HK1138893B - Wear assembly for excavating equipment - Google Patents

Description

Wear assembly for excavating equipment

Technical Field

The present invention relates to a wear assembly for securing a wear member to excavating equipment, and more particularly to a wear assembly adapted for attachment and use on a dredge cutter.

Background

A dredge cutterhead is used to excavate earthen material under water, such as a river bed. In general, a dredge cutterhead 1 includes a number of arms 2 (fig. 21) extending from a base ring 3 to a hub 4. The arms are spaced around the base ring and are formed with a broad spiral around the central axis of the cutterhead. Each arm 2 is provided with a series of spaced apart teeth 5 for excavating into the ground. The tooth consists of an adapter or base 6 fixed to the arm, and a tip 7 releasably attached to the base by a lock 8.

In use, the cutterhead is rotated about its central axis to excavate earthen material. A suction tube is positioned adjacent the ring to remove the excavated material. To excavate the desired swath of the ground, the cutterhead is moved side-to-side and simultaneously forward. The cutterhead also tends to move up and down due to water surges and other movements, and periodically impact the bottom surface. A further difficulty arises from the operator's inability to see the earth being excavated underwater, i.e. unlike most other excavation operations, to effectively guide the dredge along a path that is best suited to the terrain being excavated. The interconnection of the tip and the base is required to be stable and secure in view of heavy loads and harsh environments.

The cutterhead is rotated so that the teeth are driven rapidly into and through the ground. Consequently, considerable power is required to drive the cutterhead, particularly when excavating rock. In an effort to minimize power requirements, excavator tips typically have elongated, slender blades to more easily penetrate the ground. However, as the blade becomes shorter due to wear, the mounting portion of the tip will begin to engage the ground during the cutting operation. The mounting portion is wider than the cutting edge but is not shaped to reduce drag. The point typically changes before the cutting edge is fully worn due to the increased resistance that the resulting mounting imposes on the cutter head.

Disclosure of Invention

In accordance with one aspect of the invention, a wear member for excavating equipment is formed with side relief in the working and mounting sections for minimizing drag associated with the excavating work and, in turn, minimizing the power required to drive the equipment. The reduction in power consumption in turn leads to more efficient operation and longer service life of the wear elements.

According to the invention, the wear element has a transverse configuration in which the width of the front side is greater than the width of the corresponding rear side, so that the side wall of the wear element follows the shadow of the front side, thereby reducing drag. The use of a smaller rear side is not only provided by the working end but also at least partially into the mounting end. As a result, the resistance experienced by the worn wear elements of the present invention is less than the resistance experienced by conventional wear elements. Less resistance translates into less power consumption and longer use of the wear element before replacement is required. Thus, the working end of the wear member may be further worn before replacement is required.

In accordance with another aspect of the invention, the wear member has a digging profile defined by the transverse configuration of the portion of the wear member that penetrates the ground in the direction moving through the ground in each digging pass. In another aspect of the invention, side relief in the wear member is provided in the digging profile to reduce the resistance experienced during digging operations. In a preferred embodiment, side relief is provided in each digging profile desired over the life of the wear member, including the digging profile around the mounting portion.

In another aspect of the invention, the wear member includes a socket for receiving a nose portion secured to a base of the excavating equipment. The socket is formed with a generally trapezoidal transverse shape generally corresponding to the transverse trapezoidal outer profile of the wear member. The substantial mating of the socket with the exterior of the mounting portion eases manufacturing, maximizes the size of the nose, and improves strength to weight ratio.

In a preferred construction, one or more of the top, bottom or side surfaces of the trapezoidal nose and the corresponding wall of the socket are each curved in an arcuate shape to fit together. These surfaces and walls have a gradual curvature to ease installation, improve stability of the wear element, and resist rotation of the wear element about the longitudinal axis during use.

According to another aspect of the invention, the socket and the nose each include a rear stabilizing surface extending substantially parallel to the longitudinal axis of the wear member and substantially around the perimeter of the socket and the nose to resist rearward loads applied in all directions.

According to another aspect of the invention, the socket and nose are formed with complementary front bearing surfaces that are generally hemispherical to reduce stresses in the components and better control rattle that occurs between the wear member and the base.

