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The present application is a continuation of U.S. patent application Ser. No. 11/705,637 filed Feb. 12, 2007, now U.S. Pat. No. 7,832,129, which is a continuation of U.S. patent application Ser. No. 10/824,490 filed Apr. 15, 2004, now U.S. Pat. No. 7,174,661, which is a continuation-in-part of U.S. patent application Ser. No. 10/425,934 filed Apr. 30, 2003, now U.S. Pat. No. 7,171,771. 
    
    
     FIELD OF THE INVENTION 
     The present invention pertains to a coupling assembly for releasably securing separable parts together, and especially for securing together components of a wear assembly used in excavating or the like. 
     BACKGROUND OF THE INVENTION 
     Excavating equipment typically includes various wear parts to protect underlying-products from premature wear. The wear part may simply function as a protector (e.g., a wear cap) or may have additional functions (e.g., an excavating tooth). In either case, it is desirable for the wear part to be securely held to the excavating equipment to prevent loss during use, and yet be capable of being removed and installed to facilitate replacement when worn. In order to minimize equipment downtime, it is desirable for the worn wear part to be capable of being easily and quickly replaced in the field. Wear parts are usually formed of three (or more) components in an effort to minimize the amount of material that must be replaced on account of wearing. As a result, the wear part generally includes a support structure that is fixed to the excavating equipment, a wear member that mounts to the support structure, and a lock to hold the wear member to the support structure. 
     As one example, an excavating tooth usually includes an adapter as the support structure, a tooth point or tip as the wear member, and a lock or retainer to hold the point to the adapter. The adapter is fixed to the front digging edge of an excavating bucket and includes a nose that projects forward to define a mount for the point. The adapter may be a single unitary member or may be composed of a plurality of components assembled together. The point includes a front digging end and a rearwardly opening socket that receives the adapter nose. The lock is inserted into the assembly to releasably hold the point to the adapter. 
     The lock for an excavating tooth is typically an elongate pin member which is fit into an opening defined cooperatively by both the adapter and the point. The opening may be defined along the side of the adapter nose, as in U.S. Pat. No. 5,469,648, or through the nose, as in U.S. Pat. No. 5,068,986. In either case, the lock is inserted and removed by the use of a large hammer. Such hammering of the lock is an arduous task and imposes a risk of harm to the operator. 
     The lock is usually tightly received in the passage in an effort to prevent ejection of the lock and the concomitant loss of the point during use. The tight fit may be effected by partially unaligned holes in the point and adapter that define the opening for the lock, the inclusion of a rubber insert in the opening, and/or close dimensioning between the lock and the opening. However, as can be appreciated, an increase in the tightness in which the lock is received in the opening further exacerbates the difficulty and risk attendant with hammering the locks into and out of the assemblies. 
     The lock additionally often lacks the ability to provide substantial tightening of the point onto the adapter. While a rubber insert will provide some tightening effect on the tooth at rest, the insert lacks the strength needed to provide any real tightening when under load during use. Most locks also fail to provide any ability to be re-tightened as the parts become worn. Moreover, many locks used in teeth are susceptible to being lost as the parts wear and the tightness decreases. 
     These difficulties are not limited strictly to the use of locks in excavating teeth, but also apply to the use of other wear parts used in excavating operations. In another example, the adapter is a wear member that is fit onto a lip of an excavating bucket, which defines the support structure. While the point experiences the most wear in a tooth, the adapter will also wear and in time need to be replaced. To accommodate replacement in the field, the adapters can be mechanically attached to the bucket. One common approach is to use a Whisler style adapter, such as disclosed in U.S. Pat. No. 3,121,289. In this case, the adapter is formed with bifurcated legs that straddle the bucket lip. The adapter legs and the bucket lip are formed with openings that are aligned for receiving the lock. The lock in this environment comprises a generally C-shaped spool and a wedge. The arms of the spool overlie the rear end of the adapter legs. The outer surfaces of the legs and the inner surfaces of the arms are each inclined rearward and away from the lip. The wedge is then ordinarily hammered into the opening to force the spool rearward. This rearward movement of the spool causes the arms to tightly pinch the adapter legs against the lip to prevent movement or release of the adapter during use. As with the mounting of the points, hammering of the wedges into the openings is a difficult and potentially hazardous activity. 
