U.S. patent application number 11/877007 was filed with the patent office on 2008-04-24 for wear assembly for an excavating bucket.
This patent application is currently assigned to ESCO Corporation. Invention is credited to Terry L. Briscoe, Robert McClanahan, Rebecca A. Van Raden.
Application Number | 20080092412 11/877007 |
Document ID | / |
Family ID | 39316526 |
Filed Date | 2008-04-24 |
United States Patent
Application |
20080092412 |
Kind Code |
A1 |
McClanahan; Robert ; et
al. |
April 24, 2008 |
Wear Assembly For An Excavating Bucket
Abstract
A wear assembly for protecting the digging edge of a bucket
which includes a wear member having a lock-receiving hole in one
leg and an upstanding rib along the other leg. The rib extends
axially along the leg to be received into a slot in a base fixed to
the lip of the bucket. The rib has a rear end that engages the base
to hold the rear end of the rib between the base and the lip. The
wear member further includes an interior surface that has a front
portion formed with a curve to wrap around the digging edge and a
plurality of stabilizing surfaces. The lock has a latch and a
threaded wedge received into the passage to move the latch to its
holding position to maintain the lock in the assembly during
use.
Inventors: |
McClanahan; Robert;
(Milwaukie, OR) ; Briscoe; Terry L.; (Portland,
OR) ; Van Raden; Rebecca A.; (Beaverton, OR) |
Correspondence
Address: |
ESCO CORPORATION
2141 NW 25TH AVENUE, P.O. BOX 10123
PORTLAND
OR
97210
US
|
Assignee: |
ESCO Corporation
Portland
OR
|
Family ID: |
39316526 |
Appl. No.: |
11/877007 |
Filed: |
October 23, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60853908 |
Oct 24, 2006 |
|
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|
Current U.S.
Class: |
37/451 |
Current CPC
Class: |
E02F 9/2883 20130101;
E02F 9/2841 20130101 |
Class at
Publication: |
37/451 |
International
Class: |
E02F 9/28 20060101
E02F009/28 |
Claims
1. A wear member for an excavating bucket comprising a front
working end, a first leg and a second leg, each said leg extending
rearwardly and having an inner surface facing toward the other leg,
the legs defining a gap between the inner surfaces which is open
laterally to receive a digging edge of an excavating bucket, the
first leg including a hole for receiving a lock to secure the wear
member to the bucket, and the second leg including a rib upstanding
on the inner surface of the second leg that extends axially
rearward along most of the second leg to be slidingly received into
a slot of a base fixed to the bucket for support.
2. A wear member in accordance with claim 1 wherein the rib
includes rails each with a holding surface that generally faces
toward the inner surface of the second leg to engage complementary
holding surfaces along the slot of the base.
3. A wear member in accordance with claim 2 wherein a rear end of
the rib projects rearward of the second leg to engage a support
surface of the base which holds the rear end of the rib between the
support surface and the bucket for support of the wear member under
load.
4. A wear member in accordance with claim 3 which includes an inner
corner surface interconnecting the inner surfaces of the two legs
to collectively define an interior surface of the wear member that
is adapted to overlie the bucket, wherein the interior surface has
a generally uniform curvature along the inner corner surface and a
plurality of spaced apart stabilizing surfaces proximate the
uniform curvature wherein each said stabilizing surface extends
generally parallel to the inner surface of the second leg.
5. A wear member in accordance with claim 4 in which the inner
corner surface includes a central portion and opposite side
portions, wherein the central portion is recessed relative to the
side portions and thereby defines sidewalls to oppose and contact
side surfaces of the base for lateral support.
6. A wear member in accordance with claim 5 wherein one said
stabilizing surface is formed along the central portion proximate
each said side portion and proximate each said leg.
7. A wear member in accordance with claim 1 wherein a rear end of
the rib projects rearward of the second leg to engage a support
surface of a base fixed to the bucket which holds the rear end of
the rib between the support surface and the bucket for support of
the wear member under load.