In another aspect of the invention, the socket and nose are formed with a front curved bearing surface at each front end and a generally trapezoidal transverse shape rearward of the front end for improved stability, ease of manufacture, maximizing the size of the nose, reducing drag, stress and wear, and improving strength to weight ratio.

In accordance with another aspect of the present invention, a wear assembly includes a base, a wear member mounted to the base, and an axially oriented lock that retains the wear member to the base in a compressed state in a reliable, easy to use, easy to manufacture manner, and can secure the fit of the wear member on the base. In a preferred embodiment, the wear assembly includes an adjustable axial lock.

In another aspect of the invention, a wear member includes: an opening in which the lock is received; and a hole formed in the rear wall of the opening to be adapted to pass the lock, thereby stabilizing and easily fastening the lock.

In another aspect of the invention, the base and lock interact only through the use of a protruding stop. As a result, there is no need to provide a permanent hole, recess or passage in the nose to receive the lock. The strength of the nose portion is enhanced.

In another aspect of the invention, the latching arrangement for securing the wear member to the base may be adjustable to consistently apply a predetermined tightening force to the wear member regardless of the amount of wear that may be present in the base and/or the wear member.

In another aspect of the invention, the wear member includes a marker that can be used to identify when the lock has been sufficiently tightened.

In another aspect of the invention, the wear member is mounted and secured to the base by an axial lock that is easy to use, incorporates a new method. The wear member is mounted on a nose portion of a base fixed to the excavating equipment. The base includes a stop projecting outwardly from the nose. An axial lock is received in an opening in the wear member and extends between the stop and a bearing surface on the wear member to releasably retain the wear member to the nose.

In another aspect of the invention, the wear member is first slid over a base secured to the excavating equipment. The axially oriented locking position is such that one bearing surface abuts a stop on the base and the other bearing surface abuts a bearing wall on the wear member, such that the lock is in axial compression. The lock is adjusted to move the wear member tightly onto the base.

In another aspect of the invention, a lock for releasably retaining a wear member to a base includes: a threaded linear shaft having a support end and a tool engagement end; a nut threadedly engaged to the shaft; and a spring comprising a plurality of alternating annular elastomeric discs and annular spacers mounted around the threaded shaft between the bearing end and the nut.

Drawings

FIG. 1 is a wear assembly according to the present invention.

Fig. 2 is a side view of a wear member of the present invention.

Fig. 2A is a side view of a conventional wear member.

Fig. 3 is a cross-sectional view taken along line 3-3 in fig. 2.

Fig. 3A is a cross-sectional view taken along line 3A-3A in fig. 2A.

Fig. 4 is a cross-sectional view taken along line 4-4 in fig. 2.

Fig. 5 is a cross-sectional view taken along line 5-5 in fig. 2.

Fig. 6 is a cross-sectional view taken along line 6-6 in fig. 2.

Fig. 6A is a cross-sectional view taken along line 6A-6A in fig. 2A.

Fig. 7 is a cross-sectional view taken along line 7-7 in fig. 2.

Fig. 8 is a cross-sectional view taken along line 8-8 in fig. 2.

Fig. 9 is a cross-sectional view taken along line 9-9 of fig. 1.

Fig. 10 is a top view of a wear member.

Fig. 11 is a rear view of the wear member.

Figure 12 is a perspective view of the nose portion of the base of the present invention.

Fig. 13 is a front view of the nose.

Fig. 14 is a side view of the nose.

Fig. 15 is an enlarged perspective view of a lock in the wear assembly.

Fig. 16 is an enlarged perspective view of the lock in the wear assembly prior to tightening.

FIG. 17 is a perspective view of the lock.

Figure 18 is a side view of the lock.

Fig. 19 is an exploded perspective view of the lock.

FIG. 20 is a perspective view of a lock having a nose (the tip has been omitted).

Fig. 21 is a side view of a conventional excavator cutterhead.

Detailed Description

The present invention relates to a wear assembly 10 for excavating equipment, and is particularly suited for excavating operations. In this application, the invention is described in terms of a digging tooth adapted to be coupled to a dredge cutterhead. However, different aspects of the present invention may be used with other types of wear assemblies (e.g., shrouds) and other types of excavating equipment (e.g., buckets).

