Abstract:
Work tools, such as buckets of earthmoving machines, have a high wear rate from moving material or other activities. It is advantageous to provide replaceable wear protectors that are sacrificed to reduce or eliminate the need to repair or rebuild the work tools themselves. It is also important to provide a wear protector that is readily installed at the job site and can be securely, but simply retained in place. And the wear protector should not overly affect the operation of the work tool, such as through excess weight, resistance to material penetration or the like. Provided is a wear protector utilizing a connector element fastened to the work tool and a protector slidably engageable with the connector element. A simplified retainer assembly holds the protector in place on the connector element. The wear protector accommodates a compact design to address the problems described.

Description:
TECHNICAL FIELD  
         [0001]    The invention relates to wear protectors for work tools, and more particularly to removable wear protectors for the edge portions of work tools.  
         BACKGROUND  
         [0002]    Work tools for earthmoving and other jobs have a high wear rate because of the environments in which they work. One example is with respect to buckets on shovels or loaders. The buckets are used to dig and move many different types of materials that abrade even the toughest steels used to make the buckets. Buckets, as well as other work tools, will often have removable ground engaging portions so that high wear parts of the buckets can be protected with replaceable parts. It is economical to do this compared to the cost of replacing or substantially rebuilding a bucket or other work tool.  
           [0003]    One of the high wear areas of a work tool, such as a bucket, is on the sides. As the bucket digs into material, the side plates or bars penetrate the material and are subject to wear. Replaceable protectors are useful to protect the sides themselves and avoid costly wear or damage to the bucket. U.S. Pat. No. 5,088,214, issued to Jones on Feb. 18, 1992 discloses a wing protector removably attached to the bucket to protect it. U.S. Pat. No. 5,852,888, issued Dec. 29, 1998, to Cornelius, discloses another embodiment of such a guard.  
           [0004]    Because of the harsh environment in which such protectors operate, and the need to reduce weight and increase bucket penetration to optimize work efficiency, protector design is important. It is also important to control cost by simplifying design and reducing the time it takes to remove worn protectors and install replacements. The present invention is directed to overcoming one or more of the problems set forth above.  
         SUMMARY OF THE INVENTION  
         [0005]    In one aspect of the present invention, a work tool has an elongated surface. A protector has a mounting element and a work element. A connector element is fastened along the surface of the working portion and is slidably engaged with the mounting portion. A retainer assembly has a retainer positioned upright to the edge portion through an outer surface of the work element. The retainer assembly holds the protector from sliding relative to the connector element.  
           [0006]    In another aspect of the present invention, a protector has a working element and a mounting element. The working element has an outer surface with an opening. The mounting element has first and second end portions and a central portion. Each of the end portions has a substantially equal length and a lengthwise “T” shaped opening. The central portion has a length at least as great as the length of the end portions. The central portion also defines a cavity that, in cross-section, has a profile larger than the “T” shaped openings.  
           [0007]    In yet another aspect of the present invention, a side protector for a side of a work tool has a working element, a mounting element and a retaining element. The working element has a width substantially equal to a width of a top surface of the side. The mounting element is slidably engageable with a connector element of the side protector. The retaining element has an opening alignable with an opening of the connector when the mounting element is slidably engaged with the connector element.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a three quarter view of an illustrative work tool having an embodiment of the present invention installed on the work tool.  
         [0009]    [0009]FIG. 2 is a longitudinal, cross-sectional view along liens A-A of FIG. 1.  
         [0010]    [0010]FIG. 3 is a cross-sectional view along lines B-B of FIG. 2.  
         [0011]    [0011]FIG. 4 is a cross-sectional view along lines C-C of FIG. 2.  
         [0012]    [0012]FIG. 5 is top view of a connector element of the embodiment of FIG. 1 shown mounted to a side of the work tool.  
         [0013]    [0013]FIG. 6 is three-quarter view of an exemplary retainer assembly for the present invention.  
         [0014]    [0014]FIG. 7 is a cross-sectional view taken along lines C-C of FIG. 6. 
     
    
     DETAILED DESCRIPTION  
       [0015]    Referring to FIG. 1, a work tool  10  is shown for a work machine (not shown). In the example to be illustrated, the work tool  10  is a bucket  12 . The bucket  12  is configured for use on, for example, a shovel for mining. It should be understood that the following example with respect to the bucket  12  is for illustration only. The principles of the present invention may be used with respect to a variety of tools and on a variety of machines.  
         [0016]    The bucket  12  has a bottom element  14 , a top element  16  and a back element  18 . A pair of sides  20 ,  22  join the bottom element  14  and top element  16 , as well as the back element  18 . Depending upon the design and construction of the bucket  12 , the top, bottom and back elements  14 ,  16 ,  18  may be formed of a single piece or may be separately welded portions. In any event, the elements  14 ,  16 ,  18  and sides  20 ,  22  together form an enclosure or working portion  24  of bucket  12 . The bucket  12  is capable of penetrating material to be loaded through initial engagement of its bottom element  14 . Material is loaded into and held for dumping with the working portion  24 . Teeth  28  and edge protectors  30  assist in the ability to penetrate the material and are replaceable when they are worn. The bucket  12  is connectable to the work machine through arm or linkage mounts  32 .  
         [0017]    Thus, each side  20  or  22  encloses one end  34  or  36  of the bucket  12 . For convenience further reference will be made principally to the one (first) side  20  of the sides  20 ,  22  at end  34 . It should be understood that the other (second) side  22  of the bucket  12  will have similar construction and elements. To the extent such elements of side  22  are illustrated in the figures, each element will have a corresponding reference numeral to that of the first side  20 , but with an “a” following the reference numeral.  
         [0018]    The first side  20  has a side bar  38  that reinforces the side  20  and defines an edge portion  40  of the side  20 . The second side  22  has an associated side bar  38   a  and edge portion  40   a . The side bar  38  is of thicker material to offer additional protection from wear for edge portion  40  and adjacent parts of the side  20  which would otherwise be formed of the thinner material forming the rest of side  20 . In one example, the side bars  38 ,  38   a  may be steel of 60 mm in width, whereas the thinner material of the remainder of sides  20 ,  22  may be 20 mm width steel. Side bars  38 ,  38   a  are typically welded in place as part of the sides  20 ,  22 . More specifically, in the embodiment shown, each of the side bars  38 ,  38   a  is butt welded to a surface  42 ,  42   a  on the thinner material of side  20 , 22 . A pair of protectors  44 ,  44   a , each called a side protector or side bar protector in the embodiment shown, is further provided. Each side bar protector  44 ,  44   a  is associated with a respective side  20 ,  22 .  
         [0019]    Referring now to FIGS.  2 - 6 , an embodiment of the side bar protector  44  with reference to the first side  20  is shown. In FIG. 2, the side bar protector  44  is shown in cross-section along line A-A of FIG. 1. The side bar  38  is shown in elevation. Side bar protector  44  is shown removably attached to edge portion  40  on a surface  46 . The side bar protector  44  has a mounting element  48  and a working element  50 . The mounting element  48  includes first and second end portions  51 ,  52  and a center portion  53 . A connector element  54  is fastened or mounted to the side bar  38 . These will be more fully explained through reference to FIGS. 3, 4 and  5 .  
         [0020]    Referring to FIG. 3, a cut-a-way portion of the side bar  38  is shown. Side bar  38  has a width  56  of the edge portion  40  at surface  46  defined between the walls  57 ′,  57 ″ of the side bar  38 . The surface  46  is elongated, generally extending along the length of side  20  (best seen in FIG. 2). With respect to the side  20 , the surface  46  first engages material when the bucket  12  is in use. The connector element  54  is attached or fastened lengthwise along the surface  46  of the side bar  38 . Preferably this attachment is permanent in the sense that it is not readily displaced in order to withstand the punishment of earthmoving or other harsh environments. The attachment may, for example, be accomplished by welds  58 . The construction of the connector element  54  provides for welding in a cutout or opening  60  (shown in detail in FIG. 5). The cutout is shown in two parts  60 ′ and  60 ″, the reason for which will be explained later. In cross-section in FIG. 3, the connector element  54  is “T” shaped or in the form of a dovetail. The “T”  62  has a lower end  64  and an upper end  66 . The lower end  64  has a width that is less than the width of the upper end  66 .  
         [0021]    Referring now to the side bar protector  44 , the working element  50  has an outer surface  70  and a width  72 . The working element  50  engages material during bucket  12  use. The width  72  represents the overall width of the side bar protector  44 . This width  72  is preferably substantially the same as the width  56  of the side bar  38 . The outer surface  70  is preferably curvilinear across most of its section, with ends  74 ′,  74 ″ truncated. The overall shape of the outer surface  70  and size of the working element  68  facilitates the function of the side bar protector  44 , as will be explained.  
         [0022]    The mounting element  48  is of a construction or shape sufficient to be slidably engageable with the connector element  54 . The protector  44  has an inner surface  76  that helps define the shape of the mounting element  48  for such engagement. Referring more particularly to FIG. 2, the first and second end portions  50 ,  51  are at least partly formed in a “T” or dovetail  82  complementary to the shape of the “T”  62 . The “T”  82  is defined by a part  76 ′ of the inner surface  76 , as are two end surfaces  80 ′,  80 ″. When protector  44  is in position, the end surfaces  80 ′,  80 ″ will be immediately adjacent or touching the surface  46  of the side bar  38 . Thus, the complementary “T” or dovetail also has lower  84  and upper  86  ends formed by the inner surface  76 . Stress relievers  87 ′,  87 ″ are also shown formed by the inner surface  76 . Inner surface  76  further defines a cone shaped void  88 .  
         [0023]    When assembled, the side bar protector  44  is slidably engaged with the connector element  54  through mating of the “T” configurations  62 ,  82 . This mating and the complementary construction of the “T” configurations  62 ,  82  is in a manner sufficient to hold the protector  44  from movement relative to the connector element  54  in a direction  89  away from the sides  57 ′,  57 ″ (that is, not lengthwise to surface  42 ). It will be appreciated that this movement away from the sides  57 ′,  57 ″ is generally initiated in response to a force component on the protector  44  that is perpendicular to protector  44 .  
         [0024]    Now referring to FIG. 4, a retainer assembly  90  is shown. The retainer assembly  90  provides means for restraining the protector  44  with respect to the side bar  38 . In this case, retention refers to restraining the movement of the side bar protector  44  relative to the connector element  54  (and thus the side bar  38 ) in a direction  91  (FIG. 2) along the surface  42 . In FIG. 4, this lengthwise direction  91  is in and out of the page. The retainer assembly  90  includes a barrel  92  and a retainer, shown as a stud,  94 . The retainer assembly  90  is associated with a retainer portion  95  of the protector  44  when the protector  44  is assembled on side  20 .  
         [0025]    The center portion  53  can be seen in FIG. 2 and FIG. 4 to be free of any “T” shaped opening that will engage with the “T”  62  of connector element  54 . An opening  96  extends through the working element  50  from the outer surface  70  to a second part or portion  76 ″ of the inner surface  76 . Opening  96  opens into cavity  97  defined in and by center portion  53 , in particular by part  76 ″ of the inner surface  76 . Extending inwardly from the outer surface  70 , the opening  96  is shown with cylindrical walls  98 . The opening  96  and cavity  97  together represent retainer portion  95  to facilitate lengthwise retention of the connector element  54  with protector  44 . In other embodiments, the opening  96  may be tapered inwardly to permit easier clean out of material that becomes packed in the opening  96  during use of the bucket  12 . Other configurations may also be used. Adjacent the inner surface portion  76 ″, the opening  96  opens up to accommodate the barrel  92 . In this embodiment, the inner surface portion  76 ″ adjacent opening  96  has step  100  defining a diameter larger than that of opening  96  and then continues with cylindrical walls  102  to an inner end portion  104 . Cylindrical walls  102  define a larger diameter than cylindrical walls  98  and step  100 .  
         [0026]    The cavity  97 , in the cross-section of FIG. 4, defines a profile or area larger than the “T”  82  of the connector element  54 . Thus, the profile of the cavity will typically also be greater than the profile of the “T”  62  (shown in FIG. 3). Additionally, the cavity  97  profile is increased by the area defined by step  100  (shown in two parts,  100 ′,  100 ″). The “enlarged” profile provides the situation where the retainer element  95  will be free of any engagement or interference with the “T”  82  of the connector element  82  when the protector  44  may be slid across the connector element  54 .  
         [0027]    Referring to FIGS. 6 and 7, the retainer assembly  90  is shown in more detail. Stud  94  has a head portion  106  that has walls  108  defining a lesser diameter than walls  98  of opening  96 . The stud  94  tapers at a middle portion  110  and has a threaded bottom portion  112 . In other embodiments, the stud  94  may use a retention means other than threads, so long as it is able to engage with barrel  92 . The head portion  106  shown has a socket portion  113  to fasten or unfasten the stud  94 . Different shapes may include a hex head or other structure by which to engage the stud. The stud  94  may also be of different shapes, such as a single diameter head portion.  
         [0028]    The barrel  92  has an opening  114  of a shape or construction sufficient for stud  94  to seat or mate and to limit further movement of the stud  94  into the barrel  92 . Thus, barrel  92  will have walls  116  that have the same taper as the middle portion  110  of the stud  94 . The barrel  92  also has a threaded portion  118  to threadably engage with bottom portion  112  of stud  98 . A complementary step  119  to step  100  is also shown in FIGS. 6 and 7. The step  119  is divided into two step portions  119 ′,  119 ″ that are parallel to one another on opposite sides of barrel  92 .  
         [0029]    Referring now particularly to FIGS. 2 and 5, the preferred arrangement of the connector element  54  and protector  44  will be further discussed. In FIG. 5, the connector element  54  is shown in top view on the surface  46  of side bar  38 . The connector element  54  has two identical portions  54 ′,  54 ″ that are connected along a central axis  120 . In this embodiment, the identical portions  54 ′,  54 ″ are castings welded together. The connector element  54  is also symmetrical about a longitudinal axis  122  oriented lengthwise down surface  46 . Located at the intersection of the central and longitudinal axes  120 ,  122  is an opening  124  sized to receive barrel  92 . The opening  124  passes through the full width of connector element  54  and, when the connector element  54  is welded to the side bar  38 , opens onto the surface  42 . Opening  124  and opening  96  are positioned in the connector element  54  and protector  44 , respectively, so as to be alignable one with the other when the connector element  54  and protector  44  are assembled.  
         [0030]    Connector element  54  further has the previously described opening  60 . The opening  60  is in two parts  60 ′,  60 ″, one each being located in the identical side portions  54 ′,  54 ″. The openings  60 ′,  60 ″ provide a space for welding the connector element  54  to the side bar  38 . As shown, welds  58 ′,  58 ″ are made along edges  126 ′,  126 ″ of the openings  60 ′,  60 ″ and on the surface  42  of the side bar  38 .  
         [0031]    The dovetail or “T”  62  is also shown in two parts  62 ′,  62 ″ in first and second end portions  128 ′,  128 ″ of connector element  54 . Each part  62 ′,  62 ″ extends an equal length “L” in its respective end portion  128 ′,  128 ″ of the connector element  54 . As discussed, a portion  130  (length L′) of the connector element  54  is free from having the dovetail or “T” configuration. In FIG. 2, it can be seen that the dovetail or “T”  82  of the side bar protector  44  is similarly in two parts  82 ′,  82 ″. These parts  82 ′,  82 ″ (in effect, openings) represent a portion of “T”  82  and each have a length L″ sufficient to permit them to engage with the parts  62 ′,  62 ″, respectively. Engagement of the parts  82 ′,  82 ″ is preferably substantially along the entire length L of parts  62 ′,  62 ″. Thus length L is preferably substantially equal to length L″.  
         [0032]    Industrial Applicability  
         [0033]    The side bar protector  44  or  44   a  provides substantial protection to the side bar  38  or  38   a  and is replaceable when worn. This is preferable to replacing a work tool  10  such as a bucket  12  or rebuilding the work tool  10  to repair worn sides  20 ,  22 . In the embodiments illustrated, the use of connector element  44  or  44   a , as well as the other aspects described, provide for a side bar protector  54  or  54   a  that is of substantially equal width to the side bar  38 . This provides weight reduction and less resistance of the bucket  12  when digging into material.  
