U.S. patent application number 09/971540 was filed with the patent office on 2003-04-10 for wear plate assembly.
This patent application is currently assigned to Peninsula Alloy Inc.. Invention is credited to Grant, James.
Application Number | 20030066215 09/971540 |
Document ID | / |
Family ID | 4170186 |
Filed Date | 2003-04-10 |
United States Patent
Application |
20030066215 |
Kind Code |
A1 |
Grant, James |
April 10, 2003 |
Wear plate assembly
Abstract
A bucket assembly is provided with a kit that includes a base
plate for permanent connection to a lower part of the bucket, and
sacrificial, impermanent replaceable wear edge segments for the
forward lip and corner leading edges of an excavator or loader
bucket. These segments form a set of "bolt on" cast wear members
and wing wear segments. The base plate and wear plates are drilled
and machined to accommodate the precision fitting bolting on of the
replaceable lips and cast wing segments. The cast lip segments are
of both left and right hand configurations and come in a variety of
widths that, in combination, may tend to fit a large number of
different commercially available bucket sizes. The lip top and
bottom faces are shaped in a profile that may tend to result in
relatively uniform wear and a reduction in friction when digging
into various materials.
Inventors: |
Grant, James; (Sudbury,
CA) |
Correspondence
Address: |
BLAKE, CASSELS & GRAYDON LLP
BOX 25, COMMERCE COURT WEST
199 BAY STREET, SUITE 2800
TORONTO
ON
M5L 1A9
CA
|
Assignee: |
Peninsula Alloy Inc.
|
Family ID: |
4170186 |
Appl. No.: |
09/971540 |
Filed: |
October 9, 2001 |
Current U.S.
Class: |
37/446 |
Current CPC
Class: |
E02F 3/40 20130101; E02F
9/28 20130101; E02F 9/2883 20130101 |
Class at
Publication: |
37/446 |
International
Class: |
E02F 003/36 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 5, 2001 |
CA |
2,358,339 |
Claims
I claim:
1. A loader bucket assembly comprising: a loader bucket having a
backshell and a pair of opposed end walls mounted thereto; said
back shell and said end walls defining a bucket cavity having a
width; said backshell having a lower portion; said end walls being
spaced from each other a distance defining a width of said loader
bucket; a base plate mounted to said lower portion of said
backshell, said base plate extending forwardly thereof, said base
plate having a width extending across the width of said loader
bucket; said base plate having a leading edge, a first surface
oriented inwardly relative to said backshell and a second surface
oriented outwardly relative to said backshell; said base plate
having bores defined therethrough, said bores being inset from said
leading edge; at least one wear segment mounted to said base plate,
said wear segment having a leading edge oriented forwardly away
from said base plate; said wear segment having a trailing portion
having an accommodation for said leading edge of said base plate;
and said leading edge of said base plate having a male profile;
said accommodation of said wear segment having a female profile
matching said male profile of said leading edge of said base plate,
said female profile including a first portion engaging said first
surface of said base plate and a second portion engaging said
second surface of said wear plate; said wear segment having at
least one bore formed therein, said bore of said wear segment and a
corresponding one of said bores of said base plate being aligned
when said male and female profiles are engaged; and said wear
segment and said base plate being connected at said aligned bores
by an impermanent mechanical fastener mounted across a single
connection interface.
2. The loader bucket assembly of claim 1 wherein said trailing
portion of said wear segment includes first and second spaced apart
flanges and a root section from which said flanges extend
rearwardly, said flanges and said root co-operating to define said
accommodation.
3. The loader bucket assembly of claim 2 wherein: when said loader
bucket rests with said base plate adjacent a ground surface, said
first flange is an upper flange and said second flange is a lower
flange; said lower flange extends further rearwardly than said
upper flange; said bores of said wear segment are formed in said
lower flange; said upper flange has tool access accommodations
formed therein adjacent said bores of said lower flange.
4. The loader bucket assembly of claim 3 wherein said bores of said
lower flange have centerlines lying in a plane, and said upper
flange has a rearward edge lying abreast of the plane of the
centerlines.
5. The loader bucket assembly of claim 3 wherein said bores of said
lower flange are countersunk to accommodate a locknut.
6. The loader bucket assembly of claim 5 wherein said bores of said
base plate are countersunk to accommodate a tapered countersunk
head of a threaded fastener.
7. The loader bucket assembly of claim 1 wherein said male profile
has a chamfer, and said female profile has a matching chamfer.
8. The loader bucket assembly of claim 1 wherein said assembly
includes a plurality of said segments having a combined width
corresponding to the width of the base plate
9. The loader bucket assembly of claim 1 wherein: said base plate
has a central point and left and right hand leading edges trailing
rearwardly and outwardly from said point; and said assembly
includes a plurality of said wear segments, half of said segments
being left handed, and half of said segments being right
handed.
10. The loader bucket assembly of claim 1 wherein, when said bucket
assembly is resting with said base plate on a ground surface, said
first surface of said base plate is an upper surface, and said
leading edge of said wear member includes a tip having an abutment
intersecting said plane of said second surface of said base
plate.
11. The loader bucket assembly of claim 1 wherein all of said bores
in said base plate are on a uniform setback distance from said
leading edge.
12. The loader bucket assembly of claim 1 wherein said wear segment
includes an upper surface extending rearwardly from said tip of
said wear segment, and said upper surface is scalloped to encourage
rolling action in the work material.
13. The loader bucket assembly of claim 1 said bucket has a width
in the range of 58 to 112 inches, and said leading edge of said
base plate are chosen from an inventory of segments consisting of
segments of less than 24 inches in width.
14. The loader bucket assembly of claim 1 wherein said bucket has a
width in the range of 58 to 112 inches, and said wear segments for
said base plate are chosen from an inventory of wear segments
including wear segments of at least two widths.
15. The loader bucket assembly of claim 14 wherein said at least
two widths are chosen from an inventory of wear segments of up to
four widths selected from the set of widths consisting of (a) about
14-1/2 inches; (b) about 16 inches; (c) about 18 inches; and (d)
about 20 inches.
16. The loader bucket assembly of claim 1 wherein said wear segment
has at least two of said bores formed therein, and said wear
segment is connected to said base plate by at least two of said
impermanent mechanical fasteners.
17. The loader bucket assembly of claim 16 wherein said impermanent
mechanical fasteners are threaded fasteners.
18. The loader bucket assembly of claim 16 wherein said at least
two bores are spaced apart and stand at a common setback distance
relative to said leading edge of said base plate.
19. The loader bucket assembly of claim 1 wherein said wear segment
has a pair of side faces, said side faces lying in parallel
vertical planes, said vertical planes being oriented in a
fore-and-aft direction relative to said width of said bucket.
20. The loader bucket assembly of claim 1 wherein: said base plate
has a central lead point and left and right hand leading edges
tapered sideways outwardly and rearwardly; a plurality of left
handed wear segments is mounted side-by-side along said left hand
leading edge; a plurality of right hand wear segments is mounted
side-by-side along said right hand leading edge; and at least one
of said left hand wear segments has a leading abutment tip running
parallel to said left hand leading edge and a pair of parallel side
faces extending in a fore-and-aft orientation relative to the width
of said bucket.
21. The combination of a base plate and replaceable wear segments
for a loader bucket having a width, wherein: said base plate has a
trailing portion for attachment to a lower portion of the loader
bucket, and a leading portion extending forwardly thereof, and a
width corresponding to the width of the bucket; said leading
portion has a leading edge having a male profile; said base plate
has a first surface and a second surface, said first and second
surfaces being on opposite sides of said plate and lying in first
and second parallel planes, and, when mounted to the bucket, said
first surface of said base plate being for orientation inwardly
relative to the bucket; said plate has a plurality of apertures
formed therein, said apertures extending through said plate, said
apertures being set back from said leading edge; said wear segments
have a combined width corresponding to the width of the base plate;
each said segment has a first flange for engaging said first
surface of said base plate, and a second flange for engaging said
second surface of said base plate, said first and second flanges
being joined at a common root portion of said segment; said flanges
and said root portion defining between them a rearwardly facing
socket, said socket having a female profile matingly engageable
with said male profile of said leading edge of said base plate;
each said wear segment has a pointed leading portion for engaging
material to be carried in the loader bucket, said leading portion
extending forwardly of said socket; said second flange has at least
one aperture formed therein for alignment with a corresponding one
of said apertures of said base plate; said aperture of said wear
segment being aligned with said corresponding aperture of said base
plate when said male and female profiles are engaged; and said base
plate and said wear segment are securable by a mechanical fastener
mounted through said apertures across a single fastening
interface.
