Patent Publication Number: US-6209238-B1

Title: Excavating adapter-to-lip connection apparatus with bottom front-accessible disconnection portion

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to excavating apparatus and, in a preferred embodiment thereof, more particularly provides improved apparatus for removably attaching a wear member, such as an excavating tooth adapter, to the lip portion of an excavating device such as a bucket, dipper or the like. 
     Large excavating buckets, dippers or the like are typically provided with a series of earth-cutting teeth which are each formed from two primary parts—a relatively large adapter and a relatively small replaceable point. The adapter has a base portion which is connectable to the forward lower lip of the bucket, and a nose portion onto which the tooth point is removably secured by a suitable connecting pin or other connecting structure. Compared to that of the adapter, the useful life of the point is rather short—the adapter typically lasting through five or more point replacements until the tremendous earth forces and abrasion to which the adapter is subjected necessitates its replacement. 
     Various structures have been previously proposed for removably securing adapters, and other wear members such as wear shrouds, to excavating lip structures. For example, in U.S. Pat. No. 5,713,145 to Ruvang a wear shroud having a generally C-shaped cross section is removably secured to the front edge of an excavating bucket lip by first placing the front lip edge in the interior of the wear shroud so that the top and bottom legs of the shroud respectively extend along the top and bottom sides of the lip. A rear end portion of the top shroud leg is then removably secured, using a J-bolt, to a base structure welded to the top side of the lip. A nut threaded onto the J-bolt at the rear end of the top shroud leg and facing the welded base structure prevents the forward removal of the installed wear shroud from the bucket lip. To permit such removal, it is necessary to gain access to the rear end of the top shroud leg and rearwardly remove the nut from the J-bolt. 
     This technique securely attaches the wear shroud to a front edge portion of the lip with only the top leg of the shroud being anchored, via the top side lip weld base, to the lip. When a larger wear member, such as an excavating tooth adapter, is to be removably attached to the lip it is typically desirable to additionally anchor a rear end portion of the bottom wear member leg to the lip to increase the strength of wear member attachment. using this J-bolt attachment technique on both of the top and bottom wear member legs would, of course substantially increase the strength with which the wear member was removably held on the bucket lip. However, to decouple the bottom wear member leg from the lip it would be necessary to gain access to the rear end of the bottom wear member leg which is positioned a substantial distance from the front lip edge along the underside of the lip. This requirement to access the rear end of the bottom wear member leg beneath the typically massive bucket lip would undesirably make its decoupling from the bucket lip an awkward, difficult and potentially dangerous task. 
     It can thus be seen that a need exists for apparatus for removably securing the rear ends of both of the upper and lower leg portions of a wear member, such as an excavating tooth adapter, to a bucket lip in a manner permitting the decoupling of the lower leg from the lip without having to access the rear end of the lower leg. It is to this need that the present invention is directed. 
     SUMMARY OF THE INVENTION 
     In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, excavating apparatus is provided which includes a lip structure, disposed for example on an excavating bucket, a wear member, representatively an excavating tooth adapter, and specially designed fastening apparatus useable to removably mount the wear member on the lip structure. 
     The wear member has a generally C-shaped cross section with a front end portion from which top and bottom legs extend along a cavity. In the assembled apparatus a front edge portion of the lip structure is removably received within the cavity, with the top and bottom legs of the wear member respectively extending along the top and bottom sides of the lip structure. A first fastening structure, illustratively including a spring-loaded J-bolt assembly, removably connects a rear end portion of the top wear member leg to the top side of the lip structure rearwardly of its front edge. A second fastening structure removably connects a rear end portion of the bottom wear member leg to the bottom side of the lip structure rearwardly of its front edge. 
     According to a key aspect of the invention, the second fastening structure has a disconnection portion accessible and loosenable from a front bottom portion of the wear member, disposed forwardly of the rear end portion of the bottom leg, to permit the bottom wear member leg to be disconnected from the bottom side of the lip structure without having to reach under the lip structure to the rear end portion of the bottom wear member leg. This capability of disconnecting the bottom wear member leg from a front portion thereof, as opposed to having to reach clear back to its rear end under the lip structure, makes the overall wear member removal task safer and more convenient. 
