Patent Application
20240263429
The present invention relates to the attachment of a wear member to a lip of a shovel, bucket or other excavator. It has particular application in the connection of a shroud to an excavator lip. The invention has been developed for use in connection with rope or cable shovels, particularly for the fixing of shrouds to Whisler lips such as those manufactured by Komatsu Mining Corporation.
The Whisler lip for rope or cable shovel buckets was the subject of U.S. Pat. No. 1,992,591 filed in 1934. It remains the industry standard. A Whisler lip includes mounting points for alternating adapters and shrouds along its length. Each mounting point is associated with an aperture passing through the lip.
A shroud for a Whisler lip has a rearwardly extending leg which locates above the lip, and which has an opening arranged to align with the lip aperture. The shroud is locked into position by means of a locking pin which locates within the shroud opening and lip aperture. Traditionally, the locking pin has incorporated a wedging action which has the ability to tighten the shroud onto the bucket lip. Such locking pins include C-clamp-and-wedge fasteners and spool-and-wedge fasteners.
Traditional locking pins are limited in the degree of take-up available, that is, have limited capacity for tightening required due to wear. They also can prove difficult to remove, frequently requiring the use of a hammer. This represents a safety concern. Further, the compressive force available (that is, the degree of ‘tightness’) is relatively small, meaning that damage to the bucket lip due to rattling or vibration is often likely.
The present invention proposes a locking system which has broad application through a number of different lip configurations. Other benefits of the locking system will be detailed in the below description.
According to one aspect of the present invention there is provided a wear assembly arranged to locate over a lip of a digging apparatus, the lip having a first face and a second face, the lip having an aperture extending between the first face and the second face, the aperture including an engaging surface and a bearing surface;
The wear member is preferably a ground engaging tool, such as a shroud.
The lock is preferably formed as a discrete assembly; that is, able to be inserted and removed as a single assembled component.
It is preferred that the bearing surface of the wear member is located within the lock-receiving opening. The bearing surface may be oriented so as to face towards a wear end of the wear member.
The bearing surface may include a tool receiving aperture. Preferably, the bearing surface is annular and extends around the tool receiving aperture.
It is preferred that the actuator is able to be extended in an axial direction between a release position and a locked position, the actuator having an axial length when in the locked position greater than when in the release position. The actuator may have an extendible member, such that extension of the extendible member alters the effective length of the active portion of the lock body.
The extendible member may be formed by an externally threaded adjustment bolt located within an internally threaded barrel nut. In a preferred embodiment, the barrel nut has an outer head which forms the bearing surface of the actuator. The adjustment bolt has an inner end arranged to locate within the active portion of the lock body. It is preferred that the adjustment bolt is restricted from rotation relative to the lock body. In a preferred embodiment, this is achieved by the use of a holding pin which passes through the lock body and a corresponding aperture in an outer end of the adjustment bolt. Preferably, the pin is oriented in a transverse direction.
The extendible member may include a biasing element such as a compression spring to restrict inadvertent loosening of the extendible member.
The aperture of the lip preferably has a first wall representing the bearing surface, the first wall being opposed to a second wall, the engaging surface being located on the second wall.
The engaging surface may be formed by a shoulder located on the second wall.
Preferably, the shoulder extends across the second wall in a direction parallel to the first face of the lip. The arrangement may be such that the distance between the first wall and the second wall is greater at the second face of the lip than at the first face of the lip.
According to a second aspect of the present invention there is provided a wear member arranged to locate over a lip of a digging apparatus, the wear member having at least one extending leg, the extending leg having an outer surface arranged to face away from the lip and an inner surface arranged to face towards the lip, and a lock-receiving opening extending between the outer surface of the extending leg and the inner surface of the extending leg; wherein a bearing surface of the wear member is located within the lock-receiving opening, the bearing surface being oriented towards a wear end of the wear member and including a tool receiving aperture. Preferably, the bearing surface is annular.
According to a third aspect of the present invention there is provided a bucket of a digging apparatus, the bucket having an outer lip, the lip having a first face and a second face, the lip having an aperture extending between the first face and the second face, the aperture including an engaging surface and a bearing surface; wherein the aperture has a first wall representing the bearing surface, the first wall being opposed to a second wall, the engaging surface being located on the second wall, and the engaging surface being formed by a shoulder located on the second wall.
Preferably, the shoulder extends across the second wall in a direction parallel to the first face of the lip. The arrangement may be such that the distance between the first wall and the second wall is greater at the second face of the lip than at the first face of the lip
Preferably the digging apparatus is a cable shovel.
