Patent Description:
Wear parts are commonly attached to earth-working equipment such as excavating buckets and the like. For example, teeth and shrouds are generally mounted along the digging edge of an excavating bucket to protect the bucket from wear and to enhance the digging operation. Such wear assemblies typically include a base, a wear member, and a lock to releasably hold the wear member to the base. The base is fixed to the equipment as an integral part of the equipment, or as one or more components that are fixed to the equipment by welding or mechanical attachment. The wear member fits over the base. The assembled base and wear member cooperatively define a cavity into which the lock is received to releasably hold the wear member to the base.

Wear members for earth-working equipment are commonly subjected to harsh conditions and/or heavy loading. Accordingly, it is desirable for the locks to have the strength needed to effectively retain the wear member to the equipment, resist ejection during use, and be easy to install and remove in the field when replacement of the wear part is needed. Many different lock arrangements have been designed in an effort to meet these objectives with varying degrees of success.

According to the invention an articulated lock is provided having the features of claim <NUM> and a method of securing a wear member to earth working equipment with such a lock as defined by claim <NUM>.

The present invention pertains to wear parts <NUM> for earth-working equipment <NUM>. In one embodiment, wear part <NUM> includes a wear member <NUM> and a lock <NUM> for releasably securing the wear member <NUM> to earth-working equipment <NUM>. In this example, wear member <NUM> is a shroud secured to a lip <NUM> of an excavating bucket by a lock <NUM> (<FIG>). Nevertheless, the wear members could have other forms (for example, other kinds of shrouds, excavating teeth, runners, liners, blades, etc.). Also the wear member could be secured to other kinds of earth-working equipment (e.g., mold boards, dredge cutter heads, ore chutes, truck bodies, etc.). In this description, relative terms such as forward, rearward, up or down are used for convenience of explanation with reference to the figure; other orientations are possible.

<FIG> illustrate a shroud <NUM> fit onto a lip <NUM> between two noses <NUM> that support excavating points (not shown). In this one embodiment, lip <NUM> includes a base <NUM> that may be fixed into place via welding <NUM> (<FIG>), though the base could be cast as part of the lip. The base <NUM> includes a boss <NUM> along the front edge <NUM> of the lip <NUM>. Base <NUM> includes a rear bearing surface <NUM> on a rear side of boss <NUM>, and a rearward surface <NUM> rearward of boss <NUM>. The bearing surface <NUM> and rear surface <NUM> define a step or recess <NUM> for receiving the lock. Boss <NUM> further includes a forward facing front thrust surface <NUM> for abutting a corresponding front bearing surface <NUM> in the cavity <NUM> in the wear member. Boss <NUM> also includes side bearing surfaces <NUM> preferably extending axially from front thrust surface <NUM> to rear bearing surface <NUM>. The base, of course, could have many different constructions to cooperate with various wear members.

In this example, wear member <NUM> includes a pair of legs <NUM>, <NUM> to straddle lip <NUM>, and a wearable exterior surface <NUM>. An inner surface <NUM> of top leg <NUM> includes a recess <NUM> to provide clearance when passing the shroud <NUM> over the boss <NUM> and to receive the boss <NUM> within a forward position in the recess <NUM>. Recess <NUM> is bordered by side walls <NUM> to oppose and bear against side bearing surfaces <NUM> and front bearing surface <NUM>. The recess <NUM> may be a hole in leg <NUM> or as an offset surface around the boss at the forward portion (<FIG>). A hole <NUM> is provided through the leg <NUM> to receive lock <NUM>. In the example illustrated, the hole <NUM> has a longitudinal axis <NUM> arranged transverse to a central axis <NUM> of the shroud <NUM>. The hole <NUM> includes a back wall <NUM>, a front wall <NUM> and opposing end walls <NUM>. Hole <NUM> and recess <NUM> collectively define an opening <NUM> into which lock <NUM> is received in the hold position.

The end walls <NUM> each includes retainers <NUM>, <NUM> to interact with lock <NUM> and support the lock in release and hold positions. With the lock in the release position, wear member <NUM> can be installed on or removed from base <NUM> (i.e., the earth-working equipment). With lock <NUM> in the hold position, the wear member can be secured to the base <NUM>. In the illustrated embodiment, retainers <NUM>, <NUM> are protrusions that extend inward from end walls <NUM>. Nevertheless, retainers <NUM>, <NUM> could have other constructions such as, e.g., being formed as one or more recesses that receive complementary projections on the lock or e.g., could be formed on the front and rear walls <NUM>, <NUM>.

