Abstract:
A replaceable excavating tooth point is telescoped onto an adapter nose and releasably retained thereon by an elongated, flat connector member having an untapered side periphery. The connector member longitudinally extends through aligned point and connector openings and blocks forward removal of the point from the adapter nose. A transverse point sidewall abutment surface facing one end of the installed connector member prevents it from moving outwardly through one of the point openings, and a rotatable lock member carried by the other end of the connector member and engageable with a groove in the other point opening releasably prevents the connector member from moving outwardly through the grooved point opening. A detent structure releasably holds the lock member in locking and unlocking orientations in which the lock member is prevented from moving parallel to the length of the connector member.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to material displacement apparatus and, in a preferred embodiment thereof, more particularly relates to apparatus for releasably coupling a replaceable excavation tooth point to an associated adapter nose structure. 
     A variety of types of material displacement apparatus are provided with replaceable portions that are removably carried by larger base structures and come into abrasive, wearing contact with the material being displaced. For example, excavating tooth assemblies provided on digging equipment such as excavating buckets or the like typically comprise a relatively massive adapter portion which is suitably anchored to the forward bucket lip and has a reduced cross-section, forwardly projecting nose portion, and a replaceable tooth point having formed through a rear end thereof a pocket opening that releasably receives the adapter nose. To captively retain the point on the adapter nose, aligned transverse openings are formed through these interengageable elements adjacent the rear end of the point, and a suitable connector structure is driven into and forcibly retained within the aligned openings to releasably anchor the replaceable tooth point on its associated adapter nose portion. 
     Connector structures adapted to be driven into the aligned tooth point and adapter nose openings typically come in two primary forms—(1) wedge and spool connector sets, and (2) flex pin connectors. A wedge and spool connector set comprises a tapered spool portion which is initially placed in the aligned tooth and adapter nose openings, and a tapered wedge portion which is subsequently driven into the openings, against the spool portion, to jam the structure in place within the openings in a manner exerting high rigid retention forces on the interior opening surfaces and press the nose portion into a tight fitting engagement with the tooth pocket. 
     Very high drive-in and knock-out forces are required to insert and later remove the steel wedge and typically require a two man effort to pound the wedge in and out—one man holding a removal tool against an end of the wedge, and the other man pounding on the removal tool with a sledge hammer. This creates a safety hazard due to the possibility of flying metal slivers and/or the second man hitting the first man instead of the removal tool with the sledge hammer. Additionally, wear between the tooth/adapter nose surface interface during excavation use of the tooth tends to loosen the tight fit of the wedge/spool structure within the tooth and adapter nose openings, thereby permitting the wedge/spool structure to fall out of the openings and thus permitting the tooth to fall off the adapter nose. 
     Flex pin structures typically comprise two elongated metal members held in a spaced apart, side-by-side orientation by an elastomeric material bonded therebetween. The flex pin structure is longitudinally driven into the tooth and adapter nose openings to cause the elastomeric material to be compressed and resiliently force the metal members against the nose and tooth openings to retain the connector structure in place within the openings and resiliently press the adapter nose portion into tight fitting engagement with the interior surface of the tooth socket. 
     Flex pins also have their disadvantages. For example, compared to wedge/spool structures they have a substantially lower in-place retention force. Additionally, reverse loading on the tooth creates a gap in the tooth and adapter nose openings through which dirt can enter the tooth pocket and undesirably accelerate wear at the tooth/adapter nose surface interface which correspondingly loosens the connector retention force. Further, the elastomeric materials typically used in flex pin connectors are unavoidably subject to deterioration from hot, cold and acidic operating environments. Moreover, in both wedge-and-spool and flex pin connectors relatively precise manufacturing dimensional tolerances are required in the tooth point and adapter nose portions to accommodate the installation of their associated connector structures. 
