U.S. patent application number 11/034810 was filed with the patent office on 2006-07-20 for continuous radius axle and fabricated spindle assembly.
This patent application is currently assigned to The Boler Company. Invention is credited to Michael John Gottschalk, Robert Steven Shea.
Application Number | 20060158023 11/034810 |
Document ID | / |
Family ID | 36676916 |
Filed Date | 2006-07-20 |
United States Patent
Application |
20060158023 |
Kind Code |
A1 |
Gottschalk; Michael John ;
et al. |
July 20, 2006 |
Continuous radius axle and fabricated spindle assembly
Abstract
Axles and spindle assemblies for wheeled vehicles. More
particularly, in at least one embodiment, this invention relates to
a substantially curvilinear axle for wheeled vehicles, alone or in
combination with a spindle assembly, having a substantially
continuous radius of curvature extending from one end of the axle
to the other. In at least one additional embodiment, this invention
relates to fabricated spindle assemblies having gusset arms for
mechanical attachment to axle ends.
Inventors: |
Gottschalk; Michael John;
(Granville, OH) ; Shea; Robert Steven; (Granville,
OH) |
Correspondence
Address: |
HALL, MYERS, VANDE SANDE & PEQUIGNOT, LLP
10220 RIVER ROAD, SUITE 200
POTOMAC
MD
20854
US
|
Assignee: |
The Boler Company
|
Family ID: |
36676916 |
Appl. No.: |
11/034810 |
Filed: |
January 14, 2005 |
Current U.S.
Class: |
301/127 ;
280/124.116; 29/897.2 |
Current CPC
Class: |
B60G 2200/30 20130101;
B60G 11/27 20130101; B60B 35/08 20130101; Y10T 29/49622 20150115;
B60G 9/00 20130101; B60G 2206/30 20130101 |
Class at
Publication: |
301/127 ;
280/124.116; 029/897.2 |
International
Class: |
B60G 9/02 20060101
B60G009/02; B60G 9/00 20060101 B60G009/00; B60B 35/00 20060101
B60B035/00 |
Claims
1. An axle for a wheeled vehicle comprising: a first axle end
portion carrying a first spindle thereon for supporting a first
rotatable wheel; a second axle end portion carrying a second
spindle thereon for supporting a second rotatable wheel; a middle
beam portion connecting and extending between said first axle end
portion and said second axle end portion, said middle beam portion
having a substantially curvilinear configuration exhibiting a
substantially continuous radius of curvature throughout at least a
portion of the length thereof.
2. An axle according to claim 1 wherein configuring said middle
beam portion into said substantially continuous radius of curvature
substantially eliminates stress risers in said middle beam portion
of said axle.
3. An axle according to claim 1 wherein said middle beam portion of
said axle is, at least in part, selected from a substantially
tubular in cross-sectional configuration, or a substantially square
cross-sectional configuration.
4. An axle according to claim 3 wherein said axle is comprised of
multiple radii of curvature and wherein said axle is substantially
free of stress risers.
5. An axle according to claim 4 wherein said middle beam portion of
said axle is comprised of tubing having a substantially rectangular
cross-sectional configuration.
6. An axle according to claim 4 wherein said middle beam portion of
said axle is comprised of single, unitary tubular beam, said beam
being bent into said substantially curvilinear configuration
thereby to form said substantially continuous radius of curvature
therein.
7. An axle according to claim 6 wherein said first and second
spindles are connected to said first and second axle end portions
as components of fabricated spindle assemblies mechanically bonded
proximal said first and second axle ends respectively.
8. An axle according to claim 4 wherein said middle beam portion of
said axle is a fabricated structure constructed from at least two
stamped and formed halves bonded together to form a beam having a
tubular cross-sectional configuration.
9. An axle according to claim 4 wherein said axle is steerable and
further includes a first steering knuckle carrying said first
spindle and a second steering knuckle carrying said second spindle,
said first and second steering knuckles connected to said first and
second axle end portions, respectively.
10. An axle according to claim 9 wherein said first and second
steering knuckles are pivotally connected to said first and second
axle end portions via first and second kingpins respectively, said
first and second kingpins permitting said first and second spindles
to be rotatable about axes of said first and second king pins
respectively.
11. An axle according to claim 4 further including first and second
suspension mounting members connected to said axle proximal said
middle beam portion, said suspension mounting members including a
suspension beam mounting portion and an air spring mounting
portion.
12. The axle according to claim 11 wherein said axle is an
auxiliary lift axle operatively connected to a lift suspension.
13. In combination, a motorized wheeled vehicle having installed
thereon the axle according to claim 3.
14. An axle according to claim 5 wherein said tubing having said
substantially rectangular cross-sectional configuration is
comprised of a pair of spaced apart substantially vertical side
walls extending between a pair of spaced apart substantially
horizontal top and bottom walls.
15. An axle according to claim 14 wherein said vertical walls of
said configuration are greater in length than said horizontal
walls.
16. An axle according to claim 14 wherein said pair of spaced apart
substantially vertical side walls are oriented substantially
parallel to each other and wherein said pair of spaced apart
substantially horizontal top and bottom walls are oriented
substantially parallel to each other.
17. An axle according to claim 3 wherein said first and second
spindles are connected to said first and second axle end portions
as components of fabricated spindle assemblies mechanically bonded
proximal said first and second axle ends respectively, each said
fabricated spindle assembly comprising: a mount plate having a
spindle connected thereto, first and second arms connected to and
extending from said mount plate, said first and second arms being
welded to side surfaces of said middle beam portion of said
axle.