     Preferably, the disconnection portion of the second fastening structure is forwardly movable during loosening thereof, and is illustratively a threaded member—in one representative embodiment of the invention being a nut, and in another representative embodiment of the invention being a bolt. Additionally, at least one of the first and second fastening structures is operative to resiliently bias the front end portion of the installed wear member rearwardly toward the front edge of the excavating lip structure to thereby effect a self-tightening connection of the wear member to the lip. 
     In accordance with other features of the invention, the excavating apparatus further comprises a base member removable securable to the excavating lip structure with an upper end portion extending above the top side of the excavating lip structure and defining a portion of the first fastening structure, and a lower end portion extending below the bottom side of the excavating lip structure and defining a portion of the second fastening structure. Representatively, the excavating lip structure has an opening disposed therein rearwardly of its front edge and extending between its top and bottom sides, and the base member is removably insertable into this lip structure opening, with the bottom leg of the wear member being releasably interlockable with the lower end portion of the base member. Preferably, the second fastening structure further includes a base clamp member releasably interlockable with the lower end portion of the base member and with the bottom wear member leg in the assembled excavating apparatus, and a securement structure for releasably securing the bottom wear member leg to the base clamp member. The securement structure preferably includes a threaded member extendable from the base clamp member forwardly through a portion of the bottom wear member leg. 
     In one embodiment of the excavating apparatus, the threaded member is fixedly secured to the base clamp member and has a front end portion, the removal portion is a nut threadable onto the front end portion of the threaded member, and a spring is compressed between the nut and a facing portion of the bottom wear member leg and functions to resiliently bias the front end portion of the wear member toward the front edge of the lip structure. 
     In another embodiment of the excavating apparatus, the threaded member is a bolt defining the removal portion and having a rear end threadable into the base clamp member, and a front end with a head thereon. A spring member is positioned to be compressed between the head and a facing portion of the bottom wear member leg and resiliently bias the front end portion of the wear member toward the front edge of the lip structure. 
     In one version thereof, the base clamp member representatively has a generally U-shaped configuration with opposite leg portions releasably interlockable with opposite side portions of the lower end portion of the base member and with the bottom wear member leg. In another version thereof, the base clamp member has an opening therein through which a lower end portion of the base member may be downwardly inserted, and the base clamp member opening and the lower end portion of the base member have cooperating lug and recess portions useable to releasably interlock the base clamp member and the lower end portion of the base member. Outer side edge portions of this base clamp member embodiment are also preferably releasably interlockable with the bottom wear member leg. 
     To facilitate the removable connection of the generally C-shaped wear member to the excavating lip structure, and in accordance with another feature of the present invention, the inner side surface of the bottom wear member leg has a recess formed therein and the bottom leg further has at least one cutout area formed in an external side surface portion thereof disposed forwardly of the recess and separated therefrom by a dividing wall with an opening formed therein through which a threaded disconnection member may be extended between the cutout area and the recess. In one version of the wear member a pair of cutout areas are formed on exterior side surface portions of the bottom leg, and in another version a single cutout area is disposed on a bottom exterior side surface of the bottom wear member leg. 
