Abstract:
A connector pin assembly for releasably retaining a replaceable excavating tooth point on an adapter nose has opposite rigid body portions that are threadingly connected to one another in a manner permitting them to be selectively moved axially toward and away from one another, and a resilient structure captively retained between facing ends of the body portions. The connector pin assembly may be operatively inserted into the aligned point and adapter openings without the need to pound it in. Once the connector pin assembly is in place within the point and adapter openings the rigid body portions are threadingly moved toward one another to thereby compress the resilient structure in a manner forcing it against an interior surface portion of the adapter opening.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to material displacement apparatus and, in a preferred embodiment thereof, more particularly relates to apparatus for releasably coupling a replaceable excavating tooth point or other wear member to an associated adapter nose structure. 
     A variety of types of material displacement apparatus are provided with replaceable wear portions that are removably carried by larger base structures and come into abrasive, wearing contact with the material being displaced. For example, excavating tooth assemblies provided on digging equipment such as excavating buckets or the like typically comprise a relatively massive adapter portion which is suitably anchored to the forward bucket lip and has a reduced cross-section, forwardly projecting nose portion, and a replaceable tooth point having formed through a rear end thereof a pocket opening that releasably receives the adapter nose. To captively retain the point on the adapter nose, generally aligned transverse openings are formed through these interchangeable elements adjacent the rear end of the point, and a suitable connector structure is driven into and forcibly retained within the aligned openings to releasably anchor the replaceable tooth point on its associated adapter nose portion. 
     The connector structure typically has to be forcibly driven into the aligned tooth point and adapter nose openings using, for example, a sledge hammer. Subsequently, the inserted connector structure has to be forcibly pounded out of the point and nose openings to permit the worn point to be removed from the adapter nose and replaced. This conventional need to pound in and later pound out the connector structure can easily give rise to a safety hazard for the installing and removing personnel. 
     A need accordingly exists for an improved connector structure that eliminates or at least substantially reduces this problem typically associated with conventional pound-in type connectors used to releasably retain a replaceable tooth point on an adapter nose. It is to this need that the present invention is directed. 
     SUMMARY OF THE INVENTION 
     In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, improved connector apparatus is provided for captively retaining an excavating wear member, such as a replaceable excavating tooth point, on an adapter nose. The adapter nose is complementarily and removably receivable in a socket portion of the wear member in a manner substantially aligning connection openings extending through the wear member and adapter nose. 
     The connector apparatus is representatively a connector pin assembly comprising first and second connector body members, and cooperatively engageable threaded structures operative to forcibly move the first and second connector body members toward one another in a first direction parallel to the longitudinal axis of the connector pin assembly. A resilient structure is interposable between the first and second connector body members and is operative to be resiliently compressed thereby in the first direction in response to forcible movement of the first and second connector body members toward one another in the first direction by operation of the threaded structures. 
     The threaded structures, although they may be separate from the connector bodies, are preferably formed integrally therewith. Representatively, the connector bodies have cylindrical shapes and the threaded structures include a reduced diameter externally threaded portion of the first connector body axially projecting from one of its ends, and an internally threaded axial end opening formed in the second connector body and into which the reduced diameter projection on the first connector may be threaded. 
     In a first illustrated embodiment of the connector pin assembly, the resilient structure has a tubular shape, circumscribes the reduced diameter externally threaded first connector body projection, has opposite ends that face annular inner end surfaces on the first and second connector body portions, and is of an elastomeric material. Illustratively, annular flat washers are interposed between the tubular member ends and these annular inner end surfaces. When the first and second connector bodies are threadingly advanced axially toward one another, the tubular resilient member is axially compressed and radially expanded outwardly beyond the side peripheries of the first and second connector bodies. 
     This first embodiment of the connector pin assembly is illustratively utilized in conjunction with an overall wear member/adapter assembly in which the adapter nose opening has an annular interior side surface recess therein. With the connector pin resilient structure in its relaxed state, the connector pin assembly is axially inserted into the substantially aligned wear member and adapter nose opening until the resilient structure is generally aligned with the annular nose opening recess. Then, using outer end drive socket openings in the connector body members, the body members are threadingly advanced toward one another to axially compress and radially expand the resilient structure, thereby causing it to radially expand into the annular nose opening recess and come into forcible contact with its side surface. 