18. An axle according to claim 17 wherein said mount plate includes
at least one substantially planar surface, said substantially
planar surface being welded to one of said first and second axle
ends.
19. An axle according to claim 17 wherein said middle beam portion
of said axle is comprised of tubing having a substantially square
cross-sectional configuration.
20. An axle according to claim 19 wherein said tubing having said
substantially square cross-sectional configuration is comprised of
a pair of spaced apart substantially vertical side walls extending
between a pair of spaced apart substantially horizontal top and
bottom walls; and wherein said first and second arms are welded to
said side walls of said middle beam portion of said axle along
upper facing edge surfaces of said first and second arms.
21. The axle according to claim 20 wherein said middle beam portion
of said axle is comprised of single, unitary tubular beam, said
beam being bent into said substantially curvilinear configuration
thereby to form said substantially continuous radius of curvature
therein.
22. The axle according to claim 21 wherein forming said
substantially curvilinear configuration in said middle beam portion
substantially eliminates stress risers in said middle beam
portion.
23. The axle according to claim 21 wherein said axle is steerable
and further includes a first steering knuckle carrying said first
spindle and a second steering knuckle carrying said second spindle,
said first and second steering knuckles connected to said first and
second axle end portions, respectively.
24. The axle according to claim 23 wherein said first and second
steering knuckles are pivotally connected to said first and second
axle end portions via first and second kingpins respectively, said
first and second kingpins permitting said first and second spindles
to be rotatable about axes of said first and second king pins
respectively.
25. The axle according to claim 24 further including first and
second suspension mounting members connected to said axle proximal
said middle beam portion, said suspension mounting members
including a suspension beam mounting portion and an air spring
mounting portion.
26. The axle according to claim 25 wherein said axle is an
auxiliary lift axle operatively connected to a lift suspension.
27. In combination, a motorized wheeled vehicle having installed
thereon the axle according to claim 21.
28. A method of manufacturing a drop-type axle for a wheeled
vehicle comprising: selecting a stock beam material; affixing to a
first end of said axle beam a first axle end portion including a
first spindle for supporting a first rotatable wheel; and affixing
to a second end of said axle beam a second axle end portion
including a second spindle for supporting a second rotatable
wheel.
29. The method according to claim 28 wherein said first and second
axle end portions each comprise, respectively: a mount plate having
a spindle connected thereto, said mount plate having first and
second arms extending outwardly therefrom; and wherein said method
further comprises: welding said first and second arms and said
mount plate to said first and second axle end portions of said
first and second ends of said axle beam, respectively.
30. The method according to claim 29 wherein said axle beam is
comprised of at least first and second side surfaces; said method
further comprising: welding said first arm to said first side
surface of said axle beam; welding said second arm to said second
side surface of said axle beam.
31. The method according to claim 30 wherein each said first and
said second arm includes upper and lower facing surfaces; said
method further comprising: welding said first arm to said first
side surface along said upper facing surface of said first arm;
welding said second arm to said second side surface along said
upper facing surface of said second arm.
32. The method according to claim 31 wherein said mount plate is
substantially planar and wherein said method further comprises
welding said mount plate to one of said axle ends.
33. The method according to claim 28 wherein said stock beam
material is formed into said substantially curvilinear axle beam by
feeding said beam between at least a pair of rollers, at least one
of said rollers being actuated to impart a force to said beam which
is sufficient to form a desired curvature therein.
34. The method according to claim 32 wherein each weld connecting
said first or second axle end portion to said axle beam is a
non-tension type weld.
35. An axle for a wheeled vehicle comprising: a curvilinear axle
beam portion having a substantially continuous radius of curvature
and having first and second axle end portions; a first wheel
carrying means connected to said first axle end portion; and a
second wheel carrying means connected to said second axle end
portion.
36. The axle according to claim 35 wherein said first and second
wheel carrying means are pivotable with respect to said first and
second axle end portions, respectively, thereby to provide
steerability to said axle.
37. The axle according to claim 35 further including suspension
mounting means located on said curvilinear axle beam portion.
38. The axle according to claim 35 wherein said curvilinear axle
beam portion is at least partially tubular in cross section.
39. The axle according to claim 38 wherein said curvilinear axle
beam portion is substantially square in cross section.
40. The axle according to claim 39 wherein said curvilinear axle
beam portion is substantially rectangular in cross section.
41. An axle for a wheeled vehicle in combination with a fabricated
spindle assembly for carrying a vehicle wheel comprising: an axle
beam have an axle end portion, said axle beam having at least first
and second side walls; a mount plate connected to said axle end
portion via welds; a gusset attached to said mount plate and having
first and second gusset arms extending outwardly therefrom, each
said first and second gusset arm having upper and lower surfaces;
said first gusset arm being welded to said first side wall along
said upper surface of said first gusset arm; said second gusset arm
being welded to said second side wall along said upper surface of
said second gusset arm; and a spindle shaft connected to and
extending from said mount plate in a direction substantially
opposite said extension of said gusset arms.
42. The combination according to claim 41 wherein: said axle
includes upper and lower surfaces; said gusset having at least a
portion thereof extending below a portion of said lower surface of
said axle; said first gusset arm having a first longitudinal axle
contacting surface having an upper edge and a lower edge; said
second gusset arm having a second longitudinal axle contacting
surface having an upper edge and a lower edge; wherein said first
gusset arm is welded to said first axle side wall along a length of
said upper edge of said first longitudinal axle contacting surface;
and wherein said second gusset arm is welded to said second axle
side wall along a length of said upper edge of said second
longitudinal axle contacting surface.