     The base member preferably has a portion removably and interlockingly insertable into the recess, and the base clamp structure is preferably removably insertable into the recess into interlocking engagement with the base member and the bottom wear member leg. A threaded structure is extendable through the dividing wall opening and is useable to removably hold the base clamp member in interlocked engagement with the bottom wear member leg and the base member. Additionally, a resilient structure is provided and is connectable to the threaded structure within the cutout area to resiliently bias the base clamp structure toward the dividing wall. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view through a portion of an excavating adapter/lip assembly portion of a representative excavating bucket having incorporated therein a specially designed adapter-to-lip connection structure embodying principles of the present invention; 
     FIG. 2 is a cross-sectional view through the assembly taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a partially exploded side elevational view of a portion of the assembly; 
     FIG. 4 is a top plan view of the adapter portion of the assembly; 
     FIG. 5 is a bottom plan view of the adapter; 
     FIG. 6 is a cross-sectional view through a bottom leg portion of the adapter taken along line  6 — 6  in FIG. 3; 
     FIG. 7 is a cross-sectional view through a top leg portion of the adapter taken along line  7 — 7  of FIG. 3; 
     FIG. 8 is a cross-sectional view through the bottom leg of the adapter taken along line  8 — 8  of FIG. 3; 
     FIG. 9 is a cross-sectional view through the top and bottom legs of the adapter taken along line  9 — 9  of FIG. 3; 
     FIG. 10 is a side elevational view of a base portion of the assembly; 
     FIG. 11 is a partially cut away rear elevational view of the base; 
     FIG. 12 is a partially cut away top plan view of the base; 
     FIG. 13 is a partially cut away bottom plan view of a base clamp portion of the assembly; 
     FIG. 14 is a front end view of the base clamp; 
     FIG. 15 is a partially cut away side elevational view of the base clamp; 
     FIG. 16 is a partially cut away bottom plan view of an alternate embodiment of the excavating adapter/lip assembly; 
     FIG. 17 is a side elevational view of a modified base member used in the FIG. 16 assembly; 
     FIG. 18 is a cross-sectional view through the modified base member taken along line  18 — 18  of FIG. 17; 
     FIG. 19 is a top plan view of a modified base clamp member used in the FIG. 16 assembly; and 
     FIG. 20 is a side elevational view of the modified base and base clamp members in an assembled state. 
    
    
     DETAILED DESCRIPTION 
     Cross-sectionally illustrated in FIGS. 1 and 2 is a portion of an excavating device  10 , representatively an excavating bucket, which includes a bottom lip structure  12  having a front edge  14  from which top and bottom sides  16 , 18  rearwardly extend. A series of forwardly extending locator projections  20  (only one of which is visible in FIG. 1) are spaced apart along the length of the front lip edge  14 , and a spaced series of mounting openings  22  (only one of which is shown in FIGS. 1 and 2) are formed through the lip structure  12 . Each opening  22  is spaced rearwardly apart from the front lip edge  14 , extends between the top and bottom sides  16 , 18  of the lip structure  12 , and is aligned with one of the locator projections  20 . 
     With reference now to FIGS. 1-9, at each locator projection  20  is a wear member  24  which is representatively an excavating tooth adapter, but could be another type of wear member such as a lip protector or other wear shroud structure. In cross-section, as shown in FIGS. 1-3, the illustrated adapter  24  has a generally C-shaped configuration, having a front end or “nose” portion  26  from which elongated top and bottom legs  28 , 30  longitudinally extend rearwardly along top and bottom sides of a rearwardly opening cavity  32  between the top and bottom legs  28 , 30 . Cavity  32  has a front end portion  33  which is shown in FIGS. 1 and 3. Adapter nose  26  has a connection opening  34  extending therethrough and is configured to be removably received in the complementarily configured socket of a replaceable tooth point (not shown). In a conventional manner, a connector structure may be extended through the adapter nose opening  34 , and corresponding openings in the tooth point, to removably hold the tooth point on the adapter nose  26 . 
     The top adapter leg  28  has a downwardly opening bottom side cavity  36  (see FIGS. 7 and 9) extending along its length and defining opposing side Slots  38  along the interior surface of the leg  28 . A connection opening  40  extends downwardly through a longitudinally intermediate portion of the top leg  28  and communicates with its bottom side cavity  36  for purposes later described herein. The bottom adapter leg  30  has an upwardly opening top side cavity  42  (see FIG. 9) extending along a rear end portion of the leg  30  and defining opposing side slots  44 , and a bottom side depression  46 , along the interior surface of the leg  30 . For purposes subsequently set forth herein, cutout areas  48  (see FIGS. 1,  3  and  8 ) are formed externally on horizontally opposite sides of the bottom leg  30  forwardly of its rear end cavity  42 . Cutout areas  48  are separated from the bottom leg cavities  42  by dividing walls  50  having circular openings  52  extending therethrough between the cutout areas  48  and the cavities  42 . 