     This captively retains the inserted connector pin assembly within the adapter nose and wear member openings via both a frictional engagement between a side surface portion of the adapter nose opening and a mechanical interlock between the radially expanded resilient structure and the nose opening annular recess that receives it. The interengagement of the radially expanded resilient structure and the adapter nose resiliently mounts the connector pin in the adapter nose and wear member openings and resiliently resists axial operating loads imposed on the inserted connector pin assembly. Opposite end portions of the inserted connector pin assembly are received in the wear member openings and block the wear member against removal from the adapter nose which its socket receives. 
     While the interior of the adapter nose opening is preferably provided with the described annular side surface recess to radially receive the radially expanded resilient structure, this recess may be eliminated, if desired, so that the radially expanded resilient structure removably holds the inserted connector pin assembly in place solely by means of the frictional interengagement between the radially expanded resilient structure and a facing interior side surface portion of the adapter nose opening. 
     In a second version of the overall wear member/adapter assembly, an annular projection is formed within the adapter nose opening and has oppositely facing annular ledge surfaces thereon. A second embodiment of the connector pin assembly is used in this wear member/adapter assembly and incorporates therein a resilient structure that comprises a pair of annular flat resilient washers that are preferably of an elastomeric material. This connector pin assembly is operatively inserted into the substantially aligned wear member and adapter nose openings by inserting the first and second connector body portions inwardly through opposite ends of the aligned wear member/adapter nose openings in a manner such that the reduced diameter externally threaded portion passes through the interior adapter nose opening projection, with the resilient washers being interposed between the opposite annular ledge surfaces and the facing inner ends of the first and second connector body portions. 
     When the first and second connector body portions are threadingly advanced axially toward one another, the body portions compress the annular resilient washers against the annular ledge surfaces to thereby resiliently mount the inserted connector pin assembly within the substantially aligned wear member and adapter nose openings. Opposite ends of the inserted connector pin assembly are received in the wear member openings to block removal of the wear member from the adapter nose. 
     Neither representative embodiment of the connector pin assembly needs to be forcibly driven into the substantially aligned wear member and adapter nose openings to operatively install the connector pin assembly—it is simply inserted into such openings and then threadingly tightened to operatively deform its resilient section. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partly elevational cross-sectional view of a nose portion of an adapter and a replaceable excavating tooth point releasably held on the adapter nose by a specially designed connector pin assembly embodying principles of the present invention; 
     FIG. 2 is an exploded side elevational view of the connector pin assembly removed from the tooth point and adapter nose; 
     FIG. 3 is an assembled side elevational view of the connector pin assembly with a longitudinally intermediate resilient portion being in a relaxed state; 
     FIG. 4 is an assembled side elevational view of the connector pin assembly with the annular resilient portion being axially compressed and radially expanded; and 
     FIG. 5 is a partly elevational cross-sectional view of the replaceable excavating tooth point releasably held on a differently configured adapter nose by an alternate embodiment of the connector assembly. 
    
    
     DETAILED DESCRIPTION 
     AS illustrated in FIGS. 1-4, in a depicted preferred embodiment thereof this invention provides a specially designed cylindrical connector pin assembly  10  that is used to releasably hold a wear member, representatively an excavating tooth point  12 , on the nose  14  of an associated support member, representatively an adapter structure  16 . It will be appreciated by those of skill in this particular art that other types of wear members, such as for example an intermediate adapter, could also be captively and releasably retained on the adapter nose  14  by the connector pin assembly  10  if desired. 
     In a conventional manner, the replaceable tooth point  12  has an internal socket  18  extending inwardly from its rear end  20 , with the adapter nose  14  being complementarily received in the socket  18 . A transverse, circularly cross-sectioned opening  22  extends through the adapter nose  14  and is generally aligned with corresponding openings  24  formed in opposite side wall portions  26 , 28  of the tooth point  12 . In a manner subsequently described herein, the connector pin assembly  10  is inserted into the aligned openings  22 , 24  and is retained therein to thereby retain the tooth point  12  in place on the adapter nose  14 . 
