U.S. patent application number 11/401773 was filed with the patent office on 2006-10-12 for wear assembly.
This patent application is currently assigned to ESCO Corporation. Invention is credited to Robert McClanahan, Adam Stitzel.
Application Number | 20060225313 11/401773 |
Document ID | / |
Family ID | 37450627 |
Filed Date | 2006-10-12 |
United States Patent
Application |
20060225313 |
Kind Code |
A1 |
McClanahan; Robert ; et
al. |
October 12, 2006 |
Wear assembly
Abstract
A wear assembly for excavating equipment which has a wear member
overlying a leading edge of the excavating equipment, a removable
lock for releasably holding the wear member to the leading edge,
and a stabilizer, wherein (i) the wear member has a pair of legs to
straddle the leading edge with a first leg extending along a first
side of the leading edge and a second leg extending along a second
side of the leading edge opposite the first side, (ii) the first
leg has an opening for receiving the lock and a second leg free of
such locks, and (iii) the stabilizer is fixed to the second side of
the leading edge and includes a holding surface to overlie a
portion of the second leg to prevent the second leg from moving
away from the second side of the leading edge.
Inventors: |
McClanahan; Robert; (Tigard,
OR) ; Stitzel; Adam; (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: |
37450627 |
Appl. No.: |
11/401773 |
Filed: |
April 11, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60670255 |
Apr 12, 2005 |
|
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Current U.S.
Class: |
37/450 |
Current CPC
Class: |
E02F 9/2833
20130101 |
Class at
Publication: |
037/450 |
International
Class: |
E02F 9/28 20060101
E02F009/28 |
Claims
1. A wear assembly for excavating equipment comprising a wear
member overlying a leading edge of the excavating equipment, a
removable lock for releasably holding the wear member to the
leading edge, and a stabilizer, wherein (i) the wear member has a
pair of legs to straddle the leading edge with a first leg
extending along a first side of the leading edge and a second leg
extending along a second side of the leading edge opposite the
first side, (ii) the first leg has an opening for receiving the
lock and a second leg free of such locks, and (iii) the stabilizer
is fixed to the second side of the leading edge and includes a
holding surface to overlie a portion of the second leg to prevent
the second leg from moving away from the second side of the leading
edge.
2. A wear assembly in accordance with claim 1 further including a
boss fixed to the first side of the leading edge, and a slot within
the first leg to receive the boss.
3. A wear assembly in accordance with claim 2 wherein the
stabilizer includes a ledge to define the holding surface, and the
second leg of the wear member includes a reduced-width grip portion
to receive and cooperate with the ledge of the stabilizer.
4. A wear assembly in accordance with claim 3 wherein the grip
portion is formed in a rear end of the first leg.
5. A wear assembly in accordance with claim 2 wherein the wear
member is a shroud for a lip of a bucket.
6. A wear assembly in accordance with claim 1 wherein the
stabilizer includes a ledge to define the holding surface, and the
second leg of the wear member includes a reduced-width grip portion
to receive and cooperate with the ledge of the stabilizer.
7. A wear assembly in accordance with claim 6 wherein the grip
portion is formed in a rear end of the first leg.
8. A wear assembly in accordance with claim 1 wherein the wear
member is a shroud for a lip of a bucket.
9. A bucket having sidewalls, a rear wall, a bottom wall having a
lip defining a leading edge, and a wear assembly in accordance with
claim 1.
10. A wear member for overlying a leading edge of excavating
equipment, the wear member comprising a pair of legs to straddle
the leading edge with a first leg extending along a first side of
the leading edge and a second leg extending along a second side of
the leading edge opposite the first side, the first leg having an
opening for receiving a lock to releasably hold the wear member to
the leading edge, the second leg being free of such locks and
including a reduced-width grip portion to receive and cooperate
with a stabilizer fixed to the second side of the leading edge to
overlie the grip portion to prevent the second leg from moving away
from the second side of the leading edge.
11. A wear member in accordance with claim 10 further including a
slot within the first leg to receive a boss fixed to the first side
of the leading edge.
12. A wear member in accordance with claim 11 wherein the grip
portion is formed in a rear end of the first leg.
13. A wear assembly in accordance with claim 12 wherein the wear
member is a shroud for a lip of a bucket.
14. A wear member in accordance with claim 10 wherein the grip
portion is formed in a rear end of the first leg.