22. The combination of claim 21 wherein said male profile of said
base plate includes a chamfered edge, and said female profile has a
mating chamfer.
23. The combination of claim 21 wherein said base plate has a first
through thickness, and said first flange has a second through
thickness, said second through thickness being less than said first
through thickness.
24. The combination of claim 21 wherein said base plate has a first
through thickness, and said second flange has a second through
thickness, said second through thickness being greater than said
first through thickness.
25. The combination of claim 21 wherein said bores in said base
plate are countersunk from said first surface to admit a fastener
having a countersunk head lying in a position chosen from the set
of positions consisting of (a) flush with; and (b) shy of, said
first surface of said base plate.
26. The combination of claim 21 wherein said first flange has tool
access reliefs formed therein, said reliefs being located in
positions corresponding to said bores of said second flange.
27. The combination of claim 21 wherein: said leading portion of
said segment has first and second diverging flanks extending
rearwardly of said tip thereof; said first flank extends from said
tip toward said first flange; said second flank extend from said
tip toward said second flange; and said first flank has a surface
having a convex profile relative to said second flank.
28. The combination of claim 21 wherein: said leading portion of
said segment includes an abutment face; said abutment face and said
first flank meet along a vertex; said vertex lies between said
first and second planes; and said vertex lies closer to said second
plane than to said first plane.
29. The combination of claim 28 wherein: said leading portion
includes an abutment face; said abutment face and said first flank
meet at a first vertex; said abutment face and said second flank
meet along a second vertex; and said first vertex lies to one side
of said second plane, and said second vertex lies to the other side
of said plane.
30. The combination of claim 21 wherein: said assembly includes
wear segment attachment fitting for mounting to vertical edges of
side walls of the bucket, and shrouds for mounting to said wear
segment attachment fitting; said shrouds each include a pair of
rearwardly extending parallel flanges and a rearwardly facing slot
defined therebetween; said attachment fittings each include a
forwardly facing web; said web and said slot being matable; and
said web and one of said flanges having corresponding bores formed
therein to admit a fastener to connect each said shroud to a
respective side wear segment attachment fitting in single
shear.
31. A replaceable wear segment for impermanent mating with a
leading edge of a base plate of a loader bucket assembly, the base
plate having apertures formed therethrough adjacent to said leading
edge, wherein said wear segment comprises: a body having a leading
portion and a trailing portion; said trailing portion having a pair
of first and second spaced apart flanges, said flanges having
proximal ends joined at a root, and distal ends extending
rearwardly of the root; said first and second flanges having
respective opposed faces lying in respective first and second
spaced apart parallel planes; said opposed faces and said root
co-operating to define a rearwardly facing socket having a profile
to match the leading edge of the base plate; said socket admitting
sliding entry of the base plate between said flanges; said socket
admitting sliding entry of the base plate between said flanges; and
said second flange having an aperture defined therein to admit an
impermanent mechanical fastener to be inserted therethrough, and
through an aperture of the base plate for impermanent single flange
connection of the wear segment to the base plate.
32. The combination of claim 31 wherein said segment is a
casting.
33. The wear segment of claim 31 wherein said trailing portion of
said wear segment includes first and second spaced apart flanges
and a root section from which said flanges extend rearwardly, said
flanges and said root co-operating to define said
accommodation.
34. The wear segment of claim 34 wherein: when said first flange
rests on a ground surface, said first flange is an upper flange and
said second flange is a lower flange; said lower flange extends
further rearwardly than said upper flange; said bores of said wear
segment are formed in said lower flange; and said upper flange has
tool access accommodations formed therein adjacent said bores of
said lower flange.
35. The wear segment of claim 34 wherein said apertures of said
lower flange have centerlines lying in a plane, and said upper
flange has a rearward edge lying abreast of the plane of the
centerlines.
36. The wear segment of claim 34 wherein said apertures of said
lower flange are bores having a countersink to accommodate a
locknut.
37. The wear segment of claim 31 wherein said accommodation has a
chamfered surface at said root.
38. The wear segment of claim 31 wherein, said leading edge of said
wear member includes a tip having an abutment intersecting said
plane of said second surface.
39. The wear segment of claim 31 wherein said wear segment includes
an upper surface extending rearwardly from said tip of said wear
segment, and said upper surface is scalloped to encourage rolling
action in the work material.
40. The wear segment of claim 31 wherein said wear segment has at
least two of said bores formed therein.
41. The wear segment of claim 40 wherein said at least two bores
are spaced apart and stand at a common setback distance relative to
said leading edge of said base plate.
42. The wear segment of claim 31 wherein said accommodation has a
first through thickness measured between said first and second
parallel planes, and said first flange has a second through
thickness, said second through thickness being less than said first
through thickness.
43. The wear segment of claim 31 wherein said accommodation has a
first through thickness measured between said first and second
parallel surfaces, and said second flange has a second through
thickness, said second through thickness being greater than said
first through thickness.
44. The wear segment of claim 31 wherein said first flange has tool
access reliefs formed therein, said reliefs being located in
positions corresponding to said apertures of said second
flange.
45. The wear segment of claim 31 wherein: said leading portion of
said segment has first and second diverging flanks extending
rearwardly of said tip thereof; said first flank extends from said
tip toward said first flange; said second flank extend from said
tip toward said second flange; and said first flank has a surface
having a convex profile relative to said second flank.
46. The combination of claim 31 wherein: said leading portion of
said segment includes an abutment face; said abutment face and said
first flank meet along a vertex; said vertex lies between said
first and second planes; and said vertex lies closer to said second
plane than to said first plane.
47. The combination of claim 46 wherein: said leading portion
includes an abutment face; said abutment face and said first flank
meet at a first vertex; said abutment face and said second flank
meet along a second vertex; and said first vertex lies to one side
of said second plane, and said second vertex lies to the other side
of said plane.
Description
FIELD OF THE INVENTION
[0001] This invention relates to the field of wear plate assemblies
for loader buckets.
BACKGROUND OF THE INVENTION
[0002] In the mining and construction industries, loading and
moving of heavy materials such as sand, gravel and rock is often
accomplished using heavy machinery such as scoop trams, front-end
loaders and powered bucket digging devices. During operation, these
buckets tend to wear along their leading edges due to abrasion when
entering the material pile and during contact with the ground.
During use, the lip may tend to wear down, sometimes very quickly.
After the lip wears down to a point where the base plate or bucket
are threatened with wear, the bucket may typically be removed and
sent to be refurbished by replacing the lip. Bucket removal is a
relatively common practice in the mining industry at present.
Rework and replacement of a bucket lip can be a major undertaking
involving burning, cutting and welding. Time may be lost if the
loader is transported to a shop where the bucket can be replaced.
In a mining setting, the loader may remain inside the mine, the
bucket being cut into two pieces and transported out of the mine to
the surface. The replacement bucket may be returned in two pieces
and be welded together before being placed on the loader. If a
replacement bucket is not available or the replacement process is
too cumbersome at the time, an operator may continue operating the
loader nonetheless. As a result the base plate or the bucket itself
may be damaged through overuse and may then require much more
extensive repair than would otherwise be expected. The replacement
of the base plate or bucket may well be much more costly than the
use gained by operating the loader for the extra time.
[0003] Alternatively, the mine may keep an inventory of repaired
buckets available. It is advantageous to reduce the ratio of
buckets in inventory to the number of buckets in use, since buckets
held in inventory, or being refurbished, are capital assets that
are not earning revenue. Thus it is advantageous to make relatively
simple replacement of wear plates and teeth in the mine, and to
reduce the number of major overhauls requiring bucket removal to
the surface.
[0004] When a loader or underground scoop tram is used for loading
or transporting materials it is common to weld a base plate to the
lower front edge of the bucket, the welding join line running from
side to side across the bucket. The bucket is usually made of mild
steel and the base plate is made of a mild steel or high carbon
steel. The base plate is sometimes of greater thickness than the
bucket plate. The upper surface of the base plate is installed
flush with the inner surface of the bucket. The base plate has a
lead, provided by leading edges that extend forwardly at an angle
from the lower corners of the bucket to converge at a central point
or tip. Different leads are selected by different operators to suit
specific conditions. It is common for base plates to have leads of
six, eight, ten or twelve inches, the lead being the distance that
the tip is located forwardly of a line joining the outside corners
of the bucket. A number of known scoop tram buckets have widths in
the range of 56 to 112 inches, the tangent of the angle of the
lead, viewed from above, being the lead dimension divided by the
half width of the bucket.
