Abstract:
An elongated excavating tooth assembly includes a replaceable tooth point and an adapter structure comprising (1) an intermediate adapter having a front end nose complementarily received in a rear end pocket of the point and captively retained therein by a first connector pin structure, and (2) a main adapter having a front end nose complementarily received in a rear end pocket of the intermediate adapter and captively retained therein by a second connector pin structure, and a rear end operatively securable to an excavating bucket lip. Special configurations of the point and adapter portions of the assembly, including horizontally elongated oval configurations of the noses, horizontal orientation of the connector pins, nose stabilization bosses at the nose connector openings, and complementarily scalloped adapter and point interface areas, provide the assembly with reduced size and improved strength, wear and operational characteristics.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to excavating apparatus and, in a preferred embodiment thereof, more particularly provides a uniquely configured excavating tooth point and adapter assembly representatively including a tooth point connected to an adapter section having interconnected main and intermediate portions. 
     Large excavating buckets, dippers and the like are typically provided with a series of earth-cutting tooth assemblies each comprising a relatively large adapter section and a relatively small replaceable tooth point. The adapter section has a base portion which is connectable to the forward lower lip of the bucket, and a tapered nose portion onto which the tooth point is removably secured, with the tapered adapter nose being received in an interior pocket portion of the point, by a suitable connecting pin or other connecting structure. Compared to that of the adapter section, the useful life of the point is rather short, the adapter section typically lasting through several point replacements until the tremendous earth forces and abrasion to which the adapter section is subjected necessitates its replacement. Thus, the point may be characterized as a wear member, and the adapter section may be characterized as a support structure carrying the wear member and protected thereby against premature replacement. 
     The adapter section may be a single adapter, or may be formed from a primary adapter which is connectable to the bucket lip, and an intermediate adapter which is interposed between the replaceable tooth point and the primary adapter and releasably connected to them. The intermediate adapter has a front nose portion which is captively and releasably retained within a complementarily configured rear end pocket area of the point by a first connector structure, and the main adapter has a front nose portion which is captively and releasably retained within a complementarily configured pocket area in the rear end of the intermediate adapter by a second connector structure. Thus, the replaceable tooth point functions as a wear member carried on and protecting the intermediate adapter, with the intermediate adapter functioning both as a support structure for the point and a wear member for the main adapter which supports the intermediate adapter. 
     Designing the configuration of an adapter nose, its interfit with its associated wear member (such as a point or another adapter), and its relationship with the connector structure used to releasably couple the adapter nose to the associated wear member, presents a variety of engineering challenges. For example, to maximize the earth penetration capabilities of a particular adapter/tooth point assembly the frontal cross-section of the assembly must be as small as possible. However, in adapter/tooth point assemblies of conventional designs reductions in such frontal cross-sectional area correspondingly weakens the assembly. Other design challenges include preventing undue operational stresses from being imposed on the wear member/support member connector apparatus, configuring the nose to reduce operational stress concentrations thereon, stabilizing each wear member against excess movement relative to its associated support member during excavating operations, and optimizing the abrasion protection provided to each support member by its associated wear member. 
     It would be desirable for both economic and operational reasons to provide an adapter/tooth point assembly having improvements in one or more of these design areas. It is to this goal that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, a specially configured excavating equipment wear member/support member assembly is provided which extends lengthwise along a front-to-rear assembly axis and representatively includes a replaceable tooth point, an intermediate adapter, and a main adapter. The tooth point is telescoped onto and captively retained on a forwardly projecting nose portion of the intermediate adapter, and the intermediate adapter is telescoped onto and captively retained on a forwardly projecting nose portion of the main adapter. The main adapter has a rear end portion which is releasably securable to a front edge portion of an excavating bucket lip. 
     The nose portion of the intermediate adapter projects forwardly from a front end surface of a rear base portion of the adapter, which representatively circumscribes the rear end of the nose portion, and has a horizontally elongated, generally elliptical cross-section along substantially its entire front-to-rear length, top and bottom surfaces, and horizontally opposite left and right surfaces. Horizontally opposite stabilizing projections are disposed on and project laterally outwardly from he left and right surfaces of the nose portion, and a connector opening extends horizontally through the nose portion and opens outwardly through the stabilizing projections. Preferably, the stabilizing projections are stabilizing bosses having rectangular configurations, are positioned adjacent the front end surface of the rear base portion of the intermediate adapter, and extend through only a relatively small portion of the front-to-rear length of the nose portion. 
     The intermediate adapter nose is complementarily received in a rear end cavity of the tooth point, with horizontally opposite connector openings extending through opposite left and right side walls of the tooth point into interior side recesses therein which complementarily receive the stabilizing bosses on the intermediate adapter nose. The tooth point connector openings are in an outwardly overlying align ed relationship with opposite ends of the intermediate adapter nose connector opening, and a connector structure, representatively a front connector pin, horizontally extends through the point and adapter connector openings and captively retains the tooth point on the intermediate adapter nose. 
     Preferably, the top and bottom surfaces of the intermediate adapter nose are substantially parallel to the front-to-rear assembly axis, and the top and bottom nose surfaces have front portions which are vertically inset from the balance of the top and bottom nose surfaces. 
     The main adapter has a rear base portion with a front end surface from which a nose portion forwardly projects, the main adapter nose portion having a configuration similar to that of the intermediate adapter nose, and is similarly provided with outwardly projecting stabilizing bosses on opposite left and right sides thereof, a connector opening extending horizontally through the main adapter nose and opening outwardly through its stabilizing bosses. The main adapter nose and its associated stabilizing bosses are complementarily received within a rear end cavity of the rear base portion of the intermediate adapter. The main adapter nose connector opening is aligned with left and right side wall connector openings formed in the base portion of the intermediate adapter, and a connector structure, representatively in the form of a rear connector pin, extends through the aligned connector openings and captively retains the intermediate adapter on the nose of the main adapter. 
     Facing front and rear end surfaces of the intermediate adapter base portion and the tooth point have alternately scalloped portions around their peripheries, the scalloped peripheries being complementarily engaged in an interlocking configurational relationship. Preferably, top and bottom portions of the front end surface of the rear base portion of the intermediate adapter have forwardly convex arcuate configurations, and left and right side portions of the front end surface of the rear base portion of the intermediate adapter have rearwardly concave arcuate configurations. In this manner, the front connector pin location may be advantageously positioned further rearwardly on the intermediate adapter. 
     In a similar manner, facing front and rear end surfaces of the main adapter base portion and the intermediate adapter have alternately scalloped portions around their peripheries, the scalloped peripheries being complementarily engaged in an interlocking configurational relationship. Preferably, top and bottom portions of the front end surface of the rear base portion of the main adapter have rearwardly concave arcuate configurations, and left and right side portions of the front end surface of the rear base portion of the main adapter have forwardly convex arcuate configurations. In this manner, top and bottom side portions of the intermediate adapter extend rearwardly over corresponding underlying portions of the main adapter and provide enhanced wear protection for the main adapter. 
     Compared to tooth point/adapter assemblies of conventional configurations, the complementary configurations of the adapter noses and their associated point and adapter cavities provide the tooth point/adapter assembly with a variety of advantages including smaller size with similar strength, reduced frontal area which facilitates assembly earth penetration, enhanced rotational stability among the tooth and adapter components, and reduced operational stresses on the connector pins. While the illustrated embodiment of the invention includes a two-piece adapter section, it will be readily appreciated by those of skill in this particular art that the adapter section could alternatively be defined, if desired, by a single adapter member. Additionally, while principles of the present invention have been representatively illustrated herein as being embodies in a tooth point and adapter assembly, it will further be appreciated by those of skill in this particular art that such principles could also be utilized to advantage in other types of excavating equipment wear member/support member assemblies as well. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of an excavating tooth point and adapter assembly embodying principles of the present invention; 
     FIG. 2 is a side elevational view of the assembly; 
     FIG. 3 is an exploded perspective view of the assembly; 
     FIG. 4 is an enlarged scale front end view of an intermediate adapter portion of the assembly; 
     FIG. 5 is an enlarged scale rear end view of a tooth point portion of the assembly; 
     FIG. 6 is an enlarged scale front end view of a main adapter portion of the assembly; and 
     FIG. 7 is an enlarged scale rear end view of the intermediate adapter. 
