This disclosure relates to excavation wear assemblies, locks for use in such wear assemblies and to components and methods of such excavation wear and lock assemblies. The disclosure has application in earth working equipment such as land based digging equipment and is herein described in that context. However, it is to be appreciated that the disclosure has broader application for example in waterborne excavation equipment such as dredgers, and is therefore not limited to that application.
Wear members are provided on the digging edge of various pieces of digging equipment such as the buckets of front end loaders. The wear assembly is often formed of a number of parts, commonly a wear member, a support structure and a lock. The support structure is typically fitted to the excavation equipment and the wear member fits over the support structure and is retained in place by the lock. In some instances, one or more intermediate parts may be also included between the wear member and the support structure. For ease of description it is to be understood that, unless the context requires otherwise, the term “support structure” used in this specification includes both the support structure arranged to be fitted to, or forming an integral part of, the excavation equipment or, if one or more intermediate parts are provided, to that intermediate part(s) or to the combination of the support structure and the intermediate part(s).
The reason that the wear assembly is formed of a number of parts is to avoid having to discard the entire wear assembly when only parts of the wear member, in particular the ground engaging part of the wear assembly (i.e. the wear member) is worn or broken.
Various types of locks, wear members and support structures are known. However, there is a continuing aim to design new wear assemblies and parts thereof to take into account installation, performance and manufacturing considerations.
It is to be understood that, if any prior art is referred to herein, such reference does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country.
The present disclosure relates generally to wear assemblies for earth working equipment and to components of such assemblies including locks and wear members, and to methods associated with those assemblies.
In a first aspect, disclosed is a lock for securing a wear member to a support structure, the wear member having a body that incorporates a cavity configured to receive the support structure, and a locking hole extending to the cavity. The lock is arranged to be movable within the locking hole and includes a lock body extending along a lock body axis and having a first end region for engaging with the support structure to allow securing of the wear member with the support structure. At least one latch is disposed on the lock body and has a detent movable transverse to the lock body axis and being arranged in use to restrain movement of the lock in the locking hole.
In some forms, the locking hole may extend from the exterior of the wear member body to the cavity.
In some forms, the detent is movable to a position where it projects from the lock body. In some forms, the at least one latch further comprises a resilient member operative to allow transverse movement of the detent on deforming of the resilient member.
In some forms, the lock body includes a bore extending transverse to the lock body axis, and wherein the at least one latch is disposed in the bore. In some forms, the latch is movable within the bore to allow movement of the detent.
In some forms, the bore is a blind hole and the latch is located within the blind hole such that the detent is disposed at the opening of the bore. In some forms, the detent is arranged to project from the bore when the resilient member is in an undeformed state and is able to retract inwardly when the resilient member is compressed.
In some forms, the bore has first and second openings angularly spaced around the lock body axis. In some forms, the at least one latch includes two detents which are arranged to project from respective ones of the first and second openings.
In some forms, the resilient member is disposed between the detents and deforming of the resilient member varies the spacing between the detents. In some forms, the length of the latch between the detents is greater than the length of the bore when the resilient member is in its neutral, undeformed state.
In some forms, the latch is movable through the bore between the first and second openings.
In some forms, the lock body comprises a body region incorporating a component of an engaging structure on an exterior surface thereof which is arranged to engage with a complementary component of the engaging structure disposed on an interior wall defining at least part of the locking hole, the engaging structure being at least part of a retaining arrangement operative to resist movement of the lock in the wear member under loading in the direction of the lock body axis.
In some forms the engaging structure is helical, or part helical. In this way the lock may be axially advanced or retracted in the locking hole, whilst the components of the engaging structure is engaged, by rotation of the lock body. In some forms, the body region terminates at a second end region of the lock body, and the second end region includes a drive arrangement to receive a tool to impart rotation to the lock body.
In some forms, the engaging structure is operative to resist movement of the lock in the wear member under loading in the direction of the lock axis.
In some forms, the retaining arrangement is operative to resist axial movement of the lock body by the combined operation of the latch and the engaging structure, the latch being operative to provide torsional resistance to the lock body in the locking hole and the engaging structure operative to inhibit axial movement of the lock body when the lock body is restrained from rotating in the locking hole.
In some forms, the engaging structure is helical or part helical and has a pitch that is quite steep to promote rotation and axial movement of the lock body under loading on the lock body in the direction of the lock body axis.
In some forms, where the engaging structure is operative to resist movement of the lock in the wear member under loading in the direction of the lock axis, the pitch is quite flat.
In some forms, the body region is generally cylindrical and the engaging structure is recessed into the body. In some forms, the latch is disposed on the body region. In some forms, the first end region tapers towards the first end of the lock body.
In some forms, the latch and the engaging structure are configured and positioned relative to each other such that the latch does not cross the complementary component of the engaging structure on the inner wall of the wear member on operation of the lock.
Also disclosed is a lock for securing a wear member to a support structure, the wear member having a body that incorporates a cavity configured to receive the support structure, and a locking hole extending to the cavity, the lock being arranged to be movable within the locking hole and comprising: a lock body extending along a lock body axis and having a first end region for engaging with the support structure to allow securing of the wear member with the support structure; and a retaining arrangement operative to resist movement of the lock in the wear member under loading in the direction of the lock body axis, the retaining arrangement comprising: an a component of an engaging structure on an exterior surface of the lock body which is arranged to engage with a complementary component of the engaging structure disposed on an interior wall defining at least part of the locking hole, and one or more retainers operative to provide torsional resistance of the lock body in the locking hole, wherein the engaging structure is operative to inhibit axial movement of the lock body when the lock body is restrained from rotating in the locking hole.
The locking hole may extend from the exterior of the wear member body to the cavity.
In some forms, the at least one retainer is in the form of the latch as described above. In other forms, the at least one retainer is a separate component that may be installed in the locking hole and may be in the form of a compressible member, collar, clip, sleeve or the like, or combination thereof, that provides rotational resistance to the lock body.