According to a fourth aspect of the present invention there is provided a lock for a ground engaging tool, the lock having a lock body and an actuator, the lock body having a locating portion and an active portion, the locating portion being arranged to locate within an aperture of a lip of a digging apparatus, the locating portion having an engaging surface arranged to engage with an engaging surface of the aperture and a bearing surface arranged to bear against a bearing surface of the aperture,
It is preferred that the actuator is able to be extended in an axial direction between a release position and a locked position, the actuator having an axial length when in the locked position greater than when in the release position. The actuator may have an extendible member, such that extension of the extendible member alters the axial length of the actuator.
The extendible member may be formed by an externally threaded adjustment bolt located within an internally threaded barrel nut. In a preferred embodiment, the barrel nut has an outer head which forms the bearing surface of the actuator. The adjustment bolt has an inner end arranged to locate within the active portion of the lock body. It is preferred that the adjustment bolt is restricted from rotation relative to the lock body. In a preferred embodiment, this is achieved by the use of a holding pin which passes through the lock body and a corresponding aperture in an outer end of the adjustment bolt. Preferably, the pin is oriented in the transverse direction.
The extendible member may include a biasing element such as a compression spring to restrict inadvertent loosening of the extendible member.
The locating portion of the lock body may have a front wall including the bearing surface and an actuate tail portion. The bearing surface is preferably planar, and is oriented at about 10° away from perpendicular to the effective length of the active portion. The tail portion may curve through about 90°.
The locating portion of the lock body may have a rear wall including a first portion extending away from the active portion, and a second portion extending away from the first portion at an obtuse bend. In a preferred embodiment the obtuse bend forms the engaging surface. The obtuse bend may be between 90° and 120°, and is preferably about 100°.
According to a fifth aspect of the present invention there is provided a method of locking a wear assembly over a lip of a digging apparatus, the lip having a first face and a second face, the lip having an aperture extending between the first face and the second face, the aperture including an engaging surface and a bearing surface;
It will be convenient to further describe the invention with reference to preferred embodiments of the present invention. Other embodiments are possible, and consequently the particularity of the following discussion is not to be understood as superseding the generality of the preceding description of the invention. In the drawings:
Referring to the Figures, there can be seen a wear assembly for connection of a wear member such as a shroud 40 to a lip 10 of an excavator bucket such as a cable-shovel bucket. The wear assembly uses a lock 80.
The lip 10 of the excavator bucket is shown in
An aperture 20 extends between the first face 12 and the second face 14. The aperture 20 is spaced rearwardly of the leading edge 16. The aperture 20 has a first wall 22 facing away from the leading edge 16 and a second wall 24 facing towards the leading edge 16. It will be appreciated that the first wall 22 and the second wall 24 are opposed to each other across the aperture 20.
The first wall 22 is straight, and extends generally linearly from the first face 12 to the second face 14. The second wall 24 has three portions: a first portion 26 which extends from the first face 12 about two thirds of the distance to the second face 14, and which is parallel to the first wall 22; a second portion 28 which extends in a direction away from the leading edge 16; and a third portion 30 which extends from the second portion 28 to the second face 14, and which is parallel to and rearwardly spaced from the first portion 26.
The first portion 26 and the second portion 28 meet at a shoulder 32. The shoulder 32 extends across the second wall 24 in a direction parallel to the first face 12 and second face 14.
The shroud 40 is shown in
The shroud 40 has two legs extending rearwardly of the nose 42: an extending leg 46 which is arranged to locate across the first face 12 of the lip 10 and a short leg 48 which is arranged to locate across the second face 14 of the lip 10.
The legs are sized such that when the shroud 40 is positioned with the leading edge 16 of the lip within the cavity 44 then the extending leg 46 extends beyond the aperture 20 and the short leg 48 does not reach the aperture 20.
The extending leg 46 has an outer surface 50 arranged to face away from the first face 12 of the lip 10, and an inner surface 52 arranged to abut the first face 12 of the lip 10.
The inner surface 52 has a first recessed portion 54 extending laterally across the inner surface 52, forward of the aperture 20. The shroud 40 has a second recessed portion 56 which extends around the inner surface 52 of the extending leg 46, the cavity 44, and an inner surface of the short leg 48. The second recessed portion 56 extends across a middle portion of the shroud 40, the middle portion representing about a third of the lateral extent of the shroud 40. It will be appreciated that the first and second recessed portions 54, 56 act to reduce the weight of the shroud 40 by removing material which is considered superfluous.