8. A wear member in accordance with claim 1 which includes an inner
corner surface interconnecting the inner surfaces of the two legs
to collectively define an interior surface of the wear member that
is adapted to overlie the bucket, wherein the interior surface has
a generally uniform curvature along the inner corner surface and a
plurality of spaced apart stabilizing surfaces proximate the
uniform curvature, wherein each stabilizing surface extends
generally parallel to the inner surface of the second leg.
9. A wear member for an excavating bucket comprising: a front
working end; a pair of rearwardly extending legs defining a gap
adapted to straddle the bucket along a digging edge, each said leg
including an inner surface facing generally toward the other leg; a
hole for receiving a lock to secure the wear member to the bucket;
and an axial rib upstanding on an inner surface of one of the legs,
the rib having a rear end with a support surface free of the leg
and facing away from the other leg to engage a holding surface of a
base fixed to the bucket that holds the rear end of the rib between
the holding surface and the bucket for support.
10. A wear member in accordance with claim 9 wherein the rear end
of the rib extends rearward of the leg to which the rib is
attached.
11. A wear member in accordance with claim 9 wherein the rib
includes rails each with a holding surface that generally faces
toward the inner surface of the leg from which the rib extends to
engage complementary holding surfaces on a base fixed to the bucket
facing in an opposite direction.
12. A wear member in accordance with claim 9 which includes an
inner corner surface interconnecting the inner surfaces of the two
legs to collectively define an interior surface adapted to overlie
the bucket, wherein the interior surface has a generally uniform
curvature along the inner corner surface and a plurality of spaced
apart stabilizing surfaces proximate the uniform curvature, wherein
each said stabilizing surface extends generally parallel to the
inner surface of the leg with the rib.
13. A wear member for an excavating bucket comprising: a front
working end; a pair of rearwardly extending legs defining a gap
adapted to straddle the bucket along a digging edge; a hole for
receiving a lock to secure the wear member to the bucket; and an
interior surface adapted to face and overlie the bucket, the
interior surface including a front portion having a generally
uniform curvature to wrap around the digging edge of the bucket and
a plurality of spaced apart stabilizing surfaces wherein each
stabilizing surface extends generally parallel to an outer side
surface of the bucket along the digging edge received into the
gap.
14. A wear member in accordance with claim 13 in which the front
portion of the interior surface includes a central portion and
opposite side portions, wherein the central portion is recessed
relative to the side portions to thereby define sidewalls to oppose
and contact side surfaces of the base for lateral support.
15. A wear member in accordance with claim 14 wherein one said
stabilizing surface is formed along the central portion proximate
each said side portion.
16. A wear assembly for an excavating bucket comprising: a base
fixed to the bucket, the base including a front surface and an
axial slot having an inlet end that opens in the front surface; a
wear member including a front working end, a first leg and a second
leg, each said leg extending rearwardly and having an inner surface
facing toward the other leg, the legs defining a gap between the
inner surfaces adapted to receive a digging edge of the bucket, the
first leg including a hole and the second leg including a rib
upstanding on the inner surface of the second leg that extends
axially rearward along most of the second leg and is slidingly
received into the slot on the base through the open inlet end; and
a lock received in the hole in the wear member to secure the wear
member to the bucket.
17. A wear assembly in accordance with claim 16 in which the rib
and the slot each includes rails that engage each other such that
the rails of the slot hold the rib between the base and the
bucket.
18. A wear assembly in accordance with claim 17 wherein the base
includes a support surface facing toward the bucket, and the rib
includes a rear end that projects rearward of the second leg to
engage the support surface which holds the rear end of the rib
between the support surface and the bucket for support of the wear
member under load.
19. A wear assembly in accordance with claim 16 wherein a rear end
of the rib projects rearward of the second leg to engage a support
surface of a base fixed to the bucket to hold the rear end of the
rib between the support surface and the bucket for support of the
wear member under load.
20. A wear assembly in accordance with claim 16 which includes an
inner corner surface interconnecting the inner surfaces of the two
legs to collectively define an interior surface adapted to overlie
the bucket, wherein the interior surface has a generally uniform
curvature along the inner corner surface and a plurality of spaced
apart stabilizing surfaces proximate the uniform curvature, wherein
each said stabilizing surfaces extends generally parallel to the
inner surface of the second leg.