[0005] Although the base plate can be more abrasion resistant than
the material of the bucket, it is common practice to protect the
base plate from premature wear by mounting a replaceable
sacrificial wear lip or wear edge on the leading edges of the base
plate. Typically, these wear edges are cut to suit, and are welded
or bolted in place. Although welding and cutting operations tend to
require greater labour they have been historically preferred.
Releasable mechanical fastener systems, by contrast, tend to be
regarded with considerable scepticism in view or the high stresses
in the lip area during operation. However, mechanical fastening, as
opposed to welding, permits different casting alloys to be used for
the wear segments, and may tend to reduce reliance on specific
welding skills to produce good welds in high wear alloys, such as,
for example, Manganese steels.
[0006] It would also be advantageous to supply, and to bolt on, lip
and wing wear segments that may be replaced several times over the
life of the bucket. Some relatively complicated mechanical adapter
systems are known, such as the Hensley (t.m.) J-bolt Edge System.
This system uses a cleat that is welded to the bucket base plate,
and a J-shaped bolt that attaches to the cleat to tighten a
removable wear segment in place. The tightening action of the bolt
is fore-and-aft, as opposed to vertical. The base plate does not
have vertical bores for bolts. It would be advantageous to use a
through-hole, as opposed to welded cleats. Leaving aside the
lifting lug, the adapter fitting in the J-Bolt design stands up
into the flow of incoming material a distance that is greater than
the thickness of the base plate of the bucket. It would be
preferable to employ fittings with a lower profile, that may tend
less to stand in the way of incoming material. In some replaceable
wear equipment, the wear segments are bolted to the base plate by a
dual flange fitting. This may result in looseness and high bolt
stresses. It would be advantageous to use a single flange
attachment.
[0007] The supply of replaceable wear edge assemblies for these
wear areas, namely the forward lip and adjacent wing leading edges
of excavating or loader buckets is the subject of this application,
as is a system of standardisation that includes initial
installation of base plate and wing segments, followed by the
supply and installation of the remaining removable, and
replaceable, wing and lip wear segments.
[0008] It is usual to weld a base plate along the lower edge of the
bucket and to attach a cast, wear resistant lip along the leading
edges of the base plate, as well as wing wear segments at the lower
corners of the bucket. Usually, the base plate is welded to the
bucket and the lip is welded to the base plate. The lip is usually
made from a materiel, often as a casting, that is more wear
resistant than the material used in the base plate or the bucket
generally. For heavy digging the base plate and lip wear segments
usually have a tapered or convergent lead, i.e., their front edges
converge forwardly from the lower corners of the bucket, in some
cases to a pointed tip as noted above, having an appearance of a
pointed spade.
[0009] Loader buckets currently come in a variety of sizes. The
present supplies of lip wear components to meet the numerous
different bucket leads involves producing and stocking a wide
variety of wear segments. As a result, many different sizes of lips
may be manufactured and stocked to meet demand. This may result in
a need to maintain a relatively large inventory. Another option is
to sell one size of lips that can be trimmed by the user to match
the bucket size. The rework of permanently installed (i.e., welded)
wear components is also a major undertaking involving burning,
cutting and welding. In many case the work must be done in a
heavy-duty garage. The lost machine operating time, the extent of
the rework and the extra stocking of components may tend to be very
costly and inefficient.
[0010] Replaceable, welded, leading edge wear shroud kits have been
used in the past, but, in addition to the cutting and welding
requirement, have tended to include elements as much as 40 inches
wide or more. Such a part may weigh three hundred pounds or more.
In general, the greater the weight of the part, the more difficult
it is to handle, whether by hand or by machine, whether in
shipping, transferring from one form of transport to another,
installation or removal.
[0011] Further, the mating faces of the parts may not be planar,
and may not be aligned with the forward and rearward direction of
the bucket. Where the mating interfaces are arcuate or splayed, it
may not necessarily be possible to remove each part without first
removing another neighbouring part. The other part may not require
replacement. This may complicate the occasional replacement of a
single broken part, and may make general replacement of wear
segments more time consuming than it need be. It would be
advantageous to tend to avoid this complication by making the sides
of adjoining segments straight and parallel, and preferably running
in the fore-and-aft direction, to permit a segment to be slid into
place between its neighbours. Although larger segments can be used,
it would be advantageous to employ segments that are not more than
24 inches wide, and preferably not more than 20 inches wide.
Similarly, it would be advantageous to keep the weight of each wear
segment, or as many of them as practicable, below about 250 lbs.,
and preferably below about 200 lbs. It would also be preferable to
be able to remove one segment without having to remove others
first. That is, it would be advantageous to employ wear segments
that do not require a specific order of removal and
installation.
[0012] It would be advantageous, to adopt a wear plate system
involving relatively few components, and relatively simple
installation such as may be made in place with only minor lifting
devices and bolting tools.
[0013] The effectiveness of a loader is determined by the number of
loads per hour that can be loaded for a given material. Currently,
lips for attachment to base plates have wedge shaped or rectangular
profiles. These profiles may not be conducive to easy rolling of
muck or other materials into the bucket. As a result, the
effectiveness of the loader is reduced as muck gets caught on the
lip or is slow to roll off the lip into the bucket. It may be
advantageous to have a lip profile that may tend to encourage
rolling motion in the muck. It may also be advantageous to have a
lip profile in which the tip lies near or at the plane of the lower
surface of the base plate.
[0014] It would be advantageous to have a lip that is mechanically
attachable to, and removable from, the base plate relatively
quickly and relatively easily, that is, without cutting, grinding
or welding. It would be advantageous not to have to trim a cast or
forged part to size for installation. It would also be advantageous
if the shape of the lip were designed to encourage a rolling action
in the material to be loaded. It would also be advantageous to use
a method for providing lips which reduces inventory variety and
inventory costs while still supporting a wide variety of bucket
widths.
[0015] Accordingly, there is a need for a new lip design and a new
method for providing such lips.
SUMMARY OF THE INVENTION
[0016] In one aspect of the invention, there is a set of wear
segments developed to incorporate advantages over a number of
existing systems. The wear sections are bolted in place and are
sized for relatively easy handling and bolt-on installation. In a
method aspect of the present invention this may tend to permit
replacement in place at the worksite location, preferably without
the use of welding, heavy machinery or the bodily removal of a
bucket.
[0017] In another aspect or feature of the invention, there is a
single flange, bolted lip-to-base-plate connection that may tend to
reduce or eliminate lip movement relative to the base plate during
operation. This may tend to reduce bolt shear stresses as compared
to the dual flange arrangement mentioned above. In a further aspect
or feature of the invention, the base plate has a sloped, or
chamfered section that extends rearwardly and downwardly from the
flat abutment of the forward edge the base plate to its base side,
or surface. This chamfer may tend to permit a thicker wear lip
section in the critical area.
[0018] In another aspect or feature of the invention, the wear
segments have a wedge shape that may tend to promote relatively
even top and bottom wear and may tend to reduce friction when
penetrating a pile of loose material. The wedge shape may tend to
present a reduced impediment to material flowing into, or out of,
the bucket due to a thinner top section flange at the base plate
connection. In a further feature of that aspect of the invention,
the lip has a top curved profile that may tend to induce material
entering the bucket to roll upwards and away from the bucket,
possibly resulting in a relative reduction in friction between the
material and the steel of the wear segment.
[0019] In another aspect or feature of the invention,
standardisation of lip wear components to a limited number of sizes
as required to meet a plurality of bucket sizes, may tend to reduce
inventory stocking difficulties. In another feature of that aspect
of the invention, there is a relatively small number of sizes of
wear segments from which a selection of combinations and
permutations will permit kits to be assembled to fit a relatively
large number of bucket sizes. In an additional feature, wear
segments of differing thicknesses are provided to suit differing
thicknesses of base plates as chosen by operators according to
bucket capacity and operating conditions. In another feature of the
present invention, the bolt-on segments may tend to be relatively
more easily installed in place without the use of heavy equipment,
cutting or welding machines.