    
    
     DETAILED DESCRIPTION 
     Referring initially to FIGS. 1-3, the present invention provides a specially configured excavating tooth point and adapter assembly  10  which representatively includes a replaceable tooth point  12 , an intermediate adapter  14 , a main adapter  16 , a first connector structure illustratively in the form of a schematically depicted connector pin  18 , and a second connector structure illustratively in the form of a schematically depicted connector pin  20 . The assembly  10  is elongated in a front-to-rear direction along a longitudinal axis  22 , and is anchored to and projects forwardly beyond a front edge portion of a bottom excavating bucket lip  24 , a small section of which is illustrated in phantom in FIGS. 1 and 2. Assembly  10  is one of a spaced, parallel series of such assemblies (the other ones of which are not illustrated) similarly attached to and projecting forwardly beyond the lip  24 . 
     With reference now to FIGS. 1-4 and  7 , the intermediate adapter  14  has a rear base portion  26  and a front nose portion  28 . Base portion  26  has a front end surface  30  from which the nose  28  forwardly projects, a rear end surface  32  inwardly through which a cavity  34  extends, top and bottom walls  36  and  38 , and left and right side walls  40  and  42 . Aligned connector openings  44  and  46  respectively extend through the left and right side walls  40  and  42  into the cavity  34 . The front end surface  30  of the adapter base  26  is alternately scalloped in a front-to-rear direction around its periphery, with the top and bottom portions  30   a,   30   b  of the front end surface  30  being convexly curved in a forward direction, and the left and right portions  30   c,   30   d  of the front end surface  30  being concavely curved in a rearward direction. Similarly, the rear end surface  32  of the adapter base  26  is alternately scalloped in a front-to-rear direction around its periphery, with the top and bottom portions  32   a,   32   b  of the rear end surface  32  being convexly curved in a rearward direction, and the left and right portions  32   c,   32   d  of the rear end surface  32  being concavely curved in a forward direction. 
     The intermediate adapter nose  28  has, along its front-to-rear length, a horizontally elongated elliptical cross-section, with top and bottom surfaces  48 , 50  and left and right side surfaces  52  and  54 . Except for a slight draft angle of 5 degrees or less, the top and bottom surfaces  48 , 50  are substantially parallel to the assembly axis  22 . At the front end of the nose  28  is a reduced cross-section stabilizing tip  56  having a horizontally elongated elliptical cross-section and top and bottom surfaces  58  and  60  which are also substantially Parallel to the assembly axis  22 . Laterally outwardly projecting stabilizing bosses  62  and  64  are respectively formed on the left and right side surfaces  52 , 54  of the adapter nose  28  at their junctures with the front end surface  30  of the adapter base  26 . A connector opening  66  horizontally extends through the adapter nose  28  and opens outwardly through the bosses  62  and  64 . 
     With reference now to FIGS. 1-3 and  5 , the point  12  has a suitable cutting edge  68  formed on its front end, a rear end surface  70  through which a cavity  72  inwardly extends, top and bottom walls  74  and  76 , and left and right side walls  78  and  80  through which aligned connector openings  82 , 84  respectively extend into the interior of the cavity  72 . The rear end surface  70  is alternately scalloped around its periphery, having top and bottom portions  70   a,   70   b  which are concavely curved in a forward direction and have curvatures respectively complementary to those of the previously described front end surface portions  30   a,   30   b  of the intermediate adapter base  26 , and left and right side portions  70   c,   70   d  which are convexly curved in a rearward direction and have curvatures respectively complementary to those of the previously described front end surface portions  30   c,   30   d  of the intermediate adapter base  26 . 
     Tooth point  12  is replaceably mounted on the intermediate adapter nose  28  by first placing the nose  28  within the tooth point cavity or pocket  72 , thereby bringing the point connector openings  82 , 84  into outwardly overlying alignment with opposite ends of the horizontally oriented adapter nose opening  66 , and then operatively inserting the front connector pin  18  in the aligned connector openings  66 , 82 , 84 . The inserted connector pin  18  is suitably retained in such openings, in a conventional manner not pertinent to the present invention, and functions to captively and releasably retain the point  12  on the intermediate adapter  14 , the point  12  serving as a wear member for the intermediate adapter  14  which, in turn, may be characterized as a support member for the mounted point  12 . 