Moreover the retainers could be formed as a single retainer formation that permits mounting of the lock in both the release and hold positions. For example, the ends of the lock could have two different formations to receive a single retainer in the hole to secure the lock in two positions. Accordingly, even though this disclosure generally refers to two retainers <NUM>, <NUM> on each end wall, the number of retainers is not important. There could be one or more than two retainers provide to secure the lock in the release position and the hold position.

The first or outer retainer <NUM> is, in this embodiment, in an outward position, i.e., proximate outer surface <NUM> of wear member <NUM> (<FIG>, <FIG>). The second or inner retainer <NUM> is, in this embodiment, in an inward position, i.e., proximate inner surface <NUM> of wear member <NUM> (<FIG>, <FIG>). In this embodiment, lock <NUM> is received in gap <NUM> such that both retainers <NUM>, <NUM> function to secure lock <NUM> in the release position. In the illustrated example, the second retainer <NUM> has a substantially semi-cylindrical surface. The first retainer <NUM> includes a curvilinear portion <NUM> and a substantially straight portion <NUM> (<FIG>) to reduce its upward extension and the thickness of top leg <NUM>. Second retainer <NUM> preferably has a fuller contact with the lock to resist the anticipated heavier loads applied during use such as during a digging operation. The retainers, though, could have the same shape (e.g., both could be formed as a semi-cylindrical protrusion as shown for retainer <NUM>), or either could have different shapes than shown. The first retainer <NUM> may be continuous or discontinuous as illustrated (<FIG>), i.e., with a central gap <NUM> to provide access to enable fines to be more readily cleaned from opening <NUM>. Although not illustrated here, the second retainer <NUM> may also, or instead, be discontinuous.

The first retainer <NUM>, in this example, protrudes into hole <NUM> a shorter distance than the second protrusion <NUM>, although this is not necessary. A first or medial pocket or gap <NUM> is located between the retainers <NUM>, <NUM>. A second or inward pocket or gap <NUM> is located inward of retainer <NUM> (i.e., between retainer <NUM> and inner surface <NUM>). The pockets <NUM>, <NUM> may include straight, curvilinear or other surfaces (<FIG>, <FIG>, <FIG>). As illustrated, the second protrusion <NUM> may be made to include a substantially semi-cylindrical profile to provide a robust contact surface to contact the lock <NUM> in both an outward and an inward direction.

The lock <NUM> can be fitted within opening <NUM> to hold wear member <NUM> to the earth-working equipment <NUM>. In general, with wear member <NUM> on lip <NUM>, lock <NUM> is secured to second retainers <NUM> to oppose bearing face <NUM> of boss <NUM> and bearing surface <NUM> in hole <NUM> to hold the wear member <NUM> in place; i.e., with lock <NUM> in the hold position in opening <NUM>, the wear member cannot be pulled from the lip <NUM> (<FIG>).

In the illustrated embodiment, the lock <NUM> can be held at two different places on the wear member <NUM>. The two places may be defined as a release position (e.g., where the lock is placed for shipping, storage and/or installation) (<FIG>), and a hold position (e.g., where the lock can secure the wear member to the base) (<FIG>). The release position is where the bottom lobe <NUM> of the lock <NUM> is positioned between the inner retainer <NUM> and the outer retainer <NUM>. The release position may also be defined as the inner lobes <NUM> are fitted into complementarily sized and shaped pockets <NUM>. The pockets <NUM> may tend to "grip" the inner lobe <NUM>. Other constructions are possible.

The lock may also have two different configurations: an unlocked or folded configuration where the lock can be installed or removed from the hole <NUM> and retainers <NUM>, <NUM>, and a locked or unfolded configuration where the lock can engage the retainers <NUM>, <NUM> in hole <NUM>. The lock may be installed in the release position of the hole at the time of manufacture, i.e., wherein one lock is securely mated with one wear member for shipping, storage and/or installation. When at a jobsite, while still in the locked configuration in the release position, the shroud can be installed on the base <NUM>, i.e. installed onto the earth-working machine without modifying the lock in any way. The lock may then be adjusted to the unlocked condition and disengaged from the release position, and installed in the locked configuration engaging retainers <NUM> in the hold position on the wear member. In one example, the lock may be secured in the locked configuration with a single substantially rigid insert <NUM>. The insert <NUM> may be a metal insert <NUM> made of, for example, steel. The lock may, then, be held in place without the need for an additional element, such as a latch, or an elastomer. Other lock constructions are possible.

