U.S. patent application number 11/623116 was filed with the patent office on 2008-01-31 for working machine.
This patent application is currently assigned to JCB COMPACT PRODUCTS LIMITED. Invention is credited to Richard James Brindle.
Application Number | 20080024006 11/623116 |
Document ID | / |
Family ID | 36010647 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080024006 |
Kind Code |
A1 |
Brindle; Richard James |
January 31, 2008 |
Working Machine
Abstract
A working machine has a main frame structure which includes a
pair of endless tracks, each track is entrained about track
supporting devices mounted by a track sub-frame. The sub-frame
includes inner and outer members interconnected by cross members.
The inner and outer members are arranged side by side and mounting
at or adjacent upper edges thereof, at least one upper track
support device between the members. The inner and outer members
mount at or adjacent lower edges thereof, at least one lower track
supporting device between the members. The inner and outer members
and cross members of at least one of the track sub-frames is a
monolithic casting.
Inventors: |
Brindle; Richard James;
(Burton on Trent, GB) |
Correspondence
Address: |
MACMILLAN SOBANSKI & TODD, LLC
ONE MARITIME PLAZA FIFTH FLOOR
720 WATER STREET
TOLEDO
OH
43604-1619
US
|
Assignee: |
JCB COMPACT PRODUCTS
LIMITED
Rocester Uttoxeter
Staffordshire
GB
ST14 5JP
|
Family ID: |
36010647 |
Appl. No.: |
11/623116 |
Filed: |
January 15, 2007 |
Current U.S.
Class: |
305/199 |
Current CPC
Class: |
B62D 21/186 20130101;
E02F 9/121 20130101; Y10T 29/49826 20150115; E02F 9/02 20130101;
B62D 55/10 20130101 |
Class at
Publication: |
305/199 |
International
Class: |
B62D 55/06 20060101
B62D055/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 20, 2006 |
GB |
0601149.8 |
Claims
1. A working machine having a main frame structure which includes a
pair of endless tracks, each track being entrained about track
supporting devices mounted by a track sub-frame, the sub-frame
including inner and outer members interconnected by cross members,
the inner and outer members being arranged side by side and
mounting at or adjacent upper edges thereof, at least one upper
track support device between the members, and the inner and outer
members mounting at or adjacent lower edges thereof, at least one
lower track supporting device between the members, the inner and
outer members and cross members of at least one of the track
sub-frames being provided by a monolithic casting.
2. A machine according to claim 1 wherein the monolithic casting is
provided in a weldable casting material.
3. A machine according to claim 2 wherein the track sub-frame or
frames are attached to the remainder of the main frame structure by
welding.
4. A machine according to claim 1 wherein the cast inner and outer
members have along their respective upper and lower edges, recesses
for receiving mountings for the track supporting devices.
5. A machine according to claim 4 wherein at least some of the
track supporting devices each includes a roller carried on a
spindle.
6. A machine according to claim 4 wherein the upper and lower edges
of the inner and outer track sub-frame members include further
recesses which lighten the monolithic casting.
7. A machine according to claim 1 wherein at least one of the inner
and outer track sub-frame members provides a mounting for a track
motor which in use drive a track drive sprocket located between the
inner and outer members.
8. A machine according to claim 7 wherein the track motor mounting
includes an opening in the at least one track sub-frame member at
or towards an end of the track sub-frame member which extends
longitudinally of the machine beyond the corresponding end of the
other track sub-frame member.
9. A machine according to claim 1 wherein at least one of the inner
and outer track sub-frame members provides a mounting for a track
tensioning mechanism which includes a track tensioning element
which is resiliently biased in a direction so as to maintain a
desired tension in the track entrained about the track supporting
devices.
10. A machine according to claim 1 wherein the main frame structure
includes a main frame part which lies between the pair of track
sub-frames.
11. A machine according to claim 10 wherein the main frame part
includes a central portion for supporting a part of a slewing
mechanism, the machine including an upper frame structure which is
rotatable about a generally upright axis relative to the main frame
structure, by the slewing mechanism.
12. A machine according to claim 11 wherein the central portion of
the main frame part is attached to each of the track sub-frames by
connecting arms.
13. A machine according to claim 11 wherein the central portion of
the main frame part is attached to each of the track sub-frames by
connecting arms.
14. A machine according to claim 12 or claim 13 wherein the
connecting arms are provided by elements fabricated in a material
which is weldable to the track sub-frames.