A lock-receiving opening 60 extends between the outer surface 50 and the inner surface 52. The lock-receiving opening 60 is surrounded by a thickened portion 58 of the shroud 40, extending the outer surface 50 away from the inner surface 52. The lock-receiving opening 60 is arranged to locate, in use, over the aperture 20 of the lip 10. The lock-receiving opening 60 can be seen in greater detail in
The lock-receiving opening 60 has side walls 62, a front wall 64 and a rear wall 66. The side walls 62 include rails 68 which project internally of the side walls 62 near the inner surface 52, and which extend from the front wall 64 about two thirds of the way towards the rear wall 66. The rails 68 are generally parallel to the outer surface 50. The rails 68 act as locking assembly supporting surfaces, as will be described below.
The front wall 64 is generally perpendicular to the outer surface 50.
The rear wall 66 is generally parallel to the front wall 64. The rear wall 66 has a generally conical recess 70 centrally located, with a tool receiving aperture 72 extending from the conical recess 70 through the rear wall 66. It will be appreciated that the conical recess 70 forms an annulus around the tool receiving aperture 72. The conical recess 70 and tool receiving aperture 72 are co-axial, with a central axis aligned at about 10° relative to the rear wall 66.
The extending leg 46 has a rear alcove 74 at a rear end thereof. The tool receiving aperture 72 passes between the lock-receiving opening 60 and the rear alcove 74.
The lock 80 is shown in
The lock body 82 has two integral portions: a locating portion 86 and an active portion 88. The locating portion 86 is sized to locate within the aperture 20 of the lip 10. The locating portion 86 has a front wall 90 and a rear wall 92. The front wall 90 has a first portion 94 extending away from the active portion 88 in a direction generally parallel to the rear wall 92; a second portion 96 extending away from the first portion 94 in a direction towards the rear wall 92, and an actuate third portion 98 which curves through about 90° to form a tail 108 of the locating portion 86.
The rear wall 92 has a first portion 100 extending away from the active portion 88, a second portion 102 extending away from the first portion 100 at an obtuse bend 104 of about 100°, and a third portion 106 parallel to and spaced from the first portion 100.
The arrangement is such that the actuate third portion 98 of the front wall 90 meets with the third portion 106 of the rear wall 92 to form the tail 108 of the lock body 82.
The obtuse bend 104 extends across the rear wall 92, and forms an engaging surface of the lock 80. The first portion 94 of the front wall 90 extends across the locating portion 86, and forms a bearing surface of the lock 80.
The active portion 88 houses the actuator 84. The actuator 84 has an extendible member 109 formed by an externally threaded adjustment bolt 110 and an internally threaded barrel nut 112. The extendible member 109 has an axial length which can altered by rotation of the barrel nut 112 relative to the adjustment bolt 110. The adjustment bolt 110 has a torque locking strip 111 located in an axially aligned recess midway along its length.
The barrel nut 112 has a bulbous outer head 114 which is shaped so as to abut against the conical recess 70 within the lock-receiving opening 60 of the extending leg 46 of the shroud 40. The outer head 114 has a tool receiving recess 116 centrally located within it, sized to be accessible by a tool passing through the tool receiving aperture 72 from the alcove 74 of the extending leg 46.
The barrel nut 112 has a step-change in its external diameter remote from the outer head 114. This results in a reduced diameter inner portion 115 connected to the remainder of the barrel nut 112 at a ridge 117.
The active portion 88 of the lock body 82 has a cylindrical aperture 132 within, arranged to receive the actuator 84 such that only the outer head 114 protrudes. The cylindrical aperture 132 has a wider portion at its outer end.
A pin 118 is arranged to locate within aligned pin receiving apertures 120 in the active portion 88 and a pin receiving aperture 122 at an end of the adjustment bolt 110 so as to prevent relative rotation of the adjustment bolt 110 and the lock body 82. In this way, any rotation applied to the tool receiving recess 116 causes the barrel nut 112 to rotate relative to the adjustment bolt 110, causing relative elongate movement along the interlocking threads. The pin 118 has a thread on an outer end.
A compression spring 124 is located within the cylindrical aperture 132 and arranged to locate about the adjustment bolt 110, acting against the ridge 117 of the barrel nut 112 to provide a bias against inward movement of the barrel nut 112 relative to the lock body 82. An outer engagement ring 126 is located around the barrel nut 112 near the outer head 114, gripping the barrel nut 112 and preventing ingress of fines within the cylindrical aperture 132. In use, the outer engagement ring 126 locates within the wider portion at the outer end of the cylindrical aperture 132.