[0020] In another aspect or feature of the invention, there is a
method in which there is a first modification of a standard bucket
that involves the cutting away of existing bucket base plate
protrusions, and the welding on of machined base plate wing
sections. (The forward location of the base plate apex from the
lower pivot pin is dictated by the original manufacturer's
equipment specifications). According to a feature thereof, initial
modifications are made that involve cutting and welding such as may
tend to be of a permanent nature and such that the bucket should
not tend to require further rework of a permanent nature for the
duration of the life of the bucket.
[0021] In another aspect or feature of the invention there is a
loader bucket assembly. It has a loader bucket having a backshell
and a pair of opposed end walls mounted thereto. The backshell and
end walls define a bucket cavity having a width. The backshell has
a lower portion. The end walls are spaced from each other a
distance defining a width of the loader bucket. A base plate is
mounted to the lower portion of the backshell. The base plate has a
width extending across the width of the loader bucket. The base
plate has a leading edge, a first surface oriented inwardly
relative to the backshell and a second surface oriented outwardly
relative to the backshell. The base plate has bores defined
therethrough. The bores are inset from the leading edge. At least
one wear segment is mounted to the base plate. The wear segment has
a leading edge oriented forwardly away from the base plate. The
wear segment has a trailing portion having an accommodation for the
leading edge of the base plate. The leading edge of the base plate
has a male profile. The accommodation of the wear segment has a
female profile matching the male profile of the leading edge of the
base plate. The female profile includes a first portion engaging
the first surface of the base plate and a second portion engaging
the second surface of the wear plate. The wear segment has at least
one bore formed therein. The bore of the wear segment and a
corresponding one of the bores of the base plate are aligned when
the male and female profiles are engaged. The wear segment and the
base plate are connected at the aligned bores by an impermanent
mechanical fastener in single shear.
[0022] In an additional feature of that aspect of the invention,
the trailing portion of the wear segment includes first and second
spaced apart flanges and a root section from which the flanges
extend rearwardly, the flanges and the root co-operating to define
the accommodation. In another additional feature, when the loader
bucket rests with the base plate adjacent a ground surface, the
first flange is an upper flange and the second flange is a lower
flange. The lower flange extends further rearwardly than the upper
flange. The bores of the wear segment are formed in the lower
flange. The upper flange has tool access accommodations formed
therein adjacent the bores of the lower flange. In yet another
additional feature, the bores of the lower flange has centerlines
lying in a plane, and the upper flange has a rearward edge lying
abreast of the plane of the centerlines. In still yet another
additional feature, the bores of the lower flange are countersunk
to accommodate a locknut.
[0023] In a further additional feature, the bores of the base plate
are countersunk to accommodate a tapered countersunk head of a
threaded fastener. In still a further additional feature, the male
profile has a chamfer, and the female profile has a matching
chamfer. In yet a further additional feature, the assembly includes
a plurality of the segments having a combined width corresponding
to the width of the base plate
[0024] In an additional feature, the base plate has a central point
and left and right hand leading edges trailing rearwardly and
outwardly from the point. The assembly includes a plurality of the
wear segments, half of the segments being left handed, and half of
the segments being right handed. In another additional feature,
when the bucket assembly is resting with the base plate on a ground
surface, the first surface of the base plate is an upper surface,
and the leading edge of the wear member includes a tip having an
abutment intersecting the plane of the second surface of the base
plate.
[0025] In yet another additional feature, all of the bores in the
base plate are on a uniform setback distance from the leading edge.
In still yet another additional feature, the wear segment includes
an upper surface extending rearwardly from the tip of the wear
segment, and the upper surface is scalloped to encourage rolling
action in the work material. In a further additional feature, the
bucket has a width in the range of 58 to 112 inches, and the
leading edge of the base plate are chosen from an inventory of
segments consisting of segments of less than 24 inches in
width.
[0026] In still a further additional feature, the bucket has a
width in the range of 58 to 112 inches, and the wear segments for
the base plate are chosen from an inventory of wear segments
including wear segments of at least two widths. In yet a further
additional feature, at least two widths are chosen from an
inventory of wear segments of up to four widths selected from the
set of widths consisting of (a) about 14-1/2 inches; (b) about 16
inches; (c) about 18 inches; and (d) about 20 inches. In an
additional feature, the wear segment has at least two of the bores
formed therein, and the wear segment is connected to the base plate
by at least two of the impermanent mechanical fasteners.
[0027] In another additional feature, the impermanent mechanical
fasteners are threaded fasteners. In yet a another additional
feature, at least two bores are spaced apart and stand at a common
setback distance relative to the leading edge of the base plate. In
still yet another additional feature, the wear segment has a pair
of side faces, the side faces lying in parallel vertical planes,
the vertical planes being oriented in a fore-and-aft direction
relative to the width of the bucket.
[0028] In a further additional feature, the base plate has a
central lead point and left and right hand leading edges tapered
sideways outwardly and rearwardly. A plurality of left handed wear
segments is mounted side-by-side along the left hand leading edge.
A plurality of right hand wear segments is mounted side-by-side
along the right hand leading edge. At least one of the left hand
wear segments has a leading abutment tip running parallel to the
left hand leading edge and a pair of parallel side faces extending
in a fore-and-aft orientation relative to the width of the
bucket.
[0029] In another aspect or feature of the invention, there is the
combination of a base plate and replaceable wear segments for a
loader bucket having a width. The base plate has a trailing portion
for permanent attachment to a lower portion of the loader bucket,
and a leading portion extending forwardly thereof, and a width
corresponding to the width of the bucket. The leading portion has a
leading edge having a male profile. The base plate has a first
surface and a second surface, the first and second surfaces being
on opposite sides of the plate and lying in first and second
parallel planes. The first surface of the base plate being for
orientation inwardly relative to the bucket. The plate has a
plurality of bore holes formed therein. The bore holes extend
through the plate. The bore holes are set back from the leading
edge. The wear segments have a combined width corresponding to the
width of the bucket. Each segment has a first flange for engaging
the first surface of the base plate, and a second flange for
engaging the second surface of the base plate. The first and second
flanges are joined at a common root portion of the segment. The
flanges and the root portion define between them a rearwardly
facing socket. The socket has a female profile matingly engageable
with the male profile of the leading edge of the base plate. Each
wear segment has a pointed leading portion for engaging material to
be carried in the loader bucket, the leading portion extending
forwardly of the socket. The second flange has at least one bore
hole formed therein for alignment with a corresponding one of the
bore holes of the base plate. The bore hole of the wear segment is
aligned with the corresponding bore hole of the base plate when the
male and female profiles are engaged. The base plate and the wear
segment are securable by a mechanical fastener mounted through the
bores across a single connection interface.
[0030] In an additional feature, the male profile of the base plate
includes a chamfered edge, and the female profile has a mating
chamfer. In another additional feature, the base plate has a first
through thickness, and the first flange has a second through
thickness, the second through thickness being less than the first
through thickness. In yet another additional feature, the base
plate has a first through thickness, and the second flange has a
second through thickness, the second through thickness being
greater than the first through thickness.
[0031] In still yet another additional feature, the bores in the
base plate are countersunk from the first surface to admit a
fastener having a countersunk head lying in a position chosen from
the set of positions consisting of (a) flush with; and (b) shy of,
the first surface of the base plate. In a further additional
feature, the first flange has tool access reliefs formed therein,
the reliefs being located in positions corresponding to the bores
of the second flange.
[0032] In still a further additional feature, the leading portion
of the segment has first and second diverging flanks extending
rearwardly of the tip thereof. The first flank extends from the tip
toward the first flange. The second flank extend from the tip
toward the second flange. The first flank has a surface having a
convex profile relative to the second flank.
[0033] In yet a further additional feature, the leading portion of
the segment includes an abutment face. The abutment face and the
first flank meet along a vertex. The vertex lies between the first
and second planes. The vertex lies closer to the second plane than
to the first plane. In an additional feature, the leading portion
includes an abutment face. The abutment face and the first flank
meet at a first vertex. The abutment face and the second flank meet
along a second vertex. The first vertex lies to one side of the
second plane, and the second vertex lies to the other side of the
second plane.
[0034] In another additional feature, the assembly includes wear
segment attachment fittings for mounting to the vertical edges of
side walls of the bucket, and shrouds for mounting to the wear
segment attachment fitting. The shrouds each include a pair of
rearwardly extending parallel flanges and a rearwardly facing slot
defined therebetween. The attachment fittings each include a
forwardly facing web. The web and the slot being matable. The web
and one of the flanges has corresponding bores formed therein to
admit a fastener to connect each shroud to a respective side wear
segment attachment fitting across a single connection
interface.
