AU2016250435A1 - Interchangeable Drag Roller Element Assembly - Google Patents

Abstract

An interchangeable dragline roller element assembly for dragline cables including an elongate shaft in use, mounted transversely to the dragline cables, a number of roller elements mounted to the elongate shaft, a closed end mounting the elongate shaft at a first end thereof allowing rotation of the elongate shaft as well as pivoting of the elongate shaft out of the transverse use condition and an open end mounting the elongate shaft at a second end allowing rotation of the elongate shaft when the elongate shaft is in the transverse use condition, the open-end having a locking assembly to lock the elongate shaft in the transverse use position and free the elongate shaft to allow the elongate shaft to pivot out of the transverse use position about a first end in order to allow interchange of one or more of the roller elements.

Description

ο (Ν Ο ο r- (Ν m ο (Ν Ό Ο (Ν

INTERCHANGEABLE DRAG ROLLER ELEMENT ASSEMBLY TECHNICAL EIELD

[0001] The present invention relates to a dragline roller element assembly used in a drag line drag rope tunnel and particularly to an assembly having interchangeable parts.

BACKGROUND ART

[0002] A dragline excavator is a piece of heavy equipment used in civil engineering and surface mining.

[0003] A dragline bucket system consists of a large bucket which is suspended from a boom (a large truss-like structure) with wire ropes. The bucket is manoeuvred by means of a number of ropes and chains. The hoist rope, powered by large diesel or electric motors, supports the bucket and hoist-coupler assembly from the boom. The dragrope is used to draw the bucket assembly horizontally. By skilful manoeuvre of the hoist and the dragropes the bucket is controlled for various operations.

[0004] In a typical cycle of excavation, the bucket is positioned above the material to be excavated. The bucket is then lowered and the dragrope is then drawn so that the bucket is dragged along the surface of the material. The bucket is then lifted by using the hoist rope. A swing operation is then performed to move the bucket to the place where the material is to be dumped. The dragrope is then released causing the bucket to tilt and empty. This is called a dump operation.

[0005] Wire ropes are one of the most heavily used components in a dragline. They are subjected to harsh conditions during the regular usage of a dragline in a mining operation. Hoist ropes are subjected to fatigue due to the cyclic nature of load handling as well as due to rope bending over the sheaves and the drum under load. This leads to wire breaks due to fatigue. Accumulation of a number of wire breaks close to each other can have a detrimental effect on the rope. Eurthermore, to allow for the increasing demand for higher load capacity coupled with the inconvenience of having very large ropes, the factor of safety is often compromised, which increases the wear rate. Worn wire ropes require replacement which is a difficult, time consuming and expensive exercise.

[0006] Eor these reasons, a rotating roller wear assembly may be provided to support the wire dragline ropes. These rotating roller assemblies are subject to wear and the roller elements ο (Ν -I—> ο Ο r- (Ν m ο ίΤ) (Ν 'sD Ο (Ν are typically rotated to spread wear evenly and replaced at the end of their useful life. Standard drag tunnel rollers have an operational life of 4 to 8 weeks, before they are renewed.

[0007] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF INVENTION

[0008] The present invention is directed to an interchangeable dragline roller element assembly, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

[0009] With the foregoing in view, the present invention in one form, resides broadly in an interchangeable dragline roller element assembly for dragline cables including an elongate shaft in use, mounted transversely to the dragline cables, a number of roller elements mounted to the elongate shaft, a closed end mounting the elongate shaft at a first end thereof allowing rotation of the elongate shaft as well as pivoting of the elongate shaft out of the transverse use condition and an open end mounting the elongate shaft at a second end allowing rotation of the elongate shaft when the elongate shaft is in the transverse use condition, the open-end having a locking assembly to lock the elongate shaft in the transverse use position and free the elongate shaft to allow the elongate shaft to pivot out of the transverse use position about a first end in order to allow interchange of one or more of the roller elements.