     The adapter  24  cross-sectionally depicted in FIG. 1 as being removably mounted on a front edge portion of the lip structure  12  is one of a spaced apart series of adapters similarly positioned on the lip structure and is positioned on the lip structure  12  by rearwardly moving the adapter  24  toward the front edge  14  of the lip structure  12 , as indicated by the arrow  54  in FIG. 3, until the indicated front edge portion of the lip structure  12  is received in the adapter cavity  32 , with the lip locator projection  20  complementarily received within the front adapter cavity portion  33 . TO releasably retain the mounted adapter  24  on the front edge portion of the lip structure  12 , the present invention provides specially designed connection apparatus that includes first and second fastening structures which, as later described herein, are used to respectively and removably attach rear end portions of the top and bottom adapter legs  28 , 30  to the top and bottom sides  16 , 18  of the lip structure  12 . The connection apparatus comprises the lip opening  22 , a base member  56 , and a base clamp member  58 . 
     With reference now to FIGS. 10-12, the base member  56  has a vertically intermediate portion  60  with front and rear side edges  62  and  64 ; a forwardly offset top end portion  66  with oppositely projecting side flanges  68 , a top side depression  70 , and a rear side face  72 ; and a bottom end portion  74  with opposite side depressions  76  thereon. As illustrated by the arrow  78  in FIG. 3, the base member  56  may be downwardly and removably inserted into the lip structure opening  22  until the forwardly offset top end portion  66  of the base member  56  contacts the top side  16  of the lip structure  12  and blocks the inserted base member  56  from simply falling through the lip structure opening  22 . With the base member  56  inserted into the lip structure opening  22  in this manner, a top end portion of the base member  56 , including its top end flanges  68 , projects upwardly beyond the top side  16  of the lip structure  16 , and a bottom end portion of the base member  56 , including its opposite side recesses  76 , projects downwardly beyond the bottom side  18  of the lip structure  12 . 
     Turning now to FIGS. 13-15, the base clamp member  58  has a generally U-shaped body  80  with opposite top and bottom sides  82  and  84 ; a rear end surface  86 ; an upwardly projecting rear end boss  88 ; and spaced apart opposite parallel legs  90  having front end surfaces  92  through which threaded openings  94  rearwardly extend. A rectangular recess  96  formed in the bottom side  84  provides the legs  90  with upwardly reduced thickness facing inner side portions  98 . 
     With the base member  56  downwardly inserted into the lip structure opening  22  (see FIG.  3 ), the adapter  24  is moved rearwardly onto the front edge portion of the lip structure  12  as cross-sectionally depicted in FIG.  1 . This causes the top flanges  68  of the upper end portion  66  of the base member  56  to slidably and complementarily enter the opposing side slots  38  in the top adapter leg  28  (see FIG.  2 ), and also causes the bottom end  74  of the base member  56  to be complementarily received in the bottom side depression  46  in the bottom adapter leg  30  (see FIG.  2 ). This interlocking between top and bottom end portions of the base member  56  and the top and bottom adapter legs  28 , 30  vertically restrains rear end portions of the adapter legs  28 , 30  relative to the top and bottom sides  16 , 18  of the lip structure  12 , with such top and bottom end portions of the base member  56  respectively defining portions of the aforementioned first and second fastening structures. 
     The balance of the first fastening structure (see FIG. 1) includes a J-bolt  100  having an enlarged transverse head portion  102  and an opposite end portion  103 ; a pair of annular washers  104  and  106 ; a coiled compression spring  108 , and a nut  110 . J-bolt  100  is installed by inserting its end  103  downwardly through the top adapter leg upper side opening  40 , and then forwardly tipping the J-bolt  100  and passing its end portion  103  rearwardly through the top side recess  70  of the base member  56  until the enlarged bolt head portion  102  is seated as shown within the adapter leg opening  40 . The washers  104 , 106  and the spring  108  are then installed as shown in the bolt end portion  103 , and the nut  110  is threaded onto the bolt end portion  103 , against the washer  106 , and tightened to compress the spring  108 . In a manner similar to that shown in U.S. Pat. No. 5,713,145 to Ruvang, the compressed spring  106  transmits to the top adapter leg  28 , via the J-bolt  100 , a rearwardly directed force which resiliently biases a front end portion of the installed adapter  24  toward the front lip edge  14  to automatically tighten the adapter  24  rearwardly against a front edge portion of the lip  12  as the adapter/lip interface area begins to be worn away during use of the excavating bucket  10 . 