     The connector pin assembly  10  provides substantial improvements with respect to cylindrical “snap-ring” connectors that have bodies which must be pounded (for example, with a sledge hammer) into the aligned adapter nose and tooth point openings  22 , 24  to compress a snap ring carried in an annular groove on the pin body and then permit the compressed snap ring to expand into an enlarged opening portion within the adapter nose  14  to thereby lock the inserted pin within the adapter nose and tooth openings  22 , 24 . This previously utilized connector pin structure has several disadvantages—for example, the inherent hazards of having to pound the pin in and out of the adapter/tooth assembly, and the potential for operational impact loads imposed on the inserted pin structure to dislodge it from the tooth/adapter assembly. 
     The specially designed connector pin assembly  10  shown in exploded form in FIG. 2, includes first and second cylindrical metal longitudinal body portions  30  and  32 , upper and lower annular metal washers  34  and  36 , and a tubular resilient member  38  which is representatively of an elastomeric material. The first cylindrical portion  30  has an outer end  39  with a square or hexagonal recess  40  therein, and a reduced diameter, externally threaded inner end portion  42  projecting downwardly from an annular shoulder  44  on the first cylindrical portion  30 . 
     The second cylindrical portion  32  has an outer end  46  with a square or hexagonal recess  48  formed therein, and an inner end  50  with an internally threaded, circularly cross-sectioned opening  52  extending thereinto. To assemble the connector pin assembly  10 , as shown in FIG. 3, the externally threaded portion  42  of the first pin structure portion  30  is sequentially passed through the upper washer  34 , the tubular elastomeric member  38  and the lower washer  36  and then threaded into the second connector pin portion opening  52  as shown in FIG.  3 . In this initially assembled configuration of the connector pin assembly  10 , the shoulder  44  abuts the washer  34 , and the inner end  50  of the lower connector pin portion  32  abuts the washer  36 , but the tubular elastomeric member  38  is in a relaxed state in which it is not substantially compressed in an axial direction. 
     The connector pin assembly  10  in its initially assembled, ready-to-install FIG. 3 orientation is then inserted into the aligned adapter nose and tooth point openings  22 , 24  until the tubular elastomeric member  38  is generally opposite a radially enlarged portion  22   a  of the adapter nose opening  22 . The threaded end  42  of pin portion  30  is then screwed further into the opening  52  of the other pin portion  32  to thereby force the shoulder  44  closer to the inner end  50  of the pin portion  32 . This, in turn, forces the washers  34 , 36  closer together to thereby axially compress and radially expand the tubular elastomeric member  38  as shown in FIG.  4 . With the connector pin assembly  10  inserted into the aligned adapter nose and tooth point openings  22 , 24  as shown in FIG. 1, this causes the radially expanded tubular elastomeric member  38  to enter the radially enlarged adapter nose opening portion  22   a  and lock the inserted connector pin assembly  10  in place against axial removal from the openings  22 , 24 . This, in turn, locks the tooth point  12  on the adapter nose  14 . 
     AS can be seen in FIG. 1, the locking of the inserted connector pin assembly  10  within the generally aligned tooth point and adapter nose openings is achieved by a combination of (1) a frictional engagement between the radially expanded elastomeric member  38  and a side surface portion of the adapter nose opening  22 , and (2) a mechanical interlock between the radially expanded elastomeric member  38  and the enlarged adapter nose opening portion  22   a  that receives it. It will be readily appreciated by those of skill in this particular art, however, that the enlarged adapter nose opening portion  22  could be eliminated, if desired, so that the radially enlarged elastomeric member could frictionally engage a side portion of the opening  22  without being mechanically interlocked with the adapter nose. Alternatively, the enlarged opening portion  22   a  could be sized in a manner such that the frictional engagement of the radially enlarged elastomeric member  38  with the side of the opening portion was eliminated, and only a mechanical interlock between the elastomeric member  38  and the adapter nose was utilized. 
     To remove the inserted connector pin assembly  10  from the adapter nose and tooth point openings  22 , 24  the upper pin portion  30  is rotationally backed out of the pin portion  32  to cause the tubular elastomeric member  38  to return to its FIG. 3 relaxed configuration and permit the connector pin assembly  10  to be simply pushed out of the aligned adapter nose and tooth point openings  22 , 24 . 
     The unique construction of the connector pin assembly  10  permits it to be installed within the aligned adapter nose and tooth point openings without having to pound the connector pin assembly into such holes. Further, the expanded elastomeric member  38  within the radially enlarged adapter nose hole portion  22   a  acts as a “shock absorber” which desirably tends to hinder dislodgement of the inserted connector pin assembly  10  when axially directed operational loads are imposed thereon. 