     Proposed solutions to these various connector-based problems, limitations and disadvantages in excavation tooth point/adapter assemblies have included wedge-shaped connector members which are inserted into the aligned point and adapter nose openings having complementarily tapered configurations, with the inserted connector being resiliently biased in a longitudinal “tightening” direction relative to the point and adapter nose by a lock member carried by the connector member. The lock member is rotatably and sealingly received within an end of the connector member, bears against a portion of the tooth point, and is spring-biased longitudinally outwardly from the connector member. An example of this wedge-shaped type of connector structure is illustrated and described in U.S. Pat. No. 6,108,950 to Ruvang. 
     This particular wedge-shaped type of connector structure at least substantially reduces various of the problems, limitations and disadvantages discussed above in conjunction with conventional flex pins and wedge and spool connector sets. However, it has several limitations of its own. For example, due to the wedge shape of the connector member, excavating loading forces exerted on the connector member can generate a substantial axial force component on the connector member which can, in certain instances, damage the lock member and permit the connector member to be expelled from the tooth point and adapter nose openings. Moreover, because the spring-biased lock member is permitted to move into and out of the connector member, dirt may be drawn into the interior connector/lock member surface interface area and substantially degrade the seal carried by the lock member. Further, with the lock member maintained in its unlocking position for extended periods of time (for example when the overall connector structure is being stored prior to use), an elastomeric portion of the lock member detent portion is maintained in compression and can obtain an undesirable compression set. 
     It can be seen from the foregoing that it would be desirable to provide improved excavating tooth connector apparatus that eliminates or at least substantially reduces the above-mentioned problems, limitations and disadvantages associated with conventional excavating tooth and other material displacement equipment connector apparatus of the general type described above. 
     SUMMARY OF THE INVENTION 
     In carrying out principles of the present invention, in accordance with a representatively illustrated embodiment thereof, a specially designed connector assembly is used to releasably retain an excavating wear member, representatively a replaceable tooth point, on a support structure, representatively an adapter nose. 
     The connector assembly, in the representatively illustrated embodiment thereof, includes (1) an elongated flat connector member extending along a longitudinal axis and having a flat exterior side peripheral portion extending between opposite first and second ends and circumscribing the longitudinal axis in a parallel relationship therewith, and (2) a locking member rotatable received in the first connector member end and being rotatable between locking and unlocking positions in which a locking tab portion of the locking member respectively projects laterally outwardly beyond the connector member side surface periphery, and an unlocking position in which the locking tab does not project laterally outwardly beyond the connector member side surface periphery. 
     A detent structure within the interior of the connector member releasably retains the locking member in either selected one of its locking and unlocking positions. The locking member has no resilient force exerted thereon parallel to the length of the connector member in either of the locking and unlocking positions of the lock member, and the detent structure substantially prevents any appreciable relative movement of the lock member and the connector member parallel to the longitudinal axis of the connector member when the lock member is in either of its locking and unlocking positions. The detent structure representatively includes a rigid detent member carried by the lock member and having an associate resilient portion, and first and second circumferentially spaced detent openings disposed within the connector member interior for respectively receiving the detent member when the lock member is in its locking and unlocking positions. The resilient portion of the detent structure is in an essentially relaxed state when the lock member is in either of its locking and unlocking positions. 
     With the tooth point telescoped onto the adapter nose, side wall connector openings in the tooth point aligned with a connector opening transversely extending through the adapter nose, and the lock member in its unlocking position, the connector assembly is inserted into the connector openings until the opposite ends of the connector member are disposed in the opposite tooth point connector openings to thereby block forward removal of the tooth point from the adapter nose. The locking member is then rotated to its locking position. After this is done, abutment surface areas within the interior of the tooth point/adapter assembly prevent the installed connector assembly from moving outwardly through either tooth point connector opening. Representatively, these abutment surface areas include (1) a first abutment surface defined in an interior side surface recess of a first one of the two tooth point side wall connector openings into which the locking tab is moved when rotated to its locking position, the first abutment surface blocking the locking tab, and thus the entire connector assembly, from moving outwardly through the first tooth point connector opening, and (2) a second abutment surface formed on a side wall portion of the tooth point which extends into the second tooth point connector opening, reduces its cross-sectional area relative to that of the first tooth point connector opening, and blocks the installed connector assembly from moving outwardly through the second tooth point side wall connector opening. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a longitudinally foreshortened, horizontally directed cross-sectional view, partly in elevation, through an excavating tooth point/adapter assembly incorporating therein a specially designed rotatably locking connector structure embodying principles of the present invention; 
     FIG. 2 is a cross-sectional view, partly in elevation, through the assembly taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a top end elevational view of the connector structure with a rotatable locking portion thereof being in its locking position shown in FIG. 2; 
     FIG. 4 is a top end elevational view of the connector structure with its rotatable locking portion in its unlocking position; and 
     FIG. 5 is an enlarged scale schematic partial cross-sectional view through the connector structure taken along line  5 — 5  of FIG.  2 . 