In the illustrated embodiment, lock <NUM> includes two bodies or components <NUM>, <NUM> (<FIG>) that are pivotally coupled together for movement about a lateral axis <NUM> between a locked condition (<FIG>) and an unlocked condition (<FIG>). The two bodies or components <NUM>, <NUM> may be positioned to contact each other at respective first and second inner, or contact, faces <NUM>, <NUM> (<FIG>). The junction of the contact faces <NUM>, <NUM> may define a split line <NUM> (<FIG>) wherein the lock <NUM> is separable into the two lock bodies <NUM>, <NUM>. While faces <NUM>, <NUM> preferably contact each other (in this and the other disclosed embodiments), they could be spaced apart, i.e., where contact between the two bodies is elsewhere, e.g., in the interlocks.

Relative pivoting or hinging of the two bodies <NUM>, <NUM> may be accomplished with a hinge mechanism <NUM>. In the illustrated example, the hinge mechanism <NUM> includes an integral post <NUM> projecting from the first contact face <NUM> of the first body <NUM>. The second contact face <NUM> includes a complementary hole <NUM> sized and located to receive the post <NUM> thereby pivotally coupling the first and second bodies <NUM>, <NUM> together in an assembly <NUM> for limited movement about axis <NUM> (<FIG>). In this embodiment, the pivot axis <NUM> is generally parallel to longitudinal axis <NUM> of wear member <NUM> and perpendicular to the contact faces <NUM>, <NUM>. The pivot connection could have other constructions. For example, the hinge mechanism <NUM> could have other constructions including, for example, forming each body with a hole for receiving a pivot pin secured in place by retaining rings or the like.

Each body or component <NUM>, <NUM> may define a channel <NUM>, <NUM> (<FIG>) in faces <NUM> and <NUM>. One channel <NUM> may include helical ridge segments <NUM> for engaging a groove or grooves <NUM> in an insert <NUM>. When bodies <NUM>, <NUM> are assembled together in the locked position, channels <NUM>, <NUM> are aligned with each other to collectively form a tapered, partially threaded passage <NUM> adapted to matingly receive the insert <NUM> (<FIG>). Other shapes of passages and inserts are possible. Other ways of securing the insert in the passage besides threaded engagement are also possible.

In the illustrated embodiment, each channel <NUM>, <NUM> defines, in lateral cross-section, a semi-circle so that the two channels collectively form a complete circular passage, though less than a full semi-circle for each or one channel is possible. In one embodiment, only one channel <NUM> is formed with thread segments <NUM> though both could be threaded. The channel(s) could also be partially threaded or threaded in a discontinuous way. Each channel <NUM>, <NUM> progressively narrows so that collectively they form a generally frusta-conical bore or passage <NUM>. Nevertheless, the passage and insert could be cylindrical.

The insert <NUM>, in the form of a threaded frusta-conical rod, may be threaded into passage <NUM> with lock <NUM> in the locked position to prevent relative movement between the two components <NUM>, <NUM>. A hex socket <NUM> or other tool engaging formation is provided at the top of insert <NUM> for turning the insert <NUM>. With the insert <NUM> installed in passage <NUM>, bodies <NUM>, <NUM> cannot be pivoted about axis <NUM>. As a result, the lock presents a strong, integral pin to resist heavy loading and prevent release of wear member <NUM> from lip <NUM>. The fitting of insert <NUM> into complementary channels <NUM>, <NUM> that are formed in contact faces <NUM>, <NUM> extending perpendicular to pivot axis <NUM> provides strong resistance to pivoting of the bodies and a low risk the insert will be ejected or broken. When insert <NUM> is removed, bodies <NUM>, <NUM> can pivot about axis <NUM> from the locked configuration to the unlocked configuration (<FIG>). Insert <NUM> can have many different forms and be received in other openings provided in one or both components. For example, it could be unthreaded and secured by other means, it could have other shapes, and/or be inserted in other positions and/or at other locations. Insert <NUM> simply needs to secure lock components <NUM>, <NUM> in its locked configuration.