15. A wear assembly in accordance with claim 10 wherein the wear
member is a shroud for a lip of a bucket.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a wear assembly and, particularly,
to a replaceable assembly for protecting a leading edge or edges of
a bucket or other earth engaging equipment.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The invention finds utility in connection with excavating
equipment, for example, along the leading edge of a dragline
bucket, front end loader, face shovel, etc. In many instances the
bucket may be equipped with transversely spaced excavating teeth to
facilitate earth penetration. In the past, many operators have
found it advantageous to protect both the bucket lip between the
teeth and the bucket wings. One example of such a construction is
disclosed in co-owned U.S. Pat. No. 3,621,594 marketed by ESCO
Corporation of Portland, Oreg., U.S.A. under the trademark "ZIPPER
LIP." Another type of lip wear edge can be seen in co-owned U.S.
Pat. No. 3,865,177. Other patents dealing with lip wear edges are
U.S. Pat. Nos. 3,995,384 and 4,748,754. Other protective shrouds
can be seen in co-owned U.S. Pat. Nos. 3,171,500; 4,129,934;
4,932,478; and 5,088,214.
[0003] In this industry, it is advantageous for wear members to
possess the conflicting goals of being reliably locked in place
during operation yet being easily replaced when worn. The arduous
environments and especially the ever present shock loads hinder the
realization of these contradictory goals. It is also beneficial to
keep the weight of the wear members to a minimum in order to
maximize the potential carrying weight of the buckets. Further, it
is generally desirable to limit costs, difficulties of use, and
risks of failure.
[0004] Many of the disadvantages of the prior art were largely
overcome through the provision of a generally U-shaped wear member
that fits over the digging edge or the like and includes a slot in
one of the legs for receipt of a boss fixed to a face of the
excavator such as disclosed in U.S. Pat. No. 5,088,214, hereby
incorporated by reference. In this construction, the wear member is
equipped with an opening adjacent the rear end for the receipt of a
lock which resists forward or disengaging movement and which is not
subject to deterioration due to heavy, cyclic loadings. The bottom
leg freely extends along the bottom of the lip and helps with the
upper leg to hold the lip and thereby resist the loads applied to
the front of the wear member. This construction is reliable, easy
to assemble and replace, and requires minimal parts. It has been
found, however, that under heavy loading, particularly heavy loads
applied upward against the bottom of the wear member, that high
stresses can be found in the top leg of the wear member. Such
loading can lead to a shortened useable life for the wear member
and even breakage.
[0005] To improve on this assembly, a stabilizer is provided to
restrain the lower leg of the wear member, which previously freely
extended along the bottom of the bucket. In this way, the stress in
the wear member can be reduced in a simple, cost-effective, and
low-weight manner. While leg restraints have been used in past
assemblies, they have been limited to use facilitating the
interaction of the lock and the leg. See, for example, U.S. Pat.
Nos. 5,553,409; 5,052,134; and 3,736,664.
[0006] Other advantages and objects of the invention may be seen in
the details of the ensuing description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention is described in conjunction with the attached
illustrations described briefly below.
[0008] FIG. 1 is a fragmentary perspective view of an excavator
bucket and showing a boss-equipped lip at the lower left.
[0009] FIG. 1A is a front view of an alternate wear member.
[0010] FIG. 2 is a cross sectional view along line 2-2 applied to
FIG. 1.
[0011] FIG. 3 is a fragmentary top plan view of the wear member of
FIG. 2.
[0012] FIG. 4 is an enlarged fragmentary sectional view of a lip
equipped with a modified boss.
[0013] FIG. 5 is a bottom view of a wear member on a lip and
provided with a stabilizer.
[0014] FIG. 5A is a perspective view of a rear portion of the
bottom leg of the wear member.
[0015] FIG. 5B is an enlarged cross sectional view of the portion
noted in circle 5B in FIG. 2.
[0016] FIG. 6 is an enlarged fragmentary transverse sectional view
taken along the sight line 6-6 applied to FIGS. 2 and 3.
[0017] FIG. 7 is a view similar to FIG. 6, but with parts omitted
and as would be seen along the sight line 7-7 applied to FIG.
1.
[0018] FIG. 8 is a view similar to FIG. 7 but with the inventive
lock installed and in the process of removal.
[0019] FIG. 9 is a view similar to FIG. 8 but with the lock in a
subsequent position incident to removal.
[0020] FIG. 10 is a perspective view of a wear member of the prior
art as described in U.S. Pat. No. 5,088,214.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] With reference to FIG. 1, numeral 20 designates generally a
bucket having sidewalls or wings as at 21 equipped with a
forwardly-facing protector 22, and a rear wall 23 merging into a
bottom wall 24. The bottom wall 24 terminates in a forwardly
positioned lip 25. The sidewalls and lip form a leading edge to the
bucket. This is, of course, simply one example of an excavator
which can be provided with a wear assembly in accordance with the
present invention. The present invention could be used with other
kinds of buckets or other digging equipment (e.g., dredge
cutterheads).