In some forms, the separate retainer is in the form of a compressible member that is arranged to apply a bias to the lock body in a direction that is transverse to the lock axis.
In some forms, the separate retainer is in the form of a compressible member that is arranged to at least partially surround the lock body and applies a radial force that is exerted over at least a substantial portion of the circumference of the lock body.
In some forms, a plurality of retainers are provided, for example a latch as described above and a separate retainer.
In some forms, the plurality of retainers are arranged to be angularly spaced apart about the lock body axis when the lock is in a locked position. In some forms, a first retainer is arranged to be disposed at an angle of between 75 and 115 degrees to a second retainer and preferably substantially at right angles.
Also disclosed is a lock for securing a wear member to a support structure, the wear member having a body that incorporates a cavity configured to receive the support structure, and a locking hole extending in the body to the cavity, the lock being arranged to be movable within the locking hole and comprising: a lock body extending along a lock body axis and having a first end region for engaging with the support structure to allow securing of the wear member with the support structure; and a retaining arrangement operative to resist movement of the lock in the wear member, the retaining arrangement comprising a plurality of retainers angularly spaced apart about the lock body axis when the lock is in a locked position.
In some forms, a separate retainer is provided and includes a resilient member that is arranged to compress under load. In some forms, the separate retainer is arranged to bear against the lock body to resist pivoting of the lock body in the locking hole which may otherwise occur under operational load. In some forms, the separate retainer provides some shock absorbing capability to the lock body when installed. This shock absorbing capability may be in addition to, or instead of, the torsional resistance required as part of the retaining arrangement.
Also disclosed is a lock for securing a wear member to a support structure, the wear member having a body that incorporates a cavity configured to receive the support structure, and a locking hole extending in the body to the cavity, the lock being arranged to be movable within the locking hole and comprising: a lock body extending along a lock body axis and having a first end region for engaging with the support structure to allow securing of the wear member with the support structure; and a retaining arrangement operative to resist lateral movement of the lock body within the locking hole.
In some forms, the retainer is formed at least in part as a resilient member that provides a damping force to the lock body to resist lateral movement.
In some forms, the lateral movement is translation of the lock body within the locking hole and/or pivoting of the lock body in the locking hole.
Also disclosed is a wear member for attaching to a support structure of earth working equipment, the wear member comprising a body comprising a first end, an opposite second end that incorporates a cavity configured to receive the support structure, and a locking hole extending in the body to the cavity, the locking hole being arranged to receive a lock to secure the wear member to the support structure and being defined by an interior wall surface that incorporates at least one component of an engaging structure arranged to engage with a complementary component of the engaging structure disposed on an exterior surface of the lock.
The locking hole may extend from the exterior of the wear member to the cavity.
In some forms, the component of the engaging structure is formed as one or more ribs that projects into the locking hole. In some forms the engaging structure is helical, or part helical. The engaging structure may be continuous or may be formed of spaced components that track the helical path.
In some forms, the interior wall surface further comprising at least one notch operative to receive a detent on the lock to inhibit rotation of the lock in the locking hole. In some forms, this notch (or at least one of a plurality of notches if there is more than one corresponding detent on the latch) is located to correspond to a position wherein the lock is in engagement with the support structure to secure the wear member to that support structure. In some forms, the interior wall surface may comprise two or more notches which are spaced apart in the direction of the hole axis and which are arranged to engage with one or more detents of the lock to inhibit the rotation of the lock when the lock is in two or more discrete positions within the wear member.
Alternatively, in some forms, the interior wall surface comprises one or more detents or other latching structures to inter-engage with a complementary latching structure of the lock to locate the lock in one or a plurality of positions in locking hole. These positions may correspond to any of a locking, retracted and transport position.
In some forms, the interior wall surface further comprises a channel that terminates at the exterior surface of the wear member and is arranged to facilitate installation of the lock into the wear member.
In some forms, the interior wall surface further comprises at least one holding formation adjacent the exterior surface of the wear member and is arranged to receive a complementary engaging formation of a holder that is arranged to inhibit release of the lock body from the locking hole.
In some forms, the at least one holding formation is in the form of a re-entrant surface.
In some forms, the interior wall surface forms part of a lock receiving arrangement that includes and the locking hole and further comprises a lock cavity to receive a retainer to provide resistance to the lock body, preferably torsional resistance. In some forms, the lock cavity is in the form of a slot that extends from the locking hole in a direction that is transverse (radial) to an axis of locking hole.
Also disclosed is a wear member for attaching to a support structure of earth working equipment, the wear member comprising a body comprising a first end, an opposite second end that incorporates a cavity configured to receive the support structure, and a lock receiving arrangement defined by an interior wall surface that comprises a locking hole extending along a lock axis in the body to the cavity, and a lock cavity that extends from the locking hole transverse to the lock axis, the locking hole being arranged to receive a lock body to secure the wear member to the support structure.
In some forms, the lock cavity is arranged to receive a retainer for engaging with the lock body.
In some forms, the lock includes a latch that is mountable to the lock body and the lock cavity is arranged to provide an access to facilitate installation of the latch in the lock body when disposed in the locking hole.
In some forms, the slot is multi-purpose and arranged to facilitate installation of the latch in the lock body and to receive a separate retainer for engaging with the lock body.
In some forms, the lock body is rotatable in the locking hole. In some forms, the lock receiving arrangement further comprises at least one component of an engaging structure arranged to engage with a complementary component of the engaging structure disposed on an exterior surface of the lock body.
In some forms, the interior wall surface of the locking hole is formed from the wear member. In one form, the interior wall is cast with the appropriate profile on casting of the wear member. However, if need be, the profile may be finished in a post casting process such as milling or the like.