As the insert <NUM> moves down passage <NUM>, the insert <NUM> contacts a progressively smaller inner circumference in both channels <NUM>, <NUM>. In one embodiment, the radii of the insert <NUM> and channels <NUM>, <NUM> in a fully seated position are generally the same. In another embodiment, the radius of curvature for one channel is smaller than the radius of the insert in corresponding positions when fully seated, while the curvature of the other channel generally matches or is larger than the insert. In one embodiment, the channel with the smaller radius is unthreaded. The threaded channel, then, maintains a single line contact while the non-threaded channel maintains a double line of contact. In this way, three lines of contact may provide substantially balanced forces <NUM>, <NUM> each directed substantially toward a central axis <NUM> of the insert <NUM> having a single line of contact on one side of the central plane and a double line of contact on the opposite side. As alternatives, the smaller channel could be the threaded channel, or both or neither channel could be threaded. In a non-threaded passage, the insert would be secured by other means such as a retaining ring or latch.

Embodiments may also provide threads in passage <NUM> that extend less than the total channel circumference, i.e. less than half the way around the bore. For example, the threads may only extend from as little as a few degrees to <NUM> degrees of circumference or more. Arrow <NUM>, in <FIG>, illustrates one example circumferential range of the treads <NUM>. In some cases the threads may include a chamfer, or a fillet at each end of the thread profile nearest the slip planes which may reduce the circumferential extent of the threads. The double line loading may be delayed, or avoided, and the insert <NUM> may be threaded deeper into the bore. In this way, the insert <NUM> may be turned a considerable amount during a tightening operation. This may tend to provide a more comfortable confident feeling for the operator when tightening the insert <NUM>.

Also, while bodies <NUM>, <NUM> are disclosed as having the same or similar lengths and forming opposite ends of the lock <NUM>, other arrangements could be used. For example, the bodies could have different lengths or each extend the full length of the lock. Also, the lock could comprise a foldable element, but not consist of two components joined by a pivot pin. Other arrangements could be used to present a firm, secure lock in the retaining position, but which permits folding of the lock to the release position. For example, lock <NUM> could have multiple hinges formed by three or more components. As another example, lock <NUM> could be foldable by a resilient hinge portion. Moreover, lock <NUM> could be formed without a hinge or a foldable portion; lock <NUM> could, rather, have different means for being releasably secured to retainers <NUM>, <NUM>. In one example, the lock could have an end that telescopes inward and outward to engage or release retainers <NUM>, <NUM>.

Lock <NUM> includes end walls <NUM>, <NUM> that engage end walls <NUM> in the hole <NUM> in the wear part. For example, end walls <NUM>, <NUM> may engage retainers <NUM>, <NUM> when the lock is in the release position, which permits the wear member <NUM> to be installed and removed without removing the lock <NUM> from the wear member <NUM>. The lock may be removed entirely from the wear member when the wear member is to be installed on and for removal from the wear working equipment, though preferably the lock is installed during manufacture of the assembly for shipping, storage and installation as an integral unit. Preferably, the lock is installed into wear member <NUM> at the time of manufacture and shipped, stored and installed with the lock in this release position engaged to retainers <NUM>. End walls <NUM>, <NUM> may engage retainers <NUM> when the lock is installed in the hold position to secure the wear member to the earth-working equipment <NUM>. Lock <NUM> is in the locked configuration when secured to the retainers <NUM>, <NUM>, and in the unlocked configuration when being installed in or removed from the retainers <NUM>, <NUM>. As an alternative, retainers <NUM> could be omitted such that the lock is inserted after the wear member is installed on base <NUM>. In this example, lock <NUM> could be shipped and stored with the lock engaging retainers <NUM>, or shipped and stored separately from the wear member.

In the illustrated embodiment, end walls <NUM>, <NUM> have a generally concave, curved configuration to complement the curved surfaces on retainers <NUM>, <NUM>, though other shapes on the end walls, and/or retainers could be used. In this example, the concave curved surface <NUM> defines a pair of spaced apart lobes <NUM>, <NUM>. The inner or bottom lobe <NUM> fits in to the medial pocket <NUM> when end walls <NUM>, <NUM> engage release-position retainers <NUM>. Inner lobe <NUM> fits in inner pocket <NUM> when end walls <NUM>, <NUM> engage retainers <NUM>. The outer lobe <NUM> can fit into pocket <NUM> or be short of the pocket <NUM>. This kind of engagement or "gripping" of the retainers by the lock improves resistance against loss or ejection of the lock when insert <NUM> is in passage <NUM>. This arrangement further enhances resistance to turning of the lock under load. Nevertheless, other kinds of end walls could be used. As examples only, end walls of the lock could be stepped, include projections, or be otherwise shaped to secure the lock in place.