43. The combination according to claim 42 wherein said mount plate
is welded to said axle end portion via welds located proximal at
least said upper and lower axle surfaces.
44. The combination according to claim 43 wherein said gusset
includes a base portion welded to said mount plate.
45. The combination according to claim 44 wherein said welds along
said first and second longitudinal axle contacting surfaces are
non-tension type welds.
46. The combination according to claim 41 wherein said mount plate
includes an aperture and said spindle shaft is press fit into said
aperture.
47. The combination according to claim 44 wherein said base portion
is welded in shear to said mount plate.
48. The combination according to claim 41 wherein said axle is a
drop-type axle.
49. The combination according to claim 48 wherein said axle has a
central portion which is located at a height lower than said axles
end portions.
50. The combination according to claim 41 wherein said axle
comprises: a first axle end portion carrying a first spindle
thereon for supporting a first rotatable wheel; a second axle end
portion carrying a second spindle thereon for supporting a second
rotatable wheel; a middle beam portion connecting and extending
between said first axle end portion and said second axle end
portion, said middle beam portion having a substantially
curvilinear configuration exhibiting a substantially continuous
radius of curvature throughout the length thereof.
51. An axle for a wheeled vehicle in combination with a steering
knuckle for carrying a vehicle wheel comprising: an axle beam
having axle end portions, said axle beam having at least first and
second side walls; an axle mount plate mechanically connected to
one of said axle end portions; a spindle shaft connected to and
extending from a spindle mount plate; a kingpin interconnecting
said spindle mount plate and said axle mount plate such that said
spindle is rotatable about an axis of said kingpin thereby to
provide steerability to said axle; a gusset attached to said axle
mount plate and having first and second gusset arms extending
outwardly therefrom, each said first and second gusset arm having
upper and lower surfaces; said first gusset arm being welded to
said first side wall along said upper surface of said first gusset
arm; said second gusset arm being welded to said second side wall
along said upper surface of said second gusset arm.
52. The combination according to claim 51 wherein said kingpin is
mounted to said axle mount plate and said spindle mount plate
includes a knuckle portion rotatably connected to said king pin for
providing steerability to said axle.
53. The combination according to claim 51 wherein said king pin is
mounted to said spindle mount plate and said axle mount plate
includes a knuckle portion rotatably connected to said kingpin for
providing steerability to said axle.
54. A fabricated spindle assembly for an axle of a wheeled vehicle
comprising: a mount plate having a spindle aperture for carrying a
spindle therein; a gusset attached to said mount plate and having
first and second gusset arms extending outwardly therefrom; a
spindle shaft press fit into said spindle aperture and extending
from said mount plate in a direction substantially opposite said
extension of said gusset arms.
55. The fabricated spindle assembly according to claim 54 wherein
said gusset is substantially U-shaped.
56. In combination, a motorized wheeled vehicle having installed
thereon the axle and fabricated spindle assembly combination
according to claim 50.
57. In combination, a motorized wheeled vehicle having installed
thereon the axle and fabricated spindle assembly according to claim
50, wherein said spindle assembly includes a spindle plate
comprised of weldable steel and a spindle pin therein, said spindle
plate being weldable to axle.
58. The combination of claim 57, wherein said axle is at least in
part tubular and said spindle plate is weldable to said tubular
part of said axle.
Description
FIELD OF THE INVENTION
[0001] This invention relates to certain unique axles for wheeled
vehicles. It further relates to certain unique spindle assemblies
used with axles generally. Still further, it relates to certain
unique combinations of the aforesaid unique axles with the
aforesaid spindle assemblies attached thereto.
BACKGROUND OF THE INVENTION
[0002] The use of drop axles in vehicles, particularly trucks, has
been well-known in the trucking industry for many years. The use of
these drop axles provides various, known, commercial and safety
advantages. They are, therefore, often installed for one or more of
these purposes (or simply as a matter of choice) on light, medium,
and heavy-duty trucks.
[0003] One advantage is that by dropping the center portion of an
axle (i.e., relative to the axle ends), it is possible to extend
the drive shaft of a vehicle without the drive shaft interfering
with the center beam portion of the axle (thereby allowing direct
drive, for example), which interference often times prohibits use
of the suspension in this position, e.g., sometimes referred to as
the "pusher" position.
[0004] As an additional important advantage of such axle
configurations, such as in vehicles employing lift-type
suspensions, the drop axle provides increased clearance (as
compared to a straight axle) between the vehicle frame and the axle
beam. This, then, as one advantage, allows for a larger air spring
to be employed. As another advantage, this larger clearance space
and air spring, in turn, permits the axle to be lifted a greater
distance from the road surface which is a distinct advantage,
particularly in off-road conditions where ground obstructions may
be encountered. Moreover, the use of these drop axles provides for
a generally more stable (e.g., generally less top heavy) ride due
to its reduced ride height.
[0005] An example of a particularly successful, known, lift axle
suspension system which employs a drop axle in combination with a
lift-type suspension is disclosed in U.S. Pat. No. 5,810,377,
entitled FABRICATED STEER AXLE. This patent is commonly assigned
and has an overlapping inventorship entity herewith.