     As previously mentioned, the second fastening structure, which is used to removably connect a rear end portion of the bottom adapter leg  30  to the bottom side  18  of the lip structure  12 , includes the downwardly projecting bottom end portion 74  of the base member  56 . The second fastening structure (see FIG. 1) also includes the base clamp member  58 , a pair of straight bolts  112  having heads  114  thereon; a pair of annular washers  116  and  118 ; and a coiled compression spring  120 . 
     With reference now to FIGS. 1 and 2, the base clamp member  58  is received within the top side cavity  42  of the bottom adapter leg  30 , is rearwardly removable from the cavity  42 , and is releasably interlocked with both the bottom adapter leg  30  and a bottom portion of the base member  56 . Specifically, the inner side portions  98  of the base clamp member legs  90  (see FIGS. 13 and 14) are slidably and complementarily received in the opposite sides depressions  76  of the bottom end portion  74  of the base member  56  (see FIGS.  10  and  11 ), and outer side edge portions of the base clamp member legs  90  are slidably and complementarily received in the opposing side slots  44  (see FIGS. 2 and 9) in the lower adapter leg  30 . As best illustrated in FIG. 1, the front ends  92  of the base clamp member legs  90  are spaced rearwardly apart from the dividing walls  50  of the bottom adapter leg  30 , and the base clamp member rear end boss  88  abuts the rear edge  64  of the base member  56 . 
     The bolts  112  extend rearwardly through the lower adapter leg side cutout areas  48 , nonthreadingly and axially movably extend through the dividing wall openings  52  into the bottom leg cavity  42  (see FIGS.  1  and  6 ), and are threaded into the base clamp member leg openings  94  (see FIGS.  1  and  13 ). The bolt heads  114  are disposed within the cutout areas  48 , and the washers and spring  116 , 118 , 120  are interposed between each bolt head  114  and its associated dividing wall  50  as illustrated in FIG.  1 . The bolts  112  are tightened into the base member leg openings  94  in a manner compressing the springs  120 . This, in turn, causes the compressed springs  120  to exert on the dividing walls  50  rearwardly directed forces which assists the top spring  108  in rearwardly biasing the installed adapter  24  to maintain a resilient self-tightening force thereon relative to the lip structure  12 . 
     According to a key aspect of the invention, the lower bolts  112  form disconnection portions of the second or lower fastening structure which are accessible, loosenable and removable from a front bottom portion  122  of the adapter  24 , disposed forwardly of the rear end portion  124  of the bottom adapter leg  30 , to permit the bottom leg  30  to be disconnected from the bottom side  18  of the excavating lip structure  12  without having to reach under the lip structure  12  to the rear end  124  of the adapter  24 . As can be seen in FIG. 1, the bolt heads  114  disposed in the side cutout areas  48  of the bottom adapter leg  30  may be easily reached, for disconnection and removal, from the front of the adapter  24  without having to access the rear end  124  of the bottom adapter leg  30 . This advantageously renders the disconnection of the bottom adapter leg  30  from the lip structure  12  easier and safer. 
     An underside portion of an alternate embodiment  10   a  of the previously described excavating bucket  10  is illustrated in FIG.  16 . For ease in comparing the excavating bucket embodiments  10  and  10   a , components in the embodiment  10   a  similar to those in embodiment  10  have been given the same reference numerals having the suffixes “a”. 