    
    
     DETAILED DESCRIPTION 
     As cross-sectionally illustrated in longitudinally foreshortened form in FIGS. 1 and 2, in an illustrated embodiment thereof, this invention provides an excavating tooth point/adapter assembly  10  that includes a wear member in the form of an elongated hollow replaceable tooth point  12  extending in a front-to-rear direction along a longitudinal axis  14  and having front and rear portions  16  and  18 ; a support structure in the form of an adapter  20  having a base portion  22  from which a smaller cross-section nose portion  24  forwardly projects; and a specially designed rotatably lockable connector assembly  26  used to releasably retain the tooth point  12  on the adapter nose  24  as subsequently described herein. 
     Representatively, the tooth point  12  and adapter  20  have configurations similar to the tooth point and associated adapter illustrated and described in copending U.S. application Ser. No. 09/843,681 (now U.S. Pat. No. 6,564,482) filed on Apr. 27, 2001 and assigned to the same assignee as the assignee of the present invention. However, the tooth point  12  and the adapter  20  could have a wide variety of alternate shapes without departing from principles of the present invention. Additionally, while the present invention is illustrated and described herein as being used in conjunction with an adapter as a representative support structure and a tooth point as a representative wear member carried by the support structure, it will be readily appreciated by those of ordinary skill in this particular art that different types of support structures and associated wear members could be utilized without departing from principles of the present invention. As an example, but not by way of limitation, the adapter  20  could an intermediate adapter connected at its rear end to a base adapter, and the tooth point  12  could be an intermediate adapter having a front end portion on which a replaceable tooth point was installed. 
     Referring now to FIGS. 1 and 2, the tooth point  12  has a concavely curved rear end surface portion  28  through which a pocket  30  forwardly extends into the interior of the tooth point  12 . As can best be seen in FIG. 1, from its forward entrance into the tooth point  12  through the curved rear end surface portion  28 , the pocket  30  tapers forwardly and vertically inwardly and has a reduced cross-section stabilizing front end portion with generally horizontal opposite top and bottom side surface portions  32  and  34 . 
     Pocket  30  defines on the tooth point  12  a pair of opposite top and bottom side walls  36  and  38 , and a pair of opposite vertical side walls  40  and  42  which rearwardly terminate at the curved rear end surface  28  of the tooth point  12 . Rearwardly and vertically divergent rear end portions  36   a  and  38   a  of the top and bottom tooth point walls  36 , 38  extend rearwardly past the curved rear tooth point end surface  28 . Aligned connector openings  44 , 46  respectively extend inwardly through the vertical tooth point side walls  40  and  42  into the pocket  30  and are spaced apart along an axis  48  transverse to the axis  14 . As best illustrated in FIG. 2, a portion  42   a  of the side wall  42  extends rearwardly across the connector opening  46  in a manner reducing its cross-sectional area compared to that of the other connector opening  44 . 
     For purposes later described herein, side wall portion  42   a  (see FIG. 2) has an inner side recess which defines on the side wall portion  42   a  an inner side abutment surface  50  transverse to the axis  48  and facing the pocket area  30 . Additionally, as also shown in FIG. 2, the inner side surface of the side wall opening  44  has a circumferentially extending recess  52  formed therein inwardly of the outer side surface of the side wall  40 . Recess  52  opens inwardly into the pocket  30  and has (at its top side as viewed in FIG. 2) an abutment surface  54  transverse to the axis  48 . 