[0022] The lip 25 is equipped with transversely spaced-apart
excavating teeth generally designated 26 (see the lower right),
each of which preferably includes an adapter 27 fixed to the lip 25
and a point or tip 28 releasably mounted on each adapter 27. The
portions of the lip 25 between the teeth are protected by wear
members 30 mounted to the lip through cooperation with upstanding
bosses 29 (see the lower left).
[0023] As can be seen in FIG. 2, the wear member 30 is generally
U-shaped having a longer upper or inner leg 31 in confronting
relation with the upper or inner face 25a of the lip 25 and a lower
or outer shorter leg 32 in confronting relation with the lower or
outer face 25b of the lip 25. Of course, the upper leg could be
shorter or have the same length as the lower leg. In the
illustrated example, the legs 31, 32 are connected by a forwardly
projecting connecting portion 33 which is generally aligned with
the lip 25 and preferably includes a cutting or penetrating edge as
at 34 (see also FIG. 1). In FIG. 1, the upper leg 31 of shroud 30
is split so as to include two branches each adapted to receive a
boss 29. In a preferred alternative (FIG. 1A), the wear member 30A
is provided with a single upper leg 31A adapted to receive a single
boss (not shown). In either construction, the lower leg is
preferably formed as a single unified leg. While the invention is
particularly well suited for use as a shroud, other wear members
could be secured via concepts of the present invention.
[0024] The boss 29 (again referring to FIG. 1) is, in a preferred
construction generally T-shaped and advantageously welded to the
lip 25. Alternatively, it may be integrally cast or bolted to the
upper face 25a (compare FIGS. 6 and 4, respectively). In addition,
the boss may have other configurations besides a T-shape, such as
dovetailed or having other arrangements of rails. The boss may also
have a parallelepiped shape with no rails. The boss may have any of
a variety of shapes so long as it provides a rearwardly facing
surface against which the lock abuts to hold the wear member to the
excavator. While the boss is preferably mounted on inner face 25a,
it could alternatively be fixed to outer face 25b.
[0025] In the illustrated embodiment (see FIG. 6), the inner
surface 36 of each upper leg 31 (i.e., the surface that faces the
lip 25) is equipped with the slot 35 to develop an advantageous
longitudinal rearward mounting movement of the wear member 30 on
the boss 29. For this purpose, the slot in each upper leg 31 opens
in the rear wall of the leg to define opening 37 at the rear end
thereof (see FIG. 3) to ensleevingly receive the boss 29. In the
illustrations, the slot has a T-shaped configuration to match the
boss. If the boss is provided with dovetails, no rails or other
shapes, the slot is preferably shaped to have the corresponding
configuration. Also, although the slot is provided in the upper leg
31, it could alternatively be provided instead in the lower leg 32
if the boss is fixed to the outer surface 25b.
[0026] To accommodate the locking of the wear member 30 in place on
the lip 25, a lock generally designated 38 is provided. In the
illustrated embodiments, the lock 38 is mounted in a transversely
enlarged opening 39 (compare FIGS. 2 and 3 with FIG. 7) in the
outer or top surface 40 of the leg 31. The opening 39 communicates
with the slot 35 and is positioned a spaced distance rearwardly of
the cutting edge 34 and forwardly of the opening 37 so as to be
aligned with the rear end 41 of the boss 29 (see FIG. 2).
Nevertheless, many other locking arrangements could be used than is
disclosed. For example, the opening may have different shapes, be
in different locations, open to receive the lock laterally, or be
an opening that is not enclosed on all sides. Irrespective of the
actual boss and lock construction, the wear assembly includes a
generally U-shaped wear member that includes a pair of legs that
straddle an edge (e.g., a digging edge) of an excavator. One of the
legs (regardless of whether it is split or unified) cooperates with
a boss and includes an opening to receive a lock that holds the
wear member in place. The opposite leg extends freely over the
other side of the lip or other edge without a lock or boss. In the
preferred construction, the opposite leg without the lock is on the
underside or outside of the bucket to avoid the wear and tear on
the lock that occurs on the outside of the bucket.
[0027] In the illustrated embodiments, the lock 38 is formed of a
steel casting or block 42. Each is intended to fit within an
opening 39 in the fashion illustrated in FIG. 8. The lock block 42
is relatively elongated transversely of each leg 31 and is equipped
with a slot 43 at one end and an arcuate surface 44 at the other
end. Received within the slot 43 is a latch assembly generally
designated 45 (see FIG. 8) which includes a rubber or elastomeric
body 46 bonded to a steel latch element 47. The slot 43 is
centrally longitudinally recessed top and bottom as at 48 to
receive upstanding and depending ribs 49 on the latch assembly 45.