[0006] Although known lift axles, such as described in the '377
patent, provided various useful commercial and functional
utilities, they had certain known economic limitations or
drawbacks. In this regard, such drawbacks often related to the
highway weight limit laws which are imposed in order to limit the
permissible maximum load of a vehicle when used on a highway (and
thereby limit the profit realized from the amount of cargo that is
carried) as a function of the number of its axles. Taking into
account such laws, minimizing the weight of axle and/or suspension
systems is highly desirable and results in increased operational
profitability. In certain embodiments, this invention achieves this
desirable result.
[0007] Typical full (or partial) drop axles that were heretofore
used, exhibited abrupt curves or angles at or near the junction of
the two axle ends where they meet the middle beam portion of the
axle, thus, to form the "drop" portion of the axle. In particular,
these structural changes have been conventionally employed in order
to achieve the desired differential between the height of the axle
ends relative to the height of the middle beam portion (e.g., as
measured from ground level when installed on a truck). In some
exemplar embodiments of such prior art axles, the angles at such
junctions frequently range from approximately 20-50 degrees and, in
some cases, actually approached 90 degrees.
[0008] Unfortunately, manufacturing such abrupt or sudden angle
changes into the axle beams has been found to introduce stress
risers along the length of the beam which can potentially weaken
the axle (e.g., in part, as a result of the manufacturing process
which involves heating and bending the axle to achieve the desired
angle change). This, in turn, can reduce the axle's strength to
weight ratio or, in other instances, necessitate structural changes
which themselves can cause significant, detrimental stress risers
to occur. In order, then, to ensure that a given prior art axle had
sufficient strength, very thick axle tube walls (or solid,
non-tubular axles) were characteristically employed. This
undesirably increased the weight of the axle and, thus, reduced the
cargo limit that could be lawfully carried.
[0009] In view of the above problems in the art, there existed a
need in the art, prior to this invention, for an axle and,
optionally, a spindle assembly, as well as a combination thereof,
which would overcome these problems or, at least, mitigate them. It
is a purpose of this invention to fulfill this need in the art, as
well as other needs which will become apparent to the skilled
artisan once given the above disclosure.
SUMMARY OF THE INVENTION
[0010] Generally speaking, this invention fulfills the
above-described needs in the art by providing in one embodiment
thereof:
[0011] An axle for a wheeled vehicle comprising:
[0012] a first axle end portion carrying a first spindle thereon
for supporting a first rotatable wheel;
[0013] a second axle end portion carrying a second spindle thereon
for supporting a second rotatable wheel;
[0014] a middle beam portion connecting and extending between said
first axle end portion and said second axle end portion, said
middle beam portion having a substantially curvilinear
configuration exhibiting a substantially continuous radius of
curvature throughout the length thereof.
[0015] In another embodiment of this invention, there is
provided:
[0016] A method of manufacturing an axle for a wheeled vehicle
comprising:
[0017] selecting a stock beam material;
[0018] forming said stock beam material into a substantially
curvilinear axle beam having a configuration exhibiting a
substantially continuous radius of curvature;
[0019] affixing to a first end of said axle beam a first axle end
portion including a first spindle for supporting a first rotatable
wheel; and
[0020] affixing to a second end of said axle beam a second axle end
portion including a second spindle for supporting a second
rotatable wheel.
[0021] In a still further embodiment of this invention, there is
provided:
[0022] An axle for a wheeled vehicle comprising:
[0023] an axle beam which includes a middle portion having a
substantially continuous radius of curvature and having first and
second axle end portions;
[0024] means for carrying a first wheel, said means being connected
to said first axle end portion; and
[0025] means for carrying a second wheel, said means being
connected to said second axle end portion.
[0026] In yet a further embodiment of this invention, there is
provided:
[0027] An axle for a wheeled vehicle in combination with a
fabricated spindle assembly for carrying a vehicle wheel thereon,
comprising:
[0028] an axle beam having an axle end portion, said axle beam
having at least first and second side walls;
[0029] a mount plate connected to said axle end portion via
welds;
[0030] a gusset attached to said mount plate and having first and
second gusset arms extending outwardly therefrom, each said first
and second gusset arm having upper and lower surfaces;
[0031] said first gusset arm being welded to said first side wall
along said upper surface of said first gusset arm;
[0032] said second gusset arm being welded to said second side wall
along said upper surface of said second gusset arm; and
[0033] a spindle shaft connected to and extending from said mount
plate in a direction substantially opposite said extension of said
gusset arms.
[0034] In still an additional alternative embodiment, there is
provided:
[0035] An axle for a wheeled vehicle in combination with a
fabricated steering knuckle for carrying a vehicle wheel
comprising:
[0036] an axle beam having axle end portions, said axle beam having
at least first and second side walls;
[0037] an axle mount plate mechanically connected to one of said
axle end portions;
[0038] a spindle shaft connected to and extending from a spindle
mount plate;
[0039] a kingpin interconnecting said spindle mount plate and said
axle mount plate such that said spindle is rotatable about an axis
of said kingpin thereby to provide steerability to said axle;
[0040] a gusset attached to said axle mount plate and having first
and second gusset arms extending outwardly therefrom, each said
first and second gusset arm having upper and lower surfaces;
[0041] said first gusset arm being welded to said first side wall
along said upper surface of said first gusset arm;
[0042] said second gusset arm being welded to said second side wall
along said upper surface of said second gusset arm.
