposite ends of the leading edge and are joined by a contiguous rear wall so that when seen from above the bucket forms a somewhat U-shaped manner. Typically the leading edge of the floor and the leading 15 edges of the side walls together define a front opening or mouth through which spoil may enter the bucket while the upper edge of the walls defines an open top above the floor. Some dragline buckets include a lifting arch with a central 20 dump lug extending from one side wall to the other across the front of the bucket, more or less above the leading edge to define the upper boundary of the mouth and provide for the connection of a dump rope. However, other types of buckets omit the arch and connect the hoist chains or ropes directly to dump 25 lugs on the outside of the side walls towards the front of the bucket. Hoist chains are generally connected to trunnions which extend outwards from the side walls towards the rear wall for 30 tilting and lifting the bucket while drag chains are connected to the respective side walls near their front ends at one end and to a drag rope at their other ends for dragging the bucket through the spoil. 2026202080   18 Mar 2026 Typically, the hoist chains extend upwards from the bucket and connect to a spreader bar which in turn is connected to the hoist cable or rope, the spreader bar being arranged to hold the 5 hoist chains apart at their upper ends so as to prevent the chains rubbing on the side walls of the bucket or to at least reduce the rubbing forces of the hoist chains on the side walls. Ideally the spreader bar is long enough to hold the hoist 10 chains off the side walls at least for some of the time in normal use. Thus, the spreader bar generally needs to be longer than the width of the bucket at the trunnions. Unfortunately, spreader bars are heavy and add a significant weight component to the hoist cable. While shorter spreader bars can reduce the 15 horizontal force component applied to the sidewalls they do not eliminate the horizontal component of the forces entirely. The hoist chains themselves are also very heavy and add another significant weight component to the hoist cable. 20 Moreover, the mass of the hoist chains and the fact that chains comprise links which move relative to each other result in significant abrasion to the bucket, particularly the upper edges of the side walls of the bucket, and significant abrasion of the chain links themselves. 25 Attempts have been made to reduce the amount of contact between the hoist chains and the side walls of the bucket by constructing buckets such that the side wall portions in the region of the trunnions converge slightly away from the base. 30 However, in such buckets the hoist chains still rub on the outer face of the side walls and cause damage to themselves and to the sidewalls. 2026202080   18 Mar 2026 Another factor to be considered in the design and manufacture of dragline buckets is the flow of spoil through the mouth and into the bucket. In that respect, interference with the spoil in the front portion of the bucket can affect the 5 ability of the bucket to be filled in the rear portion of the bucket. Although there are many factors affecting the productivity of a dragline, the efficiency and effectiveness of the bucket 10 during the dig cycle (that is, fill, carry and dump) has an influence on the overall productivity of the dragline. There have been numerous attempts at increasing the efficiency and effectiveness of the bucket during the fill component of the dig cycle. However, there is still room for further improvement in 15 the overall efficiency of buckets, taking into account factors such as the volume of spoil entering the bucket during the fill cycle and the volume of spoil retained during the carry cycle. The energy required to pull the bucket through the spoil during the fill cycle is an important factor. However, the overall 20 efficiency should also take into account downtime for maintenance of the bucket and associated components such as the hoist chains. The present invention is aimed at providing a dragline 25 bucket which is more efficient than previously known buckets at least in some circumstances. With the foregoing in view, the invention in one aspect resides broadly in a dragline bucket including: 30        a floor having a ground engaging leading edge at the front and two spaced apart side walls extending upward from said floor and rearward from said leading edge, and a rear wall also extending upward from said floor rearward from said leading edge 2026202080   18 Mar 2026 and contiguous with said two spaced apart side walls, said side walls and said rear wall including a cap rail defining an open top, said cap rail of said rear wall extending inwards towards 5 the front and a rear portion of said cap rails of said respective side walls extending inwards towards the opposite side wall and a front portion of said cap rails of said respective side walls extending outwards away from the opposite side wall. 10        In another aspect, the invention resides broadly in a dragline bucket including: a floor having a ground engaging leading edge at the front and two spaced apart side walls extending upward from said floor and rearward from said leading edge, and a rear wall also 15 extending upward from said floor rearward from said leading edge and contiguous with said two spaced apart side walls, said side walls and said rear wall including a cap rail defining an open top, said cap rail of said rear wall extending inwards towards 20 the front and a rear portion of said cap rails of said respective side walls extending inwards