Additionally, the slot 43 has an inner end of partially arcuate
nature as at 50 so as to receive a similarly contoured portion 51
on the latch assembly 45. Alternatively, the lock and latch
arrangement can be manufactured as one unit using a substantially
non-compressible but flexible material such as rubber to be
confined in the opening 39. Moreover, as noted above, other locks
and other lock arrangements could be used to cooperate with one of
the legs to hold the wear member to the excavator.
[0028] For the illustrated embodiment, the basic steps of lock
removal are shown in FIGS. 8 and 9. In FIG. 8, it is seen that the
latch element 47 is positioned under a keeper means or tab 52
provided in the confronting sidewall 53 of the opening 39 (see FIG.
7). The sidewall 53 in addition to providing the keeper means 52 is
slotted as at 54 (see FIG. 3) to permit the insertion of a
screwdriver tip (or other tool) illustrated at 55 in FIG. 8. The
other sidewall 56 of the opening 39 is equipped with an arcuate
protrusion as at 57 which is normally confronted by the arcuate
recess 44 of the lock block 42 so as to provide a pivot for the
block 42.
[0029] Upon pivoting upward movement of the screwdriver tip to the
position 55' illustrated in FIG. 9, the rubber body 46 is
resiliently deformed so as to retract or upset (in effect) the
latch assembly 45 and this action enables the latch element 47 to
pass by the keeper means 52.
[0030] It will be appreciated that installation of the wear member
is accomplished by following the reverse of the steps
illustrated--the latch assembly 45 is retracted upon engaging the
ramp or sloping wall 57 (see FIG. 7) of the keeper means 52 and
thereafter snaps in place as it goes "over center" past the keeper
means 52 to assume the configuration depicted in FIG. 8.
[0031] In operation, the lock 38 including the block 42 and latch
assembly 45 is not adversely stressed by impact loads or forces as
in the prior art. The lock 38 remains confined between the rear
wall 41 of the boss 29 and the rear wall 58 of the opening 39. This
places the steel block 42 in compression but does not affect the
latch assembly 45. Any stress on the latch assembly 45 merely
shifts the latch element 47 under the keeper means 52.
[0032] The block 42 in the illustrated embodiment is equipped with
longitudinally extending flanges as at 59 (see FIG. 10) which are
received within similarly contoured recesses 60 in the top wall 40
of the wear member 30 (see also FIG. 7). These elements 59-60
enable the proper positioning of the lock 38 within the opening 39.
These elements 59-60 are, however, unnecessary and are preferably
excluded.
[0033] Under loading, the wear element 30 can be subjected to
various force components and in resisting these, the invention
provides advantages not found in the prior art. For example, there
may be a sizable positive thrust component T-see the left hand
portion of FIG. 2. With the inventive construction there is no
deformation of the boss 29. This stems from the fact that this
component extends longitudinally, i.e., the surfaces 29a, 29b on
the boss 29 and confronting surfaces 35a, 35b in the wear member
slot 35 extend longitudinally so as not to affect the bearing
therebetween.
[0034] The provision of the slot 35 in combination with the
similarly contoured boss 29 makes possible advantageous
installation and operation. By the straightforward rearward sliding
movement of the wear member 30 on the boss 29, there is no need for
any pivoting movement and this, in itself, makes possible for
longer lower legs 32, according to intended design and usage. Also,
by providing a relatively elongated bearing area between the boss
29 and the wear member 30, shock loads and other impacts can be
readily transmitted from the portion 33 to the lip 25. This also
provides an advantageous lateral stabilization but without the need
for extensive locks or secondary surfaces.
[0035] On the other hand, there may be a substantial negative
thrust, viz., a vector extending in the opposite direction to that
depicted at T in FIG. 2. This is not an unusual
occurrence--resulting, for example, from back drag. In such a
situation, the lock 38, is subjected to compression which, in the
case of the resilient locks of the prior art, results in cyclic
deformation and possible premature failure.
[0036] In contrast, the invention provides for heavy loading and
high compressive stresses on the lock generally designated 38 as a
result of reaction forces resulting from normal operative loads at
the leading edge of the wear member 30.
