HK1120580B - Releasable coupling assembly - Google Patents

Description

Releasable coupling assembly

The applicant is: eisco, filing date: on 29 th 4 th 2004, the number of the Chinese application is: 200480011300.4, the name is: divisional application of the invention of a releasable coupling assembly.

Technical Field

The present invention relates to a coupling assembly for releasably securing separate parts together, particularly for securing together elements of a wear assembly for excavating and the like.

Background

Excavating equipment typically includes various wear parts to protect the underlying product from premature wear. The wear member may simply function as a protector (e.g., wear cap) or may have another function (e.g., digging tooth). In either case, it is desirable that the wear member be securely fastened to the excavating equipment to prevent loss during use, yet be removable and installable for replacement when worn. In order to minimize equipment downtime, it is desirable that worn wear parts be easily and quickly replaced at the worksite. In order to minimize the amount of material that must be replaced due to wear, the wear part is typically constructed of three (or more) elements. As a result, the wear member typically includes a support structure secured to the excavating equipment, a wear member mounted on the support structure, and a lock for securing the wear member to the support structure.

As one example, an excavating tooth typically includes an adapter as a support structure, a tooth point or tip as the wear member, and a lock or holder to secure the point to the adapter. The adapter is secured to the front digging edge of the excavating bucket and includes a projection projecting forwardly to define a seat for the point. The adapter may be a single unitary piece or may be constructed of multiple elements assembled together. The point includes a front digging end and a rearwardly opening receptacle that receives the adapter nose. The lock is inserted into the assembly to releasably secure the nib to the adapter.

Locks for excavating teeth are typically elongated pin members that fit within openings cooperatively defined by both the adapter and the point. As in U.S. patent No.5469648, the opening may be defined along the side of the adapter nose; or through the projection as in U.S. patent No. 5068986. In either case, the lock may be inserted and removed using a large hammer. Hammering on the lock is a laborious task and risks injury to the operator.

The lock is normally tightly received in the channel to prevent ejection of the lock and consequent loss of the tooth tip during use. This tight fit can be achieved by: by partially misaligned holes in the tip defining the opening for the lock and the adapter, by including a rubber insert in the opening, and/or by providing dimensional proximity between the lock and the opening. However, it will be appreciated that increasing the degree of security with which the lock is received in the opening further exacerbates the difficulty of knocking the lock into and out of the assembly and the risk of injury to service personnel.

In addition, the lock generally lacks the ability to have the tip tightly secured to the adapter. Although the rubber insert provides some fastening to the stationary teeth, the insert does not provide any strength necessary for true fastening under the load during use. Most locks cannot be retightened when the parts wear. In addition, many locks used in teeth are susceptible to loss as the elements wear and the degree of tightening is reduced.

These difficulties are not strictly limited to the use of locks in digging teeth, but are applicable to the use of other wear parts in digging operations. In another example, the adapter is a wear member that fits over the lip of an excavating bucket defining the support structure. While the tip is subject to the most wear in the teeth, the adapter is also worn and needs to be replaced in a timely manner. The adapter may be mechanically secured to the bucket to accommodate replacement at the work site. One common approach is to use Whisler-type adapters such as those disclosed in U.S. patent No. 3121289. In this case, the adapter is formed with bifurcated legs that straddle the lip of the bucket. The adapter leg and bucket lip are formed with aligned openings for receiving the lock. In this environment, the lock includes a substantially C-shaped spool and wedge. The arms of the spool overlie the rear ends of the adapter legs. The outer surface of the leg and the inner surface of the arm are each inclined rearwardly and away from the lip. The wedge is then driven into the opening in the usual manner to force the spool rearward. This rearward movement of the spool causes the arms to clamp the adapter legs tightly against the lip to prevent the adapter from moving or loosening during use. As with the installation of the tip, driving the wedge into the opening is a difficult and potentially dangerous activity.

In many assemblies, other factors can further increase the difficulty of removing and inserting the lock when the wear member needs to be replaced. For example, access to adjacent elements (e.g., laterally inserted locks) (see U.S. patent No.4326348) can create difficulties in driving the lock into and out of the assembly. Fines may also impact the opening that receives the lock, making access and removal of the lock difficult. Additionally, in the Whisler-type configuration, it is generally necessary to rotate the bucket front upward to provide access to eject the wedge from the assembly. This orientation of the bucket can make removal of the lock difficult and dangerous because a worker must enter the opening from beneath the bucket and drive the wedge upward with a large hammer. This risk is particularly evident for dragline buckets, which can be quite large. Additionally, because the wedge may pop out during use, it is common practice in most installations to tack weld the wedge to its accompanying spool, which makes wedge removal more difficult.

