Patent Application
20090199442
The present invention relates to an improved assembly for affixing replaceable machine parts and, in particular, an assembly which permits the retention and removal of replaceable machine parts, such as teeth and shrouds on heavy mining and construction equipment working members, such as mining shovels, excavator buckets, backhoe buckets and other earth moving tools.
Heavy construction equipment, such as backhoes and other earth moving devices often have excavator buckets, shovels or other tools with projecting teeth. Often, a cutting surface is applied or affixed to an exterior surface of the teeth. Typically, the teeth are attached to the excavator device or working member using bolts and/or pins, which are used to couple or retain the teeth to a respective adaptor or adaptor end of the working member. During use of such working members, peak loads applied to the teeth create high shearing stresses that may wear the teeth and/or assembly, requiring replacement. Traditionally, the removal and/or installation of the teeth to the adaptor require the use of a hammer, which is time consuming and, in some instances, a difficult process.
The present invention provides an assembly for quickly and easily attaching or retaining a tooth or similar structure to an adaptor or adaptor end of a cutting edge of construction and mining equipment, such as buckets, shovels or other tools. The assembly provides a retention assembly that allows for the removal or installation of the teeth or similar structure to the adaptor without the use of a hammer.
The present invention, in one form, relates to a retention assembly for mounting a tooth to an adaptor of an excavating apparatus. The retention assembly includes an adaptor, a tooth and a means for securing the tooth to the adaptor. The tooth includes an exterior cutting edge for providing the work function. The tooth includes an interior cavity for receiving an end of the adaptor. The interior walls of the tooth cavity are tapered and constructed and arranged to generally mate with the adaptor. The tooth further includes an opening for receiving a fastening means such as a bolt for fastening the tooth to the adaptor. The tooth further may include a recess in the interior cavity wall opposite the opening for receiving a fastening receptacle for engaging the fastening means inserted through the opening in the opposite wall of the tooth. The adaptor includes an end portion having tapered walls constructed and arranged to generally correspond to those of the tooth cavity and to mate with the cavity of the tooth. The tooth is slidably mounted onto the adaptor such that there is minimal play between the tooth and the adaptor. However, the tooth is not so tightly held as to wedge and lock tight on the adaptor, which would require removal by hammer or other means. The tapered walls of the adaptor preclude rotation of the tooth in any direction and any linear movement in all directions, except the forward direction. In the forward direction, the tooth is constrained by the fastening member.
The adaptor further includes an opening in the end portion constructed and arranged to align with the opening in the tooth and the fastening receptacle in the tooth. A fastening means is placed through the opening in the tooth, through the opening in the adaptor and engages an opening in the fastening receptacle. The fastening means is preferably a bolt comprising a first end having a means for inserting or removing the fastening means such as a ratchet end. The fastening means includes a second end having means for engaging the fastening receptacle such as threads. As stated above, the fastening means is inserted through the openings in the tooth and adaptor and engages the fastening receptacle for securing the fastening means in place to retain the tooth on the adaptor.
The fastening receptacle includes an opening for receiving the fastening means. It includes a top face which is generally flat and which engages a face of the adaptor. The fastening receptacle further includes a bottom face which is seated in the recess of the tooth. The fastening receptacle includes interior walls adjacent the opening for engaging a fastening member such as a threaded nut. A preferred fastening member is a hexagonal nut. When such hexagonal nut is used, the interior walls of the fastening receptacle are also hexagonal to hold the nut in place and keep it from rotating when engaging the fastening member. The fastening receptacle is placed in the recess of the interior wall of the tooth. There is sufficient clearance on the top and sides of the fastening receptacle and the recess of the tooth for receiving a durable polymer resin such as a polyurethane elastomer which may be poured around it and which then hardens to encapsulate the fastening receptacle in the wall of the tooth.
When it is desired to install a tooth to an adaptor, the tooth is slidably mated with the adaptor such that the tapered walls of the adaptor are adjacent to the corresponding tapered walls of the tooth. A fastening means such as a bolt is placed through the opening in the tooth and passes through the corresponding opening in the adaptor. The threaded end of the fastening means engages the fastening receptacle. The fastening means is then secured to the fastening receptacle. In a preferred embodiment, the fastening means is a bolt having a head with a ratchet means and a threaded end, and the fastening receptacle includes a threaded nut for receiving the bolt. When ratcheting the bolt into the nut, the upward force from the fastening means as it is tightened when passing through the nut in the fastening receptacle pushes up on the fastening receptacle and causes the polymer layer around and above the receptacle to distort upward against the face of the adaptor and into the hole of the adaptor to further aid in securing the tooth to the adaptor.