[0035] In another aspect or feature of the invention, there is a
replaceable wear segment for impermanent mating with a leading edge
of a permanently affixed base plate of a loader bucket assembly.
The base plate has bore holes formed therethrough adjacent to the
leading edge. The wear segment has a body has a leading portion and
a trailing portion. The leading portion has a leading edge for
advancing into a pile of material to be loaded into the loader
bucket. The trailing portion has a pair of first and second spaced
apart flanges, the flanges having proximal ends joined at a root,
and distal ends extending rearwardly thereof. The first and second
flanges have respective opposed faces lying in respective first and
second spaced apart parallel planes. The opposed faces and the roof
co-operate to define a rearwardly facing socket. The socket has a
profile to match the leading edge of the base plate. The second
flange has a bore hole defined therein to admit an impermanent
mechanical fastener to be inserted therethrough, and through a bore
of the base plate for impermanent single shear connection of the
wear segment to the base plate.
[0036] In an additional feature, the segment is a casting. In
another additional feature, the trailing portion of the wear
segment includes first and second spaced apart flanges and a root
section from which the flanges extend rearwardly, the flanges and
the root cooperating to define the accommodation. In yet another
additional feature, when the first flange rests on a ground
surface, the first flange is an upper flange and the second flange
is a lower flange. The lower flange extends further rearwardly than
the upper flange. The bores of the wear segment are formed in the
lower flange. The upper flange has tool access accommodations
formed therein adjacent the bores of the lower flange.
[0037] In still yet another additional feature, the bores of the
lower flange have centerlines lying in a plane, and the upper
flange has a rearward edge lying abreast of the plane of the
centerlines. In a further additional feature, the bores of the
lower flange are countersunk to accommodate a locknut. In still a
further additional feature, the accommodation has a chamfered
surface at the root. In yet a further additional feature, the
leading edge of the wear member includes a tip having an abutment
intersecting the plane of the second surface.
[0038] In an additional feature, the wear segment includes an upper
surface extending rearwardly from the tip of the wear segment, and
the upper surface is scalloped to encourage rolling action in the
work material In another additional feature, the wear segment has
at least two of the bores formed therein. In yet another additional
feature, at least two bores are spaced apart and stand at a common
setback distance relative to the leading edge of the base plate. In
still yet another additional feature, the accommodation has a first
through thickness measured between the first and second parallel
planes, and the first flange has a second through thickness, the
second through thickness being less than the first through
thickness.
[0039] In a further additional feature, the accommodation has a
first through thickness measured between the first and second
parallel surfaces, and the second flange has a second through
thickness, the second through thickness being greater than the
first through thickness. In still a further additional feature, the
first flange has tool access reliefs formed therein, the reliefs
being located in positions corresponding to the bores of the second
flange. In yet a further additional feature, the leading portion of
the segment has first and second diverging flanks extending
rearwardly of the tip thereof. The first flank extends from the tip
toward the first flange. The second flank extend from the tip
toward the second flange. The first flank has a surface having a
convex profile relative to the second flank.
[0040] In an additional feature, the leading portion of the segment
includes an abutment face. The abutment face and the first flank
meet along a vertex; the vertex lies between the first and second
planes. The vertex lies closer to the second plane than to the
first plane. In another additional feature, the leading portion
includes an abutment face. The abutment face and the first flank
meet at a first vertex. The abutment face and the second flank meet
along a second vertex. The first vertex lies to one side of the
second plane, and the second vertex lies to the other side of the
plane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] For a better understanding of the present invention and to
show more clearly how it may be carried into effect, reference will
now be made by way of example to the accompanying drawings, which
show an assembly according to the preferred embodiment of the
present invention and in which:
[0042] FIG. 1 is an exploded perspective view of a front end loader
bucket having a base plate having lip wear segments bolted to its
leading edges;
[0043] FIG. 2 is an enlarged side corner view of a base plate of
the loader bucket of FIG. 1;
[0044] FIG. 3 is a plan view of the bucket front of FIG. 1 with the
wear assembly components installed;
[0045] FIG. 4 is an end view of an installed wing plate and wing
wear segment of the bucket of FIG. 1;
[0046] FIG. 5 is a sectional view of an installed wing and wing
wear segment taken along section `5-5` of FIG. 4;
[0047] FIG. 6 is a sectional view through a front lip wear segment,
the base plate and bucket base connecting plate taken along section
`6-6` of FIG. 3; and
[0048] FIG. 7 is an isometric prospective view of a lip wear
segment for the bucket of FIG. 1.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT
[0049] The description that follows, and the embodiments described
therein, are provided by way of examples of particular embodiments
of the principles of the present invention. These examples are
provided for the purposes of illustration, and not of limitation,
of those principles and of the invention. In the description that
follows, like parts are marked throughout the specification and
drawings with the same respective reference numerals. The drawings
are not necessarily to scale and in some instances proportions may
have been exaggerated in order more clearly to depict certain
features of the invention. In this description the terms "leading"
or "forward" refer to the direction of advance of the equipment
into a work substance, be it earth, or gravel, or rock, or some
other substance.
[0050] By way of general overview, FIG. 1 shows an exploded view of
a bucket 20 of a front end loader (not shown) having wear
components for installation thereon. Bucket 20 has a backshell
assembly 22 in the form of a generally rectangular plate formed on
a curve of constant radius, terminating in a leading, or lower
tangential plate portion 24 that forms the base wall of bucket 20,
and another planar portion 26 that forms the upper edge of bucket
20. The curved backshell assembly 22 is bounded at either end by
left and right end walls 28, 30. End walls 28 and backshell
assembly 22 co-operate to define the scoop area of bucket 20.
[0051] Bucket 20 has wear components for installation along the
leading portions, or leading edges, of lower tangential plate
portion 24 and end walls 28, 30. The wear components include a base
plate 32 for mounting to tangential plate 24; an array, or set, of
lip shrouds, indicated as lip wear segments 34, for mounting to
base plate 32; wing attachments 36 for mounting to end walls 28,
30; and corner shrouds indicated as wing wear segments 38 for
mounting to wing attachments 36. Each of these components is
described in greater detail below.
[0052] Bucket 20, when installed on a tram scoop (not shown) or
front end loader (not shown), is raised or lowered by means of an
external mechanism, such as a boom assembly (not shown) which
carries the weight of bucket 20 through pivot assemblies mounted at
the main pivot points, indicated as 40. Bucket 20 can be rotated
about these points through some angular range of motion. Typically,
the angular orientation of bucket 20 relative to the booms upon
which it is mounted is controlled by means of one or more hydraulic
cylinders, exemplified by a centrally located powered cylinder in
the nature of a hydraulic ram 42. Hydraulic ram 42 has one end
connected to the boom assembly, and another end connected to a
rearwardly oriented portion of the bucket exterior that is offset
by a moment arm distance from pivot points 40 such that extension
or retraction will tend to cause bucket 20 to pivot. In addition to
the bucket mechanisms, translational forward and rearward motion of
the front end loader to force the bucket into a pile of material
when excavating or digging is provided by the front end loader's
engine and drive train.
[0053] Base Plate
[0054] Base plate 32 is affixed to a front edge 44 of lower plate
portion 24 of bucket 20 by welding or other rigid mounting means. A
rear edge 46 of base plate 32 runs parallel to the lower edge of
lower plate portion 24 of bucket 20 and is pre-machined with a
chamfer 48 as shown on FIG. 6. Chamfer 48 extends along the full
length of base plate 32 and is used for the continuous bevel welded
connection between bucket 20 and base plate 32. The weld runs along
the front edge 44 of lower plate portion 24 and the rear edge of
base plate 32 such that the upper surface of base plate 32 and the
upper surface of the inside of bucket 20 lie flush with one another
as shown in FIG. 6. Base plate 32 has a chevron shaped leading edge
having two portions, indicated as left and right hand leading edges
50, 52 that extend forwardly and converge at a point, or tip, 54.
That is, the leading edges 50, 52 of base plate 32 are each tapered
rearwardly from the central point along a horizontal rake angle,
indicated as a, being the lead angle of the bucket assembly
generally. In one embodiment a is about 12 degrees.