     In many assemblies, other factors can further increase the difficulty of removing and inserting the lock when replacement of the wear member is needed. For example, the closeness of adjacent components, such as in laterally inserted locks (see, e.g., U.S. Pat. No. 4,326,348), can create difficulties in hammering the lock into and out of the assembly. Fines can also become impacted in the openings receiving the locks making access to and removal of the locks difficult. Additionally, in Whisler style attachments, the bucket must generally be turned up on its front end to provide access for driving the wedges out of the assembly. This orientation of the bucket can make lock removal difficult and hazardous as the worker must access the opening from beneath the bucket and drive the wedge upward with a large hammer. The risk is particularly evident in connection with dragline buckets, which can be very large. Also, because wedges can eject during service, it is common practice in many installations to tack-weld the wedge to its accompanying spool, thus, making wedge removal even more difficult. 
     There has been some effort to produce non-hammered locks for use in excavating equipment. For instance, U.S. Pat. Nos. 5,784,813 and 5,868,518 disclose screw driven wedge-type locks for securing a point to an adapter and U.S. Pat. No. 4,433,496 discloses a screw-driven wedge for securing an adapter to a bucket. While these devices eliminate the need for hammering, they each require a number of parts, thus, increasing the complexity and cost of the locks. The ingress of fines can also make removal difficult as the fines increase friction and interfere with the threaded connections. Moreover, with the use of a standard bolt, the fines can build up and become “cemented” around the threads to make turning of the bolt and release of the parts extremely difficult. 
     SUMMARY OF THE INVENTION 
     The present invention pertains to an improved coupling assembly for releasably holding separable parts together in a secure, easy, and reliable manner. Further, the lock of the present invention can be installed and removed simply by using a manual or powered wrench. The need to hammer or pry the lock into and out of the assembly is eliminated. 
     The present invention is particularly useful for securing a wear member to a support structure in conjunction with an excavating operation. The lock of the present invention is easy to use, is securely held in the wear assembly, alleviates the risk associated with hammering a lock into and out of a wear assembly, and operates to effectively tighten the wear member onto the support structure. 
     In one aspect of the invention, a tapered lock member is formed with a threaded formation that is used to pull the lock member into a locking position in the assembly. The lock member, then, bears against the assembly to hold the components of the assembly together. The use of a threaded formation on the lock member also reduces the risk that the lock member will be ejected during use as compared to a lock that is simply hammered into place. 
     In another aspect of the present invention, a wedge and a spool are threadedly coupled together to drive the wedge into and out of the wear assembly without hammering. The direct coupling of the wedge and spool eliminates the need for bolts, washers, nuts and other hardware so as to minimize the number of parts. As a result of this efficient construction, the lock is inexpensive to make, easy to use, and unlikely to become inoperative because of lost or broken parts or due to fines or other difficulties encountered in harsh digging environments. Further, the wedge can be selectively driven into the assembly to provide the degree of tightness necessary for the intended operation and/or to re-tighten the assembly after incurring wear during use. 
     In one preferred construction, the wedge includes a thread formation with a wide pitch to form a sizable land segment by which the wedge can directly apply pressure to the wear assembly for holding the wear member to the support structure. In one embodiment, the wedge is formed with a helical groove along its outer periphery to engage helical ridge segments formed in a generally trough shaped recess along the spool or other part of the assembly. Rotation of the wedge moves the wedge along the spool, and into and out of the wear assembly. Movement of the wedge into the assembly increases the depth of the lock, and thereby tightens the engagement of the wear member onto the support structure. 
     A latch assembly is preferably provided to securely hold the wedge in place and avoid an undesired loss of parts during use. In one preferred construction, the wedge is formed with teeth that interact with a latch provided in an adjacent component such as the spool, wear member or support structure. The teeth and latch are formed to permit rotation of the wedge in a direction that drives the wedge farther into the opening, and to prevent rotation in a direction that retracts the wedge. The latch may also function to retain the lock in the assembly when the wear member and/or support structures begin to wear. 
     The inventive lock is simple, sound, reliable, and requires only minimal components. The lock is also intuitively easy for the operator to understand. Elimination of hammering also makes replacement of a wear member easy and less hazardous. Moreover, the lock is able to provide selective tightening of the wear assembly to facilitate re-tightening of the wear members or a better original mounting when, for example, the support structure is partially worn. These and other advantageous will be evident in the drawings and description to follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a coupling assembly in accordance with the present invention securing a point to an adapter. 
         FIG. 2  is a side view of a lock in accordance with the present invention. 
         FIG. 3  is a perspective view of a wedge of the lock. 
         FIG. 4  is an enlarged, partial, perspective view of the wedge. 
         FIG. 5  is a perspective view of a spool of the lock. 
         FIG. 6  is a perspective view of a wear member having a latch of the inventive coupling assembly. 