[0010] The interchangeable drag roller element assembly of the present invention is normally mounted relative to a support assembly. The support assembly will normally have at least one overhead slap beam, normally with a number of slap blocks mounted thereto. The overhead slap beam will typically be offset from the plane of the elongate shaft of the drag roller element assembly. Preferably, the overhead slap beam will be positioned either in front of or behind the elongate shaft of the drag roller element assembly in the direction of travel of the dragline cables.

[0011] The support assembly will normally have a pair of spaced apart support arms which support the overhead slap beam. The spaced apart support arms will normally be provided with one or more side slap blocks.

[0012] Together, the overhead slap beam, the side support arms and the roller assembly will preferably define a generally rectangular opening or dragline rope tunnel through which the Ό Ο (Ν -I—> ο Ο r- (Ν m ο ίΤ) (Ν Ό Ο (Ν dragline cables or ropes extend. The dragline rope tunnel will normally guide and support the dragline cables or ropes and the slap blocks on the overhead slap beam and the spaced apart support arms together with the roller elements of the drag roller element assembly will guide and restrain the dragline cables during movement of the dragline cables.

[0013] Normally, the slap blocks, whether provided on the support arms and/or the overhead slap beam will be formed of a nylon material, preferably a reinforced nylon material. The slap blocks will normally be replaceable.

[0014] The interchangeable dragline roller element assembly of the present invention includes an elongate shaft which in use is mounted transversely to the dragline cables or ropes. The elongate shaft is preferably a unitary shaft. The shaft will normally be manufactured of metal. The shaft typically has a shaped external cross-section.

[0015] The shaped cross section may be provided as a sleeve over the shaft.

[0016] The cross sectional external shape of the shaft will preferably be generally circular with a flattened land portion. Normally, the land portion will extend over the length of the shaft and allow engagement with a roller element shell in order to fix the roller elements to the elongate shaft against relative rotation.

[0017] A bush will typically be provided at both ends of the shaft for mounting purposes. The bush is preferably mounted to a bearing at either end of the shaft to allow rotation of the shaft relative to the support assembly and thereby, rotation of the roller elements as well.

[0018] The interchangeable dragline roller element assembly of the present invention includes a number of roller elements mounted to the elongate shaft. Any number of roller elements can be provided. Typically, more than one roller element will be provided and according to the most preferred embodiment, 4-8 roller elements will be provided with the optimum number being six roller elements.

[0019] Each of the roller elements will preferably have the same configuration. In particular, each roller element will preferably be provided with an external roller element sleeve located about a roller element shell which, in use, mounts the roller element relative to the elongate shaft. The external roller element sleeve will preferably be a wear component and according to a most preferred embodiment, is manufactured from a plastic material, preferably a polyurethane material and most preferably, an elastomeric material. It is preferred that the roller element sleeve is substantially annular and cylindrical in external shape. Ό Ο (Ν -I—> ο Ο r- (Ν m ο (Ν Ό Ο (Ν 4 [0020] It is also preferred that the roller element shell is annular in shape and circular in external shape to be received closely within the preferred annular roller element sleeve. The roller element shell is typically received about the elongate shaft. The roller element shell will normally have a bore therethrough. The bore can be shaped to correspond to the external shape of the elongate shaft. In particular, the bore may be substantially circular with a flattened land portion extending over the length of the bore although other shapes could be used.

[0021] A roller element end plate may also be provided attached to the roller element shell. The roller element end plate is preferably provided with a central opening which is also shaped to correspond to and engage with the elongate shaft. In use, the roller element shell may be provided with a shaped bore or alternatively, the roller element shell is associated with the roller element end plate in the roller element end plate is provided with a shaped opening to correspond with the external shape of the elongate shaft in order to mount the roller elements to the elongate shaft to minimise relative rotation between the elongate shaft in the roller elements.