Components are sometimes described in relative terms, such as up, down, horizontal, vertical, front, and back; these terms should not be considered essential, but merely for convenience of description. The orientation of the wear elements during excavation operations, particularly during dredging operations, can vary to a large extent. Unless otherwise indicated, these relative terms should be understood in conjunction with the orientation of wear assembly 10 shown in FIG. 1.

The wear assembly 10 includes: a base 12 secured to the excavator cutterhead, a wear member 14, and a lock 16 (see fig. 1-10) that releasably retains the wear member to the base 12.

The base 12 includes: a forwardly projecting nose 18, the wear member 14 being mounted to the nose 18; and a mounting end (not shown) secured to an arm of the dredge cutterhead (fig. 1, 9 and 11-14). The base may be cast as part of the arm, welded to the arm, or attached by mechanical means. By way of example only, the base may be formed and mounted to the cutterhead as disclosed in US patent No.4,470,210 or US patent No.6,729,052.

In a tooth for a dredge, wear member 14 is a point having a working portion 21 and a mounting portion 23, the working portion 21 being in the form of an elongated slender blade, the mounting portion 23 defining a socket 20 that receives nose 18 (fig. 1-10). Point 14 is rotated by the cutterhead so that it engages the ground in substantially the same manner for each digging pass. As a result, the tip 14 includes a front side 25 and a back side 27. With each rotation of the cutterhead, the front side 25 is the side that first engages and leads into the ground. In the present invention, the rear side 27 has a smaller width (i.e., along a plane perpendicular to the longitudinal axis 28 of the tip 14) than the front side 25 by the blade 21 (fig. 5) and at least partially by the mounting portion 23 (fig. 4). In a preferred embodiment, the posterior side 27 has a smaller width than the anterior side 25 throughout the length of the tip 14 (fig. 4, 5 and 7).

The cutting edge 21 of the tip 14 preferably has a generally trapezoidal transverse configuration with a front side 25 wider than a rear side 27 (fig. 5). The term "transverse configuration" is used to refer to a two-dimensional configuration along a plane perpendicular to the longitudinal axis 28 of the wear member 14. Due to the narrowing of the point, the sidewalls 29, 31 follow the shadow of the front side 25 while digging, so that little resistance is created during the cutting operation. In a preferred configuration, sidewalls 29, 31 converge toward rear side 27 at an angle θ of about 16 degrees (FIG. 5); however, other angular configurations are also possible. The front side 25, back side 27 and sidewalls 29, 31 may be planar, curved or irregular. Further, shapes other than trapezoidal, which provide side relief (side relief), may be employed.

In use, with each excavation pass (i.e., with each rotation of the cutterhead), the dredge point 14 penetrates the ground to a certain depth. The blade alone penetrates the ground during most of the useful life of the tip. As an example, the height of the ground in one digging cycle extends approximately along line 3-3 (FIG. 2) at the center point of each digging pass. Since only the blade penetrates the ground and the blade is relatively thin, the resistance to digging operations is within a controlled range. However, as many teeth are constantly driven through the ground at a faster rate, the power requirements are always higher and, particularly when digging through rock, even reducing drag in the blade is beneficial to the operation.

In a preferred configuration, sidewalls 29, 31 not only converge toward trailing side 27, but are configured such that the sidewalls lie within the shadow of leading side 25 in the digging profile. "digging profile" is used to refer to the cross-sectional configuration of a portion of point 14 penetrating the ground along a plane (i) parallel to direction of advancement 34 at the center point of each digging pass through the ground and (ii) transverse to the longitudinal axis. The digging profile is a better representation of the drag exerted on the tip during use than a true cross-section. Providing side relief in the digging profile depends on the angle at which the sidewalls converge toward the rear side and the axial slope or expansion of the tip surface in the rearward direction. It is intended to provide a width that substantially narrows from the front side to the rear side when considering a perspective view of the digging profile. Side relief in the digging profile preferably extends through the desired cutterhead digging angle, but benefits can still be obtained if such side relief is present in at least one digging angle. As just one example, the cross-sectional configuration shown in FIG. 3 represents one digging profile 35 of a portion of point 14 being driven through the ground. As can be seen, blade 21 has side relief even in the digging profile as sidewalls 29, 31 converge toward trailing side 27 to reduce drag.