There have been some efforts to produce locks for use in excavating equipment that do not require hammering. For example, U.S. patent nos. 5784813 and 5868518 disclose screw driven wedge locks that secure the tip to the adapter, and U.S. patent No.4433496 discloses a screw driven wedge that secures the adapter to the bucket. While these devices do not require hammering, they each require many parts, thus increasing the complexity and cost of the lock. The intrusion of fines can also make removal difficult because the fines increase friction and interfere with the threaded connection. In addition, when using standard bolts, fines can form and "stick" around the threads, making rotation of the bolt and loosening of the parts extremely difficult.

Disclosure of Invention

The present invention provides a wear assembly comprising a support structure, a wear member mounted on the support structure and a lock releasably securing the wear member to the support structure; the bearing structure and the wear member cooperate to define an opening for receiving the lock, the lock including a wedge formed with a first thread formation threadably connectable with a second thread formation in the opening such that rotation of the wedge moves the wedge into the opening to secure the lock in the opening.

The present invention provides a wear assembly comprising a support structure, a wear member mounted on the support structure and a lock releasably securing the wear member to the support structure; the bearing structure and the wear member cooperate to define an opening for receiving the lock, the lock including a wedge movable into the opening to secure the lock in the opening and a cradle fitted between the wedge and a front face of the opening, the cradle having a curved front face generally about a transverse axis to fit over a complementary surface in the opening to enable shifting of the vertical orientation of the wedge as the wear member is longitudinally shifted over the lip during use.

The present invention provides a wear member adapted to be mounted on a support structure secured to excavating equipment, the wear member comprising: a front working part; a rear formation for receiving a support structure; an opening for receiving a rotatable lock to releasably secure the wear member to the support structure; and a latch disposed on a wall of the opening to secure the lock in the opening, the latch having teeth that cooperate with a set of teeth on the lock to prevent rotation of the lock in one direction in the opening.

The present invention provides a wear member adapted to be mounted on a support structure secured to excavating equipment, the wear member comprising: a front working portion, a rear formation for receiving a support structure, an opening for receiving a rotatable lock to releasably secure the wear member to the support structure, the opening including a thread formation adapted to engage with a thread formation on the lock.

The present invention provides a method of securing a wear member to a support structure, the method comprising: placing the wear member on the support structure such that the configuration of the wear member and the configuration of the support structure cooperate to define an opening; inserting a wedge having a first thread formation into the opening and into threaded engagement with a second thread formation in the opening; the wedge is rotated to drive the wedge into the opening to tightly hold the wear member on the support structure.

The present invention relates to an improved coupling assembly for releasably securing separate components together in a safe, easy and reliable manner. In addition, the lock of the present invention can be simply installed and removed by using a manual or power wrench. A hammer is not required to strike or pry the lock into and out of the assembly.

The invention is particularly useful for securing wear members to support structures in connection with excavation operations. The lock of the present invention is easy to use, can be securely fixed to the wear assembly, reduces the risk of driving the lock into and out of the wear assembly, and effectively secures the wear member to the support structure.

In one aspect of the invention, a thread formation is formed on the tapered lock element for urging the lock element into a locked position in the assembly. The lock member is then supported on the assembly, securing the components of the assembly together. The use of a threaded formation on the lock element also reduces the risk of the lock element being ejected during use as compared to simply driving the lock into position.

In a first aspect of the invention, the wedge and spool are threadably coupled together and the wedge may be pushed 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, which may reduce the number of parts. The result of this effective construction is that the lock is inexpensive to manufacture, easy to use, and does not fail because parts are lost or damaged or because of fines or other difficulties encountered in harsh excavation environments. Additionally, the wedges may be selectively driven into the assembly to provide a desired degree of tightening for intended operation and/or to re-tighten the assembly after wear during use.

In a preferred construction, the wedge member includes a wide pitch thread formation for forming land segments of comparable size, with which the wedge member can apply pressure directly to the wear assembly for securing the wear member to the support structure. In one embodiment, a helical groove is formed along the outer periphery of the wedge, engaging a helical ridge segment formed in a generally trough-shaped recess along the spool or other portion of the assembly. Rotation of the wedge moves the wedge along the spool, into and out of the wear assembly. Movement of the wedge into the assembly increases the depth of the lock, thereby tightening the engagement of the wear member on the support structure.