         FIG. 7  is a partial, exploded, perspective view of the wear member shown in  FIG. 6 . 
         FIG. 8  is a cross-sectional view of the coupling assembly taken along line  8 - 8  in  FIG. 1  in the assembled condition. 
         FIG. 9  is a perspective view of an alternative spool for the lock. 
         FIG. 10  is an exploded, perspective view of the alternative spool. 
         FIG. 11  is a side view of a second lock in accordance with the present invention including the alternative spool. This lock is adapted to secure an adapter to a bucket lip in a Whisler style connection. 
         FIG. 12  is a cross-sectional view along a longitudinal axis of another wear assembly using the lock of  FIG. 11 . 
         FIG. 13  is a cross-sectional view along the same line as  FIG. 12  for an alternative embodiment including an insert between the wedge and support structure. 
         FIG. 14  is a perspective view of the insert used in the alternative embodiment of  FIG. 13 . 
         FIG. 15  is a perspective view of an alternative wedge construction. 
         FIG. 16  is a perspective view of another alternative wedge construction. 
         FIG. 17  is a cross-sectional view along the same line as  FIG. 12  for an alternative embodiment. 
         FIG. 18  is a cross-sectional view along the same line as  FIG. 12  for another alternative embodiment. 
         FIG. 18   a  is a cross-sectional view illustrating shifting of the wear member on a lock without a cradle. 
         FIG. 18   b  is a cross-sectional view illustrating shifting of the wear member on a lock with cradle. 
         FIG. 19  is a perspective view of a cradle used in the alternative embodiment shown in  FIG. 18  with the wear member omitted. 
         FIG. 20  is a cross-sectional view along the same line as  FIG. 12  for another alternative embodiment. 
         FIG. 21  is a cross-sectional view along the same line as  FIG. 12  for another alternative embodiment. 
         FIG. 22  is a cross-sectional view along the same line as  FIG. 12  for another alternative embodiment. 
         FIG. 23  is an perspective view of another alternative embodiment wherein the wear member is partially fit onto a lip. 
         FIG. 24  is a side view of the embodiment of  FIG. 23  in the same orientation. 
         FIG. 25  is a partial cross-sectional view of the fit of the wear member in  FIG. 23  with the hole in the lip when fully fit on the lip. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention pertains to a coupling assembly for releasably holding separable parts together. While the invention has a broader application, it is particularly useful in releasably securing a wear member to a support structure in an excavating operation. The wear member may, for example, be a point, an adapter, a shroud or other replaceable component. 
     In one preferred construction, the lock  10  includes a wedge  12  and a spool  14  ( FIGS. 2-5 ). Although the lock can be used to secure a wide range of components together, it is shown in  FIG. 1  holding together the parts of an excavator tooth. In this embodiment of the invention, the lock is placed in a wear assembly  15  wherein the support structure is formed as an adapter  17  and the wear member is defined as a point or tip  19 . Lock  10  is received into an opening  21  in wear assembly  15  that is cooperatively defined by holes  23  in point  19  and hole  25  in adapter  17  so as to releasably hold the point to the adapter ( FIGS. 1 and 8 ). Holes  23  and  25  are each preferably elongated longitudinally to prevent misalignment of the wedge and spool, although the holes could be circular or have other shapes. 
     The wedge  12  preferably has a frusto-conical shape with a rounded exterior surface  16  that tapers toward a front end  18  ( FIGS. 1-4 ). A thread formation  22 , preferably in the form of a helical groove  20  with a wide pitch, is formed along the exterior surface  16  of the wedge. Accordingly, a rather wide, helically shaped land segment  24  exists between the adjacent spiraling groove segments. This land segment presents a large surface area to press against the front surface  31  of the hole  25  in adapter  17  and the wall  37  of recess  36  in spool  14 . The relatively large land segment enables the lock to resist large loads with acceptable levels of stress and without the need for threads to be formed in the wall of hole  25  in the adapter. The wide pitch of the groove  20  also permits the wedge to be quickly moved into and out of the opening  21 . 
     In one preferred construction, the pitch of the thread on the wedge is on the order of one inch and the groove forming the thread about ⅛ of an inch wide, although the pitch and groove width could vary widely. The groove is preferably formed with curved corners to form a robust thread that is not susceptible to peening or other damage. The rear end  27  of the wedge is provided with a turning formation  29  to facilitate engagement with a tool, such as a wrench, for turning the wedge. In the preferred embodiment, formation  29  is a square socket, although other arrangements could be used. 