     The tooth point cavity  72  (see FIG. 5) has an interior surface configuration complementary to that of the exterior surface of the intermediate adapter nose  28  which it releasably receives. Specifically, the cavity  72  has a portion  28   a  configured to complementarily receive the body of the inserted intermediate adapter nose  28 , and left and right interior side wall recesses  62   a,   64   a  that respectively and complementarily receive the inserted adapter nose stabilizing bosses  62 , 64 . connector openings  82 , 84  respectively extend laterally inwardly into the recesses  62   a,   64   a.    
     The unique shapes of the tooth point  12  and intermediate adapter  14  provide the tooth point/intermediate adapter subassembly  12 , 14  with a variety of advantages compared to conventional point/adapter assemblies. For example, the horizontally elongated elliptical cross-sectional shape along its length of the intermediate adapter nose  28  substantially eliminates planar areas on the nose  28 , thereby correspondingly reducing undesirable stress concentration areas thereon. This, coupled with the substantially axially extending top and bottom surfaces  48  and  50  of the nose  28 , permits the nose  28  to be smaller than noses with conventional configurations without appreciably reducing its operational strength. This, in turn, provides the point/adapter subassembly  12 , 14  with a correspondingly smaller frontal area that gives it improved earth penetration efficiency. 
     Coupled with the interfit between the nose bosses  62 , 64  and the point pocket recesses  62   a  and  64   a,  the interfit between the stabilizing tip  56  of the nose  28  and the corresponding point pocket surface area provides the mounted tooth point  12  with substantially enhanced stability against operational rotation relative to the intermediate adapter  14  about the assembly axis  22 . This anti-rotational stability is further enhanced by the substantially horizontally extending top and bottom nose surfaces  48  and  50  behind the stabilizing tip  56 . Moreover, the horizontal orientation of the elongated connector structure  18  places it on the “neutral” axis of the nose  28  (from the standpoint of tensile and compressive nose bending stresses), thereby desirably lessening the operational stresses imposed on the installed connector  18 . The substantially horizontally extending top and bottom side surfaces  48 , 50  of the nose  28  further reduce the operating loads on the connector structure  18 . 
     As can best be seen in FIGS. 1 and 2, with the tooth point  12  operatively and releasably installed on the intermediate adapter  14 , the alternately scalloped rear end surface  70  of the point  12  is complementarily engaged in an interlocked fashion with the alternately scalloped front end surface  30  of the base portion  26  of the intermediate adapter  14 . This unique arcuately scalloped interfit serves to stabilize the point  12  against rotation about the axis  22  relative to the intermediate adapter  14 . Additionally, the rearward scalloping of the front end surface portions  30   c,   30   d  on the adapter base  26  advantageously permits the placement of the connector structure  18  further back on the adapter  14  to a somewhat thicker and thus somewhat stronger location thereon. 
     The interfit between the intermediate adapter  14  and the main adapter  16  is similar to the interfit between the point  12  and the intermediate adapter  14 . Specifically, and with reference now to FIGS. 1-3,  6  and  7 , the main adapter  16  has a rear base portion  86  and a front nose portion  88 . Base portion  86  has a front end surface  90  from which the nose  88  forwardly projects, and vertically spaced apart top and bottom rearwardly extending mounting legs  92 , 94  which define therebetween a cavity  96  that receives a portion of the bucket lip  24 . Legs  92 , 94  are  35  respectively welded or otherwise anchored to the top and bottom sides of the bucket lip  24  to operatively support the main adapter  16  on the bucket lip  24 . The front end surface  90  of the main adapter base  86  is alternately scalloped in a front-to-rear direction around its periphery, with the top and bottom portions  90   a,   90   b  of the front end surface  90  being concavely curved in a rearward direction, and the left and right portions  90   c,   90   d  of the front end surface  90  being convexly curved in a forward direction. 
     The main adapter nose  88  has, along its front-to-rear length, a horizontally elongated elliptical cross-section, with top and bottom surfaces  98 , 100  and left and right side surfaces  102 , 104 . Except for a slight draft angle of 5 degrees or less, the top and bottom surfaces  98 , 100  are substantially parallel to the assembly axis  22 . At the front end of the nose  88  is a reduced cross-section stabilizing tip  106  having a horizontally elongated elliptical cross-section and top and bottom surfaces  108  and  110  which are also substantially parallel to the assembly axis  22 . Laterally outwardly projecting stabilizing bosses  112  and  114  are respectively formed on the left and right side surfaces  102 , 104  of the adapter nose  88  at their junctures with the front surface  90  of the adapter base  86 . A connector opening  116  horizontally extends through the adapter nose  88  and opens outwardly through the bosses  114  and  116 . 