[0043] In yet an additional embodiment of this invention, there is
provided:
[0044] a fabricated spindle assembly for an axle of a wheeled
vehicle comprising:
[0045] a mount plate having a spindle aperture for carrying a
spindle therein;
[0046] a gusset attached to said mount plate and having first and
second gusset arms extending outwardly therefrom;
[0047] a spindle shaft press fit into said spindle aperture and
extending from said mount plate in a direction substantially
opposite said extension of said gusset arms.
[0048] In the preferred embodiments of this invention, it will be
seen that there is provided an axle which, due to its
configuration, does not contain any significant stress risers, at
least in the middle portion of the beam. Moreover, in certain
preferred embodiments of this invention there is provided an axle
which has decreased weight and/or increased strength. Still
further, in certain of these embodiments there is provided an axle
which is more easily and/or more efficiently manufactured. In yet
other embodiments improved strength to weight characteristics are
achieved.
[0049] In even further embodiments of this invention, moreover,
there is provided a fabricated spindle assembly which is more
reliably and securely attachable to an axle end portion and, in
some of these preferred embodiments, is attached to an axle
primarily with welds which are not in tension. In still further
embodiments of this invention, there is provided a spindle assembly
which is less expensive and/or more efficient or simple to
manufacture and assemble.
[0050] This invention will now be described with respect to certain
embodiments thereof as illustrated in the following drawings in
which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] FIG. 1 is a perspective view of an embodiment of an axle
according to the subject invention.
[0052] FIG. 2A is an exemplar of one environment in which the
present invention finds utility when employed as an auxiliary lift
axle (shown in a non-road engaging position).
[0053] FIG. 2B illustrates the environment shown also in FIG. 2A,
but with the axle according to the subject invention shown in its
road engaging position.
[0054] FIG. 3 illustrates the embodiment of the axle depicted in
FIG. 1 connected to a known auxiliary lift suspension, as shown in
perspective view in FIG. 4.
[0055] FIG. 4 is a three dimensional perspective view of the
embodiment of the invention depicted in FIG. 3.
[0056] FIG. 5 is a side view of the auxiliary lift suspension and
embodiment depicted in FIGS. 3 and 4.
[0057] FIG. 6 is a partial two dimensional rear view of an
embodiment of the fabricated spindle assembly according to the
subject invention.
[0058] FIG. 7 is a partial three dimensional perspective view of
the embodiment shown in FIG. 6.
[0059] FIG. 8 illustrates an alternative, partial, three
dimensional perspective view of the embodiment shown in FIGS. 6 and
7.
[0060] FIG. 9 is a three dimensional view of an embodiment of an
axle and spindle combination according to this invention.
[0061] FIG. 10 is a top two dimensional view of the embodiment
shown in FIG. 9.
[0062] FIG. 11 is a three dimensional, exploded view of the
embodiment shown in FIGS. 9 and 10.
DETAILED DESCRIPTION OF THE INVENTION
[0063] This invention will now be described with respect to certain
embodiments thereof as illustrated in the following drawings.
[0064] With reference first to FIG. 1, there is illustrated axle 1
which overcomes or, at least, ameliorates at least one of the above
described disadvantages of the prior art.
[0065] As shown in FIG. 1, axle 1 is a drop-type axle constructed
from a substantially curvilinear middle beam portion 7 having first
and second axle ends 3 and 5, respectively. On each axle end 3 and
5, a spindle assembly 9, 11 for carrying a conventional rotatable
vehicle wheel (not shown), is mechanically attached thereon.
[0066] In certain preferred exemplar embodiments, both spindle
assemblies 9 and 11 (labeled identically in the figures because
like numerals indicate like parts) generally comprise a spindle
shaft 19, 19b, respectively, which extend outwardly from their
respective mount plate 13a, 13b. Each spindle shaft 19, 19b is
constructed to carry a vehicle wheel in a conventional manner.
Optionally included, as illustrated in FIG. 1 (but more clearly
illustrated in FIGS. 4 and 7), is gusset arms 15a, 15b (e.g., for
weight savings) which extend substantially opposite the direction
of their spindle shaft 19a and 19b and are welded to side walls of
the middle beam portion 7, thereby to reinforce the connection of
their spindle assemblies 9 and 11 to axle 1, as will be discussed
in greater detail hereinafter. Circumferential orifices 17a, 17b
merely signify the connection (usually press fit) between spindles
9 and 11 and mount plate 13a, 13b.
[0067] As shown in the drawings, middle beam portion 7 of axle 1 is
preferably configured such that it exhibits a substantially
continuous radius of curvature. In the preferred embodiments of
this invention, in this respect, this curvature extends throughout
at least a majority of the length of the axle and, more preferably,
as illustrated, over substantially its entire length. An important
feature of this curvature, which itself creates a substantial
improvement over prior art axle designs, is that it achieves
drop-axle functionality (e.g., by providing both acceptable ride
height when the wheels are disengaged from the road surface, as
well as providing the necessary clearance for the drive shaft if
present, such as on a truck whose rear axle is the drive axle). At
the same time these important features are achieved, an equally
important economic feature is achieved, i.e., the weight of the
suspension is reduced.
[0068] It is a known potential problem in the art that when a
conventional axle beam is bent or fabricated during its
manufacturing process, thereby to form a conventional drop
axle-type configuration, the heating, bending, or fabricating steps
which are used to form the axle into such a known configuration
(i.e., having abrupt or non-gradual angle transitions), tends to
give rise to the potential for causing stress risers in the axle
beam. These stress risers are known to reduce axle strength, at
least at or near the location where such stress risers occur. In
order to compensate for this loss of strength, it is typical in the
art when designing an axle to meet a specified gross vehicle weight
rating (GVWR), to utilize either solid axle beams or axle beams
having very thick-walled tubing. Such solutions of course, while
providing the necessary strength for long life of the axle,
nevertheless, also serve, detrimentally, to add significant
additional weight to the vehicle. This, in turn, can detract from
the amount of cargo weight that the vehicle may lawfully carry . .