As blade 21 wears, the ground level gradually creeps rearward so that a more rearward, thicker portion of point 14 is pushed through the ground during each digging cycle. Thus, as the tip wears, more power is required to drive the cutter head. Eventually, enough of the blade is worn away so that the mounting portion 23 of the point 14 is driven through the ground in each digging pass. In the present invention, the mounting portion 23 continuously includes side relief at least at a front end 40 (fig. 4) of the mounting portion and preferably throughout the mounting portion (fig. 4 and 7). As shown in fig. 4, mounting portion 23 is larger than blade 21 to accommodate receipt of nose 18 into receptacle 20 and to provide sufficient strength for interconnection between tip 14 and base 12. The side walls 29, 31 are inclined to converge towards the rear side 27. The slope of the sidewalls 29, 31 along line 4-4 is, in this example, an angle α (fig. 4) of about 26 degrees, although other slope angles may be used. As discussed above, the desired side relief in the digging profile depends on the relationship between the lateral sidewall inclination and the axial extension of the point.

In one conventional point 14a, blade 21a has a trapezoidal transverse configuration with a wider front side 25a than rear side 27 a. However, blade 21a does not provide side relief in the digging profile. As seen in fig. 3A, digging profile 35a in fig. 2A (i.e., along line 3A-3A) does not have sidewalls 29a, 31a (fig. 2A and 3A) that converge toward trailing side 27 a. Rather, the sidewalls 29a, 31a in the digging profile 35a expand outwardly at a progressively increasing slope as the sidewalls extend toward the rear. The rearward flaring of the side walls 29a, 31a will create increased resistance on the impeller. Effective use of side relief in the point 14 of the digging profile provides better drag reduction than use of known sidewalls in a transverse configuration alone.

In another example, blade 21 has worn to the extent that a portion of mounting portion 23 along line 6-6 (fig. 2 and 6) is driven through the ground. Even the mounting portion 23 provides side relief for reduced drag; that is, sidewalls 29, 31 converge toward the rear side even in digging profile 45. The presence of side relief in digging profile 45 provides less drag and thus less power required to drive it through the ground. The reduced resistance, in turn, enables the cutterhead to continue to operate with a point that is worn to the point where the mounting section penetrates the ground. In the conventional tip 14a, the mounting portion 23a does not have a trapezoidal transverse configuration with sidewalls 29a, 31a that converge toward the rear side 27 a. Moreover, as seen in FIG. 6A, sidewalls 29a, 31a diverge from front side 25a in a digging profile 45a taken along line 6A-6A about front end 40a of mounting portion 23 a. In particular, the lack of side relief in the digging profile, as compared to the point 14 of the present invention, exerts a significant amount of drag on the point 14a as the point 14a is driven through the ground. Because of the large resistance created by the point 14a in this case, many operators will replace the point as the mounting portion 23a begins to be driven through the ground (even if the blade 21a is not fully worn). With the present invention, tip 14 can continue on base 12 until blade 21 is further worn.

In a preferred construction, the sidewalls 29, 31 taper continuously from the front end 37 to the rear end 47 of the tip 14. As shown in fig. 7, the side walls 29, 31 converge toward the rear side 27 even at the rear of the mounting portion 23. In addition, side relief is provided even in digging profile 55 along line 8-8 (fig. 2 and 8), i.e., sidewalls 29, 31 converge toward trailing side 27 even in this trailing digging profile 55.

As noted above, the use of a point 14 with side relief in the blade 21 and mounting portion 23 may be used with virtually any nose and socket configuration. However, in one preferred construction, the forward end 58 of the nose 18 includes a forward facing bearing surface 60, the forward facing bearing surface 60 being convex and curved about two perpendicular axes (fig. 1, 9 and 11-14). Similarly, the front end 62 of the receptacle 20 is formed with a complementary concave and curved bearing surface 64 to seat against the bearing surface 60 (fig. 1, 7, 9 and 11). In the illustrated construction, the forward bearing surfaces 60, 64 each conform to a spherical segment to reduce stresses in the components resulting from the application of non-axial loads (such as disclosed in U.S. Pat. No.6,729,052, the entire contents of which are incorporated herein by reference).