Preferably, a latch assembly is provided to securely hold the wedge in place and to avoid unwanted loss of parts during use. In a preferred construction, the wedge is formed with teeth that interact with a latch provided in an adjacent member such as a spool, wear member or support structure. The teeth and latch allow the wedge to rotate in a direction that pushes the wedge farther into the opening and prevent rotation in a direction that retracts the wedge. The latch may also retain the lock in the assembly as the wear member and/or support structure begin to wear.

The lock of the present invention is simple, robust, reliable and requires a minimum of components. The operator can easily and intuitively understand the lock. The elimination of the need for hammering also makes the replacement of the wearing parts easy and less dangerous. In addition, the lock can selectively secure the wear assembly so that when the support structure is partially worn, it is easy to re-secure the wear member or to better fit the original installation. These and other advantages will be apparent from the drawings and description that follow.

Drawings

FIG. 1 is a perspective view of a coupling assembly for securing a tip to an adapter in accordance with the present invention;

FIG. 2 is a side view of a lock according to the present invention;

FIG. 3 is a perspective view of the wedge of the lock;

FIG. 4 is an enlarged partial perspective view of the wedge;

FIG. 5 is a perspective view of the barrel of the lock;

FIG. 6 is a perspective view of a wear member having a latch of the coupling assembly of the present invention;

FIG. 7 is a partially exploded perspective view of the wear member shown in FIG. 6;

FIG. 8 is a cross-sectional view of the coupling assembly in an assembled condition taken along line 8-8 of FIG. 1;

FIG. 9 is a perspective view of an alternative spool of the lock;

FIG. 10 is an exploded perspective view of the alternative bobbin;

FIG. 11 is a side view of a second lock including the alternate spool in accordance with the present invention; the lock is adapted to secure the adapter to the bucket lip in a Whisler-style connection;

FIG. 12 is a cross-sectional view along the longitudinal axis of another wear assembly using the lock shown in FIG. 11;

FIG. 13 is a cross-sectional view of another embodiment of an insert included between the wedge and the support structure along the same lines as FIG. 12;

FIG. 14 is a perspective view of the insert used in the alternative embodiment shown in FIG. 13;

FIG. 15 is a perspective view of another wedge construction;

FIG. 16 is a perspective view of yet another wedge construction;

FIG. 17 is a cross-sectional view of another embodiment taken along the same lines as FIG. 12;

FIG. 18 is a cross-sectional view of yet another embodiment taken along the same lines as FIG. 12;

FIG. 18a is a cross-sectional view showing the deflection of the wear member on a lock without a carrier;

FIG. 18b is a cross-sectional view showing the deflection of the wear member on a lock with a bracket;

FIG. 19 is a perspective view of the bracket used in the alternative embodiment shown in FIG. 18 with the wear member omitted;

FIG. 20 is a cross-sectional view of another embodiment taken along the same lines as FIG. 12;

FIG. 21 is a cross-sectional view of another embodiment taken along the same lines as FIG. 12;

FIG. 22 is a cross-sectional view of another embodiment taken along the same lines as FIG. 12;

FIG. 23 is a perspective view of yet another embodiment of a wear member partially assembled to 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 assembly of the wear member of FIG. 23 with the hole in the lip when fully installed on the lip.

Detailed Description

The present invention relates to a coupling assembly for releasably securing separate components together. Although the present invention has broader application, it is particularly useful in releasably securing a wear member to a support structure during excavation operations. The wear part may be, for example, a tip, an adapter, a cover plate, or other replaceable element.

In a preferred construction, the lock 10 includes a wedge 12 and a spool 14 (FIGS. 2-5). While the lock may be used to secure a large number of elements together, it is shown in FIG. 1 as securing the components of the excavator tooth together. 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 tip or top 19. Lock 10 is received in an opening 21 in wear assembly 15 defined by a bore 23 in tip 19 and a bore 25 in adapter 17 to releasably secure the tip to the adapter (fig. 1 and 8). Although the holes may be circular or otherwise shaped, it is preferred that the holes 23 and 25 each be longitudinally elongated to prevent misalignment of the wedge and spool.

The wedge 12 is preferably frustoconical with a rounded outer surface 16 (fig. 1-4) that tapers toward a leading end 18. A thread formation 22, preferably in the form of a broad pitch helical groove 20, is formed along the outer surface 16 of the wedge. Thus, there are relatively wide spiral land segments 24 between adjacent spiral groove segments. This land segment presents a large surface area that presses against the front surface 31 of the bore 25 in the adapter 17 and the wall 37 of the recess 36 in the barrel 14. The larger land segments enable the lock to withstand large loads with acceptable stress levels and do not require threading in the wall of the bore 25 of the adapter. The wide pitch of the groove 20 also allows the wedge to move quickly into and out of the opening 21.

