The present disclosure relates generally to wear member retention and, more particularly, to a wear member retention system for an implement.
Earth-working and excavating machines, such as wheel loaders, cable shovels, drag lines, electric rope shovels (ERS), excavators, and front shovels, include implements generally used for digging into, ripping, or otherwise moving earth, rocks, debris, or other materials. Such implements commonly are various types of buckets having shapes and dimensions dependent on the type of bucket and size of the machine employing a particular bucket. These implements are subjected to abrasion and impacts that cause them to wear. To prolong the useful life of these implements, various shrouds, or wear members, can be connected to the earth-working and excavating implements at areas which experience wear. These wear members may be connected to the implements using a retention system that permits replacement of the wear members when they become worn to the extent that they should be replaced.
Some implements which have been provided with wear members have required that one or more components be welded to the implement in order to permit retention of the wear member in place on the implement. Other implements have employed various multi-component retaining systems wherein one or more of the components must be hammered in place to hold a wear member in position on an implement. The use of welded components that may need frequent replacement themselves due to extreme conditions of wear may be problematic, particularly where maintenance must be done at a work site. The use of retaining systems that are required to be hammered in place also may be problematic and difficult to put in place and remove. A shroud/wear member retention system that is both weldless and hammerless, that is to say, one that does not require retention parts to be welded to the implement and does not require retention parts that must be hammered in place, would be both beneficial and desirable. In addition, an assembled shroud/wear member retention system should have cooperating components that are arranged in a manner to avoid premature failure.
One retaining arrangement for a wear member is disclosed in U.S. Pat. No. 5,713,145 to Ruvang that issued on Feb. 3, 1998 (“the '145 patent”). Specifically, the '145 patent discloses a bucket that includes an attachment system for a shroud, or wear member, that includes a component that the '145 patent characterizes as a retainer, the retainer being welded or otherwise fastened to an implement lip. The '145 patent discloses that a J-shaped bolt may be inserted through an opening formed vertically through a rear portion of the wear member and rotated until a threaded end of the bolt is horizontal. The J-shaped bolt may then be received in a channel of the retainer of the '145 patent when the wear member is installed on the lip portion of the bucket. Subsequently, washers, a compression member, for example a spring, and a nut may then be installed over the threaded end of the J-shaped bolt and bear against the retainer to bias the wear member toward the lip of the bucket.
Although acceptable for some applications, the wear member retaining arrangement of the '145 patent may not have broad applicability. In particular, the wear member retaining arrangement of the '145 patent may not be sufficiently robust to endure the extreme conditions of use in large, heavy-duty machines. For example, the J-bolt of the '145 patent is inherently under tension. Tightening the J-bolt enough to sufficiently secure wear members onto an implement may cause metal fatigue and bolt failure, resulting in dislodgement of the wear member and implement damage, especially with heavy-duty use in large machines. In addition, the system disclosed in the '145 patent is specialized for use with the welded-on, or otherwise secured, retainers on the implement lip. This may be problematic when such retainers require repair and/or replacement, particularly during field operations.
The disclosed wear member retention system is directed to overcoming one or more of the problems set forth above.
According to one exemplary aspect, the present disclosure is directed to a lug member for a wear member retention system for an implement. The lug member includes an elongated body having a length dimension. The lug member also includes a wear member engagement portion extending toward a distal end of the elongated body. The lug member also includes a compression bolt assembly engaging portion adjacent a proximal end of the elongated body, wherein the compression bolt assembly engaging portion defines at least one bore configured to receive a compression bolt.
According to another exemplary aspect, the present disclosure is directed to a wear member retention system. The wear member retention system includes a boss configured to engage an aperture in an implement. The wear member retention system also includes a lug member configured to engage a wear member aperture and the boss and including a compression bolt assembly engaging portion. The wear member retention system also includes a compression bolt assembly extending between a portion of the boss and the compression bolt assembly engaging portion of the lug member and configured to force the compression bolt assembly engaging portion of the lug member away from the portion of the boss.
According to yet another exemplary aspect, the present disclosure is directed to a system for retaining a wear member on a bucket. The system includes a bucket including a container portion and a lip portion and defining an aperture adjacent the lip and extending from an inner surface of the bucket to an outer surface of the bucket. The system also includes a boss including a head element, a guide element extending in a first direction from the head element, and a leg element extending in a second direction from the head element, wherein the leg element is configured to extend into the aperture of the bucket. The system also includes a lug member including a wear member engagement portion configured to engage an aperture of a wear member, a boss engagement portion configured to engage the guide element and the head element, and a compression bolt assembly engaging portion. The system also includes a compression bolt assembly including two compression bolts between the head element and the compression bolt assembly engaging portion of the lug member and configured to force the compression bolt assembly engaging portion of the lug member away from the head element.