towards the opposite side wall and a front portion of said cap rails of said respective side walls extending outwards away from the opposite side wall; a lifting arch operatively connected to said floor and / or 25 said side walls substantially above said leading edge, said leading edge, said side walls, and said lifting arch defining a mouth through which spoil may enter the bucket, and wherein said front portions of said cap rails of said side walls are connected to said lifting arch outwardly of said 30 respective side walls. It will be appreciated that such arrangement maintains a fully open mouth while providing a more effective cap rail. 2026202080   18 Mar 2026 In another aspect, the invention resides broadly in a dragline bucket including: a floor having a ground engaging leading edge at the front and two spaced apart side walls extending upward from said floor 5 and rearward from said leading edge, and a rear wall also extending upward from said floor rearward from said leading edge and contiguous with said two spaced apart side walls, said side walls and said rear wall including a cap rail defining an open top; 10        said cap rail of said rear wall extending inwards towards the front and a rear portion of said cap rails of said respective side walls extending inwards towards the opposite side wall and a front portion of said cap rails of said respective side walls extending outwards away from the opposite side wall; 15        a pair of lifting lugs or trunnions are secured to said respective side walls towards their rear ends and adjacent said floor, said lifting lugs or trunnions, each lifting lug or trunnion including a recess for receiving therein a portion of a hoist chain link; 20        a lifting arch operatively connected to said floor and / or said side walls substantially above said leading edge, said leading edge, said side walls, and said lifting arch defining a mouth through which spoil may enter the bucket, and wherein said front portions of said cap rails of said side walls are connected 25 to said lifting arch outwardly of said respective side walls; and wherein said front portions of said cap rails of said respective side walls are substantially aligned with said respective recesses in the forward direction. 30 In another aspect, the invention resides broadly in a dragline bucket including: 2026202080   18 Mar 2026 a floor having a ground engaging leading edge at the front and two spaced apart side walls extending upward from said floor and rearward from said leading edge, and a rear wall also extending upward from said floor rearward from said leading edge 5 and contiguous with said two spaced apart side walls, said side walls and said rear wall including a cap rail defining an open top; said cap rail of said rear wall extending inwards towards the front and a rear portion of said cap rails of said respective 10 side walls extending inwards towards the opposite side wall and a front portion of said cap rails of said respective side walls extending outwards away from the opposite side wall; a lifting arch operatively connected to said floor and / or said side walls substantially above said leading edge, said 15 leading edge, said side walls, and said lifting arch defining a mouth through which spoil may enter the bucket, and wherein said front portions of said cap rails of said side walls are connected to said lifting arch outwardly of said respective side walls; and 20       wherein the transition of said front portions of said cap rails of said side walls and said rear portions of said cap rails of said respective side walls is such that a greater volume of metal is provided in the transition to achieve a longer life of the cap rail in the transition region. 25        Such greater volume of metal is particularly advantageous in buckets where the front portions of the cap rails of the respective side walls are substantially aligned with the link of the hoist chains which are connected to the lifting lugs or trunnions. 30        Terms such as horizontal, vertical, upper, lower, front, rear, side and the like are used herein for the purpose of describing the invention from the perspective of its normal at rest position and are not intended to limit the invention to use 2026202080   18 Mar 2026 in any particular orientation. The term spoil is intended to encompass virgin ground and ground which has been blasted, dug or stockpiled. 5 Brief Description of the Drawings In order that the invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings wherein: 10 Fig .   1 is a pictorial representation of a dragline bucket 15 according one side; Fig. 2 is of Fig. 1 side; Fig. 3 is of Fig. 1 Fig. 4 is to the invention from the front of the bucket to a pictorial representation of the dragline bucket from below the front of the bucket and to one a pictorial representation of the dragline bucket from below the bucket and to the rear; a plan view of the dragline bucket of Fig. 1; 20 25 Fig 1; Fig 1; Fig Fig Fig .   5 .   6 .   7 .   1 .   