     The adapter nose  24  is complementarily and removably received in the tooth point pocket  30  and has a connector opening  56  extending therethrough parallel to the axis  48  and aligned with the tooth point connector openings  44 , 46 . Adapter base  22  has a convexly curved front surface  58  which circumscribes the rear end of the adapter nose  24  and is complementarily and slidably engageable by the concave rear end surface portion  28  of the tooth point  12 . With the adapter nose  24  removably received in the tooth point pocket  30  as illustrated in FIGS. 1 and 2, the rear end portions  36   a , 38   a  of the tooth point  12  protectively overlie top and bottom side surface portions of the adapter base  22 . 
     With reference now to FIGS. 1-4, the connector assembly  26  includes an elongated flat connector member  60  and a locking member  62 . Connector member  60  has opposite ends  64  and  66 , a tapered cross-section along its length which is elongated in a direction parallel to the axis  14 , opposite front and rear longitudinal side edges  68  and  70 , and corner recess areas extending laterally inwardly from the side edges  68  and  70  and defining in opposite end corner portions of the connector member  60  longitudinally inset end surfaces  72  and  74 . The outer longitudinally extending peripheral side surface  76  of the flat connector member  60  circumscribes the longitudinal axis of the connector member and is parallel thereto as opposed to being tapered with respect thereto. 
     A circular bore or opening  78  extends longitudinally inwardly through the inset end surface  72  of the connector member  60  and has a detent recess area formed in its interior side surface. Preferably, as best illustrated in FIG. 5, this detent recess area comprises two detent recesses  80 , 82  circumferentially separated by ninety degrees and longitudinally aligned within the opening  78 . 
     The lock member  62  has an elongated cylindrical body  84  a lower longitudinal portion of which (as viewed in FIG. 2) is coaxially and rotatably received within the connector member opening  78 , with an upper end portion of the body  84  projecting outwardly from the inset connector member end surface portion  72 . A transverse locking tab  86  is anchored to the exposed upper end of the lock member body  84 , and a lower end portion of the body  84  within the opening  78  has a lateral detent recess  88  extending radially inwardly through its outer side surface. As schematically depicted in cross-sectional form in FIG. 5, a detent structure  90  is received in the detent recess  88  and representatively comprises a radially outer metal detent member  92  secured to an elastomeric, radially inner detent portion  94 . The detent member  92  is resiliently biased to project outwardly from the recess  88 , but may be radially forced into recess  88  against the resilient resistance of the elastomeric portion  94 . 
     A noncircular driving structure  96  (for example, a hex or square head portion) projects upwardly from the locking tab  86  and may be engaged by a suitable driving tool (not shown) used to forcibly rotate the locking member  62  between (1) a locking position in which the locking tab  86  projects laterally outwardly beyond the outer peripheral side surface  76  of the connector member  60  as shown in FIGS. 1-3, and (2) an unlocking position in which the locking tab  86  does not project laterally outwardly beyond the outer peripheral side surface  76  of the connector member  60  as illustrated in FIG.  4 . The driving structure  96  could, of course, have a variety of alternate configurations, such as a noncircular recessed portion, a slotted area, or the like, if desired. 
     With the lock member  62  rotated to its locking position the detent member  92  snaps into the internal connector member detent recess  80  to thereby bring the elastomeric detent portion  94  to an essentially relaxed orientation and releasably retain the lock member  62  in its locking position. As the lock member  62  is subsequently being rotated from its locking position to its unlocking position, the detent member  92  is depressed into the lock member detent recess  88  and then snaps outwardly into the internal connector member detent recess  82  to thereby bring the elastomeric detent portion  94  back to an essentially relaxed state and releasably retain the lock member  62  in its unlocking position. 