21. A wear assembly for an excavating bucket comprising: a base
fixed to the bucket, the base including a front surface having a
generally uniform curved shape and a plurality of stabilizing
surfaces; a wear member including (i) a front working end, (ii) a
pair of rearwardly extending legs defining a gap adapted to
straddle the bucket along a digging edge, (iii) a hole, and (iv) an
interior surface adapted to face and overlie the bucket, the
interior surface including a front surface having a generally
uniform curvature to wrap around the digging edge of the bucket and
bear against the front surface of the base, and a plurality of
spaced apart stabilizing surfaces, wherein each stabilizing surface
of the wear member and the base extends generally parallel to an
outer side surface of the bucket along the digging edge received
into the gap and a lock received in the hole in the wear member to
secure the wear member to the bucket.
22. A wear assembly in accordance with claim 21 in which the front
portion of the interior surface includes a central portion and
opposite side portions, wherein the central portion is recessed
relative to the side portions to thereby define sidewalls to oppose
and contact side surfaces of the base for lateral support.
23. A wear assembly in accordance with claim 22 wherein one said
stabilizing surface is formed along the central portion proximate
each said side portion.
Description
FIELD OF THE INVENTION
[0001] The present invention pertains to a wear assembly for
protecting the digging edge of an excavating bucket or the
like.
BACKGROUND OF THE INVENTION
[0002] Excavating buckets are typically subjected to harsh
conditions. Wear members are usually provided to protect the
digging edges from premature wear. Such wear members have taken
many different forms. For example, wear members have been secured
to the lip of a bucket through the use of Whisler-style locking
arrangements such as used in U.S. Pat. No. 4,570,365. These locks,
however, require through-holes to be formed in the lip and the use
of large hammers to drive the wedges into place. Wear members have
also been secured to a lip of a bucket by a T-shaped base and a
hammerless look such as disclosed in U.S. Pat. Nos. 5,088,214 and
7,080,470. While these systems offer improvements over past
systems, improved stability, strength, manufacturability, and value
in a wear assembly are desirable.
SUMMARY OF THE INVENTION
[0003] The present invention pertains to an improved wear assembly
with a wear member for protecting the front digging edge of
excavating equipment, which is highly stable, is strong,
experiences reduced wear, is easy to use and manufacture, safe,
streamlined, and involves less discarded material at the end of its
life.
[0004] In one aspect of the invention, the wear assembly includes a
replaceable wear member that includes a pair of legs to straddle
the lip (or sides) of an excavating bucket. One of the legs is
provided with a hole for receiving a lock to secure the wear member
to the lip, while the other leg includes an upstanding rib along
its inner surface. The rib extends axially rearward to be slidingly
received into a slot of a base fixed to the lip for support.
[0005] In another aspect of the invention, one of the legs of the
wear member includes a rib having a rear end formed with a support
surface that is free of the leg and faces away from the other leg.
The support surface engages a holding surface of the base so as to
hold the rear end of the rib between the base and the lip (or side)
for support under load.
[0006] In another aspect of the invention, the wear member includes
an interior surface that faces and overlies the lip (or side) of
the bucket. The interior surface has a front portion formed with a
generally uniform curvature to wrap around the lip and a plurality
of spaced apart stabilizing surfaces. The stabilizing surfaces
extend generally parallel to the central axial plane of the lip for
a unique combination of enhanced stability and reduced stress.
[0007] In another aspect of the invention, the wear member and the
base are formed with a tongue and groove coupling wherein the base
is formed with a central groove and the wear member with a central
tongue to fit within the groove. The tongue and groove each
includes cooperating rails to secure the wear member to the base.
The groove opens forwardly through the front end of the base to
receive the tongue. This construction provides a stable, secure,
and strong connection between the components that is easy to
use.
[0008] In one other aspect of the invention, the lock to secure the
wear member to the bucket includes a body provided with a passage,
a movable latch, and a wedge received into the passage to move the
latch to its holding position to maintain the lock in the assembly
during use.
[0009] In another aspect of the invention, the lock includes a
threaded wedge which is received into the lock body to move a latch
to a position to retain the lock in the assembly. The latch is
movable between a retaining position where the latch prevents
unwanted loss of the lock and a release position where the latch
permits removal of the lock.