[0022] The interchangeable dragline roller element assembly of the present invention includes a closed end mounting the elongate shaft at a first end thereof allowing rotation of the elongate shaft as well as pivoting of the elongate shaft out of the transverse use condition. The closed end will normally include a housing containing a bearing relative to which the elongate shaft is mounted. The housing is preferably mounted to the support assembly via at least one and preferably a pair of mounting brackets. According to the particularly preferred embodiment, an upper mounting bracket and a lower mounting bracket are provided.

[0023] Importantly, the mounting of the housing preferably allows pivoting of the elongate shaft about a substantially vertical axis and the mounting of the elongate shaft relative to the housing allows rotation of the elongate shaft. The housing preferably supports the shaft during the pivoting movement of the shaft between the use and free conditions. In particular, the shaft with the roller elements provided thereon, may be a substantial weight and the housing and mounting brackets will preferably be capable of supporting the weight of the shaft with the roller elements provided thereon when the elongate shaft is moved to the free condition.

[0024] The bearing is typically enclosed within the housing which will protect the bearing and a housing will preferably be substantial enough to support the weight of the elongate shaft.

[0025] The housing is typically mounted to the upper and lower mounting brackets about a substantially vertical axis. Normally, an upper axial member and a lower axial member are provided relative to housing allowing the housing to rotate around the upper and lower axial Ό Ο (Ν -I—> ο Ο r- (Ν m ο (Ν Ό Ο (Ν members. The housing may be provided with mounting plates which are receivable relative to the bracket in order to allow removal of the housing from the brackets under some circumstances but the housing at the closed end will typically remain in place for the majority of the time except when removal of the entire assembly as required for maintenance and the like. During normal replacement of the roller elements, the closed-end will remain attached to the mounting brackets and thereby to the support assembly and the open-end will be unlocked and pivoted about the closed-end in order to replace, refurbish or repair the roller elements.

[0026] The interchangeable dragline roller element assembly of the present invention includes an open end mounting the elongate shaft at a second end allowing rotation of the elongate shaft when the elongate shaft is in the transverse use condition, the open-end having a locking assembly to lock the elongate shaft in the transverse use position and free the elongate shaft to allow the elongate shaft to pivot out of the transverse use position about a first end in order to allow interchange of one or more of the roller elements.

[0027] The open-end of the assembly also mounts the elongate shaft. Normally, the open-end is provided as an open collar with an entryway. The open collar is preferably substantially C-shaped with the entryway defined between the free ends of the open collar. The open collar of the preferred embodiment preferably has a spaced apart pair of substantially parallel wall portions which form the entryway and which lead to a substantially circular portion of the open collar.

[0028] The collar will preferably be mounted to an upper and a lower mounting bracket which are preferably attached directly towards one of the support arms of the support assembly. The open collar will normally remain attached to or relative to the mounting brackets in use and the elongate shaft will typically be moved relative to the open collar.

[0029] The open collar will preferably be a first part of the locking mechanism and a second part of the locking mechanism will preferably be a locking member or assembly associated with an end portion of the elongate shaft. Preferably, the locking assembly will be provided on an outer end of the elongate shaft, laterally outside the roller elements.

[0030] The locking assembly will preferably include a locking member which corresponds to the shape of the open collar. In particular, the locking member will be substantially cylindrical with a pair of preferably substantially parallel planar land portions. In use, when the pair of substantially parallel land portions are aligned with the pair of substantially parallel wall portions of the open collar, the locking member can pass into the open collar. The locking member can Ό Ο (Ν '(-> Ο ο (Ν m ο (Ν Ό Ο (Ν then be rotated moving the parallel land portions out of alignment with the parallel wall portions of the open collar, which locks the locking member within the open collar.

[0031] The locking member will normally be provided with enlarged side portions in order to receive the open collar therebetween. Normally, the enlarged side portions will be or include a flange extending radially from the locking member on either side thereof. Preferably, the enlarged side portions will be radially larger than the locking member although the enlarged side portions may be formed integrally with the locking member.

[0032] The elongate shaft is normally mounted to the locking member via a bearing allowing the elongate shaft to rotate relative to the locking member.

