Abstract:
Telescoped ground engaging telescoped wear and support members are provided with self-adjusting connector apparatus that releasably retains the wear member in a rearwardly telescoped orientation on the support member. In illustrated embodiments thereof, the connector apparatus includes cooperating ratchet structures operatively associated with the support and wear members and functioning to automatically re-tighten an abrasion-created loosened interfit between the wear and support members in response to a rearwardly directed operational force imposed on the wear member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the benefit of the filing date of provisional U.S. patent application No. 61/868,838 filed Aug. 22, 2013. The entire disclosure of the provisional application is hereby incorporated herein by this reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    In representatively illustrated embodiments thereof, this invention provides connector apparatus for telescoped ground engaging wear and support members. The connector apparatus is self-adjusting, to re-tighten the interfit between the wear and support members in response to operational forces imposed on the wear member. 
         [0003]    A long standing practice in the ground engaging art is to protect a support member from operational abrasion wear by telescoping a replaceable wear member rearwardly onto a front portion of the support member (typically larger and more expensive than the wear member) to shield the wear member-covered portion of the support member from abrasion when the wear member/support member assembly is utilized in, for example, excavation, earth moving or mining operations. Examples of such telescoped wear member/support member combinations utilized in the ground engaging art include, but are not limited to, tooth point/adapter assemblies, base adapter/intermediate adapter assemblies, and shroud/bucket lip weld base assemblies. 
         [0004]    For the wear member portion of the assembly to perform its abrasion shielding function, it must be releasably retained on the support member in a manner such that it will not be dislodged from the support member during ground engaging operations, yet is easily removable from the support member when the wear member is substantially worn away and needs to be replaced with a new wear member. Several well-known problems, limitations and disadvantages are commonly associated with conventional methods and apparatus utilized to retain a wear member on an associated support member. 
         [0005]    For example, such retention is often effected using a spool member placed in aligned wear and support openings in the telescoped wear and support members, and a wedge which is then pounded into place in the openings into forcible engagement with the spool to retain the wear member on the support member. This requirement for pounding in a connector member is typically awkward and can sometimes be dangerous. Moreover, pounded-in connector components may be loosened during use of the wear member/support member assembly to an extent that the wear member falls off, becomes lost, and subjects the underlying support member to undesirable wear. Also, such loosening can undesirably permit the wear member to rattle back and forth on the support member. Undesirable loosening of the interfit between the wear and support members may also occur due to internal operational abrasion therebetween, with the pounded-in connector components typically being unsuitable for easily re-tightening this interfit. 
         [0006]    As can readily be seen from the foregoing, a need exists for improved wear member/support member connector apparatus that eliminates or at least substantially reduces above-mentioned problems, limitations and disadvantages associated with conventional connector apparatus of the type generally described above. It is to this need that the present invention is primarily directed. 
         [0007]    In carrying out principles of the present invention, in accordance with representatively illustrated embodiments thereof, telescoped wear and support members are provided with specially designed self-adjusting connector apparatus that releasably retains the wear member in its rearwardly telescoped orientation on the support member. As will be seen, in representative embodiments thereof the connector apparatus preferably includes cooperating ratchet structures operatively associated with the support and wear members and functioning to automatically tighten an abrasion-created loosened interfit between the wear and support members in response to a rearwardly directed operational force imposed on the wear member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a longitudinally foreshortened, partially exploded side elevational view of a telescoped ground engaging wear member and support member assembly incorporating therein a self-adjusting interfit tightening structure embodying principles of the present invention; 
           [0009]      FIG. 2  is a top side view of a base member portion of the interfit tightening structure; 
           [0010]      FIG. 3  is an exploded bottom side view of the wear member and base member as shown in  FIG. 1 ; 
           [0011]      FIG. 4  is a cross-sectional view of the interfit tightening structure; 
           [0012]      FIG. 5  is an enlarged cross-sectional view of a portion of the assembled interfit tightening structure; 
           [0013]      FIG. 6  is a cut away perspective view of a portion of a second wear member and support member assembly incorporating therein an alternate embodiment of the self-adjusting interfit tightening structure; 
           [0014]      FIG. 7  is a cross-sectional view through a portion of the second wear member and support member assembly taken generally along line  7 - 7  of  FIG. 6   
           [0015]      FIG. 8  is a partially exploded bottom side view of a portion of the second wear member and support member assembly; 
           [0016]      FIG. 9  is an end view of the assembled  FIG. 8  components taken along line  9 - 9  of  FIG. 8 ; 
           [0017]      FIG. 10  is an upwardly directed cross-sectional view through a portion of the second wear member and support member assembly; and 
           [0018]      FIG. 11  is a cross-sectional view through the second wear member and support member assembly taken along line  11 - 11  of  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Referring initially to  FIGS. 1-5 , in a first representatively illustrated embodiment of the self-adjusting connector apparatus one way ratchet teeth  10  (see  FIGS. 3-5 ) are formed on a top side interior portion of a hollow wear member  12 , illustratively in the form of a wing shroud, which is rearwardly telescoped onto a base member  14  (see  FIGS. 1 ,  4  and  5 ) illustratively welded onto or otherwise secured to a support member  15  onto which the wear member  12  is also telescoped. Illustratively the support member  15  is in the form of a bucket lip to which the wear member  12  is releasably held by a specially designed interfit tightening structure  16  embodying principles of the present invention. Other types of support members may be alternatively utilized without departing from principles of the present invention. 