     An alternate embodiment  10   a  of the previously described connector pin assembly  10  is shown in FIG. 5 being used to captively retain an excavating tooth point  12   a  on an adapter nose  14   a . For the purpose of facilitating a comparison of the FIG. 5 overall point/adapter/connector pin assembly with its previously described FIG. 1 counterpart, components similar or identical to those in FIG. 1 have been given identical reference numerals with the subscripts “a”. 
     The tooth point  12   a  shown in FIG. 5 is identical to the previously described tooth point  12  and has a pocket area  18   a  and opposite sidewalls  26   a ,  28   a  with openings  24   a  formed therein. Adapter nose  14   a  which is complementarily received in the tooth point pocket  18   a  has a circularly cross-sectioned opening  54  extending therethrough and generally aligned with the tooth point openings  24   a . The adapter nose opening  54  is configured differently than the previously described adapter nose opening  22  (see FIG.  1 ), having upper and lower end segments  56  and  58  separated by a smaller diameter longitudinally intermediate segment  60 . Reduced diameter opening segment  60  is defined by an annular section  62  of the adapter nose  14   a  that radially projects into the nose opening  54  and has upper and lower axially facing annular ledges  64 , 66 . 
     The resilient intermediate portion of the connector pin assembly  10   a  is defined by upper and lower annular resilient members  68 , 70  which are representatively of an elastomeric material. Upper resilient member  68  circumscribes the reduced diameter threaded end portion  42   a  of the upper rigid body portion  30   a  received in the upper nose opening segment  56 , and is interposed between the annular shoulder  44   a  of the rigid body portion  30   a  and the upper annular nose opening ledge  64 . Lower resilient member  70  circumscribes the reduced diameter threaded end portion  42   a  of the upper rigid body portion  30   a , and is interposed between the annular shoulder  50   a  of the rigid body portion  32   a  and the lower annular nose opening ledge  66 . 
     With the adapter nose  14   a  received in the tooth point socket  18   a , the connector pin assembly  10   a  may be easily installed, without having to pound its components into the point and adapter openings, by placing the annular resilient member  68  on the reduced diameter body portion  42   a , inserting the upper rigid body portion  30   a  into the upper adapter nose opening segment  56  so that the reduced diameter body portion  42   a  extends downwardly through the middle nose opening segment  60  and into the lower nose opening segment  58 , placing the lower annular elastomeric member  70  on the lower end of the body portion  42   a , and threading the lower rigid body portion  32   a  onto the threaded body portion  42   a.    
     Finally, using the square or hexagonal recesses  40   a,    48   a  and suitable upper and lower wrench members, the rigid body portions  30   a ,  32   a  are threadingly advanced toward one another in a manner axially compressing and radially expanding the annular resilient members  68 , 70  respectively between facing annular surface pairs  44   a ,  64  and  50   a ,  66 . In this manner, the resilient members  68 , 70  are compressed against interior surface portions of the adapter nose opening  54 , thereby facilitating the retention of the connector pin assembly  10   a  within the generally aligned point and adapter openings  24   a , 54  and providing the installed connector pin assembly  10   a  with axial resiliency against axial operational loads imposed thereon. AS in the case of the previously described connector pin assembly  10 , opposite outer end portions of the installed connector pin assembly  10   a  serve to block the removal of the tooth point  12   a  from the adapter nose  14   a  onto which it is telescoped. 
     A variety of modifications could be made to the connector pin assemblies  10  and  10   a  without departing from principles of the present invention. For example, while the resilient members  38  (FIG. 1) and  68 , 70  (FIG. 5) are preferably formed from an elastomeric material, they could be of alternate resilient constructions such as, for example, metal compression springs or bellows. Additionally, while the upper and lower rigid body portion pairs  30 , 32  and  30   a , 32   a  are threadingly movable axially toward and away from another by virtue of one body portion being directly screwed into the other one, such body portion pairs could alternatively be made to be threadingly movable axially toward and away from one another using a third threaded element, such as a bolt extending axially through one of the rigid body portions and being threaded into the other one. Moreover, while the resilient members  38 , 68 , 70  are radially deflectable through a 360 degree arc, such radial deflection could extend through a lesser arc if desired. 
     The foregoing detailed description is to be clearly understood as being given by way of illustration and example, the spirit and scope of the present invention being limited solely by the appended claims.