[0055] As shown in the sectional view of FIG. 2, leading edges 50,
52 are machined to have a flat, vertical planar surface portion
indicated as 56 adjoining the horizontally planar upper surface 58,
and a chamfered planar surface portion indicated as 60 running from
a vertex at portion 56 to meet lower horizontally planar surface 62
on a chamfer angle indicated as .beta.. In one embodiment .beta. is
about 20 degrees measured from the horizontal. The vertical portion
56 is a machined vertical face sometimes referred to as the
abutment, or abutment edge.
[0056] Base plate 32 also has an array of tooth engagement
interface fittings in the nature of through-bores, or apertures,
identified as bolt holes 64. Bolt holes 64 have a uniform center
set back distance relative to leading edges 50, 52, the setback
distance being identified as .delta.. In one embodiment this
distance is about 4.17 inches. The thickness t of base plate 32 may
vary depending on the size of bucket 20 or type of application.
Thickness t may be 1-1/2", or 1{fraction (11/16)}", or 2", or some
other thickness as may be found suitable.
[0057] Base plate 32 is of a size to mate with a particular model
of bucket 20. That is, base plate 32 has a width, indicated as `W`
that permits it to be mounted to bucket 20. There may be several
types of front end loader bucket for which a leading plate of width
`W` can be used. `W` is typically in the range of 55 to 112 inches.
A person seeking to order replaceable lip members, as described
below, for a given type of loader bucket may tend to examine, for
example, a catalogue of available plates 32, locate the type, or
width, of bucket in question, and find the size of plate 32
suitable for that bucket. The catalogue may then indicate the
number of lip members of stock sizes that are to be used with that
plate, so that purchasers may select and buy them as a kit.
[0058] Wear Segments
[0059] The array of wear segments indicated in FIG. 1 as 34
includes left and right hand wear segments 66, 68. Inasmuch as wear
segments 66 and 68 are left and right hand mirror images of each
other, a description of the one will serve also to describe the
other. When seen in plan view, left and right hand lip wear
segments 66, 68 are parallelogram shaped, having a leading edge, or
front abutment; a trailing edge, or rear abutment; and a pair of
parallel side faces, 70, 72. The leading and trailing edges are
generally parallel, and are skewed with respect to side faces 70,
72 at the same angle as the horizontal rake angle .alpha. (i.e.,
the lead angle) of leading edges 50, 52. As installed, in use the
front and rear abutments run parallel to the base plate lead, and
the sides run parallel to the bucket sides. Wear segments 66, 68
are bolted in place using high strength countersunk bolts 74, as
noted below.
[0060] The body of each of wear segments 66, 68 has a leading
portion, indicated generally as 76, and a trailing portion
indicated generally as 78. Leading portion 76 is formed into a
front abutment, or leading edge indicated as tip 80 such as may be
advanced into a work material. Trailing portion 76 has a mounting
fitting, or mounting interface, acting as a slot or socket by which
it can be relatively rigidly, and removably, attached to the
leading portion of plate 32. Lip wear segments 66, 68 may be made
in various widths of cast, or forged steel, or hard wearing alloy
steel as discussed below.
[0061] When seen in section as in FIG. 6, trailing portion 78 has a
bifurcated pair of first and second legs 82 and 84 formed on either
side of a fitting or accommodation for the base plate leading edge
in the nature of a recess, or rabbet, or crotch, or slot, or
socket, however it may be termed, indicated as a wear plate leading
edge engagement slot, or groove 86. Legs 82 and 84 may also be
referred to as spaced apart first and second, or upper and lower
flanges of segment 66, 68. Groove 86 is formed to engage the
tongue, that is to say the leading edge 50 (or 52, as the case may
be), of base plate 32.
[0062] Legs 82 and 84 are unequal in length and in thickness. That
is, upper leg 82 has an upper surface 88 lying in a first
horizontal plane, H.sub.1 defining the upper extent of the wear
segment 66 or 68; and a parallel horizontally planar inwardly
facing lower surface 90 that, when installed lies adjacent to and
faces the leading margin of upper surface 58 of base plate 32. The
thickness of upper leg 82 is indicated as T.sub.1. Similarly, lower
leg 84 has an horizontally planar lower surface 92 lying in a
second horizontal plane H.sub.2, downwardly offset from plane
H.sub.1 by a distance T.sub.2. T.sub.2 defines the overall through
thickness of wear segment 66 (or 68, as may be). Lower leg 84 also
has an inwardly facing, upwardly oriented horizontally parallel
planar upper surface 94. The thickness of lower leg 84 is indicated
as T.sub.3, and the thickness of groove 86 is indicated as T.sub.4,
being the overall thickness T.sub.2 less the thicknesses T.sub.1
and T.sub.3 of the two legs. T.sub.4 corresponds to the thickness t
of base plate 32, plus a tolerance to permit the two parts, namely
the leading edge of base plate 32 and groove 86 of wear segment 66
(or 68) to be engaged in a mating manner by advancing, that is,
sliding, the male part, namely the leading edge of base plate 32
into the female part, namely groove 86. In one embodiment T.sub.1
is about 0.91 inches; T.sub.2 is about 4.45 inches; T.sub.3 is
about 2.00 inches; T.sub.4 is about 1.54 inches.
[0063] The root, or groin region 85, of the body of segment 66, is
located adjacent the innermost portion of groove 86, and joins the
proximal ends of legs 82 and 84. The rearwardly facing abutment at
the root is defined by a first vertically planar, end wall portion
96, adjoining, and extending perpendicular to, the innermost margin
of inwardly facing lower surface 90 of upper leg 82, and a second,
sloped planar surface portion 98 extending between first end wall
portion 96 and the innermost margin of inwardly facing upper
surface 94 of lower leg 84, sloped portion 98 lying on an angle
corresponding to angle .beta. of chamfered portion 60 of base plate
32. The conforming profiles of groove 86 and the chamfered leading
edge of base plate 32 are intended to mate to a relatively high
level of precision.
[0064] Upper leg 82 has rearwardly opening tool access recesses, or
reliefs in the nature of scallop shaped bolt allowances 100, 102.
In the embodiment illustrated, each wear plate has two such
allowances spaced apart, although a different number could be used.
Lower leg 84 has correspondingly placed fittings in the nature of
countersunk bores, namely bolt holes 104 by which releasable
mechanical fasteners such as threaded fasteners in the nature of
bolts 74 can fasten wear plate 66, or 68, to base plate 32 when
bores 64 are aligned with bores such as bolt holes 104. This
condition occurs when the leading edge of base plate 32 is mated
snug within groove 86. Although a single bolt can be employed, it
is advantageous that two or more bolts be used, since this will
tend to discourage the wear segment from working due to any urge to
pivot about a single bolt fitting, such as might, repetitively,
cause the bolts to loosen or fail more easily over time.
[0065] The square shouldered countersink 108 is formed on the
underside of lower leg 84 to give a recess for the nut in a
position that may be less exposed to wear than otherwise. The
recess so formed is of sufficient diameter to admit a manual or
powered socket wrench for engaging nut 110. Bolt allowances 100,
102 similarly provide space for a manual or power driven tool head
to engage the countersunk head of bolt 74 during installation and
removal as it seats in the mating counter sink of bolt hole 64. The
trailing edge of upper leg 82 terminates roughly flush with, or
somewhat rearwardly of, the vertical plane of the centreline of the
bolt holes 104. When installed, bolt 74 is in single shear relative
to loads in the horizontal direction, and, being tightened to a set
torque, the interface area of the mating parts adjacent the bolted
connection is in compression. The tight fitting single planer
interface connection may have less tendency to develop `play` than
a double shear connection that, for example, may tend to squeeze a
pair of opposed flanges together. The horizontal loads are intended
to be transferred across the end wall abutment interface, rather
than through shear in the bolts.
[0066] Upper leg 82 is relatively thin, being of lesser thickness
than either base plate 32 (or groove 86), to encourage easier
loading and unloading of bucket 20 generally. Lower leg 84 is
relatively thick, being thicker than not only upper leg 82, but
also groove 86, and base plate 32, to provide a measure of wear
when the leading portion of bucket 20 is advanced in a sliding
orientation along the ground or other surface, and into a pile of
material to be moved.