Preferably, the front ends 58, 62 are each generally hemispherical to reduce rattle between the tip 14 and the base 12 and to more effectively resist loads from all directions. The front bearing surface 64 of the socket 20 is preferably slightly wider than the hemispherical shape at its ends and center, thereby accommodating reliable mounting of the tip 14 on a different base (i.e., without binding or bottoming out) that operates as a true hemispherical socket surface on the hemispherical spherical surface of the base 12 under normal loading or subsequent wear. In a conventional tooth 10a (fig. 2A), the tip 14a moves over the nose as the tooth is forced through the ground. The front ends of the socket and nose are angled with respect to the flat support surface and the hard corners. In use, the tip 14a moves over the nose so that the front of the socket 20a rattles around and against the front end of the nose and the rear of the socket moves around and rattles against the rear end of the nose. This movement and rattling causes the tip and base to wear. In the present invention, the use of generally hemispherical front bearing surfaces 60, 64 greatly reduces rattle at the forward ends of the nose 18 and socket 20 (FIGS. 1 and 9). However, the use of a smooth continuous front bearing surface enables the tip to roll at the nose to reduce wear. A small strip 65 substantially parallel to the longitudinal axis 28 preferably extends directly behind the generally hemispherical bearing surface to provide the nose with the ability to wear while still maintaining the desired support. The term "substantially parallel" is intended to include parallel surfaces and those surfaces that are axially offset rearwardly from axis 28 by a small angle (e.g., about 1-7 degrees) for manufacturing or other purposes. The small band 65 is preferably axially inclined with respect to the axis 28 by no more than 5 degrees, most preferably by about 2-3 degrees.

The nose 18 includes a main body 66 rearward of the front end 58 (fig. 11-14). Body 66 is defined by an upper surface 68, a lower surface 69, and side surfaces 70, 71. In a preferred configuration, body surfaces 68-71 diverge rearwardly such that nose 18 flares outwardly from front end 58, thereby providing a more robust nose to withstand the rigors of digging. However, it is possible to only disperse the upper and lower surfaces 68, 69 from each other and to axially extend the side surfaces 70, 71 substantially parallel to each other. The receptacle 20 has a main portion 76 located rearward of the front end 62 to receive the body 66. The main portion 76 includes an upper wall 78, a lower wall 79 and side walls 80, 81 that conform to the body surfaces 68-71. In the preferred embodiment, body 66 and main portion 76 each have a trapezoidal transverse configuration. The use of a trapezoidal shape along primarily the length of the socket 20 and nose 18 provides four corners 67, 77, with the four corners 67, 77 acting as spaced ridges to resist rotation of the wear member 14 about the axis 28.

Further, in a preferred embodiment, at least one of (and preferably all of) body surfaces 68-71 and receptacle walls 78-81 have a configuration that is bowed with respect to one another (FIGS. 7, 11, and 13); that is, the body surfaces 68-71 are preferably concave and curved across substantially their entire width to define a groove 84 on each of the four sides of the body 66. Similarly, receptacle walls 78-81 are preferably convex and curved across substantially their entire width to define a tab 86 that is received in slot 84. The nose surfaces 68-71 and socket walls 78-81 are preferably curved in an arcuate shape across substantially their entire width, reinforcing the corners 67, 77 to provide increased resistance to rotation of the tip 14 about the base 12 during operation. The slots and protrusions also reduce rotational rattle of the tip on the base. While arcuate surfaces 68-71 and walls 78-81 are preferred, other slot and tab configurations may be employed, such as disclosed in U.S. patent application No.11/706,582, which is incorporated herein by reference. Other rotation-inhibiting configurations may also be employed.

The use of slots 84 and tabs 86, particularly slots 84 and tabs 86 that are gradually curved and extend substantially across the entire width of surfaces 68-71 and walls 78-81, facilitates assembly of tip 14 to nose 18; that is, the slots 84 and projections 86 cooperatively guide the tip 14 into proper assembly position on the nose 18 upon assembly. For example, in mounting the tip 14 onto the nose, if the tip 14 is initially mounted on the nose 18 without proper alignment with the nose, engagement of the received tab 86 into the slot 84 will rotate the tip into proper alignment as it is fed back onto the nose 18. The cooperation of the slot 84 and the tab 86 greatly simplifies and speeds installation and placement of the corner 67 into the corner 77. Some variations between the shapes of the socket and the nose may also be used, as long as the shape of the socket body matches the shape of the nose.