In use, when in the hold position, the outer sides of second retainers <NUM> contact the inner sides of the outer lobes <NUM>, and the inner sides of the retainers <NUM> contact the outer sides of the inner lobes <NUM>. In this way resistant or corrective forces can be exerted on the lock in both an upward and a downward direction. The forces can be exerted along any location along the lobes, i.e. at any spaced distance from a central axis <NUM> of the lock to the side surfaces <NUM> of the lock <NUM>. In this way, forces can be resisted by the ends of the lock engaging either set of retainers <NUM>, <NUM> that would otherwise cause the lock to be subjected to, for example, any, drop, ejection, roll, or longitudinal twist.

For example, during use, forces will be applied to the lock <NUM> on one side by the bearing surface <NUM> of the wear member <NUM>, shown with arrow <NUM>, and on the opposite side by the bearing surface <NUM> boss <NUM>, shown with arrow <NUM> (<FIG>). Because the surfaces tend to be offset from one another the opposite forces tend to urge the lock to "roll" within the opening <NUM>. However, according to the illustrated embodiment, the outer lobes <NUM> of the lock contact the outer surfaces of the second protrusions <NUM> of the wear member <NUM>, arrow <NUM>, and the inner lobes <NUM> of the lock contact the inner surfaces of the second protrusions <NUM>, arrow <NUM>. In this way, the lock <NUM> is kept from rolling within the opening <NUM>.

In the illustrated embodiment, the lock does not have a uniform length. The length along lobes <NUM> is shorter than the length along lobes <NUM> to accommodate pivoting of the lock from the extended locked configuration to the retracted unlocked configuration (Fig. 16A), i.e., for sufficient clearance for lobes <NUM> to move farther into pocket <NUM> when lock <NUM> is pivoted to the unlocked configuration. Alternatives are possible. For example, medial pocket <NUM> could have a depth sufficient to accommodate pivoting when the lobes <NUM>, <NUM> have the same length (i.e., when the inner and outer lengths of lock <NUM> are the same).

To replace a worn wear member, lock <NUM> must first be removed. To do so, insert <NUM> is removed from passage <NUM>, and bodies <NUM>, <NUM> pivoted about axis <NUM> to the unlocked configuration (<FIG>). In this position, the outer lobes <NUM> can move into the medial pocket <NUM> as illustrated. The shorter length of the lock <NUM> at the level of the outer lobes <NUM> enables the top lobe <NUM> to fit into the medial pocket <NUM> when lock <NUM> is pivoted to the un-retained or unlatched condition. The contour of the concave surface <NUM> of the lock end walls <NUM>, <NUM> is able to follow the contour of the retainer <NUM> to yield a smooth pivoting of each respective lock body <NUM>, <NUM>.

In the hold position, the inner surface <NUM> of the lock <NUM> may, or may not, contact the bottom of the cavity <NUM>. A small clearance may be allowed, or provided. The lock <NUM> may include transverse interlocks <NUM> on each of the two lock bodies <NUM>, <NUM> (<FIG>). When the lock bodies <NUM>, <NUM> are in the extended locked position, the interlocks <NUM> can keep the lock bodies <NUM>, <NUM> from separating in a transverse direction. With the lock bodies <NUM>, <NUM> fixed at the ends each body <NUM>, <NUM> may bow slightly under stress caused when the insert <NUM> is forced into the passage <NUM> in a middle portion of the lock. The interlocks <NUM> may each include complementary tab <NUM> and retention slot <NUM> pairs, i.e. each body <NUM>, <NUM> having a tab <NUM> at one end and a retention slot <NUM> at the opposite end, though other interlock constructions are possible (<FIG>). The tab <NUM> may be slideable into the slot <NUM> in the same hinging motion about the pivot axis <NUM> as the hinging and unhinging, or straightening, motion of the lock bodies <NUM>, <NUM> described herein. Each tab <NUM> may extend substantially radially from the pivot axis <NUM>, and the inner opposed walls <NUM> of each retention slot <NUM> (when in the closed extended position) may extend in close coplanar proximity to outside opposite surfaces of the tab <NUM>. The tab <NUM> surfaces and the retention walls may be angled slightly from parallel to provide a radial draft to provide rapid and unobstructed separation of the adjacent surfaces when the lock bodies <NUM>, <NUM> are pivoted open. Tab ends and/or end walls of the slots <NUM> may also define a radial draft to also, or instead, provide rapid and unobstructed separation of the adjacent surfaces when the lock bodies <NUM>, <NUM> are pivoted open. Each lock body <NUM>, <NUM> can be transversely flexed away from a longitudinal axis <NUM> of the lock <NUM> by the insert <NUM>, imparting a pre-load into the lock <NUM>. The pre-loaded lock bodies <NUM>, <NUM>, in turn provide transverse retention forces <NUM> from opposite sides of the slip plane <NUM> to resist ejection of the insert <NUM>. The resultant force components are generally perpendicular to the slip plane <NUM> and transverse to the longitudinal axis (<FIG>).