     The taper of the wedge can be varied to provide an increased or decreased take-up of the wear member on the support structure. For example, if the taper of the wedge is increased, the rate at which the wear member moves to the set position on the support structure is increased, but at the expense of tightening force (i.e., more torque is required to turn the wedge). The taper of the wedge can be designed to match the particular task. In all cases the holding power of the lock would be about the same so long as the wedge is not formed too small at the forward end to provide sufficient strength. 
     The spool  14  preferably has a generally C-shaped configuration with a body  26  and arms  28  ( FIGS. 1 ,  2  and  5 ). In this example, the arms are fairly short so as to press against the rear wall portions  30  of holes  23  in point  19  ( FIG. 8 ). However, the particular shape and size of the arms can vary widely depending on the construction and use of the parts receiving the lock. Additionally, the arms could be omitted entirely if the opening in the support structure were sized to permit the rear wall of the body to press against the rear wall portions in the openings of the wear member and the spool was adequately anchored. Similarly, in this type of construction, the lock could be reversed such that the wedge pressed against the wear member and the spool against the support structure. 
     The body  26  of spool  14  is formed with a generally trough shaped recess  36  to receive a portion of the wedge ( FIG. 5 ). The recess is provided with a thread formation  42  that is defined as at least one projection to fit within groove  20 . In this way, the wedge and spool are threadedly coupled together. Although the projection can take the form of a wide range of shapes and sizes, recess  36  preferably includes multiple ridges  40  on the spool to complement groove  20  on wedge  12 . The ridges  40  are shaped as helical segments having the same pitch as the helical groove  20  so that the ridges are received into the groove to move the wedge in or out of the opening when the wedge is rotated. While ridges  40  are preferably provided along the entire length of recess  36 , fewer ridges or even one ridge could be provided if desired. Further, each ridge preferably extends across the entire recess  36 , but can have a lesser extension if desired. 
     In the preferred construction, the helical groove  20  has the same pitch along the length of the wedge. Since the wedge is tapered, the angle of the thread changes to become more shallow as the groove extends from the forward end  18  to the rear end  27 . This variation requires the allowance of clearance space between the internal and external thread so they can cooperate and avoid binding with each other. This construction, then, forms relative loose fitting threads. 
     As an alternative construction, a ridge(s) to engage groove  20  on the wedge could be formed on the front wall portion of the hole  23  defined in point  19  in addition to or in lieu of the ridges  40  on the spool. The ridge could simply be provided by the body  62 , as seen in  FIGS. 6 and 7 , but could also include an extension and/or other ridges on the front wall portion of the hole, similar to the inclusion of body  62   a  in spool  14   a  (as seen in  FIGS. 9 and 10 ). Similarly, one or more ridges (or other projections) to engage groove  20  could instead be formed on the wall structure of the hole  25  in adapter  17  (in addition to or in lieu of the other ridges). In these alternatives where a thread formation is formed on the point and/or adapter, the wedge could be inserted into the opening without a spool to hold the wear member to the support structure. As can be appreciated, the hole in the point would need to be smaller to permit direct bearing contact between the wedge and the rear wall portions of the holes in the point or the ridge provided on the rear wall of the opening. 
     The thread formations may also be reversed so that grooves are formed in the point, adapter and/or spool to receive a helical ridge formed on the wedge. While a ridge may be used to form the thread on the wedge with grooves only in the spool and not in the adapter wall (or vice versa), the ridges do not form as good a bearing surface as land segment  24  without the matching grooves in the opposing surfaces. Nevertheless, a helical ridge on the wedge may be used even with a smooth adapter wall and/or smooth recess in the spool in lower stress environments. In this alternative, the wedge  94  would preferably have a ridge  96  with a blunt outer edge  98  ( FIG. 15 ). Nevertheless, the provision of a ridge on the wedge could be designed to bite into the adapter wall and/or spool. Finally, the wedge  101  could be formed with a tapping ridge  103  that cuts a thread in the spool and/or adapter wall as it is threaded into the assembly ( FIG. 16 ). 
     Recess  36  in spool  14  preferably tapers toward one end  38  to complement the shape of the wedge and position forward portions of the land segment  24  bearing against the adapter to be generally vertical for a solid, secure contact with the nose of adapter  17  ( FIGS. 5 and 8 ). This orientation stabilizes the wedge and lessens the stresses engendered in the components when the wedge is inserted tightly into the wear assembly  15 . In a preferred construction, the recess is tapered at twice the taper of the wedge so as to place forward portions of the land segment  24  in a vertical orientation (as illustrated). As can be appreciated, the purpose of this construction is to orient the forward portions of the land segment substantially parallel to the wall of the member which they engage as opposed being in a strictly vertical orientation. In the preferred construction, recess  36  is provided with a concave curve that is designed to complement the shape of the wedge when the wedge is at the end of its projected travel in a tightening direction. In this way, the wedge is best able to resist the applied loads and not bind with the spool during tightening. Nevertheless, other shapes are possible. 