The active portion 88 of the lock body 82 has two side faces 128 which are each in a stepped configuration, complementary in shape to the lock-receiving opening 60 in the shroud 40. Each side face 128 has a shoulder 130 which is arranged, in use, to sit on the rails 68 of the lock-receiving opening 60. The shoulders 130 serve as locating surfaces for the lock body 82. The width of the active portion 88 (between side faces 128) is greater than that of the locating portion 86, and is greater than the width of the aperture 20 in the lip 10.
The active portion 88 of the lock body 82 has a front face 134 which extends away from the front wall 90 of the locating portion 86. The active portion 88 has a rear face 136 from which the outer head 114 of the barrel nut 112 protrudes.
The active portion 88 has an effective length defined as the distance between the front face 134 of the active portion 88 and the outer head 114 of the barrel nut 112. It will be appreciated that rotation of the barrel nut 112 relative to the adjustment bolt 110 alters this effective length.
The front face 134 and rear face 136 of the active portion 88 are nearly perpendicular to the longitudinal axis of the actuator 84, albeit with a slight taper towards the locating portion 86. The first portions 94, 100 of front and rear walls 90, 92 of the locating portion 86 are each angled at about 10° relative to the front and rear faces 134, 136 of the active portion 88.
The active portion 88 has an access hole 142. The access hole 142 assists in removal of the lock body 82 from the assembly when required.
Operation of the wear assembly can be seen in
In the first instance the shroud 40 is slid onto the lip 10 so that the cavity 44 locates about the leading edge 16, with the short leg 48 abutting the second face 14 of the lip 10 and the inner surface 52 of the extending leg 46 contacting the first face 12 of the lip 10. In this position the lock-receiving opening 60 aligns with the aperture 20 to form a through-hole through the wear assembly.
The lock 80 can then be inserted into the through-hole, with the tail 108 inserted first such that the locating portion 86 locates within the aperture 20 with the front wall 90 facing the first wall 22 of the aperture and the rear wall 92 facing the second wall 24 of the aperture.
The lock 80 is inserted into the through-hole until the second portion 102 of the rear wall 92 clears the shoulder 32 of the second wall 24. This corresponds with the second portion 96 of the front wall 90 contacting an outer edge of the first wall 22, as can be seen in
The lock 80 can continue to be inserted by a slight rotation of the lock 80 relative to the shroud 40. This has the effect of allowing the shoulder 32 of the second wall 24 to locate against the obtuse bend 104 of the rear wall 92, and thus allows the shoulder 32 to act as an engaging surface of the aperture 20, engaging with the engaging surface of the lock 80.
In this position, as best seen in
In the final resting position of the lock 80 the shoulders 130 of the active portion 88 abut the rails 68 of the lock-receiving opening 60, such that the entire active portion 88 locates within the lock-receiving opening 60. This can be seen in
The lock 80 can then be activated in order to rigidly lock the shroud 40 to the lip 10. This is achieved by the application of a tool through the tool receiving aperture 72 of the extending leg 46, which is used to rotate the barrel nut 112 relative to the adjustment bolt 110 to extend the actuator 84 from a release position as shown in
In the locked position of
As a result, the shroud 40 is urged rearwardly relative to the lip 10 until the leading edge 16 of the lip 10 is tightly abutting the internal surface of the cavity 44, and the shroud 40 is tightly mounted on the lip 10.
It will be appreciated that should any loosening occur in use, due to wear or vibration, the actuator 84 can be readily retightened. Such loosening is unlikely, however, due to the biasing action of the spring 124.
In order to limit the clogging of the tool receiving aperture 72 and tool receiving recess 116 during use a plug 150 may be inserted into the rear alcove 74 once the lock 80 is tightened. The plug 150 is shown in
The plug 150 has a stepped projection having an outermost portion 152 and an inner portion 154, the inner portion 154 being of greater diameter than the outermost portion 152. The arrangement is such that the outermost portion 152 can be received within the tool receiving recess 116 when the inner portion 154 is received within the tool receiving aperture 72. The plug 150 has a winged body 156 which is arranged to locate within the rear alcove 74. It will be appreciated that wings of the winged body 156 can be pressed together in order to release the plug 150. Insertion of the plug 150 is shown in
The final locked wear assembly is shown in
Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021901662 | Jun 2021 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2022/050538 | 6/1/2022 | WO |