. and, thus, reduce the profit made from use of the vehicle.
[0069] In order, then, to avoid such problems, certain embodiments
of the subject invention utilize an axle having a unique
configuration in which at least a part of the middle beam portion 7
has a curvalinear configuration which preferably exhibits a
substantially continuous radius of curvature throughout a
substantial portion of its length and most preferably over its
entire length, until the mounting (so-called "spindle") plate in
reached (e.g., 13a, b or similar structure).
[0070] Such axle configurations as described above have been found
to possess very desirable strength to weight characteristics,
thereby enabling the axle in many instances when compared to the
prior art, to be constructed of fewer and/or thinner and/or hollow
parts. This, in turn, results in reduced weight, while
simultaneously (when compared to the prior art) retaining, or in
some instances increasing, the amount of axle strength.
[0071] In a particular, non-limiting example of an axle and/or
method according to the subject invention which achieves the
above-described improvements over the prior art, a hollow,
rectangular 5''.times.4'' stock beam material is first selected as
the material from which middle beam portion 7 is to be formed. If
necessary, the length of the beam material can be adjusted, as
desired, such as cutting the material by using known means to
accomplish this. One factor to use when choosing suitable stock
material for forming an axle according to this invention is to
choose an appropriate wall thickness of the tubing. In particular,
the stock material will typically be chosen according to
pre-selected criteria related to the strength and/or weight needs
of the axle or vehicle which is being constructed. One such
criterion is the aforesaid GVWR that the vehicle will be given. For
example, in some applications in which this invention finds
advantageous utility, an axle will be installed on a so-called
light duty truck, in which case, less strength in the axle is
needed (then in a medium or heavy duty truck) and, therefore,
weight may be saved (e.g., by using stock tubing with a lesser wall
thickness). Conversely, in heavy or medium duty applications,
stronger axles are required which, in turn, will then necessitate
the use of thicker walled tubing.
[0072] For example, when the axle being constructed is intended for
a heavy duty-type application (e.g., an auxiliary lift axle for a
heavy duty truck, as described in more detail below), the wall
thickness of the stock tube material selected will normally be
3/16-3/8 inches. Such a thickness, when configured as a
5''.times.4'' rectangular tube, as an example, (e.g., having
opposing parallel walls) has an unexpected, and has synergistically
been found to have, increase in its strength to weight ratio.
Moreover, it has been found, unexpectedly, to exhibit exceptional
resistant to torsional and bending forces.
[0073] With respect to the manufacturing process for making the
suspensions of this invention, after selecting and/or cutting the
initial stock beam material to an appropriate length for the
desired axle size, the beam stock is then formed into a curvilinear
configuration so as to preferably have a substantially continuous
radius of curvature, i.e., in the preferred embodiments of this
invention. This curvilinear configuration having a substantially
continuous radius of curvature may be achieved, for example, by
feeding the stock material through a roll forming apparatus which
imparts the desired radius or radii of curvature into the beam
material. No specific type of forming apparatus is required to
achieve this curvilinear configuration. Moreover, such apparatus
types are conventionally available and well-known to the skilled
artisan in the art, as is the method of how to use it. A
particularly efficacious and known apparatus, in this respect,
which is capable of forming the subject curvilinear configuration
contemplated herein, includes a plurality of rollers, at least one
of which is stationary, and at least one of which is biasable to
exert a bending force on the axle stock material (an example of
such an apparatus useful herein is a conventional, commercial known
apparatus having at least three rollers employed during the
forming/bending operations such as an apparatus sold by Davi, Inc.
called an MCP Series 3 Point Roller). By using such a roll forming
apparatus (or other known and conventional mechanisms or machinery
capable of achieving this configuration), the bending force(s)
exerted can, of course, be regulated or adjusted as the beam
material is fed therethrough, so as to achieve the desired
curvature. In this way, even multiple curvatures or radii of
curvatures may be formed in the axle, if desired.
[0074] An important benefit of utilizing the above-described
curvilinear configuration, as well as the method of obtaining such
a configuration (e.g., roll forming smooth, substantially
continuous curves into a tubular beam material), is that
substantially no significant stress risers will occur in the beam
material. This, then, overcomes a problem often occurring in the
prior art when a conventional, prior art drop axle was heretofore
formed, e.g., as by using conventional heating and sharp bending
techniques. It is, of course, to be noted here that it is not
expected that all stress risers can be completely prevented by the
forming process of this invention, even in its most preferred form.
However, what is achieved in the practice of this invention, is
that the number and/or extent or magnitude of such stress risers
are significantly diminished as compared to the known prior art.
This, in turn, results in a marked reduction in the potential for
beam micro-cracking which heretofore lead to beam failure. In this
manner then, marked increases in axle strength, axle life and/or
durability are obtained, thereby safely enabling the "downsizing"
(e.g., reduced wall thicknesses) of axle beams (e.g., middle beam
portion 7) and/or the elimination of the need for solid axle beams
necessitated in many prior art applications. Thus, this invention
results in increased safety of the vehicle when in use and in
certain instances, an increase in the amount of cargo that can be
safely carried.
[0075] The phrase "substantially continuous radius of curvature" is
used herein to describe a generally curvilinear configuration in
which the slope, angle and/or degree of curvature is to a
considerable and/or large degree, but not necessarily, except in
the most preferred embodiments, constant. It is noted, of course,
that a perfectly continuous radius of curvature is not required
(although it is a preferred, optimized embodiment) in order to fall
within the meaning of the above term "substantially continuous
radius of curvature." In this respect, it is to be further noted
that as a consequence of the occurrence of manufacturing tolerances
and/or imperfections or errors (e.g., in the process or method
and/or in the starting materials themselves) in the production of
such axles, the curvature achieved may differ from being perfectly
curvilinear, and yet is still to be considered "substantially
continuous," because it retains the improved features of this
invention which distinguish it from the prior art. In this regard,
it should be understood that any substantially curvilinear beam
which exhibits a sufficiently consistent radius of curvature such
that it solves one or more of the aforementioned problems of the
prior art and/or possesses the desirable strength to weight
characteristics as enumerated herein, is contemplated as part of
the scope of the subject invention. Moreover, any manufacturing
process or method of producing an axle which substantially
prevents, eliminates, and/or reduces the occurrence of any
significant stress risers in an axle beam by imparting a
substantially curvilinear shape thereto, also falls within the
scope of this invention.
[0076] In certain embodiments of this invention, moreover, it is
contemplated that the axle may be formed of non-circular tubing
(e.g., square, rectangular, or other than rectangular tubing), as
illustrated in the drawings, or in another embodiment the
cross-section of the axle may be circular or generally oval in
shape. It is, in this respect, generally not practical to friction
weld spindle assemblies (e.g., mount plates having spindle shafts
extending therefrom) to the axle beam ends. Therefore, in at least
one embodiment contemplated by this invention, the axle is
preferably constructed of square or rectangular tubing (or in other
embodiments of non-rectangular, straight sided tubing as well).
Fabricated spindle assemblies 9 and 11 are then easily welded to
axle beam ends 3 and 5, respectively, using conventional welding
procedures. Each spindle assembly 9 and 11 (each substantially
identical to the other in the preferred embodiments of this
invention) comprises a mount plate 13, a spindle shaft 19
extending, preferably perpendicularly, from the mount plate, and a
gusset plate 15a or 15b extending in a manner such that its arms
16a, 16b, respectively, can be welded to the axle beam walls.
[0077] In at least one embodiment employing such spindle
assemblies, the arms 16a, 16b of gusset plates 15a, 15b,
respectively, are welded to the side walls "S" of middle beam
portion 7 of the axle 1. In certain preferred embodiments,
moreover, these gusset plate arms are welded along the proximal
neutral axis of beam portion 7 in order to significantly reduce or
substantially prevent mechanical stresses from being exerted on the
welds during normal vehicle operation. In certain of these
preferred embodiments, moreover, such welds "W" (see FIG. 1) are
located along the upper, longitudinal edge of gusset arms 16a, 16b
where they are proximal to, or in contact with, the axle beam side
walls "S". In still further preferred embodiments, the welds "W"
are desirably located, as is well-known how to do by those skilled
in the art, so as to be in shear when normal operating forces are
applied to axle 1 during operation of the vehicle.
[0078] In still further preferred embodiments of this invention,
the axle and spindle assembly combination includes axle ends 3 and
5 which are normally formed, e.g., "cut" at an angle, thereby to
provide more surface area of the axle ends (i.e., more surface area
is provided and, thus, more axle surface area contacts mount plates
13a, 13b when welded thereto). As a result of this increased
surface area of the axle end, mount plate, and weld contact surface
areas or interfaces, increased bond strength between the spindle
assemblies and middle beam portion 7 is achieved. It is understood,
of course, that the size of gusset plates 15a, 15b may be varied
accordingly in order to increase or decrease the contact surface
area between the gusset arms and axle beam side walls, thereby to
strengthen the weld bond or reduce the weight of the axle.
[0079] Although the inventive spindle assemblies of this invention
as exemplified by spindle assemblies 9 and 11 are particularly
advantageous when employed with a curvilinear axle, it is
contemplated that such assemblies can be employed successfully with
both conventional drop axles or with conventional non-drop axles,
as a matter of choice.
[0080] Furthermore, although the exemplar axle configuration
described above and illustrated in the drawings, has proven
particularly successful in testing and use, various alternatives to
the above described methods of manufacturing this axle, as well as
other configurations of the axle are, of course, contemplated. For
example, in certain embodiments, middle beam portion 7 may be
constructed from square tubing, and in still other preferred
embodiments, middle beam portion 7 may be constructed from
rectangular, but non-square tubing. Still further, in certain other
embodiments, middle beam portion may be configured such that the
vertical walls of the tubular beam, when axle 1 is in its installed
orientation (e.g., see FIG. 1), are designed so as to be
approximately 10-40% longer than the adjacent horizontal walls of
the beam, and more preferably, approximately 15-35% longer. In the
most preferred embodiment, these vertical walls are approximately
25% longer than the adjacent horizontal walls (e.g., with a
vertical wall to horizontal wall length-to-length ratio of
approximately 4:3), thereby achieving improved twist and bend
resistance. In certain embodiments, moreover, opposing walls of the
rectangular tubing may be constructed so as to be substantially
and/or completely parallel one to the other, or they may, in still
other embodiments, be constructed so as to be generally
trapezoidal, or form a non-rectangular parallelogram.