In the embodiments illustrated, various surfaces, for example, the interlocks <NUM> and the pivot pin <NUM> increase the stability of the assembled lock components <NUM>, <NUM> even without the insert <NUM> in place. The interlocks <NUM> and the pivot pin <NUM> provide constraining surfaces that limit the degrees of freedom of relative movement between the lock components <NUM>, <NUM>, except for the relative pivoting, or hinging, movement. As discussed, the interlocks <NUM> resist relative lateral movement of the lock components. The pivot pin <NUM> extends across the contact faces <NUM>, <NUM> in a lateral direction, and is accordingly disposed to resist relative longitudinal movement between the lock components <NUM>, <NUM>. Accordingly, even without the insert <NUM> in place the lock <NUM> is easy to handle, move, and otherwise manipulate. This may be particularly useful to the operator. The insert <NUM> may be disposed to prevent a relative pivoting or hinging between the lock components <NUM>, <NUM>. Consequently, the forces on the insert are relatively limited to resisting relative pivoting tending to protect the insert from deformation, and/or ejection.

The interlocks <NUM> and the pivot pin <NUM> tend to hold the lock in place, and resist various loads that may be placed on it. For example, a bending force <NUM> (<FIG>) may impart tensile stress on one side of the central axis <NUM> and compressive forces on the other side. The bending forces will tend to pull the tab <NUM> on the side in tension out of the mating slot <NUM>. However, the outer surface of the pivot pin <NUM> in contact with inside walls of the complementary hole <NUM> will resist relative longitudinal movement of the lock components <NUM>, <NUM>, adding to the strength and stability of the lock. In addition, the pivot axis <NUM> is preferably substantially perpendicular to, and proximate with, the central axis <NUM> of the insert <NUM>. Accordingly, any relative pivoting or hinging of the lock components <NUM>, <NUM> about axis <NUM> results in minimal displacement of passage <NUM> parallel to central axis <NUM> of the insert <NUM>. Consequently, axial forces on the insert <NUM> directed to resist hinging is minimized reducing the potential for ejection or deformation.

In one alternative embodiment, the interlock includes concentric walls <NUM>, <NUM> able to slide relative one another to permit a relative pivoting motion of the lock bodies <NUM>, <NUM> about pivot axis <NUM> (<FIG>). Each body can include a tab or protrusion and a slot that interlock in a tongue and groove configuration. Lock assembly <NUM> includes tabs <NUM> and <NUM> defining walls 292A and 294A. Spaced from the tabs, the lock assembly can include slots <NUM> and <NUM> defining walls 296A and 298A. These walls <NUM>, <NUM>, <NUM>, <NUM> of the tabs and slots have generally corresponding shapes and are shown in <FIG> as being curved and concentric about the pivot axis. The walls can be any shape that allows the lock bodies to pivot about the pivot axis to fold and extend to full length without binding. Assembly of the hinge can include bringing contact face <NUM> to contact face <NUM> with the longitudinal axes of the bodies <NUM>, <NUM> generally at an angle to each other (i.e. without engagement of tabs <NUM>, <NUM> in slots <NUM>, <NUM>). With rotation of the bodies <NUM>, <NUM> in relation to each other about the pivot axis <NUM>, each of the tabs pass into the corresponding slots. The interlocking bodies once assembled to each other resist separation. Rotation of the bodies in relation to each other can be limited by the installation of insert <NUM>.