         [0034]    To assemble, the side bar protector  44  is mounted to the connector element  54  previously welded to the side bar  38 . This is accomplished by placing one of the parts  82 ′ or  82 ″ of “T”  82  over the center portion  130  of the connector element  54 . In other words, one of the parts  82 ′,  82 ″ of “T”  82  is placed in the central portion  130 . Prior to this, however, barrel  92  is placed in opening  96 . Opening  96  restrains barrel  92  in position while the side protector  44  is mounted. When positioning barrel  92 , steps  19 ′,  119 ″ are aligned parallel with longitudinal axis  122 .  
         [0035]    With one part  82 ′,  82 ″ in position in central portion  130 , the side bar protector  44  is then slid along the connector element  54  to engage with and along the dovetail or “T” parts  62 ′,  62 ″ to interlock the “T”  82 ,  82 ″ parts therewith. The side bar protector  44  is slid until opening  96  aligns with opening  114  in barrel  92 . With the steps  119 ′,  119 ″ aligned along axis  122 , the dovetail  82  of the side bar protector  44  slides without interference across or over barrel  92 . It will be appreciated that the length L′ of central portion  130  is at least as long as length L″ of the dovetail of the side bar protector  44 . Preferably it is slightly longer to permit one of the dovetail parts  62 ′ or  62 ″ to be easily placed over portion  130  to initiate mounting.  
         [0036]    Referring to FIG. 2, the preferred assembly accommodates a weld joint (such as at  132 ) made when fabricating side  20 . Because the connector element  54  and protector  44  do not extend down the side  20  beyond surface  42 , this arrangement tends to eliminate interference such a weld joint might otherwise cause.  
         [0037]    Once the connector element  54  and side bar protector  44  are in the proper position relative to one another, stud  94  is positioned in opening  114  of the barrel  92  and tightened. Thus, stud  94  as configured assumes an upright or a generally perpendicular orientation to surface  42  through engagement with barrel  92 . The barrel  92  is constrained from rotation and from removal through opening  96  by interference of steps  119 ′,  119 ″ with inner surface  76  at step  100 . Stud  94  further constrains the relative movement of side bar protector  44  relative to connector element  54  in direction  89 . This occurs through interference of head portion  106  of stud  94  with walls  98  of opening  96  in side bar protector  44 .  
         [0038]    The symmetrical construction of the side bar protectors  44 ,  44   a  and connector elements  54 ,  54   a  provide significant benefit. Typically, the bottom one-third to one-half of a side bar protector  44  that is closest to the bottom element  14  will have the highest wear. When worn, the stud  94  can be removed. The side bar protector  44  is then removed, turned around, and installed with the opposite unworn or lesser worn portion  128 ′ or  128 ″ re-installed toward the bottom element  14 . The use of two separate, but identical parts  54 ′,  54 ″ (such as illustrated in FIG. 5) to construct the connector element  54  also reduces cost in manufacture. Similarly the side bar protectors  44 ,  44   a  could be so constructed. Of course, constructions other than the symmetrical or “two part” part embodiment illustrated may be used.  
         [0039]    From FIG. 1 it can be seen that the side bar  38  is essentially straight. This accommodates easier fabrication and mounting of the side bar protector  44 . However, the side bar  38  may also be curvilinear. In such instances, the connector element  54  and protector  44  would preferably have a similar curvilinear shape. In practice, a tolerance of about 0.7 mm between the dovetail elements of the protector  44  and connector element  54  has proven adequate. Depending upon the application, construction of the particular embodiment of the side bar protector for that application, and other needs, the tolerance may need to be changed. Other constructions and orientations may be used.  
         [0040]    The embodiments illustrated above and in the drawings have been shown by way of example. There is no intent to limit the invention to the exemplary forms disclosed. All modifications, equivalents and alternatives falling within scope of the appended claims are intended to be covered.