Alternatively, or in addition, least part of the interior wall surface is formed on an insert locatable in the locking hole. The insert may be cast into the wear member (if that member is cast), or may be mechanically secured through welding or other fixings, or may otherwise be captured in position (for example by being locatable in place from within the cavity and thereby captured in place when mounted onto the support structure).
In some forms, the wear member is formed as a casting and at least a portion of the interior wall defining the locking hole, or a component disposed with that locking hole, is formed from an insert cast into the wear member.
In some forms, the component formed from the cast insert is the component of the at least one engaging structure. In one form, the cast insert may form at least part of a retainer that is arranged to engage with and apply a torsional resistance to a lock body of a lock locatable within the locking hole.
Also disclosed is a cast wear member for attaching to a support structure of earth working equipment, the wear member comprising a body comprising a first end, an opposite second end that incorporates a cavity configured to receive the support structure, and a lock receiving arrangement defined by an interior wall surface that is arranged to receive a lock for securing the wear member to the support structure, wherein at least a portion of the interior wall defining the lock receiving arrangement, or a component disposed with that arrangement, is formed from an insert cast into the wear member.
According to a further aspect, there is disclosed a wear member assembly for attaching to a support structure of earth working equipment comprising: a wear member comprising a body having a first end, an opposite second end that incorporates a cavity configured to receive the support structure, and a locking hole extending in the body to the cavity; and a lock for securing the wear member to a support structure and being arranged to be movable within the locking hole.
In some forms, the lock has a first end region for engaging with the support structure to allow securing of the wear member with the support structure.
The locking hole may extend from the exterior of the wear member to the cavity.
In some forms, a component of an engaging structure is provided on an exterior surface of the lock and a complementary component of the engaging structure is disposed on an interior wall defining at least part of the locking hole, the engaging structure forming at least part of a retaining arrangement operative to resist movement of the lock in the wear member under loading in the direction of the hole axis. In some forms, the engaging structure provides the primary retention arrangement of the locking arrangement to resist any axial loading induced on the lock body which may cause the lock body to be ejected from the locking hole or disengage from the support structure.
In some forms, the engaging structure is helical, or part helical. In this way the lock may be axially advanced or retracted in the locking hole, whilst the engaging structure is engaged, by rotation of the lock body.
In some forms, the retaining arrangement further comprising at least one retainer to restrain movement of the lock in the wear member when the engaging structure is in engagement.
In some forms, the retaining arrangement is operative to resist axial movement of the lock body by the combined operation of the retainer and the engaging structure, the retainer being operative to provide torsional resistance of the lock body in the locking hole and the engaging structure operative to inhibit axial movement of the lock body when the lock body is restrained from rotating in the locking hole.
In some form, the wear member assembly further comprises a latch arrangement to restrain movement of the lock in the wear member when the engaging structure is in engagement. In some forms, the latch arrangement is arranged to inhibit rotation of the lock when the lock is disposed in one or more positions. Further the latch arrangement may provide more general frictional resistance to rotation outside these one or more positions to prevent play in the lock and to allow more controlled movement of the lock in the locking hole.
In some forms, the latch arrangement functions as the retainer of the retaining arrangement. In some forms, the latch and retainer may be separate components.
In some forms, a plurality of retainers are provided. One retainer may be in the form of a latch arrangement. In some forms, a further latch arrangement may be provided.
In some forms, a separate retainer is provided and includes a resilient member that is arranged to compress under load. In some forms, the separate retainer is arranged to bear against the lock body to resist lateral movement (being translation and or pivoting of the lock body in the locking hole) which may otherwise occur under operational load. In some forms, the separate retainer provides some shock absorbing capability to the lock body when installed. This shock absorbing capability may be in addition to, or instead of, the torsional resistance required as part of the retaining arrangement.
In some forms, the plurality of retainers are arranged to be angularly spaced apart about the lock body axis when the lock is in a locked position. In some forms, a first retainer is arranged to be disposed at an angle of between 75 and 115 degrees to a second retainer and preferably substantially at right angles.
In some forms, the wear assembly further comprises a holder to secure the lock to the wear member independently of the engaging structures. In some forms, the holder is frangible and therefore single use. In other forms, the holder may remain intact, in either an active, or inactive state, throughout the movement of the lock in the locking hole.
In some forms, the lock is secured to the wear member in a transport position where the combination of the wear member and lock is arranged to be provided to site. In some forms, when in the transport position, the lock is positioned so as to allow the wear member to be installed on the support member. In other forms, when in the transport position, the first end region extends into the cavity and prevents installation of the wear member onto the support structure. In this later form, the lock needs to be moved from the transport position to allow for installation.
In some forms, the holder is arranged to secure the lock to the wear member in the transport position.
In some forms, the wear member assembly is arranged such that when in the transport position, the first end region extends into the cavity and prevents installation of the wear member onto the support structure. In some forms, the holder permits sufficient movement of the lock in the locking hole to enable movement of the lock from the transport position to a position where the first end region of the lock is sufficiently clear of the cavity to permit installation of the wear member onto the support structure.
In some forms, where the above transport position is provided, the first end region may include an angled, or camming surface that under the application of a force to that surface in a direction normal to the axis of the hole, the lock is biased to retract into the locking hole.
In some forms, the lock and the wear member have respective bearing surfaces that are in opposing relation when the lock is in a locked position, the bearing surfaces being arranged to be angularly offset from one another when the wear assembly is not under loaded conditions. In some forms, when in loaded condition, the lock body is biased to move relative to the wear member to cause the opposing bearing surfaces to move to reduce the angular offset so as to provided increased surface engagement between the bearing surfaces.
According to a further aspect, there is disclosed a wear member assembly for attaching to a support structure of earth working equipment comprising: a wear member comprising a body having a first end, an opposite second end that incorporates a cavity configured to receive the support structure, and a locking hole extending in the body to the cavity; and a lock for securing the wear member to a support structure and being arranged to be movable within the locking hole to a locked position, the lock and the wear member have respective bearing surfaces that are in opposing relation when the lock is in the locked position, the bearing surfaces being arranged to be angularly offset from one another when the wear assembly is not under loaded conditions and arranged, under in-use loading conditions, to be biased to move to reduce the angular offset so as to provided increased surface engagement between the bearing surfaces under the in-use loading conditions.