     In use, lock  10  is inserted into opening  21  in the wear assembly  15  when the wear member  19  is mounted on the nose  46  of adapter  17  ( FIGS. 1 and 8 ). The lock  10  is preferably placed into opening  21  as separate components (i.e., with the spool being inserted first) but may in some cases be inserted collectively as a unit (i.e., with the wedge placed partially into the recess  36 ). In either case, the free ends  50  of arms  28  are placed in engagement with the rear wall portions  30  of holes  23  in wear member  19 . The wedge is then rotated to drive it into opening  21  so that the forward portions of land segment  24  of wedge  12  press against the front wall portion  31  of hole  25 , and arms  28  of spool  14  press on the rear wall portions  30  of holes  23 . Continued rotation of the wedge further enlarges the depth of the lock (i.e., the distance in a direction parallel to the axis of the movement of the point onto the adapter nose) so that the arms  28  push the wear member  19  farther onto the support structure  17 . This rotation is stopped once the desired tightness has been achieved. By using a tapered wedge in the lock receiving opening  21 , a significant clearance exists between much of the wedge and the walls of the opening. As a result, fines from the digging operation would generally not become firmly impacted into the opening. Even if fines did become impacted in the opening, the wedge would still be easily retracted by turning the wedge with a wrench. The tapered shape of the wedge makes the opening around the lock larger at the bottom of the assembly in the illustrated orientation. With this arrangement, the fines tend to fall out as the wedge is loosened. The relatively wide groove in the wedge in the preferred construction also tends to enable release of fines from the lock and thereby avoid having the lock becoming “cemented” into the assembly. Moreover, because of the tapered shape of the threaded wedge, the assembly is quickly loosened with just a short turn of the wedge. Rubber caps or the like (not shown) could be used to inhibit the ingress of fines in socket  29  if desired. 
     In a preferred construction, a latching assembly  56  is provided to retain the wedge in the opening. As seen in  FIGS. 2-4  and  8 , ratchet teeth  58  are preferably provided within groove  20  to cooperate with a latch  60 . By being recessed within the groove, the teeth do not disrupt the threaded coupling of the wedge and the spool, or the engagement of the wedge with support structure  17  and spool  14 . The ratchet teeth are adapted to engage latch  60 , which is mounted in either the wear member  19  ( FIGS. 6-8 ), spool  14  ( FIGS. 10 and 12 ) or support structure  17  (not shown). The teeth are inclined to permit rotation of the wedge in a tightening direction but prevent rotation in a loosening direction. The teeth generally need to be only formed along about one third the length of groove  20  to ensure engagement of the latch with the teeth when the wedge is fully tightened for use. Of course, the teeth could be positioned along more or less than about one-third the length of the groove as desired. The number of teeth and their location on the wedge depend largely on the amount of travel expected between the parts being coupled together, and the expected wear of the components and retightening of the lock. The teeth will preferably be positioned along the rear end of the wedge, i.e., where the wedge is widest, so that the latch  60  is securely engaged against the teeth and stress in the wedge is minimized. Nevertheless, other arrangements are possible. The teeth may have a reversible style that inhibits unwanted turning in both directions, but which will permit turning under the force of a wrench or the like—i.e., the detent can retract under sufficient load to permit rotation of the wedge in the tightening or untightening directions. Further, omission of the teeth is possible. Another alternative is to design latch  60  to apply a force on the wedge to frictionally inhibit inadvertent turning of the wedge during use. 