[0033] A handle or other gripping mechanism in order to allow a user to more easily rotate the locking member is typically provided in association with the locking member.

[0034] A bearing plate or flange will normally be provided on an outer side of the locking member. The bearing plate or flange will typically be located such that the bearing plate or flange abuts or is closely spaced from a portion of the open collar to assist with proper location of the locking member relative to the collar. It is preferred that the bearing plate or flange be provided with an enlarged protmsion or cam portion on one edge thereof. This enlarged protrusion or cam portion can be provided with an opening there through in order to receive a lock bolt. The bearing plate or flange will typically move with the locking member.

[0035] In addition, the enlarged protrusion or cam portion can function as a part of a stop mechanism. A stop member will preferably be provided on the open collar or housing against which a user can rotate the enlarged protrusion or cam portion in order to provide visual and/or tactile feedback in relation to the movement of the locking member into the locked condition. Once the enlarged protrusion or cam portion abuts the stop member, the locking member will typically be in the locked condition and further rotation in the same direction will typically be prevented.

[0036] A lock bolt opening will typically be provided in the open collar adjacent to the stop member in order to receive a lock bolt through the opening in the enlarged protrusion or cam portion and into the lock bolt opening to prevent rotation of the lock member whilst the assembly is in use.

[0037] A further handle may be provided extending laterally from the end of the locking member. In particular, the further handle may be provided substantially coaxially with the ο (Ν -I—> ο Ο r- (Ν m ο (Ν Ό Ο (Ν elongate shaft. In use, this further handle may be provided to allow a user to more easily align the locking member with the entry way to the open collar during pivoting of the elongate shaft between the use and free conditions.

[0038] The open end and the closed end are at opposite ends of the shaft. However, depending upon user requirements, the open end can be at the left hand end or the right hand end to allow the pivoting of the elongate shaft in different directions. Therefore, the assembly can be “left-hand opening” or “right-hand opening”.

[0039] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[0040] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[0041] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows: [0042] Figure 1 is an isometric view of an interchangeable dragline roller element assembly according to a preferred embodiment of the invention.

[0043] Figure 2 is an exploded isometric view of the roller assembly as illustrated in Figure 1 separated from the mounting brackets.

[0044] Figure 3 is a detailed exploded isometric view of a single roller element of the configuration illustrated in Figures 1 and 2.

[0045] Figure 4 is an end elevation view of the assembly illustrated in Figure 1.

[0046] Figure 5 is a front elevation view of the assembly illustrated in Figure 1.

[0047] Figure 6 is a view of an open end of a left hand opening arrangement of an interchangeable dragline roller element assembly according to a preferred embodiment. Ο (Ν '(j Ο ο (Ν m ο (Ν Ό Ο (Ν 8 [0048] Figure 7 is a detailed view of the open end illustrated in Figure 6 from the direction indicated by the arrow.

[0049] Figure 8 is a view of a closed end of the left-hand opening arrangement of an interchangeable dragline roller assembly as illustrated in Figure 6.

DESCRIPTION OF EMBODIMENTS

[0050] According to a particularly preferred embodiment of the present invention, an interchangeable dragline roller assembly is provided.

[0051] The interchangeable dragline roller element assembly 10 of the present invention is particularly for supporting and guiding dragline cables (not shown). The assembly of the preferred embodiment illustrated in the Eigures includes an elongate shaft 1 Iwhich in use, is mounted transversely to the dragline cables. A number of roller elements 12 are mounted to the elongate shaft 11. A closed end 13 mounts the elongate shaft 11 at a first end thereof allowing rotation of the elongate shaft 11 as well as pivoting of the elongate shaft 11 out of the transverse use condition and an open end 14 mounts the elongate shaft 11 at a second end allowing rotation of the elongate shaft 11 when the elongate shaft 11 is in the transverse use condition. The open-end 14 has a locking assembly to releasably lock the elongate shaft 11 in the transverse use position and free the elongate shaft 11 to allow the elongate shaft 11 to pivot out of the transverse use position about the closed end in order to allow interchange of one or more of the roller elements 12.