[0081] With regard to the curvilinear nature of middle beam portion
7, the radii of curvature may be varied to meet a wide variety of
vehicles, e.g., light, medium, and heavy-duty truck or vehicle
applications. For example, in many conventional truck applications,
a radius of curvature of about 96 inches may be employed, and
thereby successfully achieves the purposes and improvements of this
invention. Furthermore, in at least one alternative embodiment, it
is contemplated that more than one radius of curvature may be
employed so long as the configuration thereof does not compromise
the structural integrity of the axle beam, particularly through the
introduction of any substantial number of stress risers.
[0082] In still further alternative embodiments, solid axle beams
in cylindrical, square, rectangular, symmetrical, and
non-symmetrical configurations may be employed and formed into one
or more of the above-described curvilinear configurations (i.e.,
preferably with a substantially continuous radius of curvature as
described above). Such solid axle beams find particular utility
where very high GVWRs are needed, or rugged off-road environments
are going to be experienced (e.g., logging, mining, etc.).
[0083] Referring now to FIGS. 2A-2B, these figures are presented
merely to illustrate an environment in which the axles of this
invention find utility. In the illustrated embodiment, wheel 107 is
configured as a liftable wheel/axle combination typically used as
an auxiliary lift axle combined with a suspension 30 using an axle
assembly 1 according to this invention. In this regard, vehicle 101
is illustrated to represent a generic vehicle which may be one of a
wide variety of types, including, but not limited to, heavy-duty
dump trucks, semi-trailers, trailers, garbage compactor trucks,
mining vehicles, logging vehicles and the like. FIGS. 2A-B, in this
respect, illustrate vehicle 101 having longitudinal frame members
105 carrying a suspension 30 which, as employed as an auxiliary
wheeled lift axle suspension, is placed forward of rear axle 103 of
a vehicle. FIG. 2A shows wheel bearing suspension 30 in its raised,
non-load bearing position (tires 107 lifted off of road surface
111). FIG. 2B shows wheel bearing suspension 30 in its lowered,
road engaging, load bearing position. In addition, it is
understood, as is known in the art, that vehicle 101 normally has a
forward steerable axle (not shown), as well as a standard rear axle
103 (including tires 109) such that the rear and forward axles
(together with wheels and tires) form the primary means of vehicle
support, such that suspension 30 may be operated to lift its tires
107 off the road.
[0084] As described above, auxiliary lift axles may be constructed
so as to be selectively engageable with and disengageable from the
road surface (using known mechanisms in the art) to increase road
safety as well as to comply with highway safety laws regarding
vehicle load limits (i.e., legal load limits as are normally
determined by the number of road engaging axles and the distance(s)
between them). However, it is to be clearly understood that it is
by no means necessary to couple axle 1 of this invention with a
lift suspension. Such a lift suspension combination is only one
embodiment of an axle of this invention combined with a
particularly successful lift axle-type suspension so as to form one
exemplar of this invention. In this respect, one exemplar lift
axle/suspension assembly, of a popular type commonly employed in a
heavy duty truck, is illustrated in FIGS. 4 and 5, and is (as
shown) constructed of a parallelogram structure in combination with
an air bellows 101a and 101b, each located between and attached to
their respective paddles 103a, 103b which, in turn, extend from
their respective parallelogram. Generally speaking, each
parallelogram structure is comprised of a pair (on each side of the
suspension) of substantially parallel beam members 105a, 105b or
105a' or 105b', which, as assembled, are pivotally mounted to their
respective hanger bracket 107a, 107b of a vehicle frame 109 at one
end, and, at their other end, are mounted to an axle seat which is
affixed via conventional, known mechanical means to the top surface
of an axle 7 (one paddle extending from each beam member). In this
manner, the air bellows 101a, 101b and ride bellows 114a, 114b can
be operated (inflated/deflated) to alternately lower and lift the
axle into or out of engagement with the road surface by causing the
parallel beam members to pivot about the hanger bracket (all in a
known, conventional manner). Air spring 114a, 114b are provided, of
course, so as to be located between their respective axle seats 113
and vehicle frames 109. These airprings 114a, 114b, thus, serve as
the primary mechanism by which road vibrations are taken up. Ride
fellows 114a and 114b also serve to support a substantial portion
of the vehicle load therewith and, thus, provide what has become
known in the art as a true air ride suspension. An example of such
a prior air ride axle/suspension assembly which does not employ
this invention therein, is illustrated and described in U.S. Pat.
No. 5,403,031. An example of a known axle seat is also described
therein, and, as can be seen, such an axle seat generally includes
a pair of u-bolts for connecting a suspension beam to the axle.
[0085] In still further embodiments, axle 1 can be configured in a
known, conventional manner, so as to be a steerable axle, simply by
employing known steerable axle parts (i.e., designs or
mechanisms).
[0086] It is to be further pointed out here that in certain
preferred embodiments of this invention, the spindle plates (e.g.,
13a, 13b) of the suspension (axle) may be made of any suitable
conventional steel alloy known to be weldable. The choice of such
an alloy is well within the skill of the artisan. When so used,
this enables a very advantageous embodiment of this invention in
which a known, conventional spindle pin (not shown for convenience)
is pressed into the spindle plate and the spindle plate is welded
to a portion of the tubular part of the axle.
[0087] Once given the above disclosure, many other features,
modifications, and improvements will become apparent to the skilled
artisan. Such other features, modifications, and improvements are
therefore considered to be part of this invention, the scope of
which is to be determined by the following claims:
* * * * *