Patent Description:
During mining and construction operations, replaceable wear members are typically used to protect earth working equipment such as excavation buckets. During use, the wear members gradually wear down due to the abrasive conditions and heavy loading. Once depleted, the wear members are removed from the equipment and replaced. Using wear members provides a cost-effective approach to digging and other earth working operations because it lessens the need of having to repair or replace the more expensive underlying equipment such as the lip or other portions of the equipment.

Wear members are commonly secured to earth working equipment by mechanical means (for example, a lock pin, bolt, or other locking mechanism). During earth working operations, wear members may be subjected to a variety of directional forces, which can include axial, vertical, and lateral loads. Retention of the wear members over their service life prevents damage to downstream equipment such as crushers, limits maintenance downtime of the earthmoving equipment and prevents damage to underlying wear surfaces.

The present invention pertains to a shroud for covering an earth-working edge on earth working equipment which includes a front end and a rearwardly-opening cavity. The cavity has opposed first and second surfaces to straddle the edge and a front surface extending between the first and second surfaces. The first surface includes a recess with opposed planar bearing surfaces to bear against a boss on the edge. These bearing surfaces converge toward the front surface. A similar shroud is taught by <CIT>.

However, the shroud of this prior art reference is not quite mechanically secured to the equipment and the object of the instant invention is to improve the attachment of the shroud to the equipment.

To this end, the instant invention relates to a shroud for an earth-working edge on earth-working equipment according to claim <NUM>.

The shroud of the invention is reliable, safe, easy to use, versatile, given to high productivity and/or readily replaceable with little machine downtime.

In another embodiment, one of the first bearing surfaces is parallel to the second bearing surfaces and the other first bearing surface is transverse to the second bearing surfaces.

In another embodiment, a lip assembly for an earth working bucket includes a lip and a shroud as defined in claim <NUM>. The lip has a forward-facing leading surface, primary segments where the leading surface extends parallel to the width of the bucket, and transition segments where the leading surface is inclined to the primary segments. The shroud is secured to a transition segment.

In another embodiment the instant invention relates to a process for installing a shroud on an earth-working edge on earth working equipment according to independent claim <NUM>.

The foregoing and other objectives, features, and advantages of the disclosed embodiments will be more readily understood in view of the following detailed description of certain embodiments and the accompanying drawings. Understanding that the drawings depict only certain embodiments and are not, therefore, to be considered limiting in nature, these embodiments will be described and explained with additional specificity and detail.

Wear members are applied to many kinds of earth working equipment to extend the service life of the equipment. The present invention is related to wear members and locking systems for securing the wear members to edges of earth working equipment, wear assemblies involving the same, edges of earth working equipment, and processes for installing wear members on such edges.

The figures show one embodiment of a wear assembly <NUM> including a wear member <NUM> for attachment to earth working equipment. In the illustrated example, the wear member is a shroud <NUM> attached to an edge of an earthmoving bucket; the edge as shown is defined by a lip <NUM> having an elongate body with a bottom or outer surface 14A, a top or inner surface 14B and a leading surface 14C. In this example, inner surface 14B includes a beveled portion or surface 14D adjacent leading surface 14C, and a rear portion rearward of the beveled portion. Shrouds in accordance with the invention may also be secured to the sidewalls of the bucket, ripper shanks, and/or other edges of earth working equipment; that is, shrouds <NUM> can be used in connection with a variety of different earth working components having earth working edges including, for example, buckets, lips, ripper shanks and the like.

The wear member <NUM> preferably includes an opening <NUM> that receives a lock <NUM> to releasably secure the wear member to the edge. The edge can have a variety of different designs including those with a linear leading surface, or a leading surface that is stepped or swept such that the center portion is forward or rearward relative to outer portions of the edge. The edge has a direction of advance during operation of the earth working equipment (e.g., a digging operation) that is generally in the direction to arrow <NUM> (<FIG> and <FIG>); this is referred to as the forward direction herein. The actual movement of the edge during operation can be a generally linear advance (such as, e.g., with a dragline bucket or ripper shank) or a compound motion with a swinging movement (such as, e.g., with a hydraulic excavator).

