Note: Descriptions are shown in the official language in which they were submitted.
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TRAILING ARM SUSPENSION WITH
WR~PPER COMPRESSION AXLE MOUNTING
BACKGROUND OF THE INVENTION
~ Technical Field
S This invention relates to vehicle suspension systems for mounting
ground-en~ ing wheels to a vehicle frame, and, more particularly, to vehicle
suspensions having an hllproved system for mounting a wheel-carrying axle
without weakening the axle.
DescriPtion of Related Art
The U.S. Patent No. 3,547,215 to Bird (issued December 15,
1970), discloses a trailing arm suspension wherein a square axle is typically
welded to a bracket which is, in turn, secured to the trailing arm of the vehicle
suspension structure. The weld securing the axle to the bracket is usually made
at the mid-point of the side of the axle where vertical bending moment stresses
are neutral. However, these areas are areas of high torsional loading which
results from brake torque, vehicle roll and diagonal axle (wheel) walk. The
welding at the mid-point of the axle may introduce a point of we~knecs where
cracks can initiate. The weakness in the typical axle welded to a bracket is
c~licerl, in part, by the undesirable heat-treating effects and microscopic cracking
caused by the welding process upon the axle structure in the localized area
adjacent to the weld. In addition, craters or strike marks may form points at
which cracks may initiate or at which stresses may become concentrated.
Axles are typically welded to the brackets in order to securely
attach the axle to the bracket under this high loading condition. The axle is
welded to the axle bracket by a line weld on either side of the bracket. Becauseit is a line weld, the weld has "ends" at which stresses are concentrated and at~ which cracks may initiate.
A solution to this weld problem is disclosed in U.S. Patent
No. 4,693,486 to Pierce et al. (issued September 15, 1987), which discloses a
30 trailing arm suspension in which an axle secured to a trailing arm by a wrapper
plate partially surrounding the axle, a bolt compresses the wrapper plate about
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the axle so that the wrapper plate supports and strengthens the axle, and a
circular plug weld is positioned on the axle in a circular opening in the wrapper
plate to attach the wrapper plate to the axle. Although this system is a
significant hlll)rovement over the previous welds to the axle, the plug weld still
may be a source of stress cracks in the axle.
The U.S. Patent No. 5,116,075 to Pierce (issued May 26, 1992),
discloses a trailing arm suspension wherein a wrapper plate is mounted to an
axle through mechanical compression and without welding to the axle. Adapter
plates mounted to the ends of the plate apply a compressive force to the corners10 of a square axle when the wrapper plate is compressed against the axle by a
bolt. The wrapper plate is mounted on a pair of side plates which in turn are
fixed to the trailing arm. Although the suspension is effective to overcome the
potential of crack initiation of the axle between the axle and the axle bracket,the wrapper plate is relatively heavy and a considerable amount of skilled labor15 is involved in assembling the axle to the trailing arm suspension, frequently at
the point of assembly to the axle and suspension to the vehicle. The forces of
compression tend to be somewhat uneven. The compressive forces exerted by
the adapter plates in particular can be relatively high compared to the
compressive forces exerted by the wrapper plate.
The U.S. patent to ~llfm~n, 5,328,159, discloses a trailing arm
suspension in which a pair of U-shaped bracket plates mount U-shaped rubber
pads and are clamped onto a square axle with the rubber pads between the
bracket plates and the axle. The axle is at a slight angle with respect to the
bracket plates so that the bracket plates present a slight diagonal force to the25 side walls of the axle. The axle is presumably welded to the bracket plates.
The U.S. patent to Dilling et al., 5,366,237, discloses a trailing arm
suspension in which a pair of semi-cylindrical bracket plates are welded to a
round axle through an opening between the two plates and along the parting
lines between the bracket plates. The axle extends through two openings in the
30 trailing arm and is secured thereto by welding the bracket plates to the beams.
The bracket plates are relatively wide and do not deflect when the axle bends.
Thus, stress risers can form on the axle at the side edges of the bracket plates.
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A brake ~ctll~tor is mounted to the trailing arms for operating brakes on the
axle wheels. Welding to the axle can also introduce undesirable microscopic
~ cracks which can initiate fatigue cracks and llltim~tely lead to failure of the axle
due to torsional stress on the axle.
S It is also common to mount a track bar between a trailing arm
and a central portion of an axle. The track bar is mounted to the axle through
a tower bracket which is welded to a central portion of the axle. The welds
between the tower bracket and the axle can introduce in the axle weak points
and microscopic cracks which can form sources of cracks which may llltim~tely
result in failure of the axle under severe or prolonged loading conditions.
DE 42 32 779 and DE 42 32 778 disclose a vehicle suspension
system with an air spring or a leaf spring wherein a relatively square axle is tied
in to the suspension through a U-bolt and axle plate which bears against the
axle at an upper portion. A filler can be provided in the bottom of the U-bolt.
A r.rlg received in an Gpening iln the ~le plate is welded lo an upper surface of
the axle. Frictional force resulting from pressure applied by the axle plate at
the upper corners of the axle and by the filler plate at the bottom corners of the
axle coupled with the welded ring is said to hold the axle against movement in
the mounting. A U-bolt does not give consistent and sufficient compressive
forces to adequately prevent slippage of an axle in the mounting and does not
work well with round axles.
SUl\IM~RY OF THE INVENTION
According to the invention, a vehicle axle has mounted thereto a
vehicle component, such as a brake actuator, a radius rod tower or a suspension
for mounting the axle to a vehicle frame, through an axle wrapper band which
uniforrnly compresses the axle to provide a substantial frictional force betweenthe axle and the wrapper band of a magnitude to prevent any appreciable
translational or rotational movement of the axle with respect to the wrapper
band in service on a vehicle. The wrapper band has a width to thickness ratio
subst~nti~lly in excess of one in that it is considerably wider than thick. The
axle mounting assemblies generally take three forms:
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(1) A square, rectangular, hexagonal or other polygonal
cross-sectional shaped axle is compression loaded with a wrapper
band which applies force at an area very near the tangent point
between the side of the axle and the corner radius. In this
S embodiment, the wrapper band has interior corners corresponding
to the corners of the axle with radii of curvature smaller than the
exterior radius of curvature of the axle corners and the wrapper
band is assembled essentially diagonally across the corners of the
axle.
(2) A square, rectangular, