U.S. patent application number 10/403635 was filed with the patent office on 2004-09-30 for structural member of a work machine.
Invention is credited to Davis, Jeremy D., Green, Timothy E..
Application Number | 20040191043 10/403635 |
Document ID | / |
Family ID | 32989989 |
Filed Date | 2004-09-30 |
United States Patent
Application |
20040191043 |
Kind Code |
A1 |
Davis, Jeremy D. ; et
al. |
September 30, 2004 |
Structural member of a work machine
Abstract
Structural members of work machines experience heavy forces and
the structural member must be able to endure such heavy forces, but
must also be sufficiently light to prevent the work machine from
using most of its available power to manipulate the structural
member. The present apparatus facilitates the heavy-duty
construction along with a reduced weight by comprising top and
bottom portions, a middle portion attached between and
substantially perpendicular with the top and bottom portions, and a
primary coupling formed at a first-end portion of the structural
member and extending from at least one of the top, bottom, and
middle portions to define a substantially I-shaped structural
member.
Inventors: |
Davis, Jeremy D.; (Ripley,
GB) ; Green, Timothy E.; (Beaufort, NC) |
Correspondence
Address: |
CATERPILLAR INC.
100 N.E. ADAMS STREET
PATENT DEPT.
PEORIA
IL
616296490
|
Family ID: |
32989989 |
Appl. No.: |
10/403635 |
Filed: |
March 31, 2003 |
Current U.S.
Class: |
414/722 |
Current CPC
Class: |
E02F 3/38 20130101 |
Class at
Publication: |
414/722 |
International
Class: |
E02F 003/00 |
Claims
What is claimed is:
1. A structural member of a work machine, the structural member
having first and second-end portions, comprising: a body having a
top portion, a bottom portion, and a middle portion, the top and
bottom portions having longitudinal centerlines, the middle portion
positioned between and substantially perpendicular with the top and
bottom portions and positioned substantially at the longitudinal
centerline of at least one of the top and bottom portions; and a
primary coupling formed with the body at the first-end portion and
extending from at least one of the top, bottom, and middle
portions.
2. The structural member of claim 1, wherein the body has a
substantial I-shaped cross-section.
3. The structural member of claim 2, wherein the top, bottom, and
middle portions consist of respective top, bottom, and middle
plates.
4. The structural member of claim 3, further including a secondary
coupling formed with the body at the second-end portion and
extending from at least one of the top, bottom, and middle
plates.
5. The structural member of claim 4, wherein the primary and
secondary couplings extend from each of the top, bottom, and middle
plates.
6. The structural member of claim 1, wherein the body has a
curvilinear portion positioned a predetermined distance from the
first-end portion and a predetermined distance from the second-end
portion, the predetermined distance from the second-end portion
being greater than the predetermined distance from the first-end
portion.
7. The structural member of claim 1, wherein the structural member
has a midpoint defined between the first and second-end portions
and further includes top and bottom mounts wherein the top mount is
positioned between the midpoint and the second-end portion and the
bottom mount is positioned substantially at the midpoint.
8. A work machine, comprising: a frame; a first member having first
and second end portions, a top portion, a bottom portion, and a
middle portion, the top and bottom portions having longitudinal
centerlines, the middle portion positioned between and
substantially perpendicular with the top and bottom portions and
positioned substantially at the longitudinal centerline of at least
one of the top and bottom portions; a second member; a primary
coupling defined at the first-end portion of the first member for
pivotable attachment with the frame; and a secondary coupling
defined at the second-end portion of the first member for pivotable
attachment with the second member.
9. The work machine of claim 8, wherein the first member has a
substantial I-shaped cross-section.
10. The work machine of claim 8, wherein the first member is one of
a structural member and a stick and the second member is one of a
structural member, a stick, and an implement.
11. The work machine of claim 8, wherein the primary coupling and
secondary coupling are formed as an integral part of the first
member.
12. The work machine of claim 8, wherein the top, bottom, and
middle portions of the first member consist of respective top,
bottom, and middle plates.
13. The work machine of claim 12, wherein the top and bottom plates
include bifurcated legs at the second-end portion, the primary
coupling includes a first boss adjacent the middle plate and
attached between the top and bottom plates, and the secondary
coupling includes an intermediate plate attached between the top
and bottom plates, and including a second boss adjacent the
intermediate plate and attached between one of the bifurcated legs
of the top and bottom plates and a third boss adjacent the
intermediate plate and attached between one of the other bifurcated
legs of the top and bottom plates.
Description
TECHNICAL FIELD
[0001] This invention relates generally to a structural member of a
work machine and, more particularly, to a particular structure of
the structural member.
BACKGROUND
[0002] In work machines, such as backhoe loaders, skid steer
loaders, and excavators, substantial forces are transmitted through
a member that connects an implement to a frame of the work machine.
The member typically includes a boom and a stick, the stick being
pivotally attached with the boom. During operation of the work
machine, the member experiences heavy forces as the implement
penetrates the ground to dig, carries heavy loads from one location
to another, or pushes or pulls material. The member, therefore,
must be able to endure such heavy forces. The member, however, must
also be sufficiently light to prevent the work machine from using
most of its available power to manipulate the member. The member,
therefore, must have a structural design that combines a heavy-duty
construction along with being relatively light weight.
[0003] One known boom design is disclosed in U.S. Pat. No.
6,158,949 issued to Walth et. al. on Dec. 12, 2000. It discloses a
boom design having a top boom support structure, a bottom boom
support structure, a first lateral boom support structure, and a
second lateral boom support structure, which cooperate with each
other to define a boom void therein. This boom design requires the
attachment of four supporting structures, which creates a heavier
boom, increases fatigue due to the additional welding required to
manufacture, and is more time consuming to manufacture. This
creates a boom design that is expensive to operate due to the
additional energy required to manipulate the heavy boom and is more
expensive to manufacture due to the additional structures and the
additional welding required.
[0004] The present invention is directed to overcoming one or more
of the problems as set forth above.
SUMMARY OF THE INVENTION
[0005] In one aspect of the present invention, a structural member
of a work machine has first and second-end portions, and comprises,
a body having a top portion, a bottom portion, and a middle
portion. The top and bottom portions have longitudinal centerlines.
The middle portion is positioned between and substantially
perpendicular with the top and bottom portions and positioned
substantially at the longitudinal centerline of at least one of the
top and bottom portions. The structural member further comprises a
primary coupling formed with the body at the first-end portion of
the structural member and extends from at least one of the top,
bottom, and middle portions.
[0006] In another aspect of the present invention, a work machine
comprises a frame, a first member, a second member, a primary
coupling, and a secondary coupling. The first member has first and
second end portions, a top portion having a longitudinal
centerline, a bottom portion having a longitudinal centerline, and
a middle portion. The middle portion is positioned between and
substantially perpendicular with the top and bottom portions and
positioned substantially at the longitudinal centerline of at least
one of the top and bottom portions. The primary coupling is defined
at the first-end portion of the first member for pivotable
attachment with the frame, and the secondary coupling is defined at
the second-end portion of the first member for pivotable attachment
with the second member.
[0007] The present invention is a structural member of a work
machine that has first and second-end portions, and comprises, a
body having a top portion, a bottom portion, and a middle portion.
The top and bottom portions have longitudinal centerlines. The
middle portion is positioned between and substantially
perpendicular with the top and bottom portions substantially at the
longitudinal centerline of at least one of the top and bottom
portions. The structural member further comprises a primary
coupling formed with the body at the first-end portion of the
structural member and extends from at least one of the top, bottom,
and middle portions. The positioning of the middle portion between
and substantially perpendicular with the top and bottom portions
provides sufficient support for the compressive and tensional
forces applied to the structural member during normal operation by
distributing such forces throughout the structural member. The
structural member, therefore, is able to handle heavy-duty
applications with a reduced weight configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side view of a work machine, such as a backhoe
loader, incorporating a boom of the present invention;
[0009] FIG. 2 is a perspective view of the boom of FIG. 1
fabricated as a unitary casting; and
[0010] FIG. 3 is an exploded view of an alternate embodiment of the
boom of FIG. 1 manufactured from various components.
DETAILED DESCRIPTION
[0011] While the invention is open to various modifications and
alternative forms, a specific embodiment thereof has been shown by
way of example in the drawings and will herein be described in
detail. There is, however, no intent to limit the invention to the
particular form disclosed.
[0012] Referring to the drawings, FIG. 1 is a work machine 1, such
as a backhoe loader, skid steer loader, or excavator, that has a
frame 10, a plurality of wheels 20 supporting the frame 10 against
the ground, and an operator's compartment 30 supported on the frame
10 and positioned substantially above the wheels 20 on the rear-end
portion of the work machine 1. The work machine 1 further includes
a front member 40 and a rear member 50 pivotally attached with the
front and rear-end portions of the frame 10, respectively. The
front member 40 includes a multi-bar linkage 60 pivotally attached
with the front-end portion of the frame 10 and a front implement 70
pivotally attached with the multi-bar linkage 60. The front
implement 70 may be a loader bucket, brush, auger, or other
suitable worktool. The rear member 50 includes a boom 80 pivotally
attached with the rear-end portion of the frame 10, a stick 90
pivotally attached with the boom 80, and a rear implement 100
pivotally attached with the stick 90. The rear implement 100 may be
a bucket, a grapple, or any other suitable worktool. The work
machine 1 also includes a first hydraulic cylinder 110 that has a
first-end portion attached with the boom 80 and a second-end
portion attached with the stick 90. A second hydraulic cylinder 120
has a first-end portion attached with the boom 80 and a second-end
portion attached with the rear-end portion of the frame 10. It
should be understood that the work machine 1 could be of any
suitable type that utilizes a boom and not just those enumerated
above or the backhoe loader depicted in FIG. 1.
[0013] In FIG. 2, the boom 80 of the work machine 1 is shown in
more detail. The boom 80 is made from a unitary casting and
includes a body 124 that has a top portion 130, a bottom portion
140, and a middle portion 150. The middle portion 150 is positioned
between and substantially perpendicular with a longitudinal
centerline 160, 170 of the top and bottom portions 130, 140 to
define a substantially I-shaped beam. It should be understood that
the middle portion 150 could a variety of other shapes, such as V,
W, M, or any other shape so long as the middle portion 150 is
located substantially along the longitudinal centerline 160, 170 of
at least one of the top and bottom portions 130, 140. The boom 80
also includes a primary coupling 180 at a first-end portion 190 of
the boom 80 and a secondary coupling 200 at a second-end portion
210 of the boom 80. The primary coupling 180 includes a boss 220
that is formed as an integral part of the boom 80 and is positioned
between the top and bottom portions 130, 140, adjacent with the
middle portion 150. The boss 220 allows for the attachment of the
boom 80 with the rear-end portion of the frame 10. The secondary
coupling 200 includes bifurcated legs 230, 240, a first boss 250,
and a second boss 260, all of which are formed as an integral part
of the boom 80. The first boss 250 is positioned at the second-end
portion 210 of the boom 80 adjacent to one of the bifurcated legs
230 of the boom 80 and the second boss 260 is positioned at the
second-end portion 210 of the boom 80 adjacent to the other
bifurcated leg 240. The first and second bosses 250, 260 allow for
the attachment of the boom 80 with the stick 90.
[0014] Further, the boom 80 includes top and bottom mounts 270, 280
formed as an integral part of the boom 80. The top mount 270
includes a top flange 290 positioned on the top portion 130 and a
boss 300 formed on the top flange 290. The top mount 270 is
positioned between a midpoint 310 of the boom 80 and the second-end
portion 210. The bottom mount 280 includes a bottom flange 320
positioned on the bottom portion 140 and a boss 330 formed on the
bottom flange 320. The bottom mount 280 is positioned so that the
boss 330 is positioned near the midpoint 310 of the boom 80.
[0015] Finally, the body 124 of the boom 80 includes a curvilinear
portion 340 positioned between the midpoint 310 of the boom 80 and
the first-end portion 190. The curvilinear portion 340 is usually
positioned a predetermined distance D.sub.1 from the first-end
portion 190 and a predetermined distance D.sub.2 from the
second-end portion 210 wherein the distance D.sub.2 is greater than
D.sub.1. Alternatively, the curvilinear portion 340 could be
positioned so that the distance D.sub.1is greater than the distance
D.sub.2. The curvilinear portion 340 is formed to position the
first-end portion 190 at an inclination of between 20 and 90
degrees with respect to the second-end portion 210 as shown at 350.
It should be understood that the angle of inclination 350 of the
first end portion 190 with respect to the second-end portion 210
could be different depending upon the particular work machine on
which the boom 80 is attached and the ranges referenced above are
not meant to limit the angle of inclination of the first-end
portion with respect to the second-end portion.
[0016] An alternative embodiment is depicted in FIG. 3 with
reference numbers of previous Figures being used to identify
similar components therein. The boom 80 is manufactured from
various components through an assembly process and has a first-end
portion 400 and a second-end portion 410. The boom 80 includes top
and bottom plates 420, 430, and a middle plate 440 welded between
and substantially perpendicular with longitudinal centerlines 450,
460 of the top and bottom plates 420, 430, to define a body 124
similar to that of FIG. 2. The top and bottom plates 420, 430 each
include bifurcated legs 470, 480, 490, 500 positioned at the
second-end portion 410. The boom 80 also includes a primary
coupling 510 defined at the first-end portion 400 and a secondary
coupling 520 defined at the second-end portion 410 of the boom
80.
[0017] The primary coupling 510 is formed by welding a boss 530
between and with the top and bottom plates 420, 430 and with the
middle plate 440. When the middle plate 440 is welded with the top
and bottom plates 420, 430, the top and bottom plates 420, 430 are
longer than the middle plate 440 and extend beyond the middle plate
440 at the first-end portion 400 thus creating a pocket 540. The
boss 530 fits into the pocket 540 and is welded with the top,
bottom, and middle plates 420, 430, 440. The primary coupling 510
pivotally attaches the boom 80 with the rear-end portion of the
frame 10.
[0018] The secondary coupling 520 is formed by positioning a
curved, outwardly extending intermediate plate 550 between the
bifurcated legs 470, 480, 490, 500 and welding it thereto. A first
boss 560 is welded between one of the bifurcated legs 470, 490 of
the top and bottom plates 420, 430 and with the intermediate plate
550, and a second boss 570 is welded between the other bifurcated
legs 480, 500 of the top and bottom plates 420, 430 and with the
intermediate plate 550. The secondary coupling 520 pivotally
attaches the boom 80 with the stick 90.
[0019] The boom 80 further includes a top mount 580 and a bottom
mount 600. The top mount 580 is welded with the top plate 420 and
is positioned between a midpoint 590 of the boom 80 and the
second-end portion 410. The bottom mount 600 is welded with the
bottom plate 430 and is positioned substantially at the midpoint
590 of the boom 80. The top and bottom mounts 580, 600 include top
and bottom flanges 610, 620 that are welded with the top and bottom
plates 420, 430, respectively. Each of the top and bottom flanges
610, 620 include apertures (not shown) therethrough, and each such
aperture has a boss 630, 635, 640, 645 welded to each side
thereof.
[0020] Finally, the boom 80 includes a curvilinear portion 650 that
is similar to the curvilinear portion 340 in FIG. 2. The
curvilinear portion 650 is formed before welding of the components
by bending the top, bottom, and middle plates 420, 430, 440 and
then welding them together. Further, although welding is mentioned
as the means for attaching the various components of the boom 80
together in FIG. 3, it should be understood that any suitable
means, such as bonding or the like, may be used to achieve similar
results.
INDUSTRIAL APPLICABILITY
[0021] During normal operation, the implement 100, stick 90, and
boom 80 work in unison to effectively perform work functions, such
as digging a hole or moving large amounts of material. During this
sort of operation, forces are transmitted through the implement 100
to the stick 90, to the boom 80, and ultimately to the frame
10.
[0022] In the embodiment depicted in FIG. 2, the boom 80 is
manufactured so that the top, bottom, and middle portions 130, 140,
150 form the body 124 as a unitary member. Additionally, the
primary and secondary couplings 180, 200 and the top and bottom
mounts 270, 280 are manufactured as part of the unitary boom 80.
The manufacturing can be accomplished by casting the boom 80, or
another suitable manufacturing process. The casting process reduces
the requirement of assembling and attaching four supporting
structures required for the box boom, reducing the time and cost
required to manufacture the boom 80. The reduction of the four
supporting structures also reduces the overall weight of the boom
80. Further, the reduction of welding reduces weld-induced stress
and fatigue concerns. Finally, the boom 80 of FIG. 2 has a cross
sectional I-shape that provides sufficient support for the
compressive and tensional forces applied to the boom 80 during
normal operation by distributing such forces throughout the boom 80
structure. The boom 80, therefore, is able to handle heavy-duty
applications with a reduced weight configuration.
[0023] Alternatively, as depicted in FIG. 3, the boom 80 can be
manufactured from various components while having the same I-shape
structure as that in FIG. 2. The middle plate 440 is welded to the
top and bottom plates 420, 430 along the longitudinal centerline of
the top and bottom plates 450, 460. The primary coupling 510 is
assembled and welded to the first-end portion 400, and the
secondary coupling 520 is assembled and welded to the second-end
portion 410. Finally, the top and bottom mounts 580, 600 are welded
to the top and bottom plates 420, 430, respectively. Even though
there are more components than the design in FIG. 2, the
manufacture of the boom 80 still reduces the time and cost because
it has fewer components to assemble than other boom designs.
Further, because there are fewer components to assemble and attach
there is less welding required, therefore, the weld-induced stress
and fatigue concerns are reduced. Again, as with the boom 80 of
FIG. 2, heavy-duty applications are achieved with a reduced weight
configuration.
[0024] As can be see from the descriptions above, the boom 80 can
be manufactured as a unitary member or with fewer components that
the box boom design requiring four supporting structures. This
causes the boom 80 to be less expensive to manufacture, less
expensive to operate, and reduces stress and fatigue thereof.
Further, the general I-shape structure provides a stronger boom 80
with a reduced weight for increased operational advantages.
[0025] Other aspects, objects and advantages of the invention can
be obtained from a study of the drawings, the disclosure and the
appended claims.
* * * * *