[0010] In one other aspect of the invention, a threaded wedge is
provided with a resilient material that is compressed by the
complementary threaded surface to resist loosening of the threaded
wedge. In one preferred embodiment, the resilient material is a
strip of an elastomer fixed within the helical groove of the
threaded wedge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an exploded perspective view of a wear assembly in
accordance with the present invention that is to be secured to a
bucket lip.
[0012] FIG. 2 is a partial, perspective view of a bucket lip where
a wear assembly of the present invention has been omitted.
[0013] FIG. 3 a perspective view of the wear assembly with an axial
cross section exposed.
[0014] FIG. 4 is a top perspective view of a base of the wear
assembly.
[0015] FIG. 5 is a bottom perspective view of the base.
[0016] FIG. 6 is a front perspective view of a wear member of the
wear assembly.
[0017] FIG. 7 is a rear perspective view of the wear member.
[0018] FIG. 8 is a perspective view of the assembled wear member
and base.
[0019] FIG. 9 is an exploded front perspective view of a lock of
the wear assembly.
[0020] FIG. 10 is an exploded rear perspective view of the
lock.
[0021] FIG. 11 is a partial cross-sectional view of the wear
assembly of the invention.
[0022] FIG. 12 is a partial cross-sectional view of the wear
assembly with an alternative lock.
[0023] FIG. 13 is a perspective view of the alternative lock.
[0024] FIG. 14 is a perspective view of a body of the alternative
lock.
[0025] FIGS. 15 and 16 are perspective views of a latch included in
the alternative lock.
[0026] FIG. 17 is a perspective view of a threaded wedge for use in
the alternative lock.
[0027] FIG. 18 is a cross-sectional view of the alternative
threaded wedge.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] in accordance with the present invention, a wear assembly 1
is provided for attachment to excavating equipment such as a
bucket. The invention is discussed below in terms of the attachment
of a shroud to the lip of a load-haul-dump (LHD) bucket. However,
the invention is not limited to the attachment of a shroud or an
LHD bucket. For example, the present invention could be used to
secure shrouds to a different kind of bucket, mount shrouds between
spaced apart teeth, and/or secure other kinds of wear members
(e.g., wings or adapters). Although one kind of lip is illustrated
in the drawings, the invention could be used with other kinds of
lips having other formations and cross sections. Moreover, wings
mounted along the sidewalls of the bucket adjacent the lip can have
the same or similar construction. For purposes of this application
the digging edge of the bucket will be deemed to include the front
edges of the bucket sides where the wings are mounted as welt as
the front edge of the lip. Further, the invention is at times
discussed in relative terms, such as up, down, front, rear,
vertical, horizontal, etc., for the sake of easing the description.
These terms are to be considered relative to the orientation of the
elements in FIG. 1 (unless otherwise noted), and are not to be
considered limitations on the invention. As can be appreciated, the
wear assembly can be used and oriented in a variety of ways.
[0029] Wear assembly 1 includes a wear member 3, a base 5, and a
lock 7 to releasably secure the wear member (FIGS. 1 and 3). The
wear assembly fits over and is secured to a lip 12 of a bucket or
the like. Lip 12 includes an inside face 14, an outside face 16,
and a front edge 17 (FIG. 2). Scallops or recesses 18 are
preferably formed along the front edge 17 to accommodate passage of
lock 7. Scallops 18 are each preferably formed to have a uniform,
continual, arcuate surface 19 with a curvature that extends no more
than about 180 degrees about an axis extending generally
perpendicular to the lip to be easily manufactured and provide a
robust base to resist the applied loads. Nevertheless, the scallops
could be formed to have a non-uniform curvature, a discontinuous or
angular shape, and/or be formed to have full or partial closure. In
some circumstances, the scallops could be omitted with the boss
extending farther forward from the lip.
[0030] A base 5 is fixed to lip 12 over each scallop 18 (FIG. 1).