The wear assembly as described in any form above may include any of the forms of lock or wear member as described in the first and second aspects above.
In a further aspect, there is disclosed a method of assembling a wear member onto a support structure of earth working equipment, the method comprising: providing the wear member as part of a wear member assembly incorporating the wear member and a lock secured to the wear member, the lock being disposed in a locking hole formed in the wear member in a transport position where a first end region of the lock projects into a cavity of the wear member shaped to receive the support structure and; mounting the wear member onto the support structure so that the support structure is received into the cavity; and causing the support structure to engage the lock during the mounting, and wherein under continued movement of the wear member onto the support structure, the lock is caused to retract into the locking hole so that the wear member can be fully mounted onto the support structure.
In a further aspect, there is disclosed a method of installing a lock into a wear member of earth working equipment comprising: providing the wear member with a lock receiving arrangement comprising a locking hole and a lock cavity projecting from the locking hole; installing a lock body of the lock into the locking hole; subsequently mounting a first retainer into the lock body installed in the locking hole via the cavity; and installing a second retainer into the lock cavity.
The present disclosure relates generally to locks, wear members and wear assemblies. In some embodiments, the wear member is secured to the support structure that is fixed to a bucket lip or other digging edge. The support structure may be part of an adapter or may be integrally formed to the digging edge. However, it is understood that embodiments of the present disclosure may be applied to excavation tooth assemblies in which the wear member is mounted to an intermediate member (which may also be referred to as a support structure or an adapter) that in turn is mounted to a nose that forms part of the digging edge or to the nose of a further support structure that is mounted to the digging edge. In the present disclosure, locking assemblies are used to secure the wear member to the support structure, however, the locking assemblies disclosed herein may also be used to secure any member that makes up the excavation wear assemblies to one another. Accordingly, the wear member in that arrangement might be an intermediate member which in turn locates within a further member which is exposed to wear.
Embodiments will now be described by way of example only, with reference to the accompanying drawings in which
In the following detailed description, reference is made to accompanying drawings which form a part of the detailed description. The illustrative embodiments described in the detailed description, depicted in the drawings and defined in the claims, are not intended to be limiting. Other embodiments may be utilised and other changes may be made without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings can be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.
The present disclosure relates generally to wear assemblies for digging equipment. In the illustrated embodiment, an excavation wear assembly is shown comprising a wear member that is mounted to a nose portion of a support structure that is fixed to a bucket lip or other digging edge. The nose portion may be part may be integrally formed with the bucket lip. However, it is to be understood that embodiments of the present disclosure could be applied to excavation wear assemblies in which the wear member is mounted to an intermediate member such as an adapter (which may also be referred to as a support structure) that in turn is releasably mounted to a nose that forms part of the digging edge. Further the wear member may form the external surface of the wear assembly or may constitute the intermediate member and therefore provide the nose to receive a further wear member. In the excavation wear assemblies of the present disclosure, a lock is used to lock the wear member to the nose of the support structure or the nose integrally formed with the digging edge. Similarly, in excavation wear assemblies comprising an intermediate member, locks are used to lock the outermost wear member (point) to the intermediate member and the intermediate member to the nose formed with the digging edge or of a tooth member attached to the digging edge.
Referring to
The lock 16 is arranged and designed to secure the wear member 12 to the support structure 14. As best shown in
The second end 28 comprises a drive arrangement 32. In the illustrated embodiment of
The first end 26 of the pin 24 is configured as a leading end of the pin. As shown in
The component 36 of engaging structure 30 engages with a complementary component 38 of the engaging structure 30 formed on an interior surface of the locking hole and causes axial movement of the pin 24 relative to the wear member 12 on rotation of the pin. As shown in
The engaging structures 30 forms at least part of a retaining arrangement to inhibit axial movement of the locking pin on the application of axial loading to pin (which prevents inadvertent release of the pin in use). In some forms, this may be achieved by having a relatively flat pitch such that axial loading is resisted solely by the engaging structure. However, in the illustrated form, the pitch of the helical arrangement is quite steep so that axial loading to the pin promotes rotational and therefore axial drive to the pin. In this way, the retaining arrangement further comprises a retainer (in one form comprising a latching arrangement 42 disclosed below) to provide torsional resistance to rotation of the pin such that the combined operation of the helical arrangement and torsional resistance from the retainer inhibit axial movement of the pin under axial loading to the pin. This allows for a more controlled mechanism to resist axial movement (as it is possible to more finely control the torsional resistance) and allows the engaging structure to be directly cast into the wear member (as a more precise thread is not required).
The helical arrangement 36 of the engaging structure 30 extends over the surface of a body portion 31 of the pin between the drive arrangement 32 and the leading end 26, helically relative to the pin axis of the locking pin 24. In the form as illustrated, the helical arrangement of the engaging structure 30 comprises respective recesses or grooves 36 and ribs or ridges 38. The helical groove 36 has both upper 37 and lower 39 openings. In one form, the lower opening 39 is shaped to allow any fines that have collected in the groove 36 to exit uninhibited from the wear assembly 10 when the pin 24 is rotated, for example towards the retracted position. This shaping is provided by a radial reduction of the lower wall that defines the groove. This creates a space (as best shown in
In the form shown, the ridge 38 on the wear member is continuous but it is appreciated that it could be in spaced sections that trace the helical path. The helical groove 36 extends approximately 360°, i.e. one revolution, from the drive arrangement 32 of the pin towards the leading end 26.