15. A machine according to claim 14 wherein the pair of connecting
arms are welded to the inner track sub-frame members of the track
sub-frames, and to the central portion of the main frame part.
16. A machine according to claim 15 wherein the central portion is
cast in steel.
17. A machine according to claim 14 wherein the inner of the track
sub-frame members of the track sub-frame monolithic casting
includes for each connecting arm, one or more integral formations
which extend inwardly of the machine towards the central portion,
the connecting arms being welded to the integral formations.
18. A method of making a working machine having a main frame
structure which includes a pair of endless tracks, each track being
entrained about track supporting devices mounted by a respective
track sub-frame, the method including making at least one of the
track sub-frames by providing a monolithic casting including inner
and outer track sub-frame members arranged side by side with there
being integral cross members interconnecting the track sub-frame
members.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed to United Kingdom patent application
Serial No. 0601149.8 filed Jan. 20, 2006.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
TECHNICAL FIELD
[0003] This invention relates to a working machine of the kind
including a frame with a ground engaging lower structure including
a pair of endless tracks each entrained about track supporting
devices mounted by a track sub-frame.
BACKGROUND OF THE INVENTION
[0004] Conventionally track sub-frames are fabricated structures
which may mount a track motor which drives a track-driving
sprocket. By virtue of the track sub-frames being fabricated they
are expensive to produce, requiring the assembly of many different
components. Typically such track sub-frames are attached by
fasteners for example to the remainder of the ground engaging lower
structure.
BRIEF SUMMARY OF THE INVENTION
[0005] According to a first aspect of the invention we provide a
working machine having a main frame structure which includes a pair
of endless tracks, each track being entrained about track
supporting devices mounted by a track sub-frame. The sub-frame
includes inner and outer members interconnected by cross members.
The inner and outer members are arranged side by side and mounting
at or adjacent upper edges thereof, at least one upper track
support device between the members. The inner and outer members
mount at or adjacent lower edges thereof, at least one lower track
supporting device between the members. The inner and outer members
and cross members of at least one of the track sub-frames are
provided by a monolithic casting of a weldable casting material
such as steel. The track sub-frame or frames may be attached to the
remainder of the main frame structure by welding, for optimum
strength.
[0006] According to a second aspect of the invention we provide a
method of making a working machine having a main frame structure
which includes a pair of endless tracks, each track being entrained
about track supporting devices mounted by a respective track
sub-frame. The method includes making at least one of the track
sub-frames by providing a monolithic casting including inner and
outer track sub-frame members arranged side by side with there
being integral cross members interconnecting the track sub-frame
members.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an illustrative side view of a working machine
which may embody the invention;
[0008] FIG. 2 is an illustrative perspective view of a track
sub-frame of the main frame structure of the machine of FIG. 1, but
with the track removed for clarity; and
[0009] FIG. 3 is an illustrative plan view of the main frame
structure of the machine of FIG. 1, again with drive tracks
removed.
DETAILED DESCRIPTION OF THE INVENTION
[0010] Referring to the drawings, a working machine 10 includes a
main frame structure 11 which includes a pair of tracks 12, one at
each side of the machine 10. Each track 12 is entrained about track
support devices which are mounted by respective track sub-frames
15, 16.
[0011] The track support devices in this example, include three
lower rollers 17, 18, 19, the track 12 passing between the lower
rollers 17, 18, 19 and the ground, and at least one upper roller
20. The track sub-frames 15, 16 each also include a mounting 47 for
a track tensioning device which includes a track tensioning element
49 which is resiliently biased so as to maintain a tension in the
track 12.
[0012] Each sub-frame 15, 16 has inner 24 and outer 25 members
arranged substantially side by side, and cross members 26 between
them, the cross members 26 interconnecting and maintaining a
spacing between the track sub-frame members 24, 25.
[0013] The track sub-frame members 24, 25 and the cross members 26
are each provided for each track sub-frame 15, 16 as a monolithic
casting. Integrally cast in lower edges 27 of each respective track
sub-frame member 24, 25 are a plurality of recesses 30-34. The
recesses 30, 31, 32 each mount a spindle of a respective lower
track support device roller 17, 18, 19 whilst recesses 33, 34 are
each provided to lighten the casting.
[0014] Integrally cast in upper edges 28, 29 of each of track
sub-frame member 24, 25 is a mount 35 for the upper track support
device, roller 20, and a further recess 36 to lighten the
casting.