[0067] Leading portion 76 has an upper flank in the nature of an
surface 114 and a lower flank in the nature of a lower surface 116,
the upper and lower surfaces 114 and 116 converging forwardly
toward narrow tip 80. (Alternatively said, the upper and lower
flanks diverge rearwardly from tip 80 to the upper and lower
flanges, namely legs 82 and 84 respectively). Upper surface 114 is
formed on an arc that runs from a vertex at the intersection of
surface 114 with the plane of upper surface 88 to another vertex at
the intersection of surface 114 with the thin vertical face of tip
80. The arc is concave upward. That is, the center of curvature of
the arc, or portions thereof, stands above leading portion 70. In
one example, the center of curvature lies in the vertical plane of
tip 80. The radius of curvature of the arc of surface 114 is
advantageously in the range of 15"to 30", and is preferably about
20" to 21". In a preferred embodiment it is 20.47". This arcuate
profile of surface 114 may tend to encourage material encountered
as bucket 20 is driven forward to have a rolling motion as it
accumulates. This rolling motion is considered desirable as it is
thought to reduce the effort of loading bucket 20. The shape of the
leading portion may also tend to promote self sharpening in
operation.
[0068] Lower surface 116 has a relatively short proximal planar
surface portion 120 adjoining, and extending forwardly of lower
surface 92 of lower leg 84. Lower surface 116 also has a relatively
longer distal planar surface portion 122 extending forwardly from a
juncture at the forward margin of portion 120 to meet tip 80 at a
vertex along the lower edge of tip 80. Distal portion 122 is set at
a shallower relief angle relative to the horizontal than proximal
portion 120. The angled portion of segment 66 lying between
proximal portion 120 and surface 98 is thicker than T.sub.3, and
increases linearly in thickness in the forward direction, being
thinnest adjacent the rearward margin of proximal portion 120. The
juncture of portions 120 and 122 lies abreast of the end of groove
86. That is, the juncture lies, roughly, level with the vertical
plane of end wall portion 96, or somewhat forward thereof toward
tip 80. Lower surface 92 of lower leg 84 extends to either side of
bolt hole in the width direction of bucket 20 only part of the
width of segment 66, 68 (indicated in phantom in FIG. 3) in the
region of the bolt and nut to provide local protection for them.
The region of the underside of segment 66, 68 away from the bolt
hole is carried through on a flat surface parallel to the plane of
surface 92, extending rearwardly from the line of intersection of
distal portion 122 and proximal portion 120.
[0069] Restating this, the recess, namely groove 86, between the
lower flange (lower leg 84) and the upper flange (upper leg 82) at
the rear of lip wear segment 66 (or 68) is defined by a narrow flat
front abutment, namely end wall portion 96; a horizontal plane in
the nature of lower surface 90 on the underside of the upper
flange, (that is, upper leg 82); a uniformly tapering plane, namely
surface 98, that extends rearwardly and downwardly from the lower
edge of the abutment; and a horizontal plane, namely plane 94 on
the upper portion of the lower flange (that is, lower leg 84). The
horizontal distance between the abutment and the centerline of bolt
hole 104 is at least.delta. so that the recess, (groove 86) will
fit about leading edges 50, 52 of base plate 32 and allow boltholes
64 and 104 to be aligned. The recess will then fit about the
machined leading edges 50, 52 of base plate 32 as the sloping
surface of chamfered portion 60 and the front vertical end face
portion 56 meet the plane of planar surface 98 and the rear
abutment, namely vertical end wall portion 96, respectively, when
the lip wear segments 66, 68 are affixed to base plate 32.
Preferably, any gaps between base plate 32 and the recess are
minimized.
[0070] Left and right hand lip wear segments 66 and 68 may be
arranged onto base plate 32 such that they present contiguous
leading left and right hand edges 130 and 132, meeting at a point
or tip 134 and such that bolt holes 64 are aligned with boltholes
104. Bolts 74 may then be passed through bolt holes 64 of base
plate 32 and bolt holes 94 of lip wear segment 34 and closed with
locknuts 110 to create a tight connection between base plate 32 and
lip wear segment 34.
[0071] Each of wear segments 66, 68 has defined in it as a means of
indicating the extent of wear and replacement time prior to
damaging base plate 32. Wear-indicating hole 136 passes through the
entire thickness of lip wear segment 66, 68 from upper surface 114
to lower surface 116. When lip wear segment 66, 68 has not been
used, hole 136 can only be seen from above and below lip wear
segment 34. If, after use and upon inspection of lip wear segments
34 it is apparent that some of the length of wear-indicating hole
120 can be seen from the front, lip wear segments 34 can be
replaced to prevent damage to base plate 32.
[0072] As shown in FIGS. 1 and 5, wing segments 38 are generally
trapezoidal plates. Wing segments 38 have an inclined upper, or
leading edge 142 and a parallel, though shorter, inclined lower or
trailing edge 144 parallel to leading edge 142. The horizontal side
of the trapezoid is indicated as a base or lower edge 146. The
vertical side of the trapezoid is indicated as a rearward edge 148.
Leading edge 142 and trailing edge 144 are angled away from the
vertical at an angle .theta..
[0073] Inasmuch as base plate 32 serves as intermediary adapter
fittings for mounting segments 66 and 68 to bucket 20 more
generally, so also wing attachments 36 serve as intermediaries, or
adapter fittings for mounting of wing wear segments 38 to the
vertically extending lower portions of the leading edges, or
margins 152, 154, of end walls 28 and 30 of bucket 20 more
generally. To that end wing wear segments 38 are cut plates that
each have a vertical side 156 welded to margin 152 or 154 of end
walls 28 and 30, and a horizontal side 158 welded to the side
margins, or edges 160, 162 of base plate 32. Each plate has a
generally triangular portion having an hypotenuse that is inclined
rearwardly and upwardly at an angle corresponding to the angle of
inclination of the wing wear segments, 38, namely angle .theta..
Each of wing attachments 36 also has a thinned web portion 164
running inwardly from the inclines edge of the hypotenuse to give a
trapezoidally shaped land on either side, leaving a tongue in the
form of a thinned leading edge 166.
[0074] Wear segment 36 has a leading edge 166 having a narrow front
abutment in the nature of a tip 168 along most of its length and
hollowed or scalloped arcuate surfaces 170, 172 extending
rearwardly from either side thereof. The trailing portion 174 of
wing segment 38 has two parallel flanges, identified as first and
second, inboard and outboard legs 180 and 182 with a slot or
recess, identified as socket 184 defined, therebetween. Socket 184
is similar in nature to groove 68. Recess 184 is shaped to fit
snugly about the thinned section, namely web portion 166 of wing
attachment 38. Flange, or inboard leg 180 has a tapered countersink
188 to accommodate the countersunk head of a bolt 190 to be engaged
therein. Flange, or outboard leg 182 has a clearance bore 192. Bore
192 is not recessed like countersunk 96, but passes completely
though outboard leg 182. As installed, wing segment 38 is aligned
over plate 36 such that bolt 150 may be passed through the step,
that is, through thinned leading edge 166 in the inner flange, leg
180, and bolt hole 190 in plate 36. A locknut 194 is threaded onto
bolt 190 and tightened to lie in bore 192 abutting the outside face
of the thinned section 166 of plate 36. All of locknut 194 lies shy
of the outside face of the outer flange, tending to obtain some
protection from wear thereby. Thus flange 180 and plate 36 may be
brought together in a tight connection similar to that of segments
66, 68 with base plate 32.
[0075] Sizes and Kits
[0076] As there are a variety of sizes of buckets, different sizes
of lip wear segments are required. There are over two dozen
standard widths of loader buckets in use in industry today. It has
been determined that four different standard widths of lip wear
segments 66, 68 (20 inch, 18 inch, 16 inch and 14.5 inch) can be
variously combined to yield rear plate sets or kits suitable for
use with at least 25 different standard size loader buckets. The
use of a few standard lip wear segment sizes will reduce
manufacturing costs, shipping costs and inventory costs as well as
serve a wide variety of bucket sizes. Other size combinations are
also possible.
[0077] In use, base plate 32 is welded onto bucket 20 along base
plate rear edge 46. Base plate 32 is selected to have a width equal
to that of bucket 20. For the given width of base plate 32, a
combination of standard lip wear segments 34 of left and right hand
orientations is obtained. The total width of lip wear segments 34
is equal to the total width of base plate 32. Similarly, wing
attachment adapter fittings, 36 are welded in place.
[0078] Either before or after base plate 32 is welded onto bucket
20, base plate 32 is drilled with boltholes 64 to align with
boltholes 94 of lip wear segments 34. As well, leading edges 50, 52
of base plate 32 may be machined to form a wedge type abutment as
described to fit snugly within recess 100 of lip wear segment 66,
68.