While bases 5 are preferably welded to the lip, they could be cast
as an integral part of the lip or secured by mechanical means. In
addition, the bases could each be formed as a multiple of parts,
which are integral or spaced apart, although a one-piece member is
preferred for simplicity and strength. Each base 5 has a pair of
legs 21, 22 that straddle lip 12 (FIGS. 1 and 3-5). A first or
inside leg 21 sets along inside surface 14 of lip 12 while a second
or outside leg 22 sets along outside surface 16. Outside leg 22 is
longer than inside leg 21 to interlock with base 5. However, the
legs could be the same length or the inside leg longer. In
addition, the base could have the opposite orientation with first
leg 21 extending along outside face 16 and second leg 22 along
inside face 14. Legs 21, 22 are interconnected by a front end
20.
[0031] The second leg 22 includes a central, axial groove 26
provided with a pair of inwardly projecting rails 24 along its
opposite sides 23 (FIG. 4). Rails 24 define holding surfaces 25
that are spaced from and facing outside face 16. Rails 24 cooperate
with complementary rails 27 of wear member 3 to prevent the
movement of leg 22 away from the lip. In some circumstances, for
example, lower stress environments, the rails could be omitted
entirely (not shown) so that the slot provides lateral support. A
brace 30 is preferably provided at the rear end of second leg 22
(FIGS. 4 and 5), though it could be omitted. In this construction,
groove 26 extends into brace 30 to define an opening 31, which is
between brace 30 and outer wall 16 when the base is welded to lip
12. While a closed opening 31 is illustrated, groove 26 could
extend entirely through brace 30 to define an opening that is open
on both ends. The opening could also be defined in leg 22 without
the addition of the brace. In either case, opening 31 receives a
support 33 of wear member 3 to strengthen and resist breakage of
the wear member under heavy loading. Groove 26 also opens forwardly
through the front end 20 of base 5 and is generally aligned with
scallop 18.
[0032] Brace 30 also preferably extends transversely beyond leg 22
to define a front wall 34 to abut the rear end 35 of shroud 3 and
thereby reduce the rearward shifting of the shroud under load,
which in turn, reduces the stress and wearing of wear member 3 on
base 5. Brace 30 also preferably has an equal or greater depth than
leg 22 to maximize the surface area in abutment with shroud 3, and
to function as a deflector for earthen material when the movement
of the bucket is reversed. A deflector face 36 inclined forward
from outer face 16 is preferably formed along the rear side of
brace 30 to direct the earthen material away from the assembled
base and shroud. Leg 22 is preferably formed as an open framework
with openings 37 to reduce the amount of needed steel and to
facilitate welding of the base to the lip.
[0033] The front end 20 of base 5 wraps around front edge 17 of lip
12 such that the interior surface 40 of the base (i.e., the surface
that faces lip 12) is shaped to generally conform to the shape of
the particular lip to which it is fixed (FIGS. 1, 4 and 5),
although derivations are possible. In this case, interior surface
40 includes an upright face 41 to set against front edge 17, an
upper face 42 to set against ramp 43 of inside face 14, and a lower
face 44 to set against outside surface 16. If the front of the lip
had a curved or other shape, interior surface 40 would be changed
to accommodate the shape of the lip. The front end 20 of base 5
preferably has a curved front bearing surface 48 to minimize stress
concentrations and wearing between the wear member and the base. In
a preferred construction, front surface 48 has a generally uniform
curvature, though other configurations are possible. A recess 51 is
formed in first leg 21 in vertical alignment with groove 26 for
receiving lock 7.
[0034] Stabilizing surfaces 49 are formed in front end 20 proximate
both legs 21, 22 to engage complementary stabilizing surfaces 50 on
wear member 3 (FIGS. 1, 4 and 5). Stabilizing surfaces 49 are
preferably limited in size so that front surface 48 is
predominantly an uninterrupted generally uniform curved surface as
it wraps around the front edge of the lip. The stabilizing surfaces
are also preferably along the side 93 of base 5 for stability but
could be provided at other locations. Also, the upper and lower
stabilizing surfaces 49 are generally aligned vertically by each
side 93 such that the upper and lower stabilizing surfaces 49 by
the one side 93 are generally aligned with each other, and the
upper and lower stabilizing 49 by the other side 93 are generally
aligned--though other positions are possible. Stabilizing surfaces
49, 50 are preferably planar and horizontal, i.e., parallel to the
central axial plane P of lip 12.