[0015] The pair of track sub-frames 15, 16 are arranged side by
side with a main frame part 40 of the main frame structure 11
between them. The inner track sub-frame members 24 of each of the
pair of track sub-frames 15, 16, each are provided with integrally
cast inwardly extending formations 42, arranged in pairs. These
inwardly projecting formations 42 are provided for attaching the
cast track sub-frames 15, 16 to the main frame part 40 as
hereinafter described.
[0016] In FIG. 2, it can be seen that the inner track sub-frame
member 24 of each of the pair of track sub-frames 15, 16 extends
longitudinally rearwardly of the machine 10, beyond an edge 38 of
the outer track sub-frame member 25, and the extended track
sub-frame member 24 part, is provided with an opening 45. This
opening 45 is for mounting a track motor (not shown) which drives a
track drive sprocket 46 (see FIG. 1) to impart drive to the track
12 and hence to the machine 10 over the ground. The track motors
conventionally are driven by hydraulic fluid provided by a pump of
the machine 10.
[0017] At least one of the track sub-frame members 24, 25, both in
this example, provide between them the mounting 47 for the track
tensioning mechanism which includes the resiliently biased track
tensioning element (roller) 49 which is biased in a direction to
maintain a desired tension in the track 12.
[0018] The main frame part 40 includes a central portion 50 which
supports a slewing mechanism, for slewing an upper frame structure
51 relative to the main frame structure 11. The upper frame
structure 51 includes a cab 53 for a machine operator, carries a
working arm 54, houses an engine and cooling pack (not seen) and
mounts the hydraulic pump. The upper frame structure 51 may be
slewed by the slewing mechanism relative to the main frame
structure 11 about a generally upright axis A.
[0019] In this example, the central portion 50 of the main frame
part 40 supports a slew ring around a generally circular opening 58
which receives a depending part of the upper frame structure 51 to
guide the upper frame structure 51 during slewing. The main frame
part 40 further includes four connecting arms 60-63 for attaching
the central portion 50 to the track sub-frames 15, 16.
[0020] A first pair of the connecting arms 60, 61 are provided by
either end of a fabricated box section element 65, whilst a second
pair of the connecting arms 62, 63 are provided by either end of
another fabricated box section element 66. The connecting arms
60-63 are each attached to respective track sub-frames 15, 16 by
welding to the integral cast inwardly extending projecting
formations 42. Although in this example, each connecting arm 60-63
is welded between a pair of such formations 42, in another example
the arms 60-63 may each be welded to a single inwardly extending
formation 42, or to more than one or two formations one or more of
which may extend within the fabricated box section element 65, 66.
The box section elements 65, 66 are each welded to the central
portion 50 as indicated at W, and extend substantially
perpendicularly relative to a longitudinal axis L of the working
machine 10.
[0021] It will be appreciated that particularly where the
monolithic castings of the track sub-frames 15, 16 are provided in
an readily weldable cast material, such as cast steel, welding of
the fabricated box section elements 65, 66 to the track sub frame
castings is facilitated. However the track sub frames 15, 16 may be
cast in any weldable material, such as cast iron although special
equipment and techniques may be required to weld the castings 15,
16 to the elements 65, 66. Moreover the central portion 50 of the
main frame structure 40 preferably is cast in steel to facilitate
welding the fabricated box section elements 65, 66 to the central
portion 50, but again may be provided in another preferably
weldable material.
[0022] During manufacture it will be appreciated that by attaching
the castings of the track sub-frames 15, 16 to the main frame part
40 as described, a very strong main frame structure 11 may be
provided.
[0023] Many modifications may be made without departing from the
scope of the invention. For example, the track sub-frame members 24
and 25 of each track sub-frame 15, 16 need not be of the exact
configurations shown and described, and more or less track
supporting devices than those shown at 17, 18, 19 and 20 may be
provided as are required to support the track 12. Although it is
preferable for the main frame part 40 to include a cast central
portion 50 and for there to be four connecting arms 60 to 63
provided by fabricated box section elements 65, 66 other main frame
part 40 configurations are possible.
[0024] In FIG. 1 the machine shown to which it has been described
the present invention may be applied, is conventionally known as a
"mini" or "micro" excavator, because the working machine 10 is
small and the working arm 54 thereof is configured to perform
excavating operations. The invention may be embodied in a larger
working machine which may or may not have a slewing mechanism for
stewing an upper frame structure 51 relative to the main frame
structure 11. Indeed the invention is applicable to any working
machine having a pair of tracks 12.
* * * * *