[0052] As illustrated in Figure 1 in particular, the assembly of the present invention is normally mounted relative to a support assembly. The support assembly will normally have an overhead slap beam 15, with a number of slap blocks 16 mounted thereto. The overhead slap beam 15 is offset from the plane of the elongate shaft 11 of the drag roller element assembly 10.

[0053] The support assembly also has a pair of spaced apart support colunms 17 which support the overhead slap beam 15. Each of the spaced apart support arms 17 are provided with a side slap block 18.

[0054] Together, the overhead slap beam 15 (with slap blocks), the support colunms 17 (with slap blocks) and the roller assembly 10 define a generally rectangular opening or draghne rope tunnel 19 through which the dragline cables or ropes extend. The dragline rope tunnel 19 normally guides the dragline cables or ropes and the slap blocks 16, 18 on the overhead slap beam 15 and the spaced apart support columns 17 together with the roller elements 12 of the Ο (Ν '(j Ο ο r- (Ν ο ιη (Ν Ό Ο (Ν 9 drag roller element assembly 10 will guide and restrain the dragline cables during movement of the draghne cables.

[0055] Normally, the slap blocks 16, 18, whether provided on the support arms 17 or the overhead slap beam 15 are formed of a nylon material, preferably a reinforced nylon material. The slap blocks 16, 18 are also normally replaceable. The side slap blocks 18 are typically height adjustable.

[0056] The interchangeable dragline roller element assembly 10 includes an elongate shaft 11 which in use is mounted transversely to the dragline cables or ropes. The elongate shaft 11 is preferably a unitary shaft and normally manufactured of metal. The shaft typically has a shaped external cross-section but the shaped cross section may be provided as a sleeve over the shaft 11.

[0057] The cross sectional external shape of the shaft (or sleeve) of the illustrated embodiment is generally circular with a flattened land portion 20 as best shown in Figure 2. Normally, the flattened land portion 20 extends over the length of the shaft 11 and allows engagement with a roller element shell 21 in order to fix the roller elements 12 to the elongate shaft 11 against relative rotation.

[0058] A hardened bush 22 will typically be provided at both ends of the shaft for mounting purposes. A bearing is normally provided at either end of the shaft 11 to allow rotation of the shaft 11 relative to the support assembly and thereby, rotation of the roller elements 12 as well.

[0059] As illustrated in Figure 2, a thrust washer 23 is provided on at least one end and preferably both ends of the elongate shaft 11 adjacent the locking member 24 discussed further below. The bearing 26 at the open-end 14 is associated with the locking member 24 allowing rotation of the shaft 11 relative to the locking member 24. An external keeper plate 25 is located adjacent to the locking member and retains the locking member 24 and thrust washer 23 to the bush 22. A shaft handle 27 is then associated with the keeper plate 25.

[0060] An annular securing washer 28 is located on the end of the shaft 20 between the end roller element 12 and a thrust washer 23. As illustrated in Figure 2, a pair of transverse openings 29 are provided in the securing washer 28 and fasteners, normally grub screws or similar (not shown) can be used extending through the transverse openings 29 to engage with a securing opening 30 in the elongate shaft 11 to hold the roller elements 12 laterally on the shaft 11.

[0061] The interchangeable dragline roller element assembly of the present invention includes a number of roller elements 12 mounted to the elongate shaft 11. Any number of roller Ό Ο (Ν -I—> ο Ο r- (Ν m ο (Ν Ό Ο (Ν 10 elements 12 can be provided with the optimum number being six roller elements as illustrated.