[0035] Wear member 3, which is a shroud in the illustrated
construction, has a front working portion 66 that tapers to a
narrowed front edge 68, and a rear mounting portion 70 that is
bifurcated to define a first or inside leg 72 and a second or
outside leg 74 (FIGS. 1, 3 and 6-8). The wear member is configured
to set over base 5 with legs 72, 74 straddling lip 12. In a
preferred construction, wear member 3 fits over lip 12 with first
leg 72 overlying inside surface 14 and second leg 74 overlying
outside surface 16. Nevertheless, the legs could be reversed so
that first leg 72 is the outside leg and second leg 74 is the
inside leg. Wear member 3 has an interior surface 80 that faces and
overlies the lip. The interior surface 80 includes inner face 83 of
outside leg 74, inner face 84 of inside leg 72, and the inner
corner surface 86 at the intersection of legs 72, 74. Inner face 83
of leg 74 overlies leg 22 and outside face 16, and inside face 84
of leg 72 overlies leg 21 and inner face 14. Interior surface 80
along inner corner surface 86 has a central portion 88 and side
portions 90. Central portion 88 generally matches front face 48 of
base 5 and abuts against it during use. Central portion 88 is
recessed relative to side portions 90 to form sidewalls 91
juxtaposed to sides 93 of base 5 for increased lateral support.
[0036] In a preferred construction, interior surface 80 along
central portion 88 defines a curved bearing surface 85 (preferably
having a generally uniform curve) that opposes and abuts front
bearing surface 48. The lack of edges on the front bearing surfaces
of the wear member and the base reduces stress concentrations in
the parts, i.e., the generally uniform matching curvature of the
two surfaces at the front bearing surface reduces the concentration
of stress that can occur in the corners of other parts as the wear
part tends to shift on the base during use.
[0037] At times, heavy vertical loads (i.e. the loads with vertical
components) are applied to the front working end 66 of wear member
3. It is desirable to resist such loads with surfaces that are
substantially horizontal, i.e., generally perpendicular to the
vertical component of the load. In the present invention, a front
end 89 of interior surface 80 forms the uniform curved surface 86
and a pair of stabilizing surfaces 50 (FIG. 7) proximate each of
the legs 72, 74 and central portion 88 to engage stabilizing
surfaces 49 on base 5 (FIGS. 4 and 5). The stabilizing surfaces 49,
50 provide better resistance and greater stability to wear member 3
under vertical loading. To avoid the creation of long edges, the
stabilizing surfaces 49, 50 are limited to discrete locations,
preferably extending only a small portion across the front ends of
the wear member 3 and base 5 (collectively no more than half), and
are preferably located at the sides of bearing surfaces 48, 86 for
increased stability. In this way, the benefit gained by the curved
bearing surfaces is not lost by the use of the stabilizing surfaces
49, 50. Transition surfaces 81, 87 are provided to ease contact
between stabilizing surfaces 49, 50 and to avoid sharp corners
where stress may concentrate.
[0038] A rib 82 is provided upstanding on the inner face 83 of leg
74 in an axial orientation for receipt within groove 26 (FIGS. 1, 3
and 6-8). Rib 82 includes rails 27 that cooperate with rails 24;
i.e., rails 27 are received between lip 12 and holding surfaces 25
of rails 24 to support wear member 3 under certain loads. While rib
82 with rails 84 preferably has a T-shaped configuration, other
shapes, such as dovetail, could be used. Alternatively, there could
be no rails in certain situations such as low load environments.
Rib 82 preferably extends over at least half of leg 22, and most
preferably over substantially the entire length of inner surface
83, for receipt within groove 26 to maximize the support available.
Alternatively, the groove could be formed on wear member 3 and the
rib on base 5. When shroud 3 is installed, it is slid over base 5
and lip 12 such that inside and outside legs 72, 74 straddle base 5
and lip 12. Rib 82 is slid into the open front end 75 of groove 26
in an easy to use manner so that rails 27 cooperate with rails 24
to hold leg 22 to lip 12.