[0079] After base plate 32 is mounted to bucket 20, wing
attachments 36 are welded to bucket 20 and base plate 32 along
edges 130 and 132. Segment 38 is then bolted to wing attachment
fitting, 36. After wing segments 38 are attached, lip wear segments
66, 68 are bolted onto base plate 32.
[0080] In operation, the loader forces bucket 20 into a material
pile such as earth or ore and lifts bucket 20 upwards. The material
rolls along lip wear segment 34 and base plate 32 into bucket 20.
The curvature in lip wear segment 34 may tend to allow the material
to roll into bucket 20 at an increased rate allowing for more loads
per hour. As well, some material that contacts wing wear segment 38
will enter bucket 20. Again, the curvature of wing wear segment 38
allows for more efficient rolling motion of the material.
[0081] Wear plate segments 66, 68 and 38 are subject to wear during
use. After some time an operator or maintenance technician, may
observe that the witness marks, namely wear indicating holes 136,
may have worn to such an extent that insufficient material is left
for further use.
[0082] It can be seen from the geometry of FIG. 6 that the upper
edge of tip 80--that is, the vertex formed at the intersection of
the arcuate surface 114 and the vertical end surface of tip 80,
lies above the plane of the lower surface of base plate 32, but
below both the planes of the mid-plate thickness and upper surface
of plate 32. The lower margin of tip 80 lies in a plane below the
plane of the lower surface of base plate 32. As such, it is thought
that the resulting action of the work material across segments 66,
68 may tend to wear away segments 66, 68 less severely than if the
tip had been place in a higher plane, such as at or above the plane
of the upper surface of plate 36. Further, it is thought that
placement of the tip in this lower plane may tend to encourage
self-sharpening of the leading edges of wear plates 66, 68.
[0083] When the wear of lip wear segment 34 is such that the rear
portion of wear-indicating hole 136 is visible from the front of
the loader, the lip wear segments need to be replaced to ensure
that additional use does not result in damage to the forward
portion of base plate 32. Lip wear segments are removed by removing
the bolts connecting base plate 32 to lip wear segments 66, 68 and
are replaced with new lip wear segments. As well, in a similar
fashion, wing wear segments 38 can be replaced at this time.
[0084] Method of Use
[0085] An aspect of this invention is directed to a method of
providing sets of lip wear segments to consumers. This method
includes three main steps. In the first step, a retailer or
distributor obtains numerous lip wear members having widths of 20
inches, 18 inches, 16 inches and 14.5 inches (although a variety of
other sizes may be used.) The retailer then determines for a given
base plate width, which combination of lip wear members would give
a total lip wear member width equal to the given base plate width.
This determination may be done by simple calculation or by
consulting prepared charts or other materials. The retailer then
supplies the lip wear segments in the selected combination to
consumers in kit form, ready for installation. The dealer may,
optionally accept the worn teeth for return
[0086] In the preferred embodiment, although different widths of
wear segments 66, 68 are available, each has two lower flange bore
holes, and the spacing of those bore holes is the same for all
sizes, the differences in width being accounted for by a change in
the width of the portion of the wear segment lying laterally
outboard of each of the bore holes. This may tend to facilitate
manufacture.
[0087] Another aspect of this invention is directed to a method of
providing base plates for use with boltable lip wear segments. The
base plates may be provided separately or in a kit with the
boltable lip wear segments. The base plates may preferably be
pre-cut to match the width of standard bucket sizes. The base
plates may also preferably have bolt holes 64 predrilled to match
the bolt holes of the boltable lip wear segments.
[0088] A number of changes may be made to the above invention. For
example, a single large lip wear segment could be used instead of a
combination of smaller lip wear segments. In addition, different
profile configurations of the leading edge tip of the lip wear
segment may be used for different applications. As well, the recess
in the lip wear segment and the corresponding leading edge of the
base plate may have different configurations to reduce stress
concentrations. In addition, other edge profiles may be used for
the wing wear segments. Further, the base plate may be formed
integrally with the loader bucket.
[0089] Although the wear plate segments are attached to the base
plate and side plate adapter fittings using releasably threaded
mechanical fasteners in the nature of bolts, those bolts are to be
taken as being representative of other types of fasteners such as
huck bolts, hot forged rivets, cold formed rivets and so on.
Releasably threaded bolts are preferred since, unlike rivets, they
can be removed relatively easily without destroying the
fastener.
[0090] In summary, form the foregoing description it can be seen
that each wear lip segment 66, 68, has a straight leading edge
abutment, namely tip 80, from which it increases in thickness in
the rearward direction. The, increases in depth of the leading
portion of the wear segment (measured by divergence of the lower
plane, or surface 116 relative to the horizontal plane of base
plate 32) in a uniform, or linear manner, while the upper surface
follows the profile of an arc R.sub.2. At the rear, the wear lip
segment has a lower flange, leg 84 and an upper flange, leg 82. The
upper flange is shorter than the lower flange, and thus may tend to
provide a lesser obstruction to the flow of materials in and out of
bucket 20 generally. The upper flange, leg 82 is shorter and
thinner than the lower flange, lower leg 84, and thus may tend to
provide a lesser obstruction to the flow of materials into and out
of the bucket. The upper flange includes semi-circular recesses,
namely allowances 100, 102 that are concentric with each bolt hole
location in the corresponding position in the lower flange, thus
tending to provide bolt hole access from above. The recesses,
namely allowances 100, 102 are smoothly radiused into the trailing
edge of the adjacent portions of the upper flange. The lower flange
is thicker than the upper flange, and includes two spaced apart
recessed, clearance holes to clear and protect the attaching bolt
locknuts.
[0091] This single interface bolted connection between the lip
bottom flange and the base plate may tend to provide for a
relatively tightly held, relatively rigid connection, thereby may
tend to reduce fatigue and may tend to reduce shear stresses in the
bolts more generally. The resultant connection may tend to be a
less time consuming procedure, and may tend to be less costly, than
a welded connection.
[0092] The shaped recess between the upper and lower flanges at the
rear portion of lip wear segment 66 or 68, namely groove 86, is
defined by the lower surface of upper leg 82 and the upper surface
of the lower leg 84, the narrow front abutment, (item 96), and the
tapered, or oblique, plane 98 that extends rearwardly from the
lower edge of abutment, (item 96). This recess is precision
machined to match very closely, and preferably precisely, the
machined left and right hand leading edges 50, 52 of base plate
32.
[0093] As noted above, a wear indicating hole 136 is provided in
each of segments 66, 68 as a means of indicating the extent of
wear, and may indicate that a replacement time is due prior to
damaging or wearing into base plate 32. Base plate 32 can be of
variable thickness depending on the size of bucket 20 or type of
application. The rear base line of base plate 32, which runs
parallel to the bucket rear edge, 46, is pre-machined with a weld
preparation chamfer 48 as shown in FIG. 6. This chamfer extends
along the full length of the plate and is used for the continuous
welding connection between bucket 20 and base plate 32.
[0094] As has been described above, the base plate front, or
leading edges 50, 52 are machined to suit the desired lead angle
.alpha. and to match the lip wear recesses, grooves 86, drilled to
conform to the selected lip wear segments, bolts, diameter and
locations. The base plate forward edges 50, 52 are machined to form
the wedge shape. The edge is tapered down and back from the narrow
abutment and all sharp corners along the abutment are machined
smooth. The two triangular wing attachments 36 may be cast or
fabricated from abrasion resistant materials. The triangular
opposed adjacent corner wear attachments 36 include recesses on the
outer edges to facilitate welding to the inside and outside lines
of the bucket vertical front corner and the topsides of the base
plate 32. The center sections of the wing segments 38 are drilled
with two holes to match the wing wear segment 38 bolt size (item
150) and locations. The center web (item 166) of the wing segment
attachment 36 is made to fit inside the rearward recess of the wing
segment 38. The cast wear wing segments 38 have a narrow front
abutment that slopes outwardly towards the rear and includes a
recess (socket 184) that fits over the wing segment center rib,
namely item 166. Two holes are drilled through the rear flanges of
the wing wear segments to match the bolt hole locations on the wing
segment. The inner hole is countersunk to match the countersunk
bolt head and the outer hole is recessed to completely clear and
enclose the bolt locknut as shown in FIG. 5. High strength
countersunk bolts and lock nuts are used throughout the
assembly.
[0095] An embodiment of the invention has now been described in
detail. Since changes in and or additions to the above-described
best mode may be made without departing from the nature, spirit or
scope of the invention, the invention is not to be limited to those
details.
* * * * *