Abstract:
A retainer for removably attaching a ground engaging tooth to an adapter. The retainer comprises a cylindrical steel member adapted to fit into a pocket defined in the outside surface of the adapter and an opening defined in an inside surface of the tooth. The retaining pin is further held in a locking position by a secondary retainer made of spring steel.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates generally to an excavating bucket and more specifically to a retention arrangement for a ground engaging tooth and adapter.  
         BACKGROUND  
         [0002]    Excavating apparatus is commonly equipped with a bucket that serves for accepting and moving a discreet quantity of material, such as soil, rock, and gravel. The bucket is typically controllably and pivotally mounted on one or more arms, enabling an operator to control the bucket. One, or preferably more teeth, extending from the bucket in such a way as to engage and break loose the material as the bucket is driven into the material. Because of the varying characteristics of the materials upon which excavating apparatus is used, it is common to provide these bucket tips as tooth subassemblies.  
           [0003]    These tooth subassemblies, typically are comprised of a tooth mounted upon an adapter that may be selectively secured to the bucket. As the bucket tips are the primary material engaging elements, they are subjected to a high degree of wear. This wear reduces the functionality of the bucket tips over time necessitating their occasional replacement. One of the more successful methods of assembling a bucket tip to the tooth sub-assembly has been to provide a bucket tip having a rearward facing opening designed to cooperatively accept a mounting protrusion from the tooth adapter base. This mounting protrusion typically provides sufficient structural support to ensure that the bucket tip remains generally in the appropriate alignment with respect to the tooth subassembly.  
           [0004]    In order to retain the bucket tip on the tooth adapter base, openings are provided for accepting a securing means through the bucket tip and the adapter. Typically a retaining pin is oriented transversely though the bucket tip the adapter base to secure the tip. Depending on the type of digging operation being performed, the retaining pin may be subject to high shear loads at the intersection between the tip and adapter. During digging operations such as back-dragging, forces tend to pull the tip from the adapter, creating abnormally high shear loads on the pin. Failure of the pin will cause loss of the tip.  
           [0005]    It is desirable to provide a tip and adapter assembly that is capable of overcoming one or more of the above stated problems.  
         SUMMARY OF THE INVENTION  
         [0006]    A ground engaging tooth having a central axis, a mounting end portion and a ground engaging portion. The tooth includes an outside surface and an inside surface. A retainer opening extends from the outside surface to the inside surface and is oriented substantially parallel to the nose surface. An access bore is defined in the inside surface and configured to lock a secondary retainer with a retainer pin. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIG. 1 is a perspective view of an adapter having a tooth position on and mechanically retention system the present invention.  
         [0008]    [0008]FIG. 2 is an exploded view of the tooth, adapter and retention system as shown in FIG. 1.  
         [0009]    [0009]FIG. 3 is a cross-sectional view of one embodiment of the retention system taken generally along line  3 - 3  of FIG. 1.  
         [0010]    [0010]FIG. 4 is a cross-sectional view of another embodiment of retention system taken generally along line  3 - 3  of FIG. 1.  
         [0011]    [0011]FIG. 5 is a perspective view of an alternative embodiment of a secondary retainer of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0012]    Referring to FIGS.  1 - 3 , a tooth  14  positioned on an adapter  16  for use with an implement bucket (not shown) is illustrated. The adapter  16  is typically secured to a cutting edge of the bucket by welding. The adapter  16  includes a forward tooth mounting portion or nose  18 , as best illustrated in FIG. 2. The nose  18  extends along a central axis  22 . The tooth  14  is a replaceable ground engaging tool  24 , which in this case is a tooth is removably fastened to the adapter  16 . The tooth  18  retained on the adapter  14  by a mechanical retention system  26  to be more fully described below.  
         [0013]    Referring to FIG. 2, the nose  18  is generally oriented along the normal direction of working forces exerted on the tooth  14  as it is in working engagement with the ground, and is depicted by arrow  28 . The nose  18  includes a blunt abutment surface  30  that is oriented perpendicular to the arrow  28 . The blunt surface  30  is configured to receive the loading forces of the tooth  14  caused by earthworking. A plurality of angled surfaces  32  extend rewardly from the blunt surface  30  and radially outward from the central axis  22 . The plurality of angled surfaces  32  define a somewhat conical member  34 . A retainer pocket  36  is provided in the conical member  34 . The retainer pocket  36  having a shape that substantially one half of a cylinder and is oriented longitudinally. The retainer pocket  36  includes a bottom surface  38  and an end abutment surface  40 . The retainer pocket  36  is preferably positioned along a side of the nose  18 , although may be positioned in any one of the plurality of the angled surfaces  32 .  
         [0014]    The tooth  14  includes a front ground engaging portion  42  and a rear mounting end portion  44 . The ground engaging portion  42  includes a top surface  46  and a bottom surface  48  that are tapered toward the front and converge to define horizontal edge  50 . A pair of side surfaces  48  (one shown) extend between the top  46  and bottom surface  48 . The mounting end portion  46  includes an outside surface  50  and an inside surface  52  defining a wall  54  there between. A cavity  56  is defined by the inside surface  52  and configured to snuggly fit over the nose  18  of the adapter  16 . The cavity  56  includes an abutment surface (not shown) defined at the bottom of cavity  56 . The abutment surface mates with the blunt surface  30  for transferring loads to the adapter  16 . A generally rectangular retainer opening  58  is formed in the wall  54  and extends from the outside surface  50  through to the inside surface  52 . When the tooth  14  is positioned on the adapter  16  the retainer pocket  36  and the retainer opening  58  align. A retainer pin  60 , defining a substantially cylindrical member is inserted into the retainer opening  58  and contacts the bottom surface  38  of the retainer pocket  36 .  
         [0015]    Referring now to FIGS. 2 and 3, a section view of the tooth  14  showing the retainer pin  60  positioned in the retainer pocket  36 . As illustrated the retainer pin  60  includes a first end  62 , a second end  64  and a shoulder portions  66  disposed at each end  62 ,  64 . A recess  68  is defined between the shoulder portions  66 . With the pin  60  seated in the retainer pocket  36  a portion of the pin  60  remains in the retainer opening  58  of the tooth  14 . Interference of the pin  60  with the retainer pocket  36  and the retainer opening  58  prevents the tooth  14  from being removed from the adapter  16 . A secondary retainer  70  engages the pin  60  and the tooth  14  or adapter  16  to hold the pin  60  in the retainer pocket  58 .  
         [0016]    One embodiment of the secondary retainer  70  is shown in FIG. 3. The secondary retainer  70  is formed of spring steel or a similar resilient material. The secondary retainer  70  includes a width  72  that is slightly smaller than the recess in the retainer pin  60 . With the pin  60  seated in the retainer pocket  36  the secondary retainer fits into a gap  74  defined between the inside surface of the tooth  14  cavity  56  and the adapter  16 . The secondary retainer  70  includes a hook portion  76  that engages and holds the retainer pin  60  in place and a bore  78  that can be fastened to either the tooth  14  or adapter  16 . An access bore  79  in the tooth  14  aligns with the bore  78  of the secondary retainer  70 . A fastener  80  such as a rivet or bolt engages the bore  78 .  
         [0017]    Referring now to FIG. 5, an alternate embodiment of the present invention is illustrated. In this embodiment the retainer pocket  36  is wider than the diameter of the retainer pin  60  and the retainer opening  58  aligns partially with retainer pocket  36 . The secondary retainer  70 ′ includes a horseshoe shaped portion  82  and a tab portion  84 . The secondary retainer  70 ′ is installed into the prior to inserting the retaining pin  60 . The tab portion  84  of the secondary retainer  70  engages the access bore  79  of the tooth  14  locking the secondary retainer  70  in place. The secondary retainer  70  can be released by depressing the tab portion  84 . As the retainer pin  60  is inserted, the pin  60  engages and compresses the horseshoe portion  82 . Upon being fully inserted into the retainer pocket  36 , the horseshoe portion  82  urges the pin  60  away from the retainer opening  58 , thus locking the pin in engaging contact with the tooth  14  and adapter  16 .  
         [0018]    It should be noted, numerous alternative secondary retainer  70  embodiments might used without deviating from the scope of the invention.  
       INDUSTRIAL APPLICABILITY  
       [0019]    In operation the tooth  14  and adapter  16  of the present invention function in a typical fashion. As the implement digs or otherwise applies forces in the normal direction, the abutment surface  56  of the tooth  14  pushes on the blunt surface  30  of the adapter  22 . In situations such as back-dragging, forces tend to pull the tooth  24  away from the adapter  16 , the retaining pin  60  is compressed between the retainer pocket  36  and the retainer opening  58 . Because the steel retainer pin  60  can withstand high compressive loading, it may be smaller than a laterally oriented pin.  
       List of Elements  
       [0020]    Title: Longitudinal Orientation of a Retainer for a Bucket Tip  
         [0021]    File: 01-832  
         [0022]    tooth  14   
         [0023]    adapter  16   
         [0024]    nose (adapter)  18  central axis  22   
         [0025]    ground engaging tool  24   
         [0026]    mechanical retention system  26   
         [0027]    arrow (direction of forces)  28   
         [0028]    blunt surface  30   
         [0029]    plurality of angled surfaces (nose)  32   
         [0030]    conical member  34   
         [0031]    retainer pocket  36   
         [0032]    bottom surface (pocket)  38   
         [0033]    end abutment surface (pocket)  40   
         [0034]    get portion  42   
         [0035]    ground engaging portion  42   
         [0036]    mounting end portion  44   
         [0037]    top surface (get end)  46   
         [0038]    bottom surface (get end)  48   
         [0039]    pair of side surfaces (get end)  48   
         [0040]    outside surface (mounting end  50   
         [0041]    inside surface  52   
         [0042]    wall  54   
         [0043]    cavity  56   
         [0044]    abutment surface (cavity)  58   
         [0045]    retainer opening (tooth surface)  58   
         [0046]    retainer pin  60   
         [0047]    first end (retainer pin)  62   
         [0048]    second end (retainer pin)  64   
         [0049]    shoulder portions (retainer pin)  66   
         [0050]    recess (retainer pin)  68   
         [0051]    secondary retainer  70   
         [0052]    width (retainer)  72   
         [0053]    gap (tooth and adapter)  74   
         [0054]    hook portion  76   
         [0055]    bore (secondary retainer  78   
         [0056]    access bore secondary retainer  79   
         [0057]    fastener (secondary retainer)  80   
         [0058]    horseshoe portion  82   
         [0059]    tab portion  84