In a preferred construction, the thread pitch on the wedge is about 1 inch and the groove forming the thread is about 1/8 inches wide, although the pitch and groove width can vary widely. Preferably, the groove is formed with curved corners to form a strong thread that is not susceptible to being struck by a hammer 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, to turn the wedge. In the preferred embodiment, the formation 29 is a square socket, but other configurations may be used.

The taper of the wedge may be varied so that the tension of the wear member on the support structure may be increased or decreased. For example, if the taper of the wedge is increased, the speed at which the wear member moves to a set position on the support structure increases, but tightening force is consumed (i.e., more torque is required to rotate the wedge). The taper of the wedge may be designed to match the specific task. In all cases, the lock will have approximately the same holding force as long as the front end of the wedge is formed to be not too small to provide sufficient strength.

Preferably, the spool 14 has a generally C-shaped configuration with a body 26 and arms 28 (FIGS. 1, 2 and 5). In this example, the arm is relatively short, pressing against the rear wall 30 of the hole 23 of the tip 19 (fig. 8). However, the particular shape and size of the arm may vary widely depending on the configuration and use of the part housing the lock. In addition, the arm may be omitted altogether if the opening in the support structure is sized to allow the rear wall of the body to be pressed against the rear wall in the opening of the wear member and the spool is sufficiently anchored. Also, in this type of configuration, the lock may be reversed such that the wedge is pressed against the wear member and the spool is pressed against the support structure.

The body 26 of the spool 14 is formed with a generally channel-shaped recess 36 to receive a portion of the wedge (FIG. 5). The recess is provided with a thread formation 42 defining at least one protrusion which fits within the groove 20. In this manner, the wedge and spool may be threadably coupled together. While the projection may take on a variety of shapes and sizes, it is preferred that the recess 36 include a plurality of ridges 40 on the spool to complement the grooves 20 on the wedge 12. The ridge 40 is formed as a helical segment having the same pitch as the helical groove 20 so that the ridge is received in the groove to move the wedge in and out of the opening when the wedge is rotated. Although it is preferred to provide a plurality of protuberances 40 along the entire length of the recess 36; but fewer or even one ridge could be provided if desired. In addition, each ridge preferably extends transversely across the entire recess 36; but may have a smaller extension if desired.

In the preferred construction, the helical flutes 20 have the same pitch along the length of the wedge. Because the wedge is formed with a taper, the angle of the thread changes, with the thread becoming shallower as the groove extends from the forward end 18 to the rearward end 27. This variation requires clearance space between the internal and external threads so that the threads cooperate and avoid sticking to each other. Thus, this configuration forms a relatively loose mating thread.

As another feature, in addition to or in lieu of the bump 40 on the barrel, bump(s) may be formed on the front wall portion of the bore 23 defined in the tip 19 that engage the groove 20 on the wedge. As shown in fig. 6 and 7, the ridge may simply be provided by the body 62; but may also include extensions and/or other ridges on the front wall portion of the bore (as shown in fig. 9 and 10) similar to the inclusion of the body 62a on the barrel 14 a. Also, (in addition to or in place of other ridges), one or more ridges (or other protrusions) may be formed on the wall structure of the hole 25 in the adapter 17 that engage the groove 20. In these arrangements, a threaded formation is formed on the tip and/or adapter and the spool, which secures the wear member to the support structure, is not required to insert the wedge into the opening. It will be appreciated that the hole in the tip needs to be smaller to allow direct bearing contact between the wedge and the rear wall portion of the hole in the tip or bulge provided on the rear wall of the opening.

The thread configuration may also be reversed such that grooves are formed on the tip, adapter and/or barrel to accommodate the helical ridge formed on the wedge. While it is possible to form the threads on the wedge with ridges that form 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 segments 24 without matching grooves on the opposite surface. However, in a less stressed environment, a helical ridge on the wedge may be used even when the adapter wall is smooth and/or the recess in the spool is smooth. In this version, the wedge 94 preferably has a ridge 96 with a blunt outer edge 98 (FIG. 15). However, it is contemplated that a bump may be provided on the wedge to snap into the adapter wall and/or spool. Finally, the wedge 101 may be formed with a tapping boss 103, the boss 103 cutting threads into the barrel and/or adapter wall when the boss is screwed into the assembly (FIG. 16).