     Latch  60  preferably comprises a body  62  and a resilient member  63  that are fit within a cavity  64  that is open in one of the holes  23  ( FIGS. 6 and 7 ). The body is provided with a detent  65  to engage ratchet teeth  58  on the wedge  12 . The resilient member presses the detent  65  into engagement with the ratchet teeth and permits the body to retract into the cavity as the wider portions of the wedge are driven into opening  21 . In the preferred construction, body  62  includes a helical ridge  66  that complements ridges  40  on spool  14 , i.e., the ridge has the same pitch and is positioned to match the trajectory of ridges  40 . Since the spool is placed into opening  21  by the operator, cavity  64  may receive body  62  with clearance to enable the body to shift as needed to ensure that ridge  66  complements ridges  40 . The clearance need not be great (e.g., on the order of 0.03 of an inch in larger systems) because the spool has only a small range of adjustment where it can be properly positioned with the arms against the walls defining holes  23 . Additionally, groove  20  could be formed with a narrowing width as it extends from front end  18  of wedge  12  toward rear end  27 . In this way, the groove could become easily engaged with ridges  40  on spool  14  and ridge  66  on body  62 , even if initially misaligned, and gradually shift body  62  into alignment with ridge  40  as the groove narrows. The body  62  is preferably bonded to resilient member  63  by an adhesive (or via casting), which in turn, is bonded in cavity  64  by an adhesive. Nevertheless, the body and resilient member could be held in cavity  64  by friction or other means. The body is preferably composed of plastic, steel or any other material that provides the requisite force to hold the wedge from turning during operation of the excavator and the resilient member of rubber, although other materials could be used. 
     In use, ridge  66  is received into groove  20 . As the wedge reaches a tightened position, detent  65  engages teeth  58 . However, due to the inclination of the teeth and the provision of resilient member  63 , the latch rides over the teeth as the wedge is rotated in the tightening direction. The detent  65  locks with teeth  58  to prevent any reverse rotation of the wedge. The detent is designed to be broken from body  62  when the wedge is turned in the release direction with a wrench. The force to break the detent is within normal forces expected to be applied by a wrench but still substantially more torque than would be expected to be applied to the wedge through normal use of the excavating tooth. Alternatively, a slot or other means could be provided to permit retraction of the latch and disengagement of the detent from the teeth for reverse rotation of the wedge. Receipt of the ridge  66  and ridges  40  in groove  20  function to retain the wedge in opening  21  even after looseness develops in the tooth on account of wearing of the surfaces. 
     Alternatively, the latch  60  could be positioned within a cavity formed along the front wall portion  51  of hole  25  in adapter  17 . The latch would function in the same way as described above when mounted in point  19 . In addition, an insert (not shown) could be positioned between wedge  12  and front wall portion  51  of hole  25  if desired. The insert may include a recess with ridges like recess  36  in spool  14  or simply have a smooth recess to receive the wedge. The insert could be used to fill the space of a large opening in the adapter (or other support structure) or to accommodate a wedge formed with threads having a smaller pitch for greater mechanical advantage or other reasons, and still provide a large surface area with which to bear against the adapter. Further, the front surface of the insert may be formed to mate with the front wall portion  51  of hole  25  to increase the bearing area between the adapter and the lock, and thereby reduce the induced stresses in the parts. A latch or the like may also be used to retain the insert in place. A latch, like latch  60 , could also be provided in the insert. 
     In an alternative embodiment ( FIGS. 9 and 10 ), lock  10   a  has the latch  60   a  mounted in a cavity  64   a  formed in recess  36   a  of spool  14   a . In the same way as latch  60 , latch  60   a  preferably includes a body with a helical ridge  66   a  and detent  65   a , and a resilient member  63   a . Latch  60   a  would operate in the same way as discussed above for latch  60 . The teeth  58  on the wedge would be formed in the same way, irrespective of whether the latch is mounted in the spool, the wear member or the support structure. As seen in  FIG. 9 , ridge  66   a  would be positioned as a continuation of one of the ridges  40 . Although latch  60  is shown aligned with the ridge  40  closest to rear end  27  of the wedge, the latch could be formed anywhere along recess  36   a . If the latch were repositioned, the teeth  58  on wedge  12  may also need to be re-positioned in the groove  20  to engage the detent  65   a  of latch  60   e.    
     Lock  10   a  is illustrated with a spool  14   a  that is adapted for use in a Whisler-style attachment ( FIGS. 11 and 12 ). Nevertheless, a spool with a latch, like latch  60   a , could be used to secure a point to an adapter, a shroud to a lip, or to secure other separable components together. In the illustrated embodiment, arms  28   a  of spool  14   a  are formed with inner surfaces  70  that diverge as they extend away from body  26   a  to mate with the inclined surfaces  72  conventionally formed on the rear end of a Whisler-style adapter  17 . In use, the bifurcated legs  74  of the adapter  17  straddle the lip  76  of the excavating bucket. Each of the legs includes an elongated hole  78  that is aligned with hole  80  formed in lip  76 . The aligned holes  78 ,  80  cooperatively define an opening  82  into which lock  10   a  is received. As with lock  10 , lock  10   a  is preferably installed as separate components with the spool  14   a  being installed in opening  82  first, but may possibly be installed as a unit with the wedge  12  only partially placed into recess  36   a . In either event, once the lock  10   a  is inserted into opening  82 , the wedge is rotated in the tightening direction to drive the wedge into the opening  82  ( FIG. 12 ). The driving is continued until the spool arms sufficiently grip the adapter against lip. With elongated holes  78  in legs  74 , the latch needs to be mounted in spool  14  or lip  80 . Nevertheless, when used with such elongated openings, the lock can be re-tightened as needed in this arrangement after wear begins to occur in order to maintain the assembly in a tightened state. The variety of lock embodiments discussed above for use with the tooth can also be used in a Whisler style connection. 