[0062] Each of the roller elements 12 will preferably have the same configuration and a particularly preferred embodiment is illustrated in Figure 3. In particular, each roller element 12 has an external roller element sleeve 31 located about a roller element shell 32 which, in use, mounts the roller element 12 relative to the elongate shaft 11. The external roller element sleeve 31 of the illustrated embodiment is a wear component and according to a most preferred embodiment, is manufactured from a reinforced nylon material. It is preferred that the roller element sleeve 31 is substantially annular and cylindrical in external shape.

[0063] The roller element shell 32 of the illustrated embodiment is annular in shape and circular in external shape to be received closely within the annular roller element sleeve 31. The roller element shell 32 is received about the elongate shaft 11. The roller element shell 32 has a bore 33 therethrough. The bore 33 can be shaped to correspond to the external shape of the elongate shaft and/or a roller element end plate 34 may also be provided attached to the roller element shell 32. The roller element end plate 34 is also provided with a central opening with a periphery shaped to correspond with and engage with the elongate shaft 11 being substantially circular with a flattened land portion 35 to minimise relative rotation between the elongate shaft 11 and the roller elements 12.

[0064] The closed end 13 of the dragline roller element assembly 10 will normally include a housing 36 containing a bearing relative to which the elongate shaft 11 is mounted. The housing 36 of the illustrated embodiment is mounted to the support assembly via a pair of mounting brackets. According to the illustrated embodiment, an upper mounting bracket 37 and a lower mounting bracket 38 are provided.

[0065] Importantly, the mounting of the housing 36 at the closed end 13 allows pivoting of the elongate shaft 11 about a substantially vertical axis and the mounting of the elongate shaft 11 relative to the housing 36 allows rotation of the elongate shaft 11. The housing preferably supports the shaft during the pivoting movement of the shaft between the use and free conditions. In particular, the shaft with the roller elements provided thereon, may be a substantial weight and the housing and mounting brackets will preferably be capable of supporting the weight of the shaft with the roller elements provided thereon when the elongate shaft is moved to the free condition.

[0066] The bearing is typically enclosed within the housing 36 which protects the bearing and the housing 36 is substantial enough to support the weight of the elongate shaft. Ό Ο (Ν -I—> ο Ο r- (Ν m ο (Ν Ό Ο (Ν 11 [0067] As illustrated best in Figures 5 and 8, the housing is typically mounted to the upper and lower mounting brackets about a substantially vertical axis. Normally, an upper axial member 39 and a lower axial member 40 are provided relative to housing 36 allowing the housing 36 to rotate around the upper 39 and lower axial members 40. During normal replacement of the roller elements 12, the closed-end 13 will support the weight of the roller assembly and the open-end 14 will be unlocked and pivoted about the closed-end 13 in order to replace, refurbish or repair the roller elements 12.

[0068] The open-end 14 of the assembly 10 also mounts the elongate shaft 11. Normally, the open-end 14 is provided as an open collar 41 with an entryway. The open collar 41 is preferably substantially C-shaped with the entryway defined between the free ends of the open collar 41. The open collar 41 of the preferred embodiment has a spaced apart pair of substantially parallel wall portions 44 which form the entryway and which lead to a substantially circular portion of the open collar 41.

[0069] The open collar 41 is mounted to an upper mounting bracket 42 and a lower mounting bracket 43 which are attached directly towards one of the support arms 17 of the support assembly. The open collar 41 of the preferred embodiment is attached to or relative to the mounting brackets 42, 43 in use and the elongate shaft 11 is moved relative to the open collar 41.

[0070] The open collar 41 is a first part of the locking mechanism and a second part of the locking mechanism is the locking member 24 associated with the elongate shaft 11. As illustrated, the locking member 24 is provided on an outer end of the elongate shaft 11, laterally outside the roller elements 12 and is retained there by the keeper plate 25.

[0071] The locking member 24 corresponds to the shape of the open collar 41. As illustrated in Figures 6 and 7 in particular, the locking member 24 is substantially cylindrical with a pair of substantially parallel planar land portions 45. In use, when the pair of substantially parallel land portions 45 are aligned with the pair of substantially parallel wall portions 44 of the open collar 41, the locking member 24 can pass into the open collar 41. The locking member 24 can then be rotated, moving the parallel land portions 45 out of alignment with the parallel wall portions 44 of the open collar 41, which locks the locking member 24 within the open collar 41.