End walls <NUM>, <NUM> of the lock clear end walls <NUM> of the opening <NUM> so that the lock can be withdrawn from the wear member <NUM>. At least one body <NUM>, <NUM> (and preferably both to enable removal from either direction) is provided with a grip <NUM> to facilitate pivoting of the bodies and pulling the lock from the opening. In one embodiment, grips <NUM> are formed as inclined cavities to receive a removal tool <NUM>; although other forms of grips could be used. Each body <NUM>, <NUM> can also include a depression <NUM> spaced from grip <NUM> to stably support a fulcrum <NUM> of tool <NUM>. In use, a gripping end <NUM> of tool <NUM> fits into cavity, or grip <NUM> on body <NUM> (or <NUM>) with fulcrum <NUM> resting in one depression <NUM>. The lever <NUM> of tool <NUM> is pushed downward to pull the middle of lock <NUM> upward such that the bodies <NUM>, <NUM> pivot about hinge mechanism <NUM>. In this position, the lock <NUM> can be pulled out of opening <NUM> with tool <NUM> to permit removal of the shroud from the equipment.

<FIG> show an alternative construction of an articulated lock. First body <NUM> and second body <NUM> include tabs <NUM> and <NUM> and slots <NUM> and <NUM> respectively that will engage in a tongue and groove configuration on assembly of the bodies. First body <NUM> has a contact or inner face <NUM> and second body <NUM> has contact or inner face <NUM>. Contact face <NUM> preferably has a generally hemispherical recess <NUM> and an opening 380A. Above and below the hemispherical recess are preferably curved bearing surfaces 384A and 386A. Contact face <NUM> includes a laterally-projecting threaded collar or protrusion <NUM> provided with a pin <NUM>. The collar has an opening or passage <NUM> extending through it along a passage axis that is generally parallel to the contact faces and generally perpendicular to the pivot axis of the lock. The passage <NUM> is provided with threads 375A in the wall of the opening. Second body <NUM> includes a recess <NUM> to receive collar <NUM>, and a hole 380A to receive pin <NUM>. Above and below the collar are curved bearing surfaces 384B and 386B.

<FIG> is an exploded view of the lock <NUM>. The bodies <NUM> and <NUM> are assembled so that the collar <NUM> with the threaded passage <NUM> and pin <NUM> are received by recess <NUM> and hole 380A respectively. The collar and the recess have complementary shapes to allow the lock bodies to pivot relative to each other about the pin and hole defining a pivot axis <NUM> with limited binding. The exterior of collar <NUM> and recess <NUM> are preferably spherical segments, though other shapes are possible. Tabs <NUM> and <NUM> are received by slots <NUM> and <NUM> as the bodies pivot to an extended position. Other shapes can be used for the surfaces of the collar and recess, and the collar and recess are not necessarily mating shapes. Preferably, the collar is symmetrical about a pivot axis and allows pivotal movement of the bodies once assembled.

With the lock in the extended position, the bearing surfaces 384A and 384B adjacent each other form a single circular upper bearing surface <NUM>. Similarly bearing surface 386A and 386B adjacent each other form lower circular bearing surface <NUM>. The bearing surfaces, though, need not form a complete circle. With the bodies <NUM>, <NUM> in the extended position, threaded insert <NUM> is received in threaded opening <NUM>. Threaded insert <NUM> preferably includes a head 300A with a recess 300B to receive a torque tool (not shown) such has a hex driver, though other tool-receiving formations could be used. Although insert <NUM> is shown with a radially expanded head, the head can simply be the trailing end of the shaft, i.e., a continuation of the shaft with no radial extension. Also, while a threaded insert <NUM> and threaded opening <NUM> are preferred, they could each be non-threaded with other means (e.g., a latch) for retaining the insert in the opening.

Threaded insert <NUM> can optionally include a biased latching tooth <NUM> extending from the insert. The tooth can engage a corresponding outer pocket or recess <NUM> in the threaded opening <NUM> of the collar. The tooth engaging the recess can limit rotation of the insert below a set level of applied torque and prevent the insert from inadvertent loss of the insert from the lock. The interlocking tooth and recess can define a stop for the fully installed position.