[0039] In a preferred construction, rib 82 extends beyond the rear
end of leg 74 to define a support 33 that is received in opening 31
beneath brace 30, although other kinds of rearward supports could
be used. For example, support 33 could be forward of the rear end
of leg 74 provided it included a holding surface 95 free of the leg
and facing away from the lip to engage a complementary support
surface (like 94) of leg 74. Support 33 is held between a support
surface 94 and lip 12 for enhanced support of the wear member 3.
The cooperation of support 33 and brace 30 supplements the
resistance provided by rails 24, 27. By providing such a support at
the rear end of leg 22, bending of the legs can be reduced, which
in turn, lessens the risk of breaking the part. For example, as
upward vertical loads are applied to front portion 66, shroud 3
tends to shift clockwise around front digging edge 17. This
shifting causes outer leg 22 to pull away from outer wall 16 of lip
12. This action of pulling away from wall 16 places a large amount
of stress in inside leg 72 which tends to resist the shifting.
While this bending is resisted by rails 24, 27, pulling can still
generate heavy loading of the leg. By including a support 33 at the
rear end of leg 22, the stresses produced in the leg pulling
outward under load are substantially reduced, thus, lowering the
risk of breakage under heavy loads. As an alternative construction,
particularly in low load environments, rails 24, 27 can be omitted
so as to rely solely on support 33 in pocket 31. As alternatives,
the rear end of the entire outer leg 74 could be received under
brace 30, or other supports, and not as extensions of rib 82.
[0040] Wear member 3 is assembled over base 5 with a direct,
continuous rearward sliding motion where rib 82 is slid through
open end 75 and into groove 26. The rearward movement of wear
member 3 over base 5 is continued until inside corner surface 86
abuts front face 48 of base 5 (FIGS. 3 and 11). At this juncture,
rear wall 35 of outside leg 74 is preferably placed in close
proximity to stop surface 34. With cast parts, it is not practical
for inside corner surface 86 and rear wall 35 to simultaneously
abut front face 48 and stop surface 34, respectively. However, by
placing rear wall 35 in close proximity with stop surface 34, the
two surfaces will typically abut under certain loads and after a
period of time as wear develops in the parts. While it is not
preferred, stop surface 34 could be the primary bearing surface
that first abuts rear wall 35, with inside corner surface 86
abutting front face 48 second.
[0041] Inside leg 72 of wear member 3 includes a hole 96 adapted to
receive lock 7 (FIGS. 68 and 11). Lock 7 includes a body 101 with a
front face 103 and a rear face 105, and a movable latch 107 (FIGS.
9 and 10). In use, lock 7 is inserted into hole 96 such that front
face 103 opposes a rearwardly facing abutting wall 111 in recess
51, and rear face 105 opposes rear wall 113 in hole 96 and front
wall 115 of rib 82 (FIGS. 1 and 3). Although the use of rib 82 to
form front wall 115 is preferred, this wall could be formed by
another projection or by an opening in leg 22. When inserted, lock
7 passes through opening 96, scallop 18, and groove 26. In this
position, lock 7 bars the removal of wear member 3 from lip 12. As
an alternative, base 5 and wear member 3 could extend forward
farther than shown to permit insertion of lock 7 without scallop
18.
[0042] In a preferred construction, front and rear faces 103, 105
converge toward each other as they extend toward the bottom or
insertion end 109 (FIGS. 9 and 10). Likewise, the collective
surfaces of walls 113, 115 preferably coverage toward abutting wall
111. In this way, the lock can be pried into and out of the
assembly 1. Latch 107 includes a rigid part 121 preferably composed
of steel provided with a locking projection 122, and a resilient
part 123 preferably formed of foam, rubber or other elastomer. The
bottom end of rigid part 121 defines a fulcrum 130 to fit within
recess 132 to form a pivot axis about which latch 107 moves. The
resilient part preferably includes detents 125 for receipt within
matching grooves 127 in body 101 to retain the latch in cavity 129,
but could be secured by other means.