8 is a front elevation of the dragline bucket of Fig. is a side elevation of the dragline bucket of Fig. is a sectional elevation of the dragline bucket of along line 7-7; and is an enlarged view of detail 8 in Fig 7. Detailed Description of the Drawings 30 The dragline bucket 10 illustrated in Fig. 1 has a substantially rectangular floor 11 with a ground engaging leading edge 12 to which a plurality of spaced apart teeth 13 are fitted in known manner, a rear wall 14 extending upward from the floor and spaced rearward of the leading edge which is 2026202080   18 Mar 2026 contiguous with two spaced apart side walls 16 and 17 which also extend upward from the floor and forward from the rear wall, the rear wall terminating at its upper edge 18 in a rear cap or top rail 19 and the side walls terminating at their upper edges 21 5   and 22 in side cap or top rails 23 and 24 respectively, the cap or top rails defining an open top 26. A lifting arch 27 is connected to the forward end portions of the side walls and to the floor (via the side walls) for 10  connecting the bucket to the dump rope at the dump lug 48 of the dragline in known manner. It will be appreciated that the leading edge 12 together with the side walls and the lifting arch define a mouth 28 through which spoil may enter the bucket. Lifting lugs or trunnions 29 and 31 are welded to the outer face of the 15 side walls towards the rear wall for attaching lifting chains for connection to the dragline cable. Similarly, drag lugs 32 and 33 are connected to the forward ends of the side walls below the lifting arch for connection to the drag chain of the dragline in known manner. 20 It will be appreciated that the top or cap rails 19, 23 and 24 of a conventional bucket all lie generally in the same horizontal plane but in the present bucket the side walls have a higher front portion, a lower-mid portion and an intermediate 25 rear portion, that being a plane substantially parallel to the plane containing the upper surface of the floor of the bucket (which is generally horizontal when at rest on level ground). Additionally, the upper portion of the rear wall is approximately at right angles to the floor but gradually 30 transitions from the horizontal floor to the vertical upper portion via an upwardly curved corner portion to allow spoil to more easily flow upwards along the rear wall. 2026202080   18 Mar 2026 Similarly, the rear wall and the side walls are substantially at right angles but the side walls transition into the rear wall via curved corner portions or sections and the two side walls are substantially parallel beyond the curved corner 5 sections. It will also be seen that the side walls substantially comprise replaceable panels 46 and 47 which can be cut out and replaced by new weld-in panels when they become too worn. It is understood in the mining industry that dragline 10 buckets fill in accordance with what is known as the “shear zone theory”. The present invention considers a belief that a cap rail which extends inwards towards the opposite side wall near the front of the bucket (towards the mouth) interferes with the shear zones and reduces the filling efficiency of the bucket in 15 at least some types of spoil. As can be seen in Fig. 6, the side walls of the bucket 10 are relatively high at the arch where the mouth begins and remain high for about one third of the length of the bucket and then 20   steadily reduce in height to about the middle of the bucket side walls where they start to rise again to a point where they level off at a point about two thirds along the length of the bucket at a height which is lower than the height of the walls adjacent the arch. 25 As can be seen more clearly in Fig. 8, the front portions 23a and 24a of the respective side wall caps 23 and 24 adjacent the lifting arch extend outwards away from the respective opposite side wall and the rear portions 23b and 24b extend 30 inwards towards the respective opposite side wall. It will also be appreciated that the cap rail approximates a right-angle triangle in cross section, with a base 41, a side face 42 and a hypotenuse 43. Advantageously, the base of the triangle is 2026202080   18 Mar 2026 always facing up irrespective of the orientation of the cap rail and the hypotenuse is always facing down either inwardly down or outwardly down irrespective of whether the cap rail is an inwardly directed cap rail or an outwardly directed cap rail. 5 Advantageously, while the cap rail strengthens the respective side walls against horizontal components of load forces in the front portions and the rear portions, the rear portions act as a barrier to “spoil” overflow and the front 10 portions do not impede spoil flow into the bucket. Additionally, the lower wall portion of the side walls gives the bucket some of the advantages of a “scoop bucket”, one advantage being reduced weight from a standard bucket which 15  allows for a heavier payload. As can be seen in the drawings, the cap rail is cast in segments which are later welded to the walls in segments and to each other to form a continuous cap rail. Notably, the segments 20  are solid castings. It can also be seen in the drawings (particularly Fig. 8), that each trunnion has a recess 51 therein arranged to receive therein a link of the hoist chains or at least a portion of a 25 link for connecting the hoist chains to the trunnions. Advantageously, the outer edge face of the front portion of the side cap rail more or less aligns with the respective trunnion recesses while the outer faces of the cap rails immediately above the trunnions being part of the rear portions of the cap 30 rails is spaced inwards from the recesses. Notably, the face of the cap rail which is to be contacted by the hoist chains at that position is the flat base of the triangular cross section of the cap rail. Thus, the triangular cap rail provides a 2026202080   18 Mar 2026 suitably large area for engagement by the hoist chains and is aimed at increasing the life of the cap rail in that contact area. 5        The foregoing description has been given by way of illustrative example of the invention and all modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as defined by the appended claims.