A shaft of the insert <NUM> preferably includes an upper bearing surface <NUM>, a lower bearing surface <NUM>, and threads <NUM> between the two. When insert <NUM> is fully threaded in passage <NUM>, the upper and lower bearing surfaces <NUM> and <NUM> are adjacent to or bearing on bearing surfaces <NUM> and <NUM> respectively. The fitting of the upper and lower bearing surfaces <NUM>, <NUM> of the insert <NUM> with the bearing surfaces <NUM>, <NUM> of the bodies <NUM>, <NUM> limits pivoting movement of the bodies <NUM> and <NUM> about pivot axis <NUM>. In use, the lock <NUM> is received in the opening of the wear member in a similar way to previous locks described above and engages the retaining structure of the opening in a similar way. The threaded opening can include complete threads that continue around the circumference of the opening. Alternatively, the opening can include thread portions or ridges in the opening to engage threads <NUM> of the insert <NUM>.

Lock bodies <NUM>, <NUM> and insert <NUM> are shown with upper and lower bearing surfaces but other constructions are possible. For example, the insert can have a head 300A, threads <NUM> and a lower bearing surface <NUM> without the upper bearing surface <NUM>. The head can act as the upper bearing surfaces in some constructions. In another example, the lock has only threads and a lower bearing surface to bear on the insert <NUM> without an upper bearing surface. In another construction, the lock has threads and an upper bearing surface to bear on the insert without a lower bearing surface.

<FIG> shows an alternative construction of a lock <NUM> that includes bodies <NUM> and <NUM> with similar features to locks described above. First body <NUM> and second body <NUM> include tabs <NUM> and <NUM> and slots <NUM> and <NUM> respectively that will engage in a tongue and groove configuration on assembly of the lock bodies. Here the bodies each preferably have a hemispherical recess <NUM> and <NUM> each with an opening 482A and 484A. A collar <NUM> separate from the bodies <NUM>, <NUM> is received in recesses <NUM>, <NUM>. The collar <NUM> is provided with an opening or passage <NUM> that passes through the collar and is provided with threads 476A in the walls of the passage. The collar has pins <NUM> and <NUM> on opposite sides.

Lock <NUM> is assembled by receiving collar <NUM> in recesses <NUM> and <NUM> with pins <NUM> and <NUM> in openings 482A and 484A. Lock bodies <NUM> and <NUM> then pivot about the pins and openings to an extended position with tabs <NUM> and <NUM> received by slots <NUM> and <NUM>. In the extended position, upper circular bearing surface <NUM> is above collar <NUM>. Lower circular bearing surface <NUM> is below collar <NUM>. Insert <NUM> is received in the threaded collar and bearing surfaces <NUM> and <NUM> bear on or are adjacent to bearing surfaces <NUM> and <NUM>. When installed, the insert limits pivotal movement of bodies <NUM> and <NUM> in relation to each other. Other embodiments are possible with only an upper bearing surface or only a lower bearing surface to bear on insert <NUM>.

Other shapes can be used for the surfaces of the collar and recess and the collar and recess are not necessarily mating shapes. Preferably, the collar is symmetrical about a pivot axis and allows pivotal movement of the bodies once assembled.

The ends of the lock can have different constructions to engage a receiving structure of the wear member opening. <FIG> is a lock <NUM> with a middle structure <NUM> similar to locks described above, i.e., for example with a tongue and groove structure and an insert that limits pivotal movement. Lock <NUM> has beveled ends <NUM> and <NUM> that converge extending upwards. Lock <NUM> can be received in an opening of a wear member with a corresponding construction. Such wear members are described in <CIT>. Any of the locks described herein could be formed with beveled ends (or other ends) to fit into different wear members and secure the wear members to the earth working equipment.

Claim 1:
An articulated lock (<NUM>) for securing a wear member (<NUM>) to earth-working equipment comprising a plurality of bodies (<NUM>, <NUM>) interconnected for pivotal movement between an extended orientation with the bodies aligned and a retracted orientation with the bodies folded where the lock in the extended orientation can engage the wear member at a retaining position to secure the wear member to the earth working equipment and in the folded orientation can disengage the wear member, characterized in that each said body has a slot (<NUM>) and a tab (<NUM>), in the extended orientation the tab of each said body is received in the slot of the other body to limit separation of the bodies, and the bodies receive an insert (<NUM>) in the extended orientation to prevent the bodies from folding out of the extended orientation.