In the example of a bucket, the edge can be defined by a lip <NUM>. Teeth <NUM> and shrouds <NUM> are secured along the front of the lip. In the illustrated example (<FIG>), each tooth <NUM> includes an adapter <NUM> with rearward extending legs that are welded to the top and bottom surfaces of the lip or secured by mechanical means. The adapter includes a forwardly projecting nose <NUM> onto which is received a point 8A that is secured to the adapter by a lock (not shown). Shrouds <NUM> are secured to lip <NUM> in between adjacent teeth <NUM>. Other configurations of the lip, the teeth and shrouds are possible. As one alternative example, the lip may include only shrouds such as in an LHD bucket. The lip can be formed by a casting process, or the lip can be cut from plate. The lip can also be welded together from separately formed sections.

The shroud <NUM> includes a front end or working portion <NUM> and a rear end or mounting portion <NUM> (<FIG>). In this embodiment, the working portion tapers to a narrowed front working edge 26A but other constructions are possible. During use, the working portion <NUM> contacts the earth or other material during the excavation process to protect the lip, ease penetration and/or gather material in the bucket. The mounting portion <NUM> includes a first leg <NUM>, which in the illustrated embodiment is an inner or top leg <NUM>, and an opposite second leg <NUM>, which is an outer or bottom leg <NUM>. The legs <NUM>, <NUM> are spaced to define a cavity <NUM> to receive the lip <NUM> such that each leg extends rearward along the lip when the shroud is installed. A front surface or end wall <NUM> joins the first and second legs at the front end of cavity <NUM>.

The first leg <NUM> has an interior surface <NUM> that forms a first or inner surface of cavity <NUM>, and which can include one or more first or inner bearing surfaces <NUM> that bear against the inner or top surface of the lip when assembled (<FIG> and <FIG>). The first bearing surfaces in this example are formed as raised bearing pads 34A, 34B, though they need not be so formed; the interior surface <NUM> itself could form the bearing surface or there could be other arrangements. The inner bearing surfaces bear on the beveled edge 14D of the lip. Alternatively, the forward bearing surfaces 34A are inclined to the rear bearing surfaces 34B such that bearing surfaces 34A bear against the front bevel surface 14D of the lip while bearing surfaces 34B bear against the inner or top surface 14B of the lip. The first leg also includes a rear surface 30A.

The second or outer leg <NUM> includes an interior surface <NUM> that defines a second or outer surface of cavity <NUM>. Interior surface <NUM> can include one or more second or outer bearing surfaces <NUM> to bear against the generally planar outer or bottom surface 14A of the lip (<FIG>). In this example, second bearing surfaces <NUM> are formed as raised bearing pads, but they need not be; the interior surface <NUM> itself could define the bearing surface or there could be another arrangement. The second leg includes a rear surface 32A (<FIG> and <FIG>).

The front surface <NUM> extends between and joins legs <NUM>, <NUM>. Front surface <NUM> is adjacent to or bears against the leading or front surface 14C of the lip <NUM> when the shroud is fully installed on the lip. Opening <NUM> extends through the first leg <NUM> and opens to cavity <NUM> to receive a lock <NUM>. Other arrangements for securing the wear member are possible. Other variations in the wear member <NUM> are also possible. For example, the cavity of the wear member is shaped to correspond to the configuration of edge <NUM>, and could have varied shapes to complement different edges.

Each shroud <NUM> has a longitudinal axis <NUM> that is defined by a centerline extending generally in the direction of advancement of the edge <NUM> during operation of the earth working equipment (<FIG> and <FIG>). A datum line <NUM> extends along the front surface <NUM> and corresponds to the leading surface 14C when the shroud is installed. While the front of cavity <NUM> (i.e., along front surface <NUM>) could have various configurations (such as including recesses), the front surface <NUM> is that portion of the front of the cavity that extends generally parallel to the leading edge it is designed to oppose.