     The intermediate adapter  14  is replaceably mounted on the main adapter nose  88  by first placing the nose  88  within the intermediate adapter rear cavity or pocket  34 , thereby bringing the intermediate adapter connector openings  44 , 46  into outwardly overlying alignment with opposite ends of the horizontally oriented main adapter nose opening  116 , and then operatively inserting the rear connector pin  20  in the aligned connector openings  44 , 46 , 116 . The inserted connector pin  20  is suitably retained in such openings, in a conventional manner not pertinent to the present invention, and functions to captively and releasably retain the intermediate adapter  14  on the main adapter  16 , the intermediate adapter serving as a wear member for the main adapter  16  which, in turn, may be characterized as a support member for the mounted intermediate adapter  14 . 
     The intermediate adapter cavity  34  (see FIG. 7) has an interior surface configuration complementary to that of the exterior surface of the main adapter nose  88  which it releasably receives. Specifically, the cavity  34  has a portion  88   a  configured to complementarily receive the body of the inserted main adapter nose  88 , and left and right interior side wall recesses  112   a,   114   a  that respectively and complementarily receive the inserted main adapter nose stabilizing bosses  112  and  114 . Connector openings  44 , 46  respectively extend laterally inwardly into the recesses  112   a,   114   a.    
     The unique shapes of the intermediate adapter  14  and the main adapter  16  provide the intermediate adapter/main adapter subassembly  14 , 16  with a variety of advantages compared to conventional excavating wear member/support member assemblies. For example, the horizontally elongated elliptical cross-sectional shape of the adapter nose  88  substantially eliminates planar areas on the nose  88 , thereby correspondingly reducing undesirable stress concentration areas thereon. This, coupled with the substantially axially extending top and bottom surfaces of the nose  88 , permits the nose  88  to be smaller than noses with conventional configurations without appreciably reducing its operational strength. This, in turn, provides the intermediate adapter/main adapter subassembly  14 , 16  with a correspondingly smaller frontal area that gives it improved earth penetration efficiency. 
     Coupled with the interfit between the nose bosses  112 , 114  and the point pocket recesses  112   a  and  114   a,  the interfit between the stabilizing tip  106  of the nose  88  and the corresponding intermediate adapter pocket interior surface area provides the mounted intermediate adapter  14  with a substantially enhanced stability against operational rotation relative to the main adapter  16  about the assembly axis  22 . This anti-rotational stability is further enhanced by the substantially horizontally extending top and bottom nose surfaces  108  and  110  behind the stabilizing tip  106 . Moreover, the horizontal orientation of the elongated connector structure  20  places it on the “neutral” axis of the nose  88  (from the standpoint of tensile and compressive nose bending stresses), thereby desirably lessening the operational stresses imposed on the installed connector structure  20 . The substantially horizontally extending top and bottom surfaces  108 , 110  of the nose  88  further reduce the operating loads on the connector structure  20 . 
     As can best be seen in FIGS. 1 and 2, with the intermediate adapter  14  operatively and releasably installed on the main adapter  16 , the alternately scalloped rear end surface  32  of the intermediate adapter  14  is complementarily engaged in an interlocked fashion with the alternately scalloped front end surface  90  of the base portion  86  of the main adapter  16 . This unique arcuately scalloped interfit serves to stabilize the intermediate adapter  14  against rotation about the axis  22  relative to the main adapter  16  about the assembly axis  22 . Additionally, the rearward scalloping of the front end surface portions  90   a,   90   b  on the main adapter base  86  advantageously positions top and bottom rear wall portions of the intermediate adapter  14  in an overlying, abrasion-protecting relationship with corresponding front top and bottom portions of the main adapter  16  thereby desirably increasing the operating life of the main adapter  16 . 
     While the excavating tooth point and adapter assembly  10  has been representatively depicted herein as including a two piece adapter section, it will be readily appreciated by those of skill in this particular art that the two adapter portions  14  and  16  Could be replaced with a single adapter member if desired. Additionally, while the assembly  10  has been representatively depicted herein as being defined by point and adapter structures, it could be alternatively formed from other types of associated wear and support members if desired. 
     The foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims.