Abstract:
A method and apparatus for installing and removing shrouds from the lips of an earth moving bucket. The lips have forwardly converging upper and lower surfaces which are engaged by correspondingly rearwardly diverging legs of the shrouds that overly and are in contact with the lip surfaces. A hole is provided in the lip and an oblong hole in one of the legs that is aligned with the hole and has axially extending, spaced-apart flat walls which define engagement ledges that face and overlap the bore. A connector for securing the shroud to the lip is placed in the bore and the hole and has shaped exterior surfaces for positioning between the walls so that the connector is axially movable along the walls and past the engagement ledges while relative rotations between the connector and the hole in the leg are prevented.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/018,502, filed on Jun. 27, 2014, which is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Ground-moving, breaking and excavating equipment employs buckets, dragline buckets, shovels and other containers (hereafter collectively “buckets”) with which earth, gravel, rock formation and the like are excavated and moved around. Typically, such buckets carry a lip defining their digging edges, and the lips in turn mount consumable components which need periodic replacement, such as shrouds, adapters for digging teeth, digging teeth themselves and the like (hereinafter collectively “shrouds”). 
         [0003]    The shrouds and their connections to the lips of the buckets are subject to the most wear and tear of the entire bucket because they are exposed to constant abrasion, shaking, impacts and the like encountered during ground moving operations. As a result, they require frequent replacement. Replacing shrouds in accordance with the prior art is relatively time-consuming and labor intensive because it typically requires a combination of wedges and clamp like structures which must be manually hammered into place or out of their locked positions. The excavating equipment must sit idle during that time, all of which is undesirable because it reduces profits. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is directed to the manner in which the shrouds are secured to the lips of buckets, and replaced when worn or damaged, and concerns both a method and apparatus for rapidly and efficiently installing and removing shrouds from the lips. 
         [0005]    The lips typically have forwardly converging upper and lower surfaces which are engaged by correspondingly rearwardly diverging legs of the shrouds that overly and are in contact with the lip surfaces. In many embodiments, a hole can be formed in the lip and an oblong-hole in the legs that is aligned with the hole and has axially extending, spaced-apart flat walls which define engagement ledges that face and overlap the hole. A connector for securing the shroud to the lip can be placed in the oblong-bore and the hole and has shaped exterior surfaces for positioning between the walls so that the connector is axially movable along the walls and past the engagement ledges while relative rotations between the connector and the oblong-bore in the leg are prevented. In another embodiment the exterior of the connector pin and the hole in the lip and the bore in the shroud leg can be cylindrical. 
         [0006]    In many embodiments, the connector can have a base for insertion into the hole in the lip and a housing that extends from the bore into the hole. The housing is split in the axial direction and defines opposing housing halves which surround the base to keep the base and the housing in axial alignment with each other. The base can have flat wall sections in alignment with the flat walls on the exterior of the housing and the housing and base are further prevented from rotationally moving relative to each other. 
         [0007]    A first, lateral projection inside the bore can extend from the housing to an enlarged portion of the bore and laterally past the hole to limit how far the housing can move axially into the bore. A second, lateral projection can extend from the base in lateral alignment with the first projection from the hole and into a space between the first projection and the lip. Retractable locking arms can be embedded in recesses formed in surfaces of the base opposite the wall. Portions of the arms, e.g. their ends facing the bore in the housing, can be resiliently urged, laterally and outwardly, towards the walls. 
         [0008]    The shroud can be secured to the lip by aligning the respective bore and hole and axially sliding the connector, connector base first, into the bore and from there into the hole. During this motion of the connector the outwardly biased locking arm ends are forced and retracted into the associated recesses in the base. As soon as the locking arm ends clear the engagement ledges during the downward movement of the connector pin the arm ends are automatically moved laterally and outwardly to contact the engagement ledges that overlap hole, thereby automatically locking the base and the housing to the shroud and to the lip. 
         [0009]    In many embodiments, the housing and the base of the connector are secured to each other with an axially extending bolt that engages a threaded hole in the base. Upon tightening the bolt the housing and the base are drawn together to set an axial distance between the end of the locking arms facing the bore in the housing and the engagement ledges formed by the housing which allows minimal play between the locking arms and the engagement ledges, just sufficient to permit the arms to pivot inwardly when their free ends clear the ledges. To install the shroud on the lip the connector is simply dropped, base first, into the bore and, to the extent necessary, urged, e.g. manually pushed into the bore until the locking arms can laterally expand into engagement with the engagement ledges, which secures and locks the shroud to the lip. 
         [0010]    Following the lateral release of the locking arms they are in lose engagement with the engagement surfaces which alone secures the connector to the lip. Moreover the bolt can be tightened to firmly press the locking arms into contact with the engagement ledges of the connector housing. 
         [0011]    The parting lines between the components of the configured to form narrow gaps, typically in the order of no more than about 1/64″ to ⅛″, into which fine granular material such as fine sand or powder, for example, will migrate during operational use of the bucket. With use this granular material becomes compacted in the gaps and thereby further rigidifies the installed connector. 
         [0012]    The shroud is securely attached to the lip with a connector pin between the top surface of the lip and the upper shroud leg that engages the top surface of the lip. The connector pin resists downward forces acting on the shroud because it acts as a rigid upright post. The shroud becomes attached to the lip because the legs of the shroud are in snug contact with the converging surfaces of the lip and the post formed by the connector pin prevents movements of the shroud relative to the lip. In some embodiments, the shroud can only be replaced by first unthreading the bolt while it is still in the hole and the bore and then individually sliding the components of the connector out of the bore and the hole. 
         [0013]    To speed up the replacement of shrouds it is preferred to provide the bolt with a head that can be power rotated, for example with an electric drill fitted with suitable rotating implements such as screw drivers or sockets, for example. Activation of the electric drill rapidly unthreads the bolt, releases it from the base and raises the bolt and the housing upwardly in the bore where the connector pin can be grasped, pulled out or the bore and the fresh shroud can be installed. Rotation of the bolt raises both the bolt and the housing in the bore since the base of the connector remains locked to the lip. 
         [0014]    In this manner, a worn shroud can typically be removed in less than one minute, much less time than is needed to remove worn shrouds in accordance with past practices. This leads to significant cost savings because of the relatively large number of shrouds on industrial buckets and the frequency with which they must be replaced. 
         [0015]    A further advantage provided by this invention is that removal of the worn shroud with an electric drill or the like automatically provides access to the bolt even when, as is frequently the case, the bolt head inside the bore in the shroud becomes embedded in hardened particulate matter, and even hardened concrete, that accumulate during operational use. In the past this required that the hardened material be tediously removed with chisels and the like. 
         [0016]    In contrast thereto, the activated drill bit is pushed against the embedded material which causes it to shatter, thereby freeing and providing access to the bolt head so that continued activation of the electric drill will unthread the bolt from the base as earlier described. 
         [0017]    In the other embodiment mentioned earlier, the pivoting arms are replaced by reciprocating pawls that are moved over the locking surface to secure and lock the connector pin in place. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a plan view and shows a shroud demountably attached to a lip of a bucket in accordance with the invention; 
           [0019]      FIG. 2  is a cross-section taken along line A-A of  FIG. 1 , and shows the shroud in its installed condition securing the shroud to the lip; 
           [0020]      FIG. 3  is a cross-section taken along line B-B of  FIG. 2  and also shows the shroud in its installed condition; 
           [0021]      FIGS. 4 and 5  are cross-sections also taken along lines A-A and B-B of  FIGS. 1 and 2 , respectively, but show the connector pin in its separated condition and ready for removal; 
           [0022]      FIG. 6  shows an assembled connector pin constructed according with the invention; 
           [0023]      FIG. 7  is an exploded view of the connector pin shown in  FIG. 6 ; 
           [0024]      FIG. 8  shows the components of the connector pin shown in  FIGS. 6 and 7  separated from each other to better illustrate their individual constructions; 
           [0025]      FIG. 9  is a plan view similar to  FIG. 1  and shows another embodiment of a connector pin constructed according to the invention; 
           [0026]      FIG. 10  is an upright cross-section taken along line A-A of  FIG. 9 ; and 
           [0027]      FIG. 11  is an enlarged cross-sectional view of the connector pin shown in  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Referring to  FIGS. 1-6 , a lip  2  of a bucket (not separately shown) of earthmoving equipment (not separately shown) has forwardly converging upper and lower surfaces  4 ,  6  that terminate at a forward end  8  of the lip  2 . A shroud  10  (as mentioned the term also encompasses consumable components such as adapters for teeth, teeth alone and other attachment demountably secured to the lip) has rearwardly diverging legs  12  that overly and engage the lip surfaces  4 ,  6 . 