Referring now to
In the extended position, the leading end of the pin 24 is arranged to extend into the socket 18 when mounted to a support structure. The locking pin extends into a recess 40 of the support structure 14 so as to secure the wear member 12 to the support structure 14.
The helical arrangement 30 may define a start and end locating position for the pin 24. In some embodiments, the start locating position defines the retracted position, whilst the end locating position defines the extended position.
In some forms, the pin may be positioned in a transport position. In that arrangement, the wear member is arranged to be supplied onsite with the lock preinstalled and disposed in the transport position. Whilst this transport position may correspond to the retracted position of the lock or the extended (or locking) position, it may also be a position separate from either of those position as shown in
As shown in the sequence illustrated in
This movement may be done manually or may occur as a consequence of fitting the wear member onto the support structure as shown in the sequence of
Referring now to
In some forms, such as illustrated, the latching arrangement is also adapted to provide the function of the retainer of the retaining arrangement to provide the torsional resistance to rotation of the locking pin.
As best shown in the embodiment of
In the illustrated embodiment of
In use, the engaging structure 30 causes the pin 24 to rotate as it moves between the retracted, transport and extended position. The keepers 44′, 44″ arranged at opposing ends of the locking hole 22 are able to retain the pin in either of the predetermined transport or extended positions. As best shown in
A variation of the latch is shown in
Turning back to
The rigid detents 48′ 48″ of the latch engage with the locking hole 22 such that resilient portion 50 compresses. The resilient portion 50 can comprise concentric layers of elastomeric material positioned in the hole between the rigid detents 48′ 48″. The resilient portion 50 can comprise a hollow core 51. The resilient portion 50 compresses upon engagement of the pin 24 in the locking hole 22. The locking hole 22 does not allow for the resilient portion 50 to expand outwardly when compressed. Instead, the loading induced on the rigid detents 48′ 48″ compress the resilient portion 50 whereby it resiliently expands into the empty space of the hollow core 51.
In a variation, not shown, the through hole 49 in the pin 24 comprises a void that defines a hole or groove along at least one wall surface of the hole 49. In use, the void locates adjacent the resilient portion 50, whereby when the resilient portion 50 is compressed by the rigid detents 48′ 48″ moving inwardly towards each other, the resilient portion 50 is able to expand into the void.
Alternatively, in some variations, the resilient portion may be replaced by any resilient material, such as a spring, also compressible within the hole, or a combination of a spring and compressible material (as discussed below with reference to
The rigid detents 48′ 48″ are biased by the resilient portion so as to extend into the path of the locking hole 22. In operation, as the helical groove 36 of the pin 24 rotates through the helical ridge38 of the locking hole 22, the rigid portions of the latch mechanism are compressed against the bias of the resilient portions to apply a radial pressure into the locking hole 22 of the wear member 12 such that the pin 24 is resistant to movement through the locking hole. Consequently, the resistance to movement of the pin can require a corresponding torque applied to the drive arrangement 32 in order to rotate the pin 24 between the extended and transport positions.
Advantageously, the radial pressure applied to the locking hole can hold the pin within the locking hole when the helical ridge and groove of the engaging structure are not engaged. This can allow the wear member to be positioned in an inverted orientation without the pin 24 falling from the locking hole because of gravity.
When one of the rigid detents 48′ 48″ of the latch mechanism pass over one of the keepers 44′, 44″, the pin 24 moves into a latched position. In the latched position, the latch 46 may move into an offset position, i.e. is not centred about the pin axis. As shown in
In one form, one or both of the keepers 44′, 44″ may each include opposing notches so that both detents 48′ 48″ are received in notches of that keeper. In another form, the respective keepers only include a single notch. The pin may also be arranged to rotate through less than 360 degrees and the notches of the respective keepers are offset radially from each other around the pin axis so that one detent 48′ engages the notch of one keeper 44′ in the transport position and the other detent 48″ engages the notch of the other keeper 48″ in the extended position.
In operation, rotating the pin 24 so as to move the latch member 46 away from engagement with the keeper 44′ or 44″ disengages the rigid detent 48′ 48″ from the keeper. Disengagement from the keeper moves the rigid detent against its bias as it travels away from the keeper and along the groove of the helical ridge of the locking hole.
The recess 40 in the support structure 14 extends into the support structure and is shaped to receive the corresponding leading end 26 of the locking pin 24. In operation, when the wear member is mounted to the support structure, the recess 40 is aligned with the locking hole 22 of the wear member. The tool (not shown) is able to access the drive arrangement 32 of the locking pin 24 to move the locking pin 24 from the transport to the extended position and vice versa.
As best shown in
Referring now to
The spring clip can be releasably mounted about an edge 58 of the opening of the socket 18 of the wear member. In the form shown in
In some arrangements, the pin 24 may be retained in the locking hole by the latch in one of the transport or retracted position, and retained by the holder in the other, or the locking pin may be retained by both the holder and latch in one or both of the transport or retracted positions.
In an alternative embodiment, the locking pin 24 can be retained in the transport position by a holder in the form of a single-use frangible connection. These variations are disclosed in
Referring now to
As best shown in
Various methods can be utilised in order to remove the cap and move the locking pin from the transport position into the extended position. In some forms, the cap can be designed to break, i.e. shear apart, if twisted from the locking hole upon when a tool rotates the pin about the drive arrangement 132. The arm may be perforated to create a weak point so as to direct the break to occur at a specific location on the arm. In this form, once torn from the arm, the cap may be re-used, i.e. reinserted into the hexagonal recess 134 to protect against the ingress of fines.
The cap may be pulled from its position by an operator. The length of the arm may be designed such that it is short enough to ensure that it pulls out from between the latch and the wall if the plug is removed by a pulling force.
In a variation shown in
Referring now to
Referring to the form shown in
Referring now to the detent 268′ shown in
Referring now to the detent 268″ shown in
In an alternative to the above, the detents in the wall may not shear and thus become a permanent fixture of the locking hole 222.
Referring now to
In the form shown in
In another form as shown in
Additionally, the tie can block access to the hexagonal recess 334 of the drive arrangement such that the tie must be removed before the locking pin can be moved into an extended position.
Referring to
In this embodiment, the primary difference is that the retaining arrangement 542 includes two retainers (or latches)—an upper latch 546 (
Both the upper and lower latches comprise respective resilient portions (580, 550) and rigid portions (582, 548′).
The lower latch 547 functions in a similar manner to the latch described above and has a resilient portion 550 and a rigid detent 548″ and is arranged to shorten (compress) under load. In the illustrated form the lower latch is generally cylindrical and the detent 548′ is generally hemispherical. However, the latch is not limited to these shapes. In some forms, the resilient portion 550 of the lower latch 547 may include a hollow portion to enhance its ability to compress. In other forms, the resilient portion can be a solid structure.
Similar to the earlier embodiments, the lower latch 547 is disposed in the body of the locking pin 524. In contrast with the previously described embodiments, the locking pin 524 includes a blind bore 549 as opposed to a through hole and the lower latch is single sided (ie.it has a detent 548′ only on one end of the latch 547). In use, the resilient portion 550 of the lower latch 547 functions to bias the detent 548 against the wall of the locking hole 522 and enables the detent to locate into keepers (544′ and 544″) as discussed in more detail below.
A variation of the lower latch 547 is disclosed in
In the embodiment of
In some forms, the upper latch 546 is arranged to bear against the locking pin to resist lateral movement (being translation and or pivoting of the locking pin in the locking hole) which may otherwise occur under operational load. In this way, the upper latch 546 provides some shock absorbing capability to the locking pin when installed.
In the locking assembly 516, the primary torsional resistance to the locking pin 524 is provided by the lower latch 547 and its engagement in with the two keepers 544′ and 544″. As such, the locking arrangement can function without the upper latch 546. As such in this regard, the upper latch may be considered optional to the basic latching function. The purpose of the upper latch 546 is to provide the additional shock absorbing capability to the locking pin to enhance its function under load. It can also provide other retaining functions (as discussed below).
The use of the upper latch may be incorporated solely to provide the shock absorbing capability and therefore may not including any “latching” capability. The use of the term, “upper latch” should not be construed as limiting to the component to be used necessarily in conjunction with latching in this arrangement.
In one form as best shown in
In one form, the upper keeper 544′ may be reshaped so that it does not retain the detent 548′ when first installed in the locking hole 522 but rather provides a clearance 588 for the detent so that it does not engage with the wear member. This arrangement is best shown in
Further, in comparison between
In one form, neither the upper or lower latch provide a defined position when first installed. In this way there is no defined retracted or transport position. Rather the locking pin is able to be merely inserted and becomes engaged with the upper latch 546 which provides some frictional resistance and then can be rotated and driven axially under the helical arrangement of the engaging structure 530 as per a more conventional threaded arrangement.
Once the pin 524 is ready to be installed to lock the wear member 512 to the support structure 14, it is rotated (through for example approximately 180 degrees) to allow the rigid detent 548″ of the lower latch 547 to come in contact with the second keeper 544″. This corresponds to the locked or latched position.
In some forms, the pin 524 includes a radial projection 551 at its second end 528. The radial projection 551 is configured to engage a complementary surface 558 on the wear member 512. In the illustrated form, the complementary surface forms part of the cavity 543 that houses the upper latch 546. This arrangement creates a hard stop mechanism that prevents the pin 524 from rotating further and thus moving along the axial direction.
As best illustrated in
In other forms, the radial projection may not include this additional locking function. For example, as shown in
As with previous embodiments, the latching arrangement 542 also comprises a helical engagement structure in the form of a groove 536 on the locking pin 524 and thread 538 on the wear member. However, the threads on the wear member of the illustrated embodiment are located such that during installation of the pin 524 in the wear member 512, the lower latch 547 does not travel over the threads. Moreover, the threads can be positioned outside the load bearing zone between the wear member and pin that could otherwise result in crushing of the thread 538.
During assembly, the upper latch 546 is first installed in the cavity 543 of the wear member 512. Following this, the pin 524 is inserted such that the rigid detent 548″ of the lower latch 547 comes into frictional contact with the keeper 544′. Once the pin 524 is ready to be installed, the pin is rotated by 180o until the radial projection 555 encounters the complementary surface on the wear member 12 and comes to a hard stop. At this position, the rigid detent 548″ of the lower latch 547 will be in frictional engagement with the keeper 544″ in the pin cavity of the wear member. Simultaneously, the upper portion 559 of the upper latch 546 will also be in frictional engagement with the pin 524. In this locked position, the lower and upper latches will be located at an angle of 90o to each other.
An advantage of this embodiment is that, it can allow the application of locking force in two planes. Thus, the pin can be locked using forces that act in two different directions thus allowing for a much better fit within the wear member/adapter. As discussed above, the latching arrangement 542 can work with just the lower latch 546 itself (i.e. without the upper latch 547). However, the addition of the upper latch provides further advantages of this embodiment, including the ability of the upper latch 546 to absorb impact loads, to resist lateral movement (being translation and or pivoting) of the pin 524 within the locking hole 522, to allow latching of the pin 524 in transverse axial planes, and to provide redundancy to the latch function.
The primary difference in the wear member is that the interior shape and features of the lock receiving arrangement 790 is not formed directly as a casting of the wear member 712 but is provided as part of an insert 792 that is manufactured separately (say for example by an investment casting process) and is then placed within a mold (typically being a sand mold) and the wear member 712 is cast around the insert. The advantage of this arrangement is that the insert can be manufactured to a finer tolerance than generally possible under the sanding casting process usually employed in wear member manufacture. This in turn can assist in improving the performance of the resulting lock assembly incorporated in the lock receiving arrangement. Other advantages may include the ability to use different material for the insert as compared to the balance of the wear member 712 thereby allowing better control over performance and durability of the lock.