     As noted above, an insert  90  can be provided as part of the lock between the front wall portion of the hole in the support structure and the wedge ( FIGS. 13 and 14 ). In the illustrated embodiment, lock  10   b  is the same as lock  10   a  with the addition of insert  90 ; hence, common reference numbers have been used. The insert preferably includes a rear surface  91  provided a smooth recess to complement the shape of the wedge when the wedge is in the fully advanced position, although other shapes and/or the provision of ridges to be received in groove  20  (in addition to or in lieu of ridges  40 ) are possible. To prevent movement of the insert during turning of the wedge, the insert preferably includes lips  92  that are welded to lip  76 . Nevertheless, a latch or other means could be used to secure the insert in place. The insert functions to protect the lip from wear and/or to fill an enlarged opening in the lip or other components. 
     A lock in accordance with the present invention could be used to secure other styles of adapters (or other wear members) to a bucket lip, such as disclosed in the co-pending patent application Ser. No. 10/425,606 filed Apr. 30, 2003, entitled Wear Assembly for the Digging Edge of an Excavator, which is hereby incorporated by reference in its entirety, or as disclosed in co-pending patent application Ser. No. 10/425,605 filed Apr. 30, 2003, entitled Wear Assembly for Excavating Digging Edge, also herein incorporated in its entirety by reference. 
     Other various alternatives can be used to provide additional support or to reduce the stress within the wedge during use and thereby increase the life of the components. 
     As one example, a wedge  12  and spool  114  ( FIG. 17 ), having essentially the same construction as spool  14   a  (although other variations are possible), are shown holding an adapter  119  to a lip  176  of an excavating bucket. In this example, the ends of legs  174  of adapter  119  are adapted to fit against stop blocks  120  for additional support, although the stop blocks are not essential and could be omitted. In addition, insert  190 , between wedge  12  and the front wall of the opening  180  in the lip, is provided with extended arms  192  to overlie the inner and outer surface of the lip. These extended arms provide additional support for the insert and increased surfaces by which the arms can be welded to the lip. As can be appreciated, a clearance  193  can be provided within the adapter to accommodate the increased arm length. 
     In a further example ( FIGS. 18 and 19 ), a cradle  200  is provided between the insert  190   a  and wedge  112 . Cradle  200  preferably includes a trough shaped rear surface  202  (like surface  91  of insert  90  in  FIG. 14 ) to bear against the wedge (although other surfaces are possible), and a curved, concave front face  204  (i.e., curved generally about a transverse axis). In this embodiment, the rear surface  191   a  of insert  190   a  complements cradle surface  204  so as to be curved generally about a transverse axis (instead of a vertical axis as shown, e.g., in  FIG. 14  for insert  90 ). Nevertheless, front surface  204  of cradle  200  could also have a concave, curved form to define a generally vertical tough to receive insert  190  generally as spool  14   a  or insert  90  receive wedge  12 . The rear wall  191   a  of the insert  190   a , then, would have a complementary convex or crowned surface shape be received within the formed trough. The trough and crowned surface could also be reversed with the trough on the insert and the crowned surface on the cradle. The front wall of opening  180  in lip  176  could be formed with the convex wall to directly abut the front face  204  of cradle  200 , but an insert  190  is preferred to protect the lip and enable the fit with existing lip constructions. 
     When adapter  119  is used, the applied loads will tend to cause the adapter legs  174  to shift longitudinally, i.e., forward and rearward, along the inside and outside surfaces of the lip  176 . Although the use of stop blocks  120  will limit the rearward motion, the legs will still tend to pull forward. In any event, this shifting of the legs can apply substantial compressive loading on the wedge and a build up of stress on the wedge, which leads to a reduced usable life. By using cradle  200 , the wedge  12  and cradle  200  can swing about insert  190   a  (i.e., about the generally transverse axis) to accommodate the alternative shifting of the legs and thereby reduce the stress in the wedge, thus, increasing the usable life of the wedge. 