     The same movement of the detent member  92 , of course, when the lock member  62  is subsequently rotated back to its locking position from its unlocking position. An annular resilient seal member  98  (see FIG. 2) is supported on and coaxially circumscribes the lock member body  84 , between the locking tab  86  and the lock member detent recess  88 , and slidingly engages the interior side surface of the connector member opening  78  to inhibit the entry of dirt and other abrasive material into the interior of the connector member  60  during use of the tooth adapter assembly  10 . 
     As can best be seen in FIG. 2, the vertical heights of the interior connector member detent recesses  80 , 82  (as viewed in FIG. 2) are substantially identical to the height of the detent member  92 . Accordingly, the interaction between the detent member  92  and these detent recesses  80 , 82  substantially prevents relative longitudinal movement between the connector member  60  and the lock member  62  when the locking member  62  is in either of its locking and unlocking positions. 
     With the tooth point  12  rearwardly telescoped onto the adapter nose  24  as illustrated in FIG. 2, the connector assembly  26  is operatively Installed by first rotating its lock member  62  to its unlocking position and then inserting the connector assembly  26 , connector end  66  first, downwardly (as viewed in FIG. 2) through the aligned connector openings  44 , 56 , 46 , with the front edge  68  of the connector member  60  facing forwardly, so that the connector member  60  is complementarily received in the nose connector opening  56 , and the connector member end abutment surface  74  contacts the tooth point abutment surface  50 . In this inserted orientation of the connector assembly  26 , the opposite ends  64 , 66  of the connector member  60  respectively extend into the tooth point connector openings  44 , 46  to thereby block forward removal of the installed tooth point  12  from the adapter nose  24 . 
     The inserted connector assembly  26  is then releasably locked in this blocking orientation by simply rotating the lock member  62  from its unlocking position to its locking position to cause the locking tab  86  to enter the tooth point recess  62  and face outwardly face its associated abutment surface  54  as may be best seen in FIG.  2 . Thus, the cooperating abutment surfaces  50 , 74  adjacent the connector member end  66  preclude the connector assembly  26  from passing outwardly through the tooth point connector opening  46 , and the cooperating abutment surfaces  54 , 72  prevent the connector assembly from passing outwardly through the tooth point connector opening  44 . 
     The representatively illustrated abutment surface configuration within the interior of the tooth poinvadapter assembly  10 , namely the abutment surface sets  50 , 74  and  54 , 72 , may be altered in a variety of manners without departing from the principles of the present invention. For example, but not by way of limitation, the tooth point abutment surface  50  could be relocated to within the adapter nose  24  (and the corresponding connector member abutment surface accordingly relocated to face this adapter nose abutment surface). As another example, but also not by way of limitation, the lower abutment surface set  50 , 74  (as viewed in FIG. 2) could be eliminated, and the tooth point recess  52  modified to have two facing abutment surfaces which face the opposite sides of the locking tab  86  in its locking position and serve to prevent the connector assembly  26  from longitudinally moving outwardly through either of the tooth point connector openings  44 , 46 . 
     Because the outer peripheral side surface  76  of the connector member  60  is parallel to the axis  48 , operating loads on the tooth point/adapter assembly  10  do not impose appreciable longitudinally directed loads on the connector member  60  which might tend to expel it from the connector openings  44 , 46 , 56  and exert substantial forces on the lock member  62 . Moreover, the connector assembly  26  may be installed without the need to pound it into the connector openings. Because of this, two or more of the assemblies  10  may be placed closer together due to the lack of required pounding room. Also, because the detent structure in the connector assembly  26  substantially prevents relative longitudinal movement between the connector member  60  and the lock member  62  during use of the tooth/adapter assembly  10 , entry of dirt and other abrasive material into the interior of the connector member  60 , and associated degradation of the interior resilient seal member  98 , is substantially reduced. Additionally, because the resilient portion of the lock member detent structure is in an essentially relaxed state in the lock member&#39;s unlocking position, undesirable “compression set” in this resilient detent portion resulting from lengthy storage periods of the connector assembly with the lock member in its unlocking position is substantially eliminated 
     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.