[0072] The locking member 24 will normally be provided with enlarged side portions 46 in order to receive the open collar 41 therebetween. Normally, the enlarged side portions 46 will each include a flange extending radially from the locking member 24 on either side thereof. Ό Ο (Ν -I—> ο Ο r- (Ν m ο (Ν Ό Ο (Ν 12

Preferably, the enlarged side portions 46 are radially larger than the locking member 24 although the enlarged side portions 46 are generally formed integrally with the locking member 24.

[0073] A handle 47 is provided in association with the locking member 24 in order to allow a user to more easily rotate the locking member 24.

[0074] The outer wall portion 48 of the locking member 24 is an enlarged wall portion (larger than the inner wall portion 46) located such that the outer wall portion 48 abuts or is closely spaced from a portion of the open collar 41 to assist with proper location of the locking member 24 relative to the collar 41. It is preferred that the outer wall portion 48 is provided with an enlarged protrusion 49 on one edge thereof. This enlarged protrusion 49 can be provided with an opening 50 therethrough in order to receive a lock bolt 51.

[0075] In addition, the enlarged protrusion 49 can function as a part of a stop mechanism. A stop member 52 can be provided on the open collar 41 against which a user can rotate the enlarged protrusion 49 in order to provide visual and/or tactile feedback in relation to the movement of the locking member 24 into the locked condition. Once the enlarged protrusion 49 abuts the stop member 52, the locking member 24 will typically be in the locked condition and further rotation in the same direction is prevented.

[0076] A lock bolt opening 53 is provided in the open collar 41 adjacent to the stop member 52 in order to receive a lock bolt 51 through the opening 50 in the enlarged protrusion 49 and into the lock bolt opening to prevent rotation of the lock member 24 whilst the assembly is in use. This configuration is illustrated in Figure 6 in particular.

[0077] A further handle 54 is provided extending laterally from the end of the locking member 24. In particular, the further handle may be provided substantially coaxially with the elongate shaft 11. In use, this further handle 54 may allow a user to more easily align the locking member 24 with the entry way to the open collar 41 during pivoting of the elongate shaft 11 between the use and free conditions. An elongate rest 55 is provided to support the weight of the assembly 10 when unlocked and at the beginning and end of the pivoting.

[0078] In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0079] Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the Ό Ο (Ν -I—> ο Ο r- (Ν m ο (Ν Ό Ο (Ν 13 embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0080] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims (22)

1. An interchangeable dragline roller element assembly for dragline cables including an elongate shaft in use, mounted transversely to the dragline cables, a number of roller elements mounted to the elongate shaft, a closed end mounting the elongate shaft at a first end thereof allowing rotation of the elongate shaft as well as pivoting of the elongate shaft out of the transverse use condition and an open end mounting the elongate shaft at a second end allowing rotation of the elongate shaft when the elongate shaft is in the transverse use condition, the open-end having a locking assembly to lock the elongate shaft in the transverse use position and free the elongate shaft to allow the elongate shaft to pivot out of the transverse use position about a first end in order to allow interchange of one or more of the roller elements.

2. An interchangeable dragline roller element assembly as claimed in claim 1 wherein the elongate shaft having a shaped external cross-section.

3. An interchangeable dragline roller element assembly as claimed in claim 2 wherein the external cross sectional shape of the elongate shaft is generally circular with a flattened land portion extending over the length of the shaft and allowing engagement with a roller element shell in order to fix the roller elements to the elongate shaft against relative rotation.

4. An interchangeable dragline roller element assembly as claimed in any one of the preceding claims further including a bush provided at both ends of the elongate shaft for mounting purposes.