     Bucket  10   a  is provided with a modified adapter  24   a  in which the previously described opposite side cutout areas  48  (see FIG. 6) are replaced on the modified bottom adapter leg  30   a  shown in FIG. 16 with a single bottom side cutout area  48   a  which is separated from the rear bottom leg cavity  42   a  by a dividing wall  50   a  having a circular opening  52   a  extending therethrough between the bottom side cutout area  48   a  and the rear leg cavity  42   a . A modified base member  56   a , as illustrated in FIGS. 17 and 18, is provided in which the upwardly facing ledge surfaces  124  of the bottom end portion  74   a  of the base member  56   a  have spaced apart pluralities of notches  126  formed therein and extending downwardly therethrough. 
     Additionally, as illustrated in FIGS. 19 and 20, a modified base clamp member  58   a  is provided and includes a generally rectangular body  128  having top and bottom sides  130  and  132 , front and rear ends  134  and  136 , an upstanding rear end boss  88   a , and an elongated rectangular central opening  138 . The opening  138  is sized to permit the lower end  74   a  of the base member  56   a  to pass downwardly therethrough, and has opposite side edges  140  from which opposing pairs of lugs  142  project toward one another. The lugs  142  are sized and spaced to pass upwardly through the notches  126  in the lower base member end  74   a  as the lower base member end  74   a  is being passed downwardly through the opening  138 . An elongated threaded stud  144  longitudinally projects forwardly from the front base clamp member end  134 . 
     Turning now to FIG. 20, the base clamp member  58   a  is removably and interlockingly installed on the lower end of the base member  56   a  by passing the lower end  74   a  of the base member  56   a  downwardly through the base clamp member opening  138  in a manner such that the base clamp member lugs  142  pass upwardly through the notches  126  in the lower end  74   a  of the base member  56   a  and the clamp member body  128  is aligned with the lower side depressions  76   a  of the base member  56   a . The base clamp member  58   a  is then slid forwardly through the depressions  76   a  until the lugs  142  overlie non-notched portions of the base member ledges  124  to thereby prevent the installed base clamp member  58   a  from falling off the base member  56   a . In this manner, the base clamp member  58   a  is releasably interlocked with the base member  56   a.    
     With the base clamp member  58   a  and the lower end  74   a  of the base member  56   a  operatively disposed within the lower adapter leg cavity  42   a  (see FIG.  16 ), the base clamp member  58   a  is also releasably interlocked with the lower adapter leg  30   a  by means of the complementary receipt of outer side edge portions  146  of the base clamp member body  128  (see FIG. 19) in the opposing side slots  44   a  (see FIG. 16) in the lower adapter leg cavity  42   a . The threaded stud  144  extends forwardly, nonthreadingly and movably through the dividing wall opening  52   a  (see FIG. 16) into the bottom side cutout area  48   a  of the bottom adapter leg  30   a . A nut  148  is threaded onto the exposed front end of the stud  144  and, as illustrated in FIG. 16, a pair of annular washers  116   a , 118   a  and a coiled compression spring  120   a  are interposed between the nut  148  and the front surface of the dividing wall  50   a.    
     The nut  148  is tightened onto the front end of the stud  144  to compress the spring  120   a , thereby exerting a rearwardly directed resilient force on the bottom adapter leg  30   a  relative to the lip structure  12   a . In combination with the similar resilient force exerted on the adapter  24   a  by the spring-loaded J-bolt structure (not shown) associated with the top leg (also not shown) of the adapter  24   a , this maintains a resilient, rearwardly directed self-tightening force on the installed adapter  24   a.    
     This modified version of the second or lower fastening structure, which releasably connects the bottom adapter leg  30   a  to the bottom side  18   a  of the lip structure  12   a  provides a front access advantage similar to the previously described second fastening structure used in conjunction with the adapter  24  shown in FIG.  1 . As can be seen in FIG. 16, the nut  148  forms for this modified second fastening structure a disconnection portion accessible, loosenable and removable from a front bottom portion  122   a  (see FIG. 16) of the adapter  24   a  (or other type of wear member as the case may be), disposed forwardly of the connected rear end portion of the bottom leg  30   a , to permit the bottom adapter leg  30   a  to be disconnected from the bottom side  18   a  of the lip structure  12   a  without having to reach rearwardly under the lip structure  12   a  to the rear end  124   a  of the bottom adapter leg  30   a.    
     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.