Bucket 12 may include a lip portion 16, sometimes referred to as a digging edge, cutting edge, edge member, etc., and one or more wall members defining a container portion 17 for material. For example, container portion 17 of bucket 12 may include a primary wall member 18 which may serve as a bottom and back, and two side wall members 20 and 22. Other bucket forms are contemplated, depending on the type of machine on which the bucket may be employed. Lip portion 16 may be provided with a plurality of tooth assemblies 24, and with a plurality of wear members 14. For example, a wear member 14 may be provided between each pair of adjacent tooth assemblies 24. Lip portion 16 may be detachable from bucket 12, e.g., secured by bolts or other fasteners, or it may be a fixed component of bucket 12, e.g., welded to primary wall member 18.
Lug member 44 may include an elongated body 54 having a length dimension L. Lug member 44 may include a wear member engagement portion 56 extending toward a distal end 58 of elongated body 54. A wear member engaging protrusion 60 may extend from wear member engagement portion 56 adjacent distal end 58. Wear member engaging protrusion 60 may be shaped so as to have a generally frustoconical profile. Alternatively, wear member engaging protrusion 60 may have other profiles, such as cylindrical, oval, polygonal, etc. Lug member 44 also may include a compression bolt assembly engaging portion 62 adjacent a proximal end 64 of elongated body 54.
Compression bolt assembly 46 may include at least one compression bolt 66. For example, in an embodiment, compression bolt assembly 46 may include two compression bolts 66 and each compression bolt 66 may be substantially identical to the other. Compression bolt 66 may include a head 68, for example a hex head, and a threaded shaft 70. Threaded shaft 70 may be threaded along its entire length, or it may be threaded only partially along its length. Compression bolt assembly 46 also may include thumb nuts 72 and jam nuts 74 for each of compression bolts 66. Compression bolt assembly 46 also may include one or more spacers 75 positioned, for example, between head 68 and jam nut 74.
A portion 76 of boss 42, for example a portion of head element 48, may include at least one recess 78 configured to receive a head 68 of a compression bolt 66. The recess 78 for each compression bolt 66 may be shaped to engage the head 68 of a compression bolt 66 so as to prevent rotation of the compression bolt 66 relative to boss 42. For example, where a bolt 66 includes a hex head, recess 78 may be shaped at least partially hexagonally in order to closely engage the hex head and prevent rotation of the compression bolt 66. Alternatively, where bolt 66 includes a square head, recess 78 may be shaped so as to closely engage the square head and prevent rotation of compression bolt 66. Recess 78 may be a hexagonal, square, or otherwise shaped blind bore within head element 48, or it may be a slot open to a surface 77 of head element 48 and having sides capable of confining head 68 of compression bolt 66 against rotation. Compression bolt assembly engaging portion 62 of lug member 44 may define at least one bore 80 configured to receive threaded shaft 70 of a compression bolt 66. Bore 80 may extend generally parallel to the length dimension L of elongated body 54. In the embodiment illustrated in
Thumb nut 72 of each compression bolt 66 may be configured to be finger tightened during use of compression bolt assembly 46. Each thumb nut 72 may include a knurled surface 82 to facilitate turning without a tool. Surface textures or profiles other than knurling that may be conducive to finger tightening also may be employed and are contemplated. Alternatively or additionally, each thumb nut 72 may be configured to receive a tool for turning. For example, each thumb nut 72 may include one or more apertures 84 adapted to receive a tool for apply leverage for turning thumb nut 72. Jam nut 74 of each compression bolt 66 may be configured to be tightened by a tool. Jam nut 74 may be, for example, a hex nut and may be tightened against thumb nut 72 in order to inhibit loosening of thumb nut 72.
A recess 86 may be defined by boss 42, for example adjacent the juncture of leg element 50 and head element 48, and a third bore 88 may be defined by the elongated body 54 of lug member 44. Third bore 88 may extend transverse to first and second bores 80 in compression bolt assembly engaging portion 62 and may extend in second direction B transverse relative to length dimension L of elongated body 54. A retention bolt 90 may extend through third bore 88 and cooperate with a nut 92. Retention bolt 90 may be of sufficient length to extend through third bore 88 and into recess 86 when lug member 44 is assembled with boss 42. Upon assembly of lug member 44 with boss 42 and compression bolt assembly 46, retention bolt 90 may be threaded into nut 92, and retention bolt 90 may extend into recess 86 in order to inhibit separation of the assembled components during transport or when being manipulated to engage a bucket 12 and wear member 14.
Still referring to
Transverse member 100 may have a thickness dimension extending in first direction A for a portion of length dimension L of elongated body 54. Transverse member 100 may include a pull-back ledge 110 extending from transverse member. Pull-back ledge 110 also may include a thickness dimension extending in first direction A for a portion of length dimension L of elongated body 54. The thickness dimension of pull-back ledge 110 may be less than the thickness dimension of transverse member 100.