     For example, as shown in  FIGS. 18   a  and  18   b , the application of a downward load on the front of the adapter will tend to cause the upper leg of adapter  119  to shift forward along the inside surface of the lip  176 . When used without stop blocks  120 , there will also be a concomitant rearward shifting of the lower leg. In regard to the present example, this forward shifting of the upper leg can cause a high compressive force to be applied to the wedge and create an interference fit H of certain magnitude that is usually accommodated by compression of the wedge. With the use of a cradle, as illustrated in  FIG. 18   b , the forward shifting of the upper leg is at least partially accommodated by shifting of the cradle so that the interference fit h is smaller in magnitude than interference H for the same amount of forward shifting of the adapter leg. The shifting of the wedge enables the lock to automatically adjust so as to increase the contact surface area resisting the loads and thereby reduce the likelihood of localized peening or other damage to the lock components—particularly the wedge. 
     In an alternative embodiment ( FIG. 20 ), cradle  210  includes a curved convex front surface  212  (i.e., curved about a generally transverse axis) to be received against a concave rear surface of insert  190   b . In this embodiment, the cradle and wedge are adapted to shift to accommodate the shifting of the legs of the adapter  119  under load as discussed above for cradle  200 . 
     As another alternative construction ( FIG. 21 ), cradle  220  is formed with a front face  224  having an offset formation. More specifically, front face  224  includes an upper portion  225  and a lower portion  226 , each having a convex curvature such as used in cradle  210 . The central portion  227  of front face  224  has recessed convex curved surface preferably about the same radius of curvature origination point as upper and lower portions  225 ,  226 . Insert  190   b  has a complementary rear surface. Cradle  220 , thus, operates in essentially the same way as cradle  210 , but is thinner for use in smaller openings in lip  176  and adapter  119 . 
     As another alternative, cradle  230  can be used with a shortened wedge  112  to accommodate the shifting of the adapter legs  174 . In this embodiment, the spool is also eliminated. More specifically, cradle  230  includes a convex front face  234 , in generally the same way as cradle  210 . However, cradle  230  also includes an extended arm  231  which abuts against the lower leg  174  in place of spool  14 . 
     Further, cradles can be used in the same way with conventional wedge and spool arrangements (i.e., non-rotating wedges) to provide the same shifting of the lock to better accommodate shifting of the legs. 
     In another alternative embodiment ( FIGS. 23-25 ), the spool  314  is formed integrally with the wear member  319 . In this construction, a shroud  319  or other wear member includes a pair of legs  374  to straddle the lip  376 . One leg  374   a  (in this example, the inner leg) is formed with an opening  378  for receiving a wedge  12 . A spool  314  is cast (or otherwise formed) as an integral portion of leg  374  to form the rear wall of opening  378 . Spool  314  is provided with the same front construction as disclosed above for spool  14   a  (or spool  14 ). Spool  314  further projects from an inner side  375  of leg  374  to fit within hole  380  in lip  376  against rear wall  381 . Leg  374   b  is shorter than leg  374   a  to enable the wear member  319  to swing onto lip  376  and place shroud  314  into opening  380 . In  FIGS. 23 and 24 , wear member  319  is shown partially swung about lip  376  with shroud  314  about to be placed within hole  380  in lip  376 . Once wear member  319  is fully fit on lip  376 , wedge  12  is inserted and tightened as disclosed above. 
     The lock of the present invention can also be used in a variety of different assemblies to hold separable parts together. While the invention is particularly suited for use in securing a point to an adapter, and an adapter or shroud to a lip, the invention can be used to secure other wear members in excavating operations, or simply other separable components that may or may not be used in excavating operations. Further, the above-discussion concerns the preferred embodiments of the present invention. Various other embodiments as well as many changes and alterations may be made without departing from the spirit and broader aspects of the invention as defined in the claims.

Summary:
A lock that includes a wedge that is used to releasably secure separable components of an assembly together. The wedge can be used with a spool. The wedge and spool are threadedly coupled together to drive the wedge into and out of an opening in the assembly without hammering or prying. The direct coupling of the wedge and spool eliminates the need for bolts, washers, nuts and other hardware so as to minimize the number of parts. As a result, the lock is inexpensive to make, easy to use, and unlikely to become inoperative because of lost or broken parts or due to fines or other difficulties encountered in harsh digging environments. Further, the wedge can be driven into the assembly to provide the degree of tightness necessary for the intended operation and/or to re-tighten the assembly after incurring wear during use. A latch assembly is preferably provided to securely hold the wedge in place and avoid an undesired loss of parts during use.