A recess 36 in the spool 14 tapers toward one end 38 to complement the shape of the wedge and to position the forward portion of the land segment 24 bearing against the adapter generally vertically for strong, secure contact with the nose of the adapter 17 (fig. 5 and 8). This orientation may stabilize the wedge and reduce stresses induced in the components when the wedge is tightly inserted into the wear assembly 15. In a preferred construction, the recess tapers twice the taper of the wedge member to place the forward portion of land segment 24 in a vertical orientation (as shown). It will be appreciated that the purpose of this configuration is to have the front of the land segment substantially parallel to the wall of the diametrically opposed element with which the front is engaged. In the preferred construction, the recess 36 carries a concave curve designed to complement the shape of the wedge when it is at the end of its protruding travel in the tightening direction. In this manner, the wedge is preferably able to withstand the applied load and does not stick to the spool during tightening. However, other shapes are possible.

In use, when wear member 19 is installed on nose 46 of adapter 17, lock 10 is inserted into opening 21 of wear assembly 15 (fig. 1 and 8). Preferably, the lock 10 is placed in the opening 21 as a separate element (i.e., the spool is inserted first), but in some cases may be inserted together as a unit (i.e., the wedge is partially placed into the recess 36). In either case, the free end 50 of the arm 28 is placed in engagement with the rear wall portion 30 of the hole 23 in the wear member 19. The wedge is then rotated to drive it into opening 21 so that the forward portion of land segment 24 of wedge 12 presses against the forward wall portion 31 of bore 28 and the arms 28 of spool 14 press against the rearward wall portion 30 of bore 23. Continued rotation of the wedge further increases the depth of the lock (i.e., the distance in a direction parallel to the axis of movement of the point on the adapter nose) so that the arm 28 pushes the wear member 19 further on the support structure 17. This rotation is stopped once the desired degree of tightening has been reached. By using a tapered wedge in the opening 21 that receives the lock, there is a large gap between most of the wedge and the walls of the opening. As a result, fines from the excavation work generally do not impinge strongly on the opening. Even if the fines do hit the opening, the wedge can be easily returned by turning the wedge with a wrench. The taper of the wedge makes the bottom of the assembly in the orientation shown larger around the opening of the lock. With this arrangement, swarf can fall out when the wedge is released. In the preferred construction, the wider groove of the wedge also releases swarf from the lock and thereby prevents the lock from "binding" in the assembly. In addition, because of the tapered shape of the threaded wedge, the assembly can be quickly released with only a slight rotation of the wedge. If desired, a rubber cap or the like (not shown) may be used to prevent the intrusion of debris into the receptacle 29.

In a preferred construction, a latch assembly 56 is provided to retain the wedge in the opening. As shown in fig. 2-4 and 8, ratchet teeth 58 are preferably provided in the groove 20 to cooperate with a latch 60. By recessing the teeth into the groove, the teeth do not disrupt the threaded coupling of the wedge and the spool or the engagement of the wedge with the support structure 17 and spool 14. The ratchet teeth are adapted to engage a latch 60 mounted on either the wear member 16 (fig. 6-8), the spool 14 (fig. 10 and 12), or the support structure 17 (not shown). The tooth inclination allows the wedge to rotate in the tightening direction but prevents rotation in the loosening direction. The teeth are typically formed only along about 1/3 the length of the channel 20 to ensure that the latch engages the teeth when the wedge is fully tightened for use. Of course, the teeth could be positioned along a length greater than or less than about 1/3 of the groove, if desired. The number of teeth and their location on the wedge depends largely on the amount of movement desired between the components to be coupled together, as well as the desired wear on the components and retightening of the lock. Preferably, the tooth is located along the rear end of the wedge (i.e., where the wedge is widest) so that the latch 60 securely engages the tooth and the stress on the wedge is minimal. However, other configurations are possible. The teeth may be of a reversible form which prevents unwanted rotation in both directions but allows rotation under the force of a wrench or the like-i.e. the pawl can be retracted under sufficient load to allow rotation of the wedge in either the tightening or loosening direction. In addition, the teeth may also be omitted. Another alternative is to design the latch 60 to apply a force to the wedge to frictionally resist inadvertent rotation of the wedge during use.

The latch 60 preferably includes a body 62 and a resilient member 63 that fit within a cavity 64, the cavity 64 being open in one of the apertures 23 (fig. 6 and 7). The body is provided with pawls 65 which engage with ratchet teeth 58 on the wedge 12. The spring compresses the pawl 65 into engagement with the ratchet teeth and allows the body to be retracted into the cavity when the wider portion of the wedge is driven into the opening 21. In the preferred construction, the body 62 includes a helical ridge 66 that is complementary to the ridge 40 on the barrel 14, i.e., the ridges have the same pitch and are positioned to match the trajectory of the ridge 40. As the operator places the cartridge in opening 21, cavity 60 can accommodate body 62 with clearance to enable the body to deflect as needed to ensure that ridge 66 is complementary to ridge 40. The gap need not be large (e.g., about 0.03 inch in larger systems) because the spool has a small adjustment range, which can be properly placed on the wall defining the hole 23 using the arm. In addition, because the groove 20 extends from the front end 18 to the rear end 27 of the wedge 12, the width of the groove 20 may be formed narrower. In this manner, even if misalignment begins, the groove may easily engage the bump 40 on the barrel 14 and the bump 66 on the body 62, and gradually deflect the body 62 into alignment with the bump 40 as the groove narrows. Preferably, the body 62 is bonded to the resilient member 63 with an adhesive (or by casting), and the resilient member 63 is bonded to the cavity 64 with an adhesive. However, the body and resilient member may be retained in the cavity 64 by friction or other means. The body is preferably constructed of plastic, steel or any other material that provides the force necessary to prevent the wedge from rotating during excavator operation, as well as a rubber spring, although other materials may be used.

In use, the ridge 66 is received in the groove 20. When the wedge reaches the tightened position, the pawl 65 engages the teeth 58. However, due to the inclination of the teeth and the provision of the resilient member 63, the latch bears on the teeth when the wedge is rotated in the tightening direction. The pawl 65 locks with the teeth 58 to prevent reverse rotation of the wedge. The pawl is designed to disengage from the body 62 when the wedge is rotated in a loosening direction with a wrench. The force to disengage the pawl is within the normal force expected to be applied by the wrench, but is still much greater than the torque applied to the wedge by normal use of the digging tooth. Alternatively, a slot or other means may be provided to allow the latch to retract and the pawl to disengage from the teeth to facilitate reverse rotation of the wedge. The placement of ridge 66 and ridge 40 in groove 20 serves to retain the wedge in opening 21 after the teeth loosen due to surface wear.

Alternatively, the latch 60 may be placed within a cavity formed along the front wall 51 of the aperture 25 in the adapter 17. When mounted on the tip 19, the latch will function as described above. Additionally, if desired, an insert (not shown) may be placed between wedge 12 and front wall 51 of hole 25. The insert may include a recess with a bump like the recess 36 in the barrel 14; or simply have a smooth recess to accommodate the wedge. For greater mechanical advantage or other reasons, the insert may be used to fill the space of a large opening in the adapter (or other support structure) or to accommodate a wedge with a smaller pitch thread; and also provides a large surface area that can bear against the adapter. In addition, the front surface of the insert may be mated with the front wall portion 51 of the bore 25 to increase the bearing area between the adapter and the lock and thereby reduce the stresses generated in the components. Latches or the like may also be used to hold the insert in place. A latch, like latch 60, may also be provided in the insert.

In another embodiment (FIGS. 9 and 10), the latch 60a of the lock 10a is mounted in a cavity 64a formed in the recess 36a of the barrel 14 a. As with latch 60, latch 60a preferably includes a body with a helical ridge 66a and a detent 65a, and a resilient member 63 a. Latch 60a operates in the same manner as latch 60 described above. The teeth 58 on the wedge are formed in the same manner whether the latch is mounted on a spool, wear member or support structure. As shown in fig. 9, the ridge 66a is provided as a continuation of one ridge 40. Although latch 60 is shown aligned with the bump 40 closest to the rear end 27 of the wedge, the latch may be formed anywhere along the recess 36 a. If the latch is repositioned, the teeth 58 on the wedge 12 also need to be repositioned in the groove 20 to engage the pawl 65a of the latch 60 a.

Lock 10a is shown with a barrel 14a (fig. 11 and 12) adapted for use in a Whisler-type configuration. However, a barrel with a latch like latch 60a may be used to secure the tip to the adapter, the cover plate to the lip, or other separate components together. In the illustrated embodiment, the arms 28a of the barrel 14a are formed with an inner surface 70 that diverges to engage a ramped surface 72 formed generally on the rearward end of the Whisler-style adapter 17 as the arms extend distally from the body 26 a. In use, the diverging legs 74 of the adaptor 17 ride over the lip 76 of the excavating bucket. Each leg includes an elongated aperture 78 aligned with an aperture 80 formed in the lip 76. The aligned apertures 78, 80 cooperate to define an opening 82 for receiving the lock 10 a. As with the lock 10, preferably the lock 10a may be installed as a separate element with the barrel 14a first installed in the opening 82; but may be installed as a unit with the wedge 12 only partially received in the recess 36 a. In either case, once the lock 10a is inserted into the opening 82, the wedge is rotated in the tightening direction, driving the wedge into the opening 82 (FIG. 12). This driving action continues until the arms of the spool sufficiently grip the adapter to rest on the lip. When there are elongated holes 78 in the legs 74, it is desirable to mount the latch on the spool 14 or lip 80. However, when such an elongated opening is used, the lock may be re-tightened as required by the structure after wear begins to occur in order to maintain the assembly in a tightened state. The various lock embodiments described above that use teeth can also be used in Whisler-type connections.

As mentioned above, an insert 90 may be provided as part of the lock between the front wall portion of the hole in the support structure and the wedge (fig. 13 and 14). In the illustrated embodiment, lock 10b is identical to lock 10a except for insert 90, and therefore common reference numerals are used. Preferably the insert includes a rear surface 91 that provides a smooth recess complementary to the shape of the wedge when the wedge is in the fully advanced position, but other shapes and/or providing a ridge (in addition to or in place of ridge 40) that is received in groove 20 are possible. To prevent movement of the insert during rotation of the wedge, it is preferred that the insert include a lip 92 welded to the lip 76. However, latches or other means may be used to secure the insert in place. The insert functions to protect the lip from wear and/or to fill large openings in the lip or other components.

Other forms of adapters (or other Wear members) may be secured to the bucket lip using a lock in accordance with the present invention, such as disclosed in co-pending patent application No.10/425,606 entitled "Wear Assembly for the Digging Edge of an Excavator" filed on 30/4/2003, which is hereby incorporated by reference in its entirety; or co-pending patent application No.10/425,605 entitled "Wear Assembly for Excavating cutting Edge for Excavating" filed on 30/4/2003, which is hereby incorporated by reference in its entirety.

Various other alternative structures may be used to provide additional support or to reduce stresses within the wedge during use, thereby extending the life of the element.

As an example, the wedge 12 and spool 114 (FIG. 17) are shown securing the adapter 119 to the lip 176 of an excavating bucket, the wedge 12 and spool 114 having substantially the same configuration as the spool 14a (although other variations are possible). In this example, the ends of the legs 124 of the adapter 119 are adapted to fit over the stop blocks 120 for additional support, although the stop blocks are not necessary and may be omitted. In addition, an insert 190 between the wedge 12 and the front wall of the opening 180 in the lip is provided with extending arms 192 to overlap the inner and outer surfaces of the lip. The extended arms provide additional support to the insert and an enlarged surface on which the arms can be welded to the lip. It will be appreciated that to accommodate the increased arm length, a gap 193 may be provided in the adapter.

In another example (fig. 18 and 19), a bracket 200 is provided between the insert 190a and the wedge 112. Preferably the cradle 200 includes a grooved rear surface 202 (like surface 91 of insert 90 in fig. 14) that bears against the wedge (although other surfaces are possible) and a curved concave front surface 204 (i.e., curved generally about a transverse axis). In this embodiment, the rear surface 191a of the insert 190a is complementary to the cradle surface 204 so as to be generally curved about a transverse axis (instead of the vertical axis of the insert 90 shown in, for example, fig. 14). However, generally as the spool 14a or insert 90 receives the wedge 12, the front surface 204 of the cradle 200 also has a concavely curved shape to define a generally vertical slot that receives the insert 190. The rear wall 191a of the insert 190a will then have a complementary convex or raised surface shape that can be placed within the formed groove. The groove and raised surface may also be reversed, with the groove on the insert and the raised surface on the bracket. The front wall of the opening 180 in the lip 176 may be formed with a convex wall to abut directly against the front face 204 of the bracket 200, but the insert 190 preferably protects the lip and is able to mate with existing lip structures.

When the adapter 119 is used, the applied load will cause the adapter legs 174 to be offset longitudinally, i.e., forwardly and rearwardly, along the inner and outer surfaces of the lip 176. Although the use of the stop block 120 limits rearward movement, the legs still attempt to pull forward. In any event, such deflection of the legs can place a significant compressive load on the wedge and create stress on the wedge, which can shorten service life. By using the bracket 200, the wedge 12 and bracket 200 may be rotated about the insert 190a (i.e., about a generally transverse axis) to accommodate additional shifting of the legs, thereby reducing stress in the wedge and thus increasing the service life of the wedge.

For example, as shown in fig. 18a and 18b, applying a downward load to the front end of the adapter will cause the upper leg of the adapter 119 to deflect forwardly along the inner surface of the lip 176. When the block 120 is not used, the lower leg is accompanied by a rearward offset. In this example, this forward deflection of the upper leg can place a large compressive force on the wedge and create a magnitude of interference fit H that is normally accommodated by compression of the wedge. As shown in fig. 18b, when the bracket is in use, the forward offset of the upper leg is at least partially accommodated by the offset of the bracket such that the magnitude of the interference fit H is less than the interference fit H for the same forward offset of the adaptor leg.

The shifting of the wedges allows the lock to self-adjust to increase the contact surface area subject to loading, thereby reducing the likelihood of partial striking or other damage to the lock elements, particularly the wedges.

In another embodiment (fig. 20), the bracket 210 includes a curved convex front surface 212 (i.e., curved about a generally transverse axis) to be placed on the concave rear surface of the insert 190 b. In this embodiment, the bracket and wedge are deflectable under load to accommodate deflection of the legs of the adapter 119, as described above for the bracket 200.

As another alternative structure (fig. 21), the bracket 220 is formed with a front surface 224 having an offset configuration. More specifically, the front surface 224 includes an upper portion 225 and a lower portion 226, each having a convex curvature as used in the bracket 210. The central portion 227 of the front surface 224 has a concave cut convex curved surface, preferably with the origin having the same radius of curvature as the upper and lower portions 225, 226. Insert 190b has a complementary rear surface. The carrier 220 thus operates in substantially the same manner as the carrier 210, but is thinner for use in the smaller openings of the lip 176 and the adapter 119.

Alternatively, the bracket 230 may be used with a cut-out wedge 112 to accommodate the offset of the adapter legs 174. The bobbin is also removed in this embodiment. More specifically, the bracket 230 includes a convex front surface 234, substantially identical to the bracket 210. However, the bracket 230 also includes an extended arm 231 that abuts the lower leg 174 in place of the bobbin 14.

Additionally, the cradle may be used with conventional wedge and spool structures (i.e., non-rotating wedges) as well to provide the same offset of the lock, better accommodating the offset of the legs.

In another embodiment (fig. 23-25), the barrel 314 is formed integrally with the wear member 319. In this configuration, the coverplate 319 or other wear member includes a pair of legs 374 that straddle the lip 376. One leg 374a (the inner leg in this example) is formed with an opening 378 for receiving the wedge 12. The barrel 314 is cast (or otherwise formed) as an integral part of the legs 374 to form the back wall of the opening 378. The spool 314 is provided with the same nose structure as described above for spool 14a (or spool 14). The barrel 314 also further projects from the inner side 375 of the leg 374 to fit within the bore 380 of the lip 376 against the rear wall 381. Leg 374b is shorter than leg 374a to enable wear member 319 to be rotated onto lip 376 and place cover plate 314 into opening 380. In fig. 23 and 24, the wear member 319 is partially rotated about the lip 376 and the cover plate 314 is then generally placed within the aperture 380 of the lip 376. Once the wear member 319 is fully fitted on the lip 376, the wedge 12 is inserted and tightened as described above.

The lock of the present invention may also be used in a variety of different assemblies to secure separate components together. While the invention is particularly useful for securing a point to an adapter and an adapter or cover plate to a lip, the invention may also be used to secure other wear members in excavation operations, or simply to secure other separate components that may or may not be used in excavation operations. In addition, the above discussion is directed to the preferred embodiments of the present invention. Various other embodiments, as well as many changes and modifications, may be made without departing from the spirit and broader aspects of the invention as set forth in the claims.

Claims (6)

1. A wear member adapted to be mounted on a support structure secured to excavating equipment, the wear member comprising: a front working part; a rear formation for receiving a support structure; and an opening for receiving a rotatable lock to releasably secure the wear member to the support structure, the opening including a threaded formation adapted to engage with a threaded formation on the lock and a latch biased towards the lock, wherein the threaded formation in the opening includes a projection adapted to be received in a helical groove in the lock, wherein the projection is formed on the latch.

2. A wear member in accordance with claim 1 wherein the thread formation includes at least one helical ridge adapted to be received in a helical groove in the lock.

3. A wear member in accordance with claim 1 further comprising a spool projecting outwardly from the rear end of the opening to form a rear surface of the opening that engages the lock.

4. A wear member in accordance with claim 3 wherein the spool includes a slot for receiving a lock having a curved configuration.

5. A wear member in accordance with claim 4 wherein the groove includes a threaded formation.

6. A wear member in accordance with any one of claims 1-5 wherein the thread formation includes a plurality of spaced apart helically shaped ridge segments adapted to engage the thread groove on the wedge.