The first leg <NUM> preferably includes a first or clearance recess <NUM> in interior surface <NUM> that extends forward from rear leg surface 30A (<FIG>). Within first recess <NUM> is a first supporting recess <NUM> that extends at a greater depth from the interior surface <NUM> than first recess <NUM>. Recess <NUM> includes bearing surfaces 50A and 50B that converge in a forward direction, i.e., toward front surface <NUM>. In this example, bearing surfaces 50A, 50B extend forward of opening <NUM> but other arrangements are possible. Bearing surfaces 50A, 50B can be planar, but other surface shapes are possible such as curved converging surfaces. A first recess axis <NUM> extends centrally between bearing surfaces 50A, 50B, and perpendicular to front surface <NUM>. A rear recess 50C extends between rear leg surface 30A and opening <NUM> in general alignment with supporting recess <NUM>, though in this example with a different extension (which is not necessary). Although recesses <NUM>, 50C are discussed herein as separate recesses separated by opening <NUM>, they could be considered as a single recess with front and rear portions. Rear recess axis <NUM> extends as a centerline of rear recess 50C and is generally parallel to the longitudinal axis <NUM> of shroud <NUM>. Other alternatives are possible. For example, the first leg may only have a supporting recess <NUM> without the rear recess 50C provided sufficient clearance exists to receive the corresponding boss <NUM>. Also, as another example, the bearing surfaces 50A, 50B could project from interior surface <NUM> to form recess <NUM> rather than be formed within a depression in the interior surface. Bearing surfaces 50A, 50B could also alternatively be formed in second leg <NUM> with a corresponding shift of the boss <NUM> it receives to the opposite surface 14A of edge <NUM>. Other constructions are possible. In some embodiments, the rear recess axis <NUM> can be generally parallel to recess axis <NUM>. Other arrangements are possible.

The lip <NUM> includes a first or inner boss <NUM> on the bevel 14D of an inner or upper surface 14B of the lip (<FIG> and <FIG>). Nevertheless, boss <NUM> could be rearward of bevel 14D or used on a lip without a bevel. The first boss includes side bearing surfaces 20A and 20B (<FIG>, <FIG>) against which bearing surfaces 50A, 50B bear, and a rear bearing surface 20E against which lock <NUM> bears when shroud <NUM> is installed on lip <NUM>; though other locks that bear on other surfaces are possible. The first boss <NUM> can include a base with a mounting surface 20F that sets against the edge. The base may include mounting wings 20W, though other mounting arrangements are possible. As one example, the wings could be omitted. The side bearing surfaces 20A and 20B can be formed on a lug 20D extending upward from the base. The rear bearing surface 20E extends transversely between side bearing surfaces 20A and 20B and faces generally rearward to abut lock <NUM>.

The side bearing surfaces 20A, 20B of the boss <NUM> are preferably planar and converge in a forward direction from transverse bearing surface 20E. Side bearing surfaces 20A and 20B can, for example, converge forward at an angle of <NUM>-<NUM> degrees to each other. Preferably, the side bearing surfaces converge forward at an angle of <NUM>-<NUM> degrees to each other. The convergence of bearing surfaces 20A, 20B, though, could be outside these ranges. Bearing surfaces 50A, 50B also preferably have the same angular orientation as side bearing surfaces 20A, 20B. Boss <NUM> has a first boss axis 100A defined by the centerline between side bearing surfaces 20A, 20B. Boss axis 100A is generally perpendicular to the leading surface 14C of the lip that is closest to where boss <NUM> is fixed. Boss <NUM> can be attached to the lip by welding or other attachment means (e.g., bolts), machined in the lip or as cast configuration of the lip.

On assembly of shroud <NUM> to lip <NUM>, cavity <NUM> receives lip <NUM> as the shroud moves rearward. Installing shroud <NUM> in a direction parallel to the direction of advance of the lip limits interference with adjacent teeth and/or noses secured to or forming part of the lip. This arrangement permits removal and/or installation of the shrouds without the need to remove points and/or adapters of adjacent teeth. Supporting recess <NUM> receives boss <NUM> such that bearing surfaces 50A, 50B oppose bearing surfaces 20A, 20B when shroud <NUM> is installed on lip <NUM>. First recess <NUM> and rear recess 50C provide clearance for receiving boss <NUM> in recess <NUM>, and/or for the boss mounting wings 20W or other mounting arrangement.