[0043] During insertion of lock 7, latch 107 is pressed rearward
against the bias of resilient part 123 by its engagement against
wear member 3. A curved slope 131 eases the latch rearward into
cavity 129 during insertion Once locking projection 122 clears stop
133, the resilient part 123 biases rigid part 121 outward such that
projection 122 engages beneath stop 133 to retain lock 7 in wear
assembly 10. To remove lock 7, a pry tool is inserted along the
curved slope 131 to retract latch 107 into cavity 129 until stop
133 is released. The pry tool can, through engagement with ledge
137 of latch 107, pull lock 7 from passage 54. When latch 107 is
retracted, the top face 139 of rigid part 121 abuts top wall 141 of
cavity 129 to enable the lock to be pried out through engagement
with the latch. Pry slot 126 is also preferably formed on rear face
105 to engage either a second pry tool or an alternative pry
location to help remove lock 7 from passage 54. A hole 128 in the
back of the lock allows rock fines to be pushed out of cavity 129.
A notch 117 is formed on top wall 119 to accommodate the receipt of
a pry too during installation. Other means for inserting or
removing the locks, or the use of other locks are possible.
[0044] An alternative lock 200 can be used to secure wear member 3
to lip 12 (FIGS. 12-18). In general, lock 200 uses a threaded wedge
202 such as disclosed in U.S. Pat. No. 7,171,771, incorporated
herein by reference, instead of the elastomer as used in lock 7.
Threaded wedge 202 has a rounded exterior 208 that tapers from the
trailing end 210 to the leading end 212 (FIG. 17). A helical groove
213 preferably extends the entire length of the wedge, though some
portions of the wedge could remain unthreaded. A tool-engaging
formation 214 for receiving a wrench or other tool is defined in
trailing end 210 for turning of the wedge.
[0045] Lock 200 also includes a body 204 and a latch 206 that are
similar to the body and latch in lock 7 (FIGS. 12-16). Body 204 is
formed with a channel 230 that receives latch 206 and threaded
wedge 202 (FIG. 14). A hole 232 is formed in top side 234 to define
an inlet end for receiving threaded wedge 202 into channel 230. A
trough 236 with threads 238 in the form of at least one helical
ridge segment and preferably a plurality of helical ridge segments
238a is preferably provided along the rear wall 239 of channel 230
to engage the helical groove 213 on threaded wedge 202. A recess
218 is formed at the bottom of channel 208 to receive and form a
pivot support for fulcrum 220 of latch 206.
[0046] Except for rear side 216, latch 206 has essentially the same
construction and function as latch 107; i.e., latch 206 has a
locking projection 218, a fulcrum 220, a ledge 222 and a top face
224 (FIGS. 12, 15 and 16). However, unlike latch 107, rear side 216
includes a recess 226 adapted to receive a front portion of
threaded wedge 202 (FIG. 16). Retainers, preferably in the form of
elastomeric brakes 228 or the like, may be optionally provided to
press against wedge 202 and resist its loosening during use. As
another alternative, a resilient material 229 may optionally be
provided within helical groove 213 of threaded wedge 202 to engage
ridges 238 and thereby resist loosening of the wedge (FIG. 18). The
resilient material 229 is preferably a strip of rubber, foam, or
other elastomer which is fixed within helical groove 213 by an
adhesive. The resilient strip 229 preferably extends the entire
length of groove 213, but could be formed only along part of the
groove. The resilient strip 229 could be used alone or in
combination with brakes 228. The threaded wedge 202 with resilient
strip 229 can also be used in other wear assemblies such as
disclosed in U.S. Pat. Nos. 6,986,216 and 7,174,661 and U.S. patent
application Ser. No. 11/818,483, filed Jun. 13, 2007, which are all
hereby incorporated by reference.
[0047] In use, lock 200 is inserted into assembly 1 like lock 7
(FIG. 12). Lock 200 is preferably inserted into wear assembly 1
with threaded wedge 202 partially inserted into channel 230, but
the wedge could be installed after body 204 is placed into the
assembly. Threaded wedge 202 is then threaded farther into channel
230 to force latch 206 forward so that locking projection 218
engages stop 133 to retain lock 200 in the assembly during use. A
tool-engaging formation 240 is preferably provided at trailing end
210 of wedge 202 to facilitate its turning.
* * * * *