         [0020]    Interfit tightening structure  16  (see  FIGS. 4 and 5 ) includes the ratchet teeth  10 , a vertically movable metal contact block  18  having a series of projections  20  formed on its top side in staggered rows as shown in  FIG. 2 , and an elastomeric member  22  underlying the block  18 . The elastomeric member  22  and a reduced cross-section lower portion  18   a  of the contact block  18  are slidably received in a top side recess  24  of the base member  14 . 
         [0021]    A bolt  26  has a head portion  28  rotatably received in a top side opening of the contact block  18  and having a noncircularly cross-sectioned drive recess  30  therein, and a body portion  32  extending downwardly through the a bottom portion of the contact block  18  and the underlying elastomeric member  22  and threaded into a nut  34  (see  FIG. 5 ) nonrotatably received in a lower side opening  36  of the support member  14 . Tightening the bolt  26  vertically compresses the elastomeric member  22  and lowers the contact block  18 , and subsequently loosening the bolt  26  relaxes the elastomeric member  22  and permits it to raise the contact block  18 . Instead of the illustrated single nut  34 , two nuts could be utilized to further assure that the bolt  26  stays in place during operation of the ground engaging apparatus. 
         [0022]    With the elements  18 ,  22 ,  26  and  34  installed on the base member  14 , and the bolt  26  tightened to lower the contact block  18  against the resilient force of the compressed elastomeric member  22 , the wear member  12  is rearwardly telescoped onto the base member  14  (and also onto the support member  15 ) to an initially tightened orientation on the base member  14  and thus on the support member  15  as well. Using a suitable tool (not shown) moved downwardly through an access opening  38  in the top side of the wear member  12  and into the bolt head recess  30 , the bolt  26  is then loosened to permit the contact block  18  to be raised by the underlying elastomeric member  22  in a manner causing the contact block projections  20  to upwardly enter corresponding ones of the gaps between adjacent pairs of the one-way ratchet teeth  10  of the wear member  12  (see  FIG. 5 ). Due to the one-way configuration of the ratchet teeth  10 , this prevents the installed wear member  12  from moving forwardly relative to the base member  14  and coming off the support member  15  to which the base member  14  is secured. 
         [0023]    As the wear member/support member assembly  12 , 15  is utilized in ground engaging operations, operational abrasion wear between these elements will loosen the original interfit therebetween. However, when this interfit loosening reaches a certain extent, rearwardly directed operational forces on the wear member  12  will shift it rearwardly in a manner causing the projections  20  to rearwardly ratchet into the next available set of grooves between the one-way ratchet teeth  10 , thereby again locking the wear member  12  against forward movement relative to the support member  15  and retightening the wear member  12  thereon. 
         [0024]    A second interfit tightening structure embodiment  40  is shown in  FIGS. 6-11  and is similar in operation to that of the previously described interfit tightening structure  16 . Specifically, the interfit tightening structure  40  (see  FIGS. 6 ,  7 ,  10  and  11 ) automatically functions to tighten a loosened interfit between a wear member  42 , representatively in the form of a wing shroud, telescoped onto a base member  44  welded or otherwise secured to a support member  45  illustratively in the form of an excavating bucket lip, in response to rearwardly directed operational force exerted on the wear member  42 . 
         [0025]    In this interfit tightening structure embodiment  40 , however, a set of one-way ratchet teeth  46  (see  FIG. 8  and) is formed directly on a right side edge portion of the base member  44  (as viewed in  FIG. 10 ) and cooperates with projections  48  on a metal contact block  50  similar to the previously described contact block  18  and secured with an underlying resilient member  52  by a bolt  54  within an internal side edge recess  56  of the base member  44  (see  FIG. 6 ). As can be seen in  FIGS. 6 ,  7  and  10 , rearward movement of the wear member  42  relative to the support member  44  caused by rearwardly directed operational forces on the wear member  42  ratchets it rearwardly to retighten it on the base member  44  and thus on the support member  45  to which the base member  44  is welded or otherwise secured. If desired, a second interfit tightening structure  40  (not shown) may be installed on the left side edge portion of the wear member  42  (as viewed in  FIG. 10 ), with its projections  48  staggered in a front-to-rear direction relative to the projections  48  on the right side interfit tightening structure  40 , for mating with one way ratchet teeth  46  (not shown) formed on the left side edge of the base member  44 . As illustrated, the projections  48  may have one-way ratchet tooth configurations (as may the previously described projections  20 ). 
         [0026]    As will be readily appreciated by those of skill in this particular art, the horizontally oriented interfit tightening structure depicted in  FIG. 6  could be alternatively utilized in a vertical orientation, if desired, simply by rotating it ninety degrees in a manner placing the bolt  54  on the top side of the re-oriented interfit tightening structure. 
         [0027]    While the representative embodiments of the present invention have been previously described herein in conjunction with a shroud structure connected to a weld base structure in turn secured to a bucket lip, principles of the invention are not limited to these illustrative types of wear and support members and could be utilized to advantage with a wide variety of other types of wear and support member combinations such as, for example, a tooth point and an adapter or an intermediate adapter and a base adapter.