Claims

1. A dragline bucket including:a floor having a ground engaging leading edge at the front and two spaced apart side walls extending upward from said floor and rearward from said leading edge, and a rear wall also extending upward from said floor rearward from said leading edge and contiguous with said two spaced apart side walls, said side walls and said rear wall including a cap rail defining an open top,said cap rail of said rear wall extending inwards towards the front and a rear portion of said cap rails of said respective side walls extending inwards towards the opposite side wall and a front portion of said cap rails of said respective side walls extending outwards away from the opposite side wall.

2. A dragline bucket according to Claim 1 including a lifting arch operatively connected to said floor and / or said side walls substantially above said leading edge, said leading edge, said side walls, and said lifting arch defining a mouth through which spoil may enter the bucket; andwherein said front portions of said cap rails of said side walls are connected to said lifting arch outwardly of said respective side walls.

3. A dragline bucket according to claim 1 or claim 2 including a pair of lifting lugs or trunnions secured to said respective side walls towards their rear ends and adjacent said floor, and wherein each of said lifting lugs or trunnions includes a recess for receiving therein a portion of a hoist chain link, and wherein said front portions of said cap rails of said respective side walls are substantially aligned with said respective recesses in the forward direction.2026202080   18 Mar 20264. A dragline bucket according to any one of the preceding claims wherein the transition of said front portions of said cap rails of said side walls to said rear portions of said cap rails of said respective side walls is such that a greater volume of metal is provided in the transition than in a simple bend.

5. A dragline bucket according to claim 4 wherein said transition is constructed to achieve a longer life of the cap rail in the transition region.

6. A dragline bucket according to any one of the preceding claims wherein the floor of the bucket is horizontal when at rest on level ground and the side walls have a higher front portion, a lower-mid portion and an intermediate rear portion and wherein said intermediate rear portion is substantially parallel to the plane containing the upper surface of the floor of the bucket.

7. A dragline bucket according to anyone of the preceding claims wherein the upper portion of the rear wall is approximately at right angles to the floor and gradually transition from the horizontal floor to the upper portion via an upwardly curved corner portion.

8. A dragline bucket according to claim 7 wherein the rear wall and the side walls are substantially at right angles and the side walls transition from the rear wall via curved corner portions or sections and the two side walls are substantially parallel beyond the curved corner sections.2026202080   18 Mar 20269. A dragline bucket according to any one of the preceding claims wherein the cap rail approximates a right angle triangle in cross section.

10. A dragline bucket according to claim 9 wherein the hypotenuse of the cap rail of the rear wall and the rear portions of the side wall faces inwards and downwards.

11. A dragline bucket according to claim 9 or claim 10 wherein the hypotenuse of the cap rail of the front portions of the side wall cap rails rear wall and the rear portions of the side wall faces outwards and downwards.

12. A dragline bucket including:a floor having a ground engaging leading edge at the front and two spaced apart side walls extending upward from said floor and rearward from said leading edge, and a rear wall also extending upward from said floor rearward from said leading edge and contiguous with said two spaced apart side walls, said side walls and said rear wall including a cap rail defining an open top,said cap rail of said rear wall extending inwards towards the front and a rear portion of said cap rails of said respective side walls extending inwards towards the opposite side wall and a front portion of said cap rails of said respective side walls extending outwards away from the opposite side wall;a lifting arch operatively connected to said floor and / or said side walls substantially above said leading edge, said leading edge, said side walls, and said lifting arch defining a mouth through which spoil may enter the bucket; andwherein said front portions of said cap rails of said side walls are connected to said lifting arch outwardly of said respective side walls.2026202080   18 Mar 202613. A cap rail for a dragline bucket having a cross section which is substantially the shape of a right angle triangle in cross-section and wherein the hypotenuse face is concave along a substantial part of the length of the cap rail.

14. A cast segment for use as part of a cap rail of a dragline bucket, the segment having a cross section which is substantially the shape of a right angle triangle and wherein the hypotenuse face is concave along a substantial part of the length of the cap rail.

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