5. An interchangeable dragline roller element assembly as claimed in any one of the preceding claims wherein each of the roller elements is provided with an external roller element sleeve located about a roller element shell which, in use, mounts the roller element relative to the elongate shaft.

6. An interchangeable dragline roller element assembly as claimed in claim 5 wherein the roller element shell is annular in shape having a bore therethrough shaped to correspond to the external shape of the elongate shaft and circular in external shape to be received closely within an annular roller element sleeve.

7. An interchangeable dragline roller element assembly as claimed in any one of the preceding claims wherein the closed end include a housing containing a bearing relative to which the elongate shaft is mounted.

8. An interchangeable dragline roller element assembly as claimed in claim 7 wherein the mounting of the housing allows pivoting of the elongate shaft about a substantially vertical axis and the mounting of the elongate shaft relative to the housing allows rotation of the elongate shaft.

9. An interchangeable dragline roller element assembly as claimed in any one of the preceding claims wherein the open-end of the assembly is provided as an open collar with an entryway defined between a pair of spaced apart free ends of the open collar as a spaced apart pair of substantially parallel wall portions and which lead to a substantially circular portion of the open collar.

10. An interchangeable dragline roller element assembly as claimed in claim 9 wherein the open collar is mounted to an upper and a lower mounting bracket associated with a support assembly with the open collar remaining attached to or relative to the mounting brackets in use and the elongate shaft moved relative to the open collar.

11. An interchangeable dragline roller element assembly as claimed in claim 9 or claim 10 wherein the open collar forms a first part of the locking mechanism and a second part of the locking mechanism is a locking member or assembly associated with an end portion of the elongate shaft.

12. An interchangeable dragline roller element assembly as claimed in claim 11 wherein the locking assembly includes a locking member which corresponds to the shape of the open collar.

13. An interchangeable dragline roller element assembly as claimed in claim 12 wherein the locking member is substantially cylindrical with a pair of substantially parallel planar land portions, such that in use, when the pair of substantially parallel land portions are aligned with the pair of substantially parallel wall portions of the open collar, the locking member can pass into the open collar and the locking member can then be rotated moving the parallel land portions out of alignment with the parallel wall portions of the open collar, which locks the locking member within the open collar.

14. An interchangeable dragline roller element assembly as claimed in either one of claims 12 or 13 wherein the elongate shaft is mounted to the locking member via a bearing allowing the elongate shaft to rotate relative to the locking member.

15. An interchangeable dragline roller element assembly as claimed in any one of claims 12 to 14 further including a handle or other gripping mechanism is provided in association with the locking member in order to allow a user to more easily rotate the locking member.

16. An interchangeable dragline roller element assembly as claimed in any one of claims 12 to 15 further including a bearing plate or flange provided on an outer side of the locking member to assist with proper location of the locking member relative to the collar.

17. An interchangeable dragline roller element assembly as claimed in claiml6 further including an enlarged protrusion or cam portion associated with the bearing plate and provided with an opening there through in order to receive a lock bolt.

18. An interchangeable dragline roller element assembly as claimed in claiml6 further including an enlarged protrusion or cam portion associated with the bearing plate function as a part of a stop mechanism with a stop member provided on the open collar or housing against which a user can rotate the enlarged protrusion or cam portion in order to provide visual and/or tactile feedback in relation to the movement of the locking member into the locked condition.

19. An interchangeable dragline roller element assembly as claimed in any one of the preceding claims wherein mounted relative to a support assembly having at least one overhead slap beam with a number of slap blocks mounted thereto.

20. An interchangeable dragline roller element assembly as claimed in claim 19 wherein the overhead slap beam is offset from the plane of the elongate shaft of the drag roller element assembly.

21. An interchangeable dragline roller element assembly as claimed in claim 19 or claim 20 wherein the support assembly has a pair of spaced apart support arms which support the overhead slap beam, the spaced apart support arms provided with one or more side slap blocks.

22. An interchangeable dragline roller element assembly as claimed in any one of claims 19 to 21 wherein the slap blocks are replaceable.