With the shroud seated on the lip and boss <NUM> received in recess <NUM> of the shroud, lock <NUM> can be inserted into a hole or opening <NUM>. Opening <NUM> includes a bearing wall 24A to bear against a rear side of lock <NUM>. The opposite front side of the lock bears on bearing surface 20E of first boss <NUM>. Longitudinal forces on the shroud that urge the shroud off the lip are countered as the lock bears on the bearing wall 24A and bearing surface 20E to secure the shroud on the lip <NUM>. Opening <NUM> is preferably elongate and defines a major axis 24B along its length, though other opening shapes are possible. Opening axis 24B is preferably parallel to front surface <NUM>, though opening axis 24B may be inclined or perpendicular to the longitudinal axis <NUM> of the shroud. In one example, opening axis 24B is angled relative to longitudinal axis <NUM> between <NUM> to <NUM> degrees, though orientations outside this range are possible. The orientation of the lock opening (i.e., the opening axis 24B) corresponds to the orientation of the first boss <NUM> (i.e., to transverse surface 20E). Other locks fit into other openings is possible.

In the illustrated embodiment, lock <NUM> can include two portions that fold between an extended position that has a length that is longer than opening <NUM> (along major axis 24B) in exterior surface <NUM> of first leg <NUM> to prevent loss or removal of the lock from the wear member, and a folded position with a length that is shorter than opening <NUM> to permit release and/or removal of the lock from the opening, which may be when the shroud is installed on and/or removed from the lip. The lock can be of the kinds such as disclosed in <CIT> or <CIT>. Other lock configurations for securing the shroud to the lip are possible; various hammerless and hammered locks can be used.

As loads are applied to the shroud during earth working operations, bearing surfaces 50A and 50B of the supporting recess <NUM> bear on boss surfaces 20A and 20B to transfer loads to the lip. Mounting the first boss to the beveled portion of the lip allows the shroud to be mounted to certain lips of differing thicknesses. This enables the manufacture and/or stocking of fewer shroud sizes. Securing boss <NUM> to the bevel surface 14D can also enable the shroud to have a lower weight, a slimmer profile for easier penetration and/or less blocking of material in and out of the bucket. In one alternative embodiment, a boss <NUM> is only provided on one surface of the lip, which in this example is on the inner side 14B and specifically on ramp 14D, though the one boss could be provided rearward of ramp 14D or on outer side 14A. In another example, boss <NUM> could have a forward extension that overlies leading surface 14C.

The second leg <NUM> of shroud <NUM> includes a second supporting recess <NUM> in interior surface <NUM> that extends forward from back wall 32A to receive a second or outer boss <NUM>. Recess <NUM> includes side bearing surfaces 46A and 46B and, optionally, a chin recess 46C further recessed from interior surface <NUM>. The recess <NUM> has a second recess axis <NUM> defined by a centerline between side bearing surfaces 46A, 46B, and which is generally parallel to longitudinal axis <NUM> of shroud <NUM>. The chin recess 46C can be defined by a ramp surface 46D inclined to interior surface <NUM>. Alternatively, the chin recess can optionally also or in lieu of include a base surface 46E generally parallel to the interior surface <NUM> forward of ramp surface 46D. Other configurations of a chin recess are possible.

The lip includes a second or outer boss <NUM> on the lower surface 14A of the lip. The second boss includes side bearing surfaces 22A and 22B, and optionally a chin 22E that extends outward from the lip in a forward direction (<FIG>). Side bearing surfaces 22A and 22B can be parallel to each other. Alternatively, the side bearing surfaces can converge in a forward direction. Other configurations are possible. Boss <NUM> includes a mounting surface 22F that sets against the lip and an opposite outer surface 22D. Boss <NUM> can be attached to the lip by welding or by other attachment means (e.g., bolts). Boss <NUM> includes a second boss axis 102A defined by a centerline between bearing surfaces 22A, 22B, which will be generally parallel to the direction of lip advancement shown by arrow <NUM>.

On assembly of shroud <NUM> to lip <NUM>, cavity <NUM> receives lip <NUM> as the shroud moves rearward in relation to the lip along a direction opposite of arrow <NUM>. First recess <NUM> receives first boss <NUM> and second recess <NUM> receives second boss <NUM>. With the shroud fully seated on the lip, the side bearing surfaces 50A and 50B of first supporting recess <NUM> oppose bearing surfaces 20A and 20B of the first boss <NUM>, and side bearing surfaces 46A and 46B of second supporting recess <NUM> oppose side bearing surfaces 22A and 22B of second boss <NUM>. In the illustrated example, chin 22E is received in chin recess 46C, and lock <NUM> is received in opening <NUM> to secure the shroud to the lip as previously described.

As loads are applied to the shroud during earth working operations, bearing surfaces 50A and 50B of recess <NUM> bear on the bearing surfaces 20A and 20B of boss <NUM> to transfer loads applied to the shroud during earth working operations to the lip. Bearing surfaces 46A and 46B of recess <NUM> also bear on bearing surfaces 22A and 22B of boss <NUM> to transfer loads to the lip. Applied loads are transferred from the shroud to the lip through the bosses and bearing surfaces to limit wear to the lip. Applied loads are also transferred through the legs of the boss to the edge. The chin and the chin recess include inclined surfaces to resist reverse forces on the shroud urging the shroud off the lip, and thereby reduce such forces acting on the lock; as noted above, the chin and chin recess could be omitted. The use of a top boss only or the use of separate top and bottom bosses (<FIG>) allow the same shroud to be mounted to lips of different thicknesses, which can reduce the number of different kinds and/or sizes of shrouds that need to be made or kept in inventory. In the illustrated example, the bosses are welded to the lip. Alternatively, one or both bosses can be integral with the lip; for example, the bosses could be included as part of a cast lip. Alternatively, one or both bosses could be formed by adding welding material to the lip or by other means.

<FIG> shows an exploded top view of lip <NUM> with shrouds <NUM> and teeth <NUM>. The lip is stepped or swept so the center of the lip extends farther forward than the outer portions. In an alternative construction, the center portion could extend farther rearward than the outer portions. In this example, lip <NUM> includes a plurality of spaced apart stepped segments <NUM> where the leading edge 14C of the lip extends generally perpendicular to the advance of the lip along arrow <NUM>, and a plurality of transition segments <NUM> interconnecting adjacent step segments <NUM>. As shown in <FIG>, lip <NUM> includes a central step segment 60A and an outer step segment 60B, 60C to each side of the central step segment 60A. Additional outer step and transition segments could and would usually also be included outside step segments 60B, 60C (not shown). Each step segment <NUM> could be identical or there could be differences. The leading edges 14C of transition segments <NUM> are inclined to the leading edges 14C of step segments <NUM>; the angle of inclination α is commonly less than <NUM>°, but other configurations are possible. Straight lips have a linear leading edge across the width of the bucket and, thus, will have zero angle of inclination on the transition segments extending between adjacent teeth. With a straight plate lip, there may be no differences between step and transition segments. Transition segments <NUM>, 62R to each side of central step segment 60A are preferably mirror images of each other, with transition segment <NUM> inclined in one direction and transition segment 62R inclined in the opposition direction, but all preferably at the same angle of inclination. In this example, two teeth <NUM> are secured to each step segment, and a shroud <NUM> is secured between each pair of adjacent teeth <NUM>. Accordingly, shrouds <NUM> are secured to both step segments and transition segments. Nevertheless, various other configurations are possible. As one example alternative, one tooth could be secured to each step segment and a shroud secured to each transition segment.