To ensure adequate performance, it is important that the insert 792 is adequately secured to the wear member 792. This may be achieved in a number of ways. In one form, the insert may be caused to fuse with the wear member as it is cast around the insert, such that the insert becomes intimately bonded with the wear member 712. With this arrangement the separation between the insert and the wear member is less distinct as there is not a clear material separation between the insert the cast wear member.
In another form, the insert may be mechanically keyed to the cast wear member as the liquid metal is able to flow around the exterior 793 of the insert 792.
In a further form, the insert is secured by a combination of bonding (fusing) and mechanical arrangement. Further, whilst the insert has been shown in relation to the embodiment of
A further variation of the locking assembly 516 shown in
The primary difference with the lock 816 is in the design of the upper latch or retainer 846. In the lock 816, the retainer 846 is formed from a spring-like or resiliently flexible material, such as spring steel into a substantially C-shaped clip.
The wear member 812 comprises a ledge-like cavity 892 around the inwardly facing sidewalls of the locking hole 822, the cavity being substantially C-shaped so as to generally correspond to the shape of the retainer 812. The retainer 812 is sized so as to enable insertion into the cavity 892 from outside of the wear member 412 with the outer diameter of the retainer 846 fitting within the inner diameter of the cavity 892.
As best seen in
The retainer 846 has an interference fit with the locking pin 824 as, in its natural state, the substantially circular aperture formed by the arms 893 and body of the C-shaped clip has a smaller diameter than the diameter of the pin 824. As the locking pin 824 is engaged between the arms 893 of the retainer 846, the arms 893 can be resiliently flexed outwards, with the inward bias of the arms 893 (towards their natural state) applying a positive force that clamps against the locking pin 824 and resists rotation of the pin by friction. The positive force of the inward bias of the arms 893 against the locking pin 824 can generate a friction based torsional resistance that assists the retainer 846 in gripping and retaining the locking pin 824 in use. This torsional resistance can help reduce the effects of vibrations that may otherwise cause the locking pin 824 to rotate and come loose, or from moving axially towards the retracted position. The frictional resistance may therefore form part of the retaining arrangement (operating in conjunction with the lower latch 847) to maintain the locking pin 824 in the locking hole 822 under axially loading on the pin 824. The frictional resistance can be overcome with a wrench applied by an operator during installation or removal of the locking pin 824.
A further variation of the locking assembly 516 shown in
A feature of the lock 916 is that the locking pin 924 is inserted into the locking hole 922 independent of the lower latch 547. This arrangement allows the locking hole design to be simplified (as it does not require the same lead entry 588) on the interior wall of the locking hole to accommodate the lower latch when the locking pin is installed together with the lower latch. Also, it relieves compression on the lower latch during installation.
To enable this arrangement, the cavity 943 forming part of the lock receiving arrangement 990 is modified to accommodate the drop in of the lower latch. A complementary modification is made to the upper latch 946 so that it fits within the cavity. In the form as shown, the cavity 943 includes a planar back wall 991 and does not include the undercut 545. This assists in installing the upper latch 946 after installation of the locking pin 924.
The installation sequence of the locking assembly is shown in
In use, the locking pin 924 is rotated towards the extended position to a position where the locking bore 949 aligns with the cavity 943 and just above the floor of the cavity. In this position, the lower latch 946 is able to be dropped into the cavity 943 to be aligned with locking bore 949. Once in that position, the latch can then be translated into the bore 949 and is thereby captured within locking pin body 924. This sequence is best illustrated in
In the illustrated form, when in this intermediate position, the upper latch is then abled to be inserted into the cavity 943, thus rendering the locking assembly fully operational.
Whilst the fitting of the lock assembly 916 to the wear member 912 may be done onsite, typically it is preinstalled and the wear member 916 is delivered on site with the locking assembly installed as an assembly. As such once installed, the locking assembly 916 may be moved to any one of the retracted position or transport position as required before installation on the support structure 12 as required and as detailed above in relation to the previous embodiments.
Once in this operational state and delivered to site, the wear member can then be fitted to the support structure 14 in a similar manner as discussed above and as shown in the sequence of
Referring now to
In this embodiment, the latching arrangement 642 comprises of a single latch 646 (similar to the upper latch 546 in the previous embodiment) that locates in a cavity 643 of the wear member 612. However, in this case, the latch 646 provides both the torsional resistance to the locking pin to maintain the pin in its locked position and to maintain the pin firmly within the locking hole 622.
The latch 646 comprises a rigid detent portion 682 that has an inner face 653 that bears against the pin 624 and a resilient backing portion 680. The latch 646 locates in the cavity 643 of the wear member and is retained thereby in an undercut arrangement 645, as per the earlier embodiment.
The resilient portion 680 is arranged to compress in operation to apply a bias to the pin. Similar to the earlier embodiment, this bias provides a shock absorbing effect and is especially useful to buffer the impact of loads acting on the pin and thereby inhibit damage to the pin 624/locking hole 622.
To provide a latching function, the pin 624 incorporates a keeper 690 located on the body 631 of the locking pin 624 formed as a recess or notch within the pin body 631. The keeper 690 is arranged to move into register with the latch 646 as the pin is moved to its locking position. As it moves into register, the inner face 653 moves into keeper recess 690 (under the bias of the resilient member 680) thereby capturing the rigid detent portion 682 resisting further rotation of the pin 624 within the locking hole 622. The detent portion 682 and keeper 690 can be formed with appropriately chamfered edges to allow adequate entry and exit to the of the latch into the keeper recess to enable release of the lock 616 from the locking position to enable removal of the locking pin 624.