The present invention will now be described with regard to the several views of the drawings, where like numbers are identified using like numbers among the figures. It is to be understood that the excavation retention assembly of the invention may have a number of uses, including for excavating equipment, mining shovels, dragline buckets and the like. The retention assembly of the invention may be used for attaching teeth onto adaptors, for attaching lip shrouds to bucket lips, for installing an adaptor onto a bucket or for similar purposes as known to those skilled in the art. For purposes of describing the invention, the invention will be illustrated with reference to the attachment of a tooth to an adaptor of a work member. However, the invention is not so limited and is to be considered broader in scope than the description of the illustrated embodiment.
Referring now to
Referring now to
The adaptor 40 may be separate and apart from the work member 12 or may be integral to work member 12. The adaptor 40 includes an end portion 42 for slidable insertion with cavity 26 of tooth 20. The end portion 42 includes tapered walls 44 which are constructed and arranged to mate with the corresponding tapered walls 28 of cavity 26. It is understood that a preferred embodiment of the general geometry of the tapered walls is shown in the
Additionally, adaptor 40 includes an opening 46 through end portion 42. The opening is constructed and arranged to align with the opening 30 in tooth 20 and an opening 62 in fastening receptacle 60 to allow passage of fastening means 50 through openings 30, 46 and 62.
Fastening receptacle 60 includes a top face 64 which is generally flat and engages the bottom wall 48 of the end portion 42. There is an opening 62 in this top wall 64 through which fastening member 50 is allowed to pass to engage a fastening member 70. Fastening receptacle 60 includes a bottom face 66 which is seated in recess 32 of tooth 20. Receptacle 60 includes an interior wall 68 constructed and arranged to receive the fastening member 70 which in the preferred embodiment is a threaded hexagonal nut. When the fastening member 70 is hexagonal, the interior wall 68 is also hexagonal as shown in
Fastening receptacle 60 may be held in place in recess 32 by a durable polymer resin such as a polyurethane elastomer. In the preferred embodiment, the fastening receptacle is placed into recess 32 in the bottom interior wall of tooth 20 with sufficient clearance on the top and sides so that the polyurethane elastomer can be poured around it and then it hardens so as to encapsulate and hold in place the fastening receptacle 60. It should be understood that other means may be used to retain fastening receptacle 60 in recess 32 without departing from the scope of the invention.
A fastening means 50 is used to secure tooth 20 to adaptor 40. In the preferred embodiment, the fastening means 50 comprises a bolt having an upper end 52 having a ratchet opening 54 for engagement with a ratchet wrench to install the tooth on the adaptor or to remove the tooth from the adaptor. Fastening means 50 includes a shoulder wall 56 which is seated on corresponding shoulder portion 31 of opening 30 as best shown in
In use, the tooth 20 can be secured to the adaptor 40 by slidably inserting the tooth cavity 26 onto adaptor end 42. As previously mentioned, the interior walls 28 of cavity 26 are constructed and arranged to generally mate with the tapered walls 44 of adaptor 40 while at the same time not being so tight as to not be removable without a hammer or other implement. When tooth 20 is so engaged with adaptor 40, the openings 30 in tooth 20, 46 in adaptor 40, and 62 in receptacle 60 are in alignment. Fastening bolt 50 is inserted through these openings and a ratchet wrench is used to tighten bolt 50 into fastening nut 70. The upward force from the bolt 50 as it is tightened when passing through nut 70 pushes up on receptacle 60 and causes the polymer resin around the receptacle 60 to distort upward against the lower face of adaptor 40 and around and into hole 46 to further secure the tooth to the adaptor.
Although the invention has been described above in relation to preferred embodiments thereof, it will be understood by those skilled in the art that variations and modifications can be effected in these preferred embodiments without departing from the scope and spirit of the invention. For example, while the fastening means and fastening member of a preferred embodiment are engaged by thread means and a ratchet, other securing means may be used without departing from the scope of the invention. Additionally, while a preferred embodiment includes a recess in the tooth for engaging the fastening receptacle, the fastening receptacle may be secured in the tooth by other means without the need for the recess.