         [0029]    The terms “forward”, “aft”, “up” and “down” as used herein to simplify the description and they refer to the typically horizontal orientation of the lip during installation and removal of the shroud and connector pin. 
         [0030]    The lip  2  has a cylindrical hole  16  that communicates with an enlarged, oblong bore  18  in at least one of the legs of the shroud  10 . The hole  16  and bore  18  are vertically oriented and to secure the shroud  10  to the lip  2  all that is required that the connector pin of this invention be manually dropped into the upwardly open end of the bore and be pushed down as needed until it has arrived in its locked position as is further explained below. 
         [0031]    Connector pin  20  has a base  22  that is principally disposed in and substantially immovable fixed to the lip  2  in lip hole  16 . A housing  24  extends from bore  18  in the upper shroud leg into hole  16  in the lip  2  and a threaded bolt  26  secures the housing  24  and the base to each other. 
         [0032]    As described in more detail below, installed base  22  is locked to the lip  2  so that it cannot move into the hole past a preset, fully inserted locked position. In that position the base cannot be moved out of the hole. As a result, the entire connector is locked and fixed to the lip as well. When the shroud needs replacement bolt  26  is backed up, that is unthreaded from the base into its released position shown in  FIGS. 4 and 5 . 
         [0033]    Referring to  FIGS. 5-7  and addressing the construction of connector pin  20  in greater detail, its base  22 , disposed in lip hole  16 , has a generally cylindrical center section  28  with pivotally mounted, laterally projecting locking arms  30  and a stop nose  32  formed by a projection  33  that extends outward and upward from the center section and is located circumferentially midway between the locking arms. A curved outer surface  40  of the projection has a diameter that corresponds to the diameter of hole  16  in the lip and permits snug movements of the base in the hole. 
         [0034]    Diametrically opposite pivot pockets  34  at the lower end of the center section each have an upwardly open recess which forms cooperating pivot surfaces  36  at the lower ends of the locking arms and their opposing interior pivot pocket surfaces. A resilient member  38 , such as a spring or a compressible foam pad, for example, is placed between the inside of the locking arms and the center section and resiliently urges the upper ends of the arms outwardly. 
         [0035]    Stop nose  32  at the upper end of projection  33  is located inside shroud bore  18 . An underside  42  of the stop nose faces downwardly and is dimensioned so that when it engages upper lip surface  4  as best seen in  FIG. 2  the upper end  43  of the center section is positioned slightly below the upper lip surface. 
         [0036]    Housing  24  is longitudinally split along a vertical parting line  50  into first and second housing halves  44 ,  48  which leaves the earlier mentioned small gaps between opposing surfaces of the halves. Together the two halves form a tubular structure which, on its outside, movably engages both lip hole  16  and shroud hole  18  and is slidable along them. On the inside of the housing is threaded bolt  26 . The bolt is placed inside one of the housing halves and thereafter the halves are placed over each other and over the bolt in a cavity between them. When assembled the cavity inside the housing forms the insides of both housing halves form an upper aperture section  52 , where bolt head  78  is located, an intermediate, reduced diameter middle aperture section  54 , which houses a section of the shaft between the bolt head and the upper end of the threads on the shaft, and a lower aperture section  55  which surrounds the base. The thickness of the middle aperture section is selected so that the lower end  62  of the intermediate aperture section  54  engages the upper end  43  of the center section when bolt  26  is tightened and the free ends of the locking arms  30  are moved into contact with engagement ledges  86  formed by the shroud legs as further described below. 
         [0037]    The bolt has a ring flange  56  at the lower end of the head the underside  58  of which rests on a ring-shaped ledge formed by the upper end  60  of middle aperture section  54 . The bolt further has a groove  64  between the underside  58  of ring flange  56  and the beginning of threads  66  on the shaft of the bolt. The groove is sufficiently wide to accommodate and straddle middle aperture section  54  and allows the bolt rotate in the cavity of the housing. 
         [0038]    The connector pin is assembled prior to its installation and use by separating the housing halves  44 ,  48  and initially placing a bolt  26  in one of them so that its ring flange  56  rests on the upper end  60  of middle aperture section  54  and its groove  64  straddles the middle aperture section. The other housing half is then placed over the bolt and the bolt is threaded into the center section. This moves the housing halves  44 ,  48  and the base from the initial assembly position, as generally illustrated in  FIGS. 4 and 5 , into the fully assembled position, as illustrated in  FIGS. 2 and 3 . A gasket, such as an O-ring  68  is placed between the underside  58  of ring flange  56  on the bolt and upper end  43  of center section  28  to shield the threads from contamination during use. 
         [0039]    First housing half  44  extends over substantially the full length of the connector pin. Its exterior is semi-circular and conforms to the diameter of hole  16  and the shape of bore  18  in the shroud leg so that the housing is axially slidable in the hole. 
         [0040]    Second housing half  48  has the same axial length as the first housing. A lower part  69  of this housing has the same diameter as the exterior of the first housing and includes an axially extending, elongated cut-out  70  that is dimensioned to accommodate projection  33  extending upwardly from the center section  28  of the base and positioned midway between the respective locking arms  30   
         [0041]    An upper part  72  of the second housing half  48  has an enlarged cross-section relative to the diameter of lip hole  16  in the lip that is oblong and forms opposing, parallel, flat surfaces  74  which are spaced apart by less than the diameter of hole  16 . As a result portions of the shroud leg  12  overly hole  16  in the lip and form a pair of opposite, downwardly facing engagement ledges  86 . The upper part of the housing further defines another vertically projection  71  that is aligned with and overlies stop nose  32  at the end of projection  33 . 
         [0042]    The exterior configuration of bore  18  in shroud leg  12  corresponds to that of the upper housing part  72  so that the housing and therewith the entire connector pin are non-rotatable relative to shroud leg  12 . This enables the tightening and loosening of the bolt into and out of the base. On the lower part of the housing corresponding flat surfaces are aligned with flat surfaces  74  on the upper part of the housing. These flat surfaces are formed by outer surfaces of the pivot pockets  34  and by outer surface portions of the lower housing half adjacent the pivot pockets. 
         [0043]    To facilitate the assembly of the connector bolt head  78  includes a power-drive coupling, such as a screw driver slot  80 , a socket-head  82  or the like for electrically turning the bolt, as with an electric drill. 
         [0044]    Prior to its installation, e.g. at the time of its manufacture, bolt  26  of the connector pin is tightened to secure the parts to each other. The connector pin is installed by manually compressing the arms locking arms inwardly so they fit into open bore  18 . The connector pin is next dropped or pushed into the bore where it can slide gravitationally downwardly, if needed assisted by manually pushing. Once the biasing force exerted by resilient member  38  has moved the upper ends of the locking arms  30  to beneath engagement ledges  86  overlying hole  16  in the lip, the laterally expanded locking arms lock and fix the connector pin in place on the lip and ready for use. To protect the inside of bore  18  from contaminants a cap  84 , preferably made of a resiliently deformable material such as rubber or plastic, is placed into the bore and over bolt head  78  in the bore after the installation is complete. 
         [0045]    To replace a worn shroud, cap  84  is first removed and connector pin  20  is disassembled while in place inside hole  16  and bore  18  by backing up bolt  26 , preferable with an electric drive to save time and shatter any compacted solid material that may have accumulated in the bore during use. The unthreaded bolt and the housing halves  44 ,  48  are then slidably removed from the bore and base  22  is slidably removed from the hole. 
         [0046]      FIGS. 9-11  illustrate another embodiment of the invention for securing a shroud  10  to a lip  2  of a bucket. Legs  12  of the shroud engage upwardly and downwardly facing surfaces  4 ,  6  of the lip as was previously described. In this embodiment the upper leg of the shroud has a round through bore  90  which communicates with an upwardly open depression  92  in upper surface  4  of the lip. The depression includes an upwardly open chamber  94  that extends laterally away from bore  90  in the leg. A connector pin  96  extends from bore  90  into the portion of depression  92  disposed directly beneath the bore. A connector pin locking device  98  is located in chamber  94 . 
         [0047]    Similar to connector pin  20  shown and described earlier, connector pin  96  has a base  100 , a housing  102  partially surrounding the base, and a threaded bolt  104  which releasably secures the housing to the base. 
         [0048]    Base  100  includes a cylindrical center section  106  with a threaded, upwardly open hole, and an enlarged diameter lower end  108 . Along a portion of one side, e.g. its aft side as seen in  FIG. 10 , lower end  108  has a downwardly facing, upwardly diverging first contact surface  111  that intersects a horizontally oriented locking surface  114  formed in turn by a recess  107  on the exterior of the housing. A second, upwardly diverging contact surface  112  extends from the locking surface upwardly at an inclined angle as is illustrated in  FIGS. 10 and 11 . 
         [0049]    Housing  102 , like the housing of connector pin  20  described above, is longitudinally split into two housing halves. Its exterior is cylindrical and shaped so that it can be slidably inserted into and withdrawn from bore  90  in shroud leg  12  and depression  92  in lip  2 . Schematically illustrated dowel pins  128  extend across the opposing surfaces of the halves and align them in the vertical direction. 
         [0050]    To assure proper rotational alignment of the locking surface  114  with locking device  98 , the housing and the base are rotationally fixed relative to each other, for example by providing a cooperating radially oriented groove and a groove-engaging projection interlock (not shown) between opposing, surfaces of the base and the housing. 
         [0051]    To prevent rotation of housing  102  relative to lip bore  90  and fix the orientation of the connector pin  96  in the bore, the upper part of the housing includes a laterally projecting, vertically oriented projection  116 . The lower end  118  of the projection engages upper lip surface  4  which limits the downward movement of the connector pin. The position of projection  116  is selected so that when it engages its mating vertically oriented groove (not separately shown) in bore  90 , the recess  107  and contact surfaces  111 ,  112  face towards aft chamber  94 . 
         [0052]    Locking device  98  has a body  121  that snugly but slidably fits into recess chamber  94 . A forward side  120  of the body snugly but slidably faces the outside of connector pin  9  over an arc of less than 180 degrees and helps stabilize the fully inserted connector pin. A locking pawl  122  is slidably arranged in a forwardly open passage in body  121  and includes an engagement surface  124  which, in use, overlaps locking surface  114  on base  100  and thereby restrains the connector pin to lip  2 . An actuator  126 , such as a resilient foam pad, or magnetic, electric, hydraulic or pneumatic device, for example, resiliently urge pawl  122  in a forward direction toward the housing so that the underside  124  of the pawl contacts locking surface  114 . 
         [0053]    Connector pin  96  is installed by first assembling its parts and tightening bolt  104  to secure all components of the connector pin to each other. Locking device  98  is placed into recess chamber  94  so that its pawl  122  extends into the portion of depression  92  which overlies bore  90  in leg  12 . Projection  116  of the connector pin is aligned with its associated groove and inserted into the bore. As the connector moves downwardly lower contact surface  111  of base  100  engages the upwardly inclined nose end  130  of the pawl and pushes the pawl out of the downward path of the connector pin so that it can be fully inserted into the depression. 
         [0054]    After engagement surface  124  of the pawl has moved past locking surface  114  on base  100 , actuator  126  pushes the pawl into space  107  above locking surface. This locks the base and therewith the housing and entire connector pins to lip  2 . The connector pin remains fixed relative to the lip because the overlying shroud leg does not permit the locking device to move out of its chamber. 
         [0055]    The connector pin is removed in essentially the same manner in which connector  20  is removed as earlier described, i.e. by first unthreading bolt  104  and then, following the removal of the shroud from the lip, manually withdrawing all parts of the connector and locking device from lip bore  90  an depression  92 . 
         [0056]    Other variations are within the spirit and scope of the present invention. Thus, while the invention is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. 
         [0057]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0058]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.