Bosses <NUM> are secured to each segment <NUM>, <NUM> that mounts a shroud <NUM>. In this example, the lip includes a left boss <NUM> on a left transition segment <NUM>, a center boss 20C on center step segment 60A, and a right boss 20R on a right transition segment 62R; left and right used herein is solely for ease of explanation based on the view in <FIG>. A left shroud <NUM> is shown to mount to boss <NUM>. A center shroud 12C is shown to mount to boss 20C. A right shroud 12R is shown to mount to boss 20R. While bosses <NUM> all preferably have the same construction, they are each secured at different orientations on the lip. Left and right shrouds are inclined in opposite directions to correspond to the inclination of the leading surfaces of transition segments <NUM> to which each attach. The boss axis 100A for each first boss <NUM> is generally perpendicular to the leading edge 14C of the step or transition segment <NUM>, <NUM> to which it is secured, and generally perpendicular to the front surface <NUM> of the shroud <NUM> mounted over it. In <FIG>, datum lines <NUM>, 38C, 38R show the orientation of the front surfaces <NUM> of the three different shrouds <NUM>, 12C, 12R. As can be seen, front surfaces <NUM> of left and right shrouds <NUM>, 12R are inclined to the advance direction <NUM> of lip <NUM>. Since front surfaces <NUM> correspond to leading edge 14C of the different lip segments <NUM>, <NUM>, front surfaces <NUM> of left and right shrouds <NUM>, 12R are preferably inclined more than <NUM>° to the direction of advance of the lip (i.e., arrow <NUM>); though other orientations are possible. The front surface <NUM> of center shroud 12C will be generally perpendicular to the direction of lip advancement (i.e., arrow <NUM>), and perpendicular to boss axis 100A of center boss 20C. Some lips can include only left shrouds and right shrouds with no center shrouds. Alternatively, a straight lip with no inclination will include only center shrouds.

<FIG> shows an exploded bottom view of lip <NUM> with shrouds <NUM> and teeth <NUM>. The bottom surface 14A of the lip includes bosses <NUM> secured to each lip segment <NUM>, <NUM> to which a shroud is secured. In this example, boss <NUM> is secured to transition segment <NUM>, boss 22C is secured to primary or step segment 60A, and boss 22R is secured to transition segment 62R. Each of the second bosses <NUM> preferably have the same construction, and the same orientation, i.e., such that second boss axes 102A are each generally parallel to the direction of lip advancement (i.e., line <NUM>).

<FIG> shows shroud <NUM> about to be installed on transition segment <NUM> of lip <NUM>. First boss <NUM> will be received in first supporting recess <NUM>, and second boss <NUM> will be received in second supporting recess <NUM>. As can be seen, the boss axes 100A, 102A are angularly oriented to each other (<FIG>, <FIG> and <FIG>) in a lateral direction (i.e., in a side-to-side direction and not with respect to axial or vertical directions). The second recess axis <NUM> is parallel to and aligned with second boss axis 102A. The receipt of boss <NUM> into recess <NUM>, then, controls the installation movement of shroud <NUM>. This movement is parallel to the direction of lip advancement along arrow <NUM> and to the extension of teeth <NUM> from the lip so the shroud may be installed and removed without interference from the teeth. Bearing surfaces 20A, 20B and 50A, 50B are angled to resist the rearward and side loads applied to shrouds. When shroud <NUM> is secured to a transition segment <NUM>, recess axis <NUM> and boss axis 100A are inclined to the direction of lip advancement. In connection with shroud <NUM>, bearing surface 20A of first boss <NUM> is generally aligned with bearing surface 22A of second boss <NUM>. During installation of shroud <NUM>, then, bearing surface 50A will move parallel to bearing surface 20A, bearing surface 46A will move parallel to bearing surface 22A, and bearing surface 46B will move parallel to bearing surface 22B. However, bearing surface 50B will move toward bearing surface 20B until they meet in opposition to each other when shroud <NUM> is fully seated on lip <NUM>. Clearance recess <NUM> and rear recess 50C enable boss <NUM> to be pass into a fully seated position against bearing surfaces 50A, 50B on shroud <NUM>. Other shaped recesses or other constructions could be used to provide the needed clearance. Removal of shroud <NUM> will be the reverse of the installation.