Lug member 44 may include a boss engaging surface 112 configured to engage a surface of boss 42. Boss engaging surface 112 may be generally planar. Lug member 44 also may include a profiled surface 114 opposite boss engaging surface 112. Profiled surface 114 may include surface portions defining features of lug member 44 that enable wear member retention system 26 to effectively retain a wear member 14 on bucket 12 in cooperation with boss 42 and compression bolt assembly 46. For example, profiled surface 114 may include a surface portion defining the compression bolt assembly engaging portion 62, a portion for extending through a boss aperture 116 (
Leg element 50 may extend from guide element 52 and head element 48 approximately 160 mm, for example. The maximum extent of leg element 50 in direction C from second curved surface portion 124 to end surface 119 may be on the order of 150 mm. The radius of curvature of first curved surface portion 122 may be on the order of 8.5 mm, and may be between 7 mm and 10 mm, for example. The radius of curvature of second curved surface portion 124 may be approximately 120 mm, and may be between 110 mm and 130 mm, for example. The radius of curvature of third curved surface portion 126 may be approximately 65 mm, and may be between 60 mm and 70 mm, for example. The radius of curvature of fourth curved surface portion 128 may be approximately 50 mm, and may be between 40 mm and 60 mm, for example. The radius of curvature of fifth curved surface portion 132 may be approximately 20 mm, and may be between 10 mm and 30 mm, for example. The dimensions given for leg element 50 may be typical examples, but they are not intended to be limiting since dimensions may vary based on the size of machine and/or implement on which the disclosed wear member retention system 26 may be employed, and/or based on the size and shape of an aperture 36 with which boss 42 may be associated, for example.
Disclosed embodiments of wear member retention system 26 may be applicable to various earth-working machines, such as wheel loaders, cable shovels, drag lines, electric rope shovels (ERS), excavators, and front shovels, and other machines that include implements generally used for digging into, ripping, or otherwise moving earth, rocks, debris, or other materials. Presently disclosed embodiments of wear member retention system 26 require no welded-on parts and include no parts that must be forced in place by hammering. In addition to being both weldless and hammerless, presently disclosed embodiments of wear member retention system 26 may be employed with existing wear members and on buckets and other implements that include existing lip holes (e.g., lip holes provided for retaining various existing ground engaging components) without modification. Because the disclosed wear member retention system employs a compression bolt assembly including bolts that exert and maintain compression forces to pull back and secure a wear member onto a lip of an implement instead of tension forces, the system is much less subject to bolt failure.
Boss 42 may include a leg element 50 that is profiled for ease of insertion into and removal from an implement aperture, such as, for example, aperture 36 of bucket 12. For example, first portion 118 of leg element 50 of boss 42 may include an installation recess 136 on a proximal side 138 of boss 42. Installation recess 136 may include a concave curved surface portion, for example third curved surface portion 126, having a radius of curvature that is optimized to aid installation of boss 42. At the same time, leg element 50 is robustly dimensioned for stiffness to enhance resistance to stress failure. Accordingly, ease of insertion of leg element 50 of boss 42 into aperture 36 may be gained without compromising stress failure resistance of boss 42.
The unique shape and cooperating arrangement of boss 42 and lug member 44 permit the use of one or more compression bolts 66 to exert a force pulling back and retaining a wear member 14 on the lip 16 of an implement 10 that places bolts 66 under compression rather than under tension. As a result, the bolts are more enduring and less apt to fail. Advantageously, the disclosed compression bolt assembly 46 makes it possible to exert sufficient force to pull back and retain a wear member 14 using nuts for the compression bolts 66 that do not require tools. Thus, thumb nuts 72 may be used to manually adjust the wear member retention system 26.
Use of the term “generally,” within this specification, (e.g., generally perpendicular, generally equal, generally planar, etc.) is intended to take into account those situations wherein the components and relationships referenced may deviate from an absolute by normal and accepted industry manufacturing tolerances.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed wear member retention system. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice using the disclosed wear member retention system. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.
Number | Name | Date | Kind |
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2167425 | Page | Jul 1939 | A |
5653048 | Jones | Aug 1997 | A |
5713145 | Ruvang | Feb 1998 | A |
6209238 | Ruvang | Apr 2001 | B1 |
6240663 | Robinson | Jun 2001 | B1 |
7121022 | Bierwith | Oct 2006 | B2 |
7578081 | Bearden et al. | Aug 2009 | B2 |
8943718 | Ruvang | Feb 2015 | B2 |
20170022690 | Tasovski | Jan 2017 | A1 |
20180044895 | Rol Corredor | Feb 2018 | A1 |
Number | Date | Country | |
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20170370076 A1 | Dec 2017 | US |
Number | Date | Country | |
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62354215 | Jun 2016 | US |