The pin 624 may comprise a radially extending projection 652 at its second end 626 similar to the previous embodiment described. This radially extending projection can engage with a complementary surface 658 on the wear member 612 to prevent further rotation of the pin 624 once the pin is locked into position. Further, the second end 626 may also comprise a cut-away section 692 or discontinuity to provide clearance for the thread 638 (which may extend to the exterior surface of the wear member) when the pin is in its locked position. In this way the end 626 of the pin can be located at or below the exterior of the wear member when in the locked position (see
During assembly, the latch 646 is first inserted into the cavity 643. Next, the pin 624 is inserted in the locking hole 622 and rotated which causes the engaging surfaces 630 and 638 to engage progressively brings the body 631 of the pin into engagement with the inner face 653 of the latch 646 causing the resilient member 680 to compress and increasing frictional contact between the pin 624 and the latch 646. In the present embodiment, the inner face 653 may include multiple mating surface (694,696, 698) at various inclinations that facilitates this progressive engagement. The latch engages the pin on installation of the pin in the locking hole and progressively increases its retaining force as the pin is rotated into the locking hole towards the locked position and engages the different surfaces (being surface 694 initially, then surface 696, and finally surface 698). For example, during transport, the pin 624 can be rotated to a position (see
A feature of this design is that the locking pin 624 has no bore/ through hole to accommodate an integrated latch as per the earlier embodiments. This has an advantage as the bore/through hole can act as a stress raiser that forms regions of concentrated stress on the locking pin that may impact pin performance
Referring now to
Under loading conditions on the wear member, there is a tendency that the wear member will rotate on the support structure particularly as loads parallel to the longitudinal centreline of the assembly are induced (because the taper provided on the stabilising surfaces between the support structure and wear member). The closer these stabilised flats become to horizontal, or parallel to the longitudinal centreline of the assembly, the less resultant horizontal load is placed on the wear member, which thus has to be counteracted by the resistance of the lock to maintain the wear member on the support structure. The stabilisations are not completely parallel to the longitudinal centreline for two reasons; first these parts are almost all either cast or forged and some taper, or draft, must be used on these parts or they would not be able to be removed from the mold. Secondly, if these stabilised flats both front and rear, which are generally designed to be the load bearing pads for the forces on the wear member, were completely horizontal then installing a wear member onto the support structure would require larger clearances to ensure the assembly could be completed. The wear member would also be more likely to become wedged onto the support structure making them harder to be removed. A slight taper on these bearing pads is therefore required for easier manufacture and also assembly and disassembly of the parts.
This taper and also the required clearance between the support structure and the wear member allow for a certain amount of movement between the support structure and the wear member when the wear member is loaded while in use. The larger the clearance, and the larger the taper, means that there is generally more movement of the wear member on the support structure when a load is applied to the wear member. This necessitates a very robust lock, which can hold the wear member onto the supporting structure even in the presence of these high loads.
Furthermore, with the added desirability of locks that provide a hammerless system, such as those disclosed in this disclosure, the accommodation of the horizontal loads become more problematic as the locks need to be able to be installed and removed without a hammer so as such need to have some tolerance or movement to accommodate installation and release of the locking pin.
In accordance with this further aspect of the disclosure, at least one bearing surface defined by an internal wall of the locking hole and or support structure is configured to be angularly offset from at least one corresponding bearing surface defined by an external surface of the locking pin when the wear member is installed on the support structure, and the lock is in the locked position, and without any load transfer on the wear assembly from ground penetration.
Moreover, when under loading condition, the angular offset is designed to reduce (i.e. the bearing surfaces move more into mating arrangement) as the locking pin is caused to move relative to the wear member and the support structure, particularly under the horizontal induced loads discussed above. As such, when a load is placed on the wear assembly from ground penetration in use, the bearing surfaces are biased into increased surface engagement.
With this arrangement, the surface area contact is increased under the bias of the load transfer. The profile of the at least one bearing surface of the pin and/or locking hole and/or support structure may be planar or include a radius or radii of curvature so the surface is arcuate.
Turning to
Region 700 is a rearward section (relative to the tip of the wear member) between the body 531 of the pin 524 and interior surface of the locking wall 522 (being in opposing relation to keeper 544″). Region 702 is a forward section between the lower end of the pin (towards the first end 526) and a rear surface of the interior wall 552 of the cavity 540 of the support structure 514.
The angle of the offset is typically less than 5 degrees but can be adjusted based on the tolerance in the lock, the expected design load conditions. In one form, the feature may increase the life of the support structure and pin by providing a larger bearing contact surface area between the parts (more contact surface area =less contact stress). Offsetting the angle between the pin and support structure accommodates for the rotation/tilt of the pin relative to the nose due to the initial gaps closing up. The pin and support structure bearing faces ‘roll’ into alignment when the wear member is under load. Similarly, this may be applied to the other pin bearing faces (e.g. between pin and wear member (region 700)).
A further benefit of this arrangement when applied to the lock 516 is that the wear member can be held firmly on the support structure by the action of the compressed/pre-loaded latch 546 (not shown in
A further advantage of the angular offset of the bearing surfaces is that there may be greater clearance provided when the pin is installed or removed with the wear member in an unloaded condition. This can facilitate installation and removal of the pin.
Further, the wear assembly may be manufactured to suit a particular digging application. For example, specific bearing surfaces may be predetermined to be angularly offset relative to the corresponding support structure bearing surfaces in the installed position. These are the surfaces that are anticipated to wear the most in the particular digging application, and it may be any combination of corresponding bearing surfaces.
In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.
Number | Date | Country | Kind |
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2020903796 | Oct 2020 | AU | national |
2021901737 | Jun 2021 | AU | national |
This application is a national stage application under 35 USC 371 of International Application No. PCT/AU2021/050972, filed Aug. 25, 2021, which claims the priority of Australian Application No. 2020903796, filed Oct. 20, 2020 and Australian Application No. 2021901737, filed Jun. 9, 2021, the entire contents of each priority application are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/AU2021/050972 | 8/25/2021 | WO |