The installation of right shrouds 12R would be the mirror image of the installation of shrouds <NUM>. In particular, bearing surface 50B of first supporting recess <NUM> will move parallel to bearing surface 20B of first boss 20B, while bearing surfaces 46A, 46B move parallel to bearing surfaces 22A, 22B. Bearing surface 50A during installation will move toward and then meet bearing surface 20A when the shroud is fully seated. Removal of shroud 12R will be the reverse of the installation.

In the installation of a center shroud 12C, bearing surfaces 46A, 46B of second supporting recess <NUM> move parallel to bearing surfaces 22A, 22B of second boss <NUM>. However, both bearing surfaces 50A, 50B of recess <NUM> will move toward bearing surfaces 20A, 20B, respectively, until both meet in opposition to each other. This is also the case for shrouds mounted on straight lips and spade lips with spade lips where the transition segments have a smaller inclination. Removal of shroud 12C will be the reverse of the installation.

Shroud <NUM> can optionally include an opening <NUM> that receives a mechanically attached lifting eye <NUM> such as disclosed in <CIT>. A cast-in eye (not shown), one or more eyes in other locations, or no eye could be used.

One or both bosses can optionally incorporate strain reliefs. The first boss <NUM> can include strain relief <NUM> between the side bearing surfaces and the boss wings 20W (<FIG>). The boss wings can be welded to the lip and the middle portion of the boss (i.e., the portion between boss wings 20W and supporting boss lug 20D) remains without being rigidly secured to the lip. Strain reliefs such as cutouts of the boss material or a section of material with different material properties can be incorporated between the boss lug and the wings. Loads applied to the boss will, then, cause the boss lug to deflect. The loads may be partially absorbed at the strain reliefs at the sides of the boss lug to spread the load more evenly over the wing welds. This limits stress concentrations that can result in cracking at the welds. Other kinds of strain relief such as disclosed in <CIT>, by could also be used.

Opening <NUM> can optionally be configured with two positions for lock <NUM> (<FIG>), a locking position and a release position, such as disclosed in <CIT>.

The wear assembly provides support for the wear member during operation. Forces applied to the wear member <NUM> can cause the wear member to shift and bear on the leading surface 14C, converging faces 20A, 20B of the first boss <NUM>, the side bearing surfaces 22A, 22B of the second boss <NUM> and/or the outer and inner surfaces 14A, 14B. Bottom and/or reverse loads can be resisted in part through chin 22E and recess 46C if a chin is provided. The loads applied to the bosses are transferred through the bosses to the lip. The first boss <NUM> can be attached to the beveled front surface of the lip. This allows the wear member to be used with a range of different lip thicknesses without stocking different bases for different lip configurations, thus reducing the need to manufacture or hold inventory of additional kinds of parts for certain lips with different thicknesses. The wear assembly can provide reduced weight and/or profile and/or efficient replacement of worn wear members, and/or can reduce downtime and/or operating expenses for earth working equipment.

Claim 1:
A shroud (<NUM>) for an earth-working edge (<NUM>) on earth working equipment comprising a front end (<NUM>) and a rearwardly-opening cavity (<NUM>) including opposed first (<NUM>) and second (<NUM>) surfaces to straddle the edge and a front surface (<NUM>) extending between the first and second surfaces, the first surface (<NUM>) including a recess (<NUM>) with a first longitudinal axis (<NUM>) and opposed planar bearing surfaces (50A, 50B) to bear against a first boss (<NUM>) on the edge (<NUM>), wherein the bearing surfaces (50A, 50B) converge toward the front surface (<NUM>), and the second surface (<NUM>) including a recess (<NUM>) with a second longitudinal axis (<NUM>) and opposed planar bearing surfaces (46A, 46B) to bear against a second boss (<NUM>) on the edge (<NUM>), characterized in that the second longitudinal axis (<NUM>) is angularly oriented in a lateral direction to the first longitudinal axis (<NUM>).