[0037] Still further, the loading on the wear element 30 may
produce a vertical component, viz., one at right angles to the
vector T, such as vector F (FIG. 2). In accordance with the present
invention, the lower side of the bucket or other excavator (i.e.,
the side opposite the boss and lock irrespective of whether it is
the lower side) is provided with a stabilizer 70 to restrain
movement of the free leg 32 (i.e., the unlocked leg) away from the
bucket during such vertical loading (FIGS. 2, 5, 5A, and 5B). In
one preferred embodiment, the stabilizer is welded W, but could be
cast, bolted, or otherwise fixed to the surface of the bucket. The
stabilizer includes a ledge or holding surface 72 that overlies the
face 25b of lip 25. A grip portion 74 formed on the rear end 76 of
leg 32 is adapted to be slipped under ledge 72. The grip portion 74
is preferably defined as a reduced thickness portion at the rear
end of leg 32 to minimize the extension of the stabilizer from the
bucket, but it could have other configurations. As seen in FIG. 5B,
leg 32 tends to shield stabilizer 70 during use. To facilitate
sliding together of the wear member and the stabilizer, the grip
portion 74 and ledge 72 are preferably formed to have inclined
complementary contact surfaces 78, 80. Nevertheless, other
arrangements could be used such as, for example, contact surfaces
that are not inclined, or a grip portion that is simply the rear
end of the leg 32 without any special configuration, or a leg that
includes a tab that fits into a cavity in a solid block
stabilizer.
[0038] When a vertical load is applied to the underside of the wear
member, such as F, the load in wear member of the prior art (i.e.,
as described in U.S. Pat. No. 5,088,214) is primarily resisted by
the U-shaped configuration of the wear member straddled about the
digging edge of the bucket. Under heavy loading, high levels of
stress can develop in the upper leg, i.e., the leg with the lock.
To reduce this stress, the stabilizer prevents the bottom leg from
swinging outward away from the bottom of the bucket and thereby
provides additional support to resist such loading. Moreover, this
additional support is provided without a substantial increase in
the weight, complexity or cost of the wear assembly.
[0039] The invention provides positive but releasable retention of
a protective wear member to the leading edge of a bucket lip or
bucket wings or sidewalls--these latter also having wearable edges
like the bucket lip.
[0040] The invention also finds advantageous application to the
sides or wings 21 as well as other earth-engaging edges of an
excavator. As previously pointed out relative to FIG. 1, the wing
21 is covered by the protector 22.
[0041] The wear member 22 is again seen to be generally U-shaped
but in this embodiment has legs which are substantially of the same
length in proceeding rearwardly from the forward connecting portion
33.
[0042] Exemplary of the invention is a wear member utilized to
protect the leading edge of a large front end loader bucket lip.
Protection of earth-engaging bucket lips is a constant maintenance
problem and many forms of protection have been utilized over the
years. Normally, wear edge protectors are welded, bolted, or
mechanically attached. The most desirable designs are those that
are mechanically attached and easy to install and remove. Although
the structure is illustrated for a front end loader lip and wings,
variations of this design could be utilized on face shovels, cable
shovels, draglines and other earth moving equipment.
[0043] The invention includes an easily changeable wear member 30
with one or more rearwardly projecting portions or legs 31. As
illustrated, the leg 31 includes a T-shaped longitudinally
extending slot 35 which engages a mating or similarly contoured
boss 29. The required number of bosses may either be bolted or
welded to the lip or integrally cast therewith. The rearward
sliding of the wear member on the lip also places grip portion 74
under ledge 72 of the stabilizer 70.
[0044] The wear member 30 is releasably held in position by means
of a lock 38 installed in an opening 39 (see FIG. 3) in each leg
31. The opening 39 is located rearwardly of the rear end of the
boss 29. Thus, when a lock 38 is installed into each opening 39,
the wear member 30 is prevented from moving off of the lip 25.
Conversely, removal of each lock 38 allows easy disassembly of the
wear member 30 from the lip 25.
[0045] In the illustrated embodiment, the lock opening 39 has an
arcuate protrusion 57 (see FIG. 7) at the upper edge normal to the
leading edge or forward wall of the opening 39. The arcuate
protrusion 57 serves as a pivot point for installation of the lock
as illustrated in FIG. 9. The sidewall 53 opposite to that equipped
with the arcuate protrusion 57 is equipped with a tab or keeper
means 52 which retains the latch assembly 45 in place-until the
rubber body 46 is deformed under the influence of a screw driver
tip 55 so as to permit passage of the latch element 47 past the
keeper means 52. By providing the keeper means to the side, i.e.,
laterally offset from the slot 35, the latch assembly 45 is not
substantially subjected to adverse stresses yet is advantageously
located for easy replacement.
[0046] While in the foregoing specification a detailed description
of an embodiment of the invention has been set down for the purpose
of illustration, many variations in the details herein given may be
made by those skilled in the art without departing from the spirit
and scope of the invention.
* * * * *