The nose surfaces 68-71 with the slots 84 are each preferably axially inclined so as to expand outwardly as they extend rearwardly to provide strength to the nose 18 until reaching a rear stabilizing surface 85 of the nose 18. Likewise, socket walls 78-81 with projections 86 also each expand to conform to surfaces 68-71. Socket walls 78-81 also define rear stabilizing surfaces 95 to bear against stabilizing surfaces 85. The rear stabilizing surfaces 85, 95 are substantially parallel to the longitudinal axis 28. In a preferred embodiment, each stabilizing surface 85, 95 diverges axially rearward at an angle of about 7 degrees relative to axis 28. The rear stabilizing surfaces 85, 95 also preferably surround (or at least substantially surround) the nose 18 and the socket 20 to better resist non-axial loads. While contact between the various socket surfaces and the nose may occur during digging operations, the contact between the respective front bearing surfaces 60, 64 and rear stabilizing surfaces 85, 95 is intended to primarily resist loads imposed on the tooth, thereby providing the desired stability. While stabilizing surfaces 85, 95 are preferably formed with short axial extensions, they may have longer or different configurations. Further, in some cases, for example, in light duty operations, benefits may be obtained without the need for stabilizing surfaces 85, 95.

The front bearing surfaces 60, 64 and the rear stabilizing surfaces 85, 95 are provided to stabilize the tip on the nose and relieve stress in the components. The generally hemispherical bearing surfaces 60, 64 at the forward ends 58, 62 of the socket 20 and nose 18 are able to stably resist axial and non-axial rearward forces that are directly opposite the load (regardless of their direction of application). The use of a curved continuous front bearing surface reduces rattling of the tip on the nose and reduces stress concentrations that may occur when corners are present. The rear stabilizing surfaces 85, 95 are complementary to the front bearing surfaces 60, 64 by reducing rattling of the rear of the tip and providing a stabilizing resistance against the rear of the tip, as disclosed in U.S. patent No.5,709,043, which is incorporated herein by reference. By virtue of the stabilizing surfaces 85, 95 extending around the entire circumference, or at least substantially around the entire circumference, of the nose 18 (fig. 7, 9 and 11-14), they are also able to resist non-axially directed loads applied in any direction.

The main portion 76 of the socket 20 preferably has a generally trapezoidal transverse configuration to receive the matingly shaped nose 18 (fig. 7 and 11). The generally trapezoidal transverse configuration of the socket 20 generally follows the generally trapezoidal transverse configuration of the outer portion 97 of the tip 14. The cooperative shaping of the socket 20 and the outer portion 97 maximizes the size of the nose 18 that can be received within the tip 14 and allows the tip 14 to be easily manufactured during the casting process and improves the strength to weight ratio.

A wide variety of different locks may be used to releasably secure wear member 14 to base 12. However, in the preferred embodiment, lock 16 is received into an opening 101 in wear member 14, opening 101 preferably being formed in rear wall 27, although it could be formed elsewhere (fig. 1, 9 and 15-20). The opening 101 preferably has an axially elongated shape and comprises a front wall 103, a rear wall 105 and side walls 107, 109. A rim 111 is built around the opening 101 to protect the lock and provide additional strength. Rim 111 also expands along rear wall 105 to extend further beyond outer surface 97 and define an aperture 113 for passage of lock 16. This hole stabilizes the position of the lock 16 and allows easy access by the operator.

The nose 18 includes a stop 115 that projects outwardly from the upper side 68 of the nose 18 to engage the lock 16. The stop 115 preferably has a rear face 119 with a concave curved recess 121 into which the front end 123 of the lock 16 is received and retained in use, but other arrangements for cooperating with the lock may be employed. In a preferred configuration, opening 101 is long enough and rear wall 27 is sloped enough to provide clearance for stop 115 when wear member 14 is installed onto nose 18. However, if desired, a relief or other form of clearance may be provided in the socket 20 to allow the stop 115 to pass. Further, the protrusion of the stop 115 is preferably limited by providing a depression 118 to accommodate a portion of the lock 16.

Lock 16 is a linear lock oriented generally axially to retain wear member 14 to base 12 and secure the mounting of wear member 14 to nose 18. The use of an axially oriented linear lock increases the lock's ability to secure the wear member to the nose; i.e. it provides a greater length of tightening. In a preferred embodiment, lock 16 includes a threaded shaft 130 having a front end 123 and a rear end 134 with a head, a nut 136 threadedly engaged to shaft 130, and a spring 138 (FIGS. 1, 9 and 15-20). The spring 138 is preferably formed by a series of resilient discs 140, the discs 140 being constructed of foam, rubber or other resilient material and separated by spacers 142, the spacers 142 preferably being in the form of washers. The plurality of discs 140 are used to provide sufficient force, elasticity and take-up. The washers isolate the resilient discs so that they operate as a series of individual spring elements. The gasket 142 is preferably constructed of plastic, but may be made of other materials. Furthermore, a spring of preferred construction is economical to manufacture and assemble on the shaft 130. However, other types of springs may be employed. A thrust washer 142a or other device is preferably provided at the end of the spring to provide adequate support.

The shaft 130 extends centrally through a spring 138 to engage the nut 136. The front end 123 of the shaft 130 fits into the recess 121 such that the shaft 130 is disposed against the stop 115 for support. Rear end 134 of lock 16 extends through aperture 113 in wear member 14 to enable a user to access the lock outside of opening 101. The shaft is preferably set at an angle relative to axis 28 to allow easier access by head 134. A spring 138 is disposed between rear wall 105 and nut 136 such that it may apply a biasing force to the wear member during tightening of the lock. Aperture 113 is preferably larger than head 134 to allow passage thereof during installation of lock 16 to assembly 10. The hole 113 may also be formed as an open slot to accommodate simple insertion of the shaft 130 from above. Other tool engaging structures may be used in place of the illustrated head 134.

In use, the wear member 14 slides over the nose 18 such that the nose 18 fits into the socket 20 (fig. 1 and 9). The lock may be temporarily retained in the hole 113 for transport, storage and/or installation by a releasable retainer (e.g., a simple twist tie) located outside the opening 101 and mounted around the shaft 130, or it may be installed after the wear member is mounted on the nose. In any case, the shaft 130 is inserted through the hole 113 with its front end 123 disposed in the recess 121 of the stopper 115. Lock 16 is positioned along the exterior of nose 18 so that no holes, slots, etc. need be formed in the nose to accommodate the lock, thereby resisting loading. The head 134 is engaged and rotated by a tool to secure the lock in compression, thereby retaining the wear member; that is, the shaft 130 is rotated relative to the nut 136 such that the leading end 123 is pressed against the stop 115. This movement in turn draws the nut 136 back against the spring 138, the spring 138 being compressed between the nut 136 and the rear wall 105. Tightening of lock 16 pulls wear member 14 tightly onto nose 18 (i.e., front bearing surfaces 60, 64 engage) so that a snug fit is achieved during use with less wear. Continued rotation of the shaft 130 further compresses the spring 138. The compressed spring 138 then forces the wear member 14 rearward as the nose and socket begin to wear. The preferred nose 18 and tip 14 stability enables the use of an axial lock, i.e., no significant bending forces are applied to the lock, so that the wear member can be retained to the base with the high axial compressive strength of the bolt. The lock 16 is lightweight, striker-free, easy to manufacture, does not take up much space, and does not require any openings in the nose.

In a preferred construction, the lock 16 also includes an indicator 146 (fig. 15-20) mounted to the shaft 130 along with the nut 136. Indicator 146 is preferably a plate made of steel or other rigid material having side edges 148, 149 that fit proximate to side walls 107, 109 of opening 101, but not tightly into opening 101. The indicator 146 includes an opening that fully or partially receives the nut 136 to prevent the nut from rotating as the shaft 130 is rotated. The close receipt of the side edges 148, 149 to the side walls 107, 109 prevents the indicator 146 from rotating. Alternatively, the indicating portion may have a threaded hole serving as a nut; if the indicator is omitted, additional means are required to keep the nut 136 from rotating. The indicator 146 may also be discontinuous with the nut 136.

Indicator 146 provides a visual indication as to when shaft 130 has been properly tightened to apply the desired pressure to the wear element so as not to place undue stress on shaft 130 and/or spring 138. In a preferred configuration, the indicator 146 cooperates with a marker 152 formed along the opening 101, i.e., along the rim 111 and/or the sidewalls 107, 109. The marker 152 is preferably located on the rim 111 along one or both of the side walls 107, 109, but may have other configurations. The marker 146 is preferably a ridge or some structure, not just a marker, so that it can be used to re-tighten the lock 16 when wear begins to occur and is initially tightened.

When the shaft 130 is rotated and the nut 136 is pulled rearward, the indicator 146 moves rearward (from the position in fig. 16) with the nut 136 in the opening 101. When the indicator 146 is aligned with the marker 152 (fig. 15), the operator knows that the tightening can be stopped. In this position, lock 16 exerts a predetermined pressure on wear member 14 regardless of wear on the nose and/or in socket 20. Therefore, insufficient fastening and excessive fastening of the lock can be easily avoided. Alternatively, indicator 146 may be omitted and shaft 130 tightened to a predetermined amount of torque.

The various aspects of the invention are preferably employed together for optimal performance and advantages. However, the different aspects may be employed separately to provide the benefits that each provides.

Claims (18)

1. A wear member for excavating equipment comprising:

a working portion and a mounting portion generally aligned along a longitudinal axis, the mounting portion including a socket for receiving a base secured to the excavating equipment to mount the wear member on the excavating equipment, and the working portion being the portion of the wear member forward of the socket,

a front side adapted to act as a forward surface during advancement of the wear member through the ground during a digging operation, an

A rear side adapted to act as a rearward surface during advancement of the wear member through the ground,

the front and rear sides extend axially across the working portion and the mounting portion, and the front side has a greater width than the rear side in a cross-section perpendicular to the longitudinal axis along at least a portion of the mounting portion and the working portion.

2. A wear member in accordance with claim 1 including an opening for receiving a lock to secure the wear member to the base.

3. A wear member in accordance with claim 1 wherein the working portion is an elongated blade.

4. A wear member in accordance with claim 1 wherein the mounting portion has a generally trapezoidal transverse configuration perpendicular to the longitudinal axis.

5. A wear member in accordance with claim 4 wherein the working portion has a generally trapezoidal transverse configuration perpendicular to the longitudinal axis.

6. A wear member in accordance with claim 4 wherein substantially the entire length of the mounting portion has a generally trapezoidal transverse configuration perpendicular to the longitudinal axis.

7. A wear member in accordance with claim 1 wherein at least one wall of the socket is bowed inwardly to define a tab that fits into a slot formed in the base.

8. A wear member in accordance with claim 1 wherein the socket has a generally trapezoidal transverse configuration.

9. A wear member in accordance with claim 8 wherein each wall defining the trapezoidal shaped socket has a generally curved convex shape across substantially the entire width of the wall.

10. A wear member in accordance with any one of the preceding claims further comprising:

in the digging profile of at least the forward portion of the mounting portion, the sidewalls extending between the front and rear sides generally converge toward the rear side, the digging profile being a cross-section extending parallel to a direction of travel through the ground at a digging penetration center point and extending transversely to the longitudinal axis at least one digging angle.

11. A wear member in accordance with claim 10 wherein the sidewalls generally converge toward the rear side in the digging profile across substantially the entire length of the mounting portion.

12. A wear member in accordance with any one of claims 1-9 wherein the socket has a generally trapezoidal configuration transverse to the longitudinal axis and is defined by surfaces that are each inwardly curved in an arcuate shape.

13. A wear member in accordance with claim 12 wherein the surface of the socket is bowed inwardly across substantially the entire width of the surface of the socket.

14. A wear member in accordance with claim 12 wherein the front end of the socket includes a generally hemispherical front bearing surface.

15. A wear member in accordance with any one of claims 1-9 wherein the socket includes a front end defining a front bearing surface that is concave and curved about two axes each perpendicular to the longitudinal axis, and a main portion rearward of the front end and having a generally trapezoidal configuration transverse to the longitudinal axis.

16. A wear assembly for excavating equipment comprising:

a base secured to the excavating equipment;

a wear element according to any one of claims 1-9; and

a lock releasably securing the wear member to the base.

17. A wear assembly in accordance with claim 16 wherein the base includes a nose received into the socket, and wherein the nose and the socket each have a generally trapezoidal transverse configuration perpendicular to the longitudinal axis.

18. The wear assembly of claim 16 wherein the base includes a nose received into the socket, the nose including a plurality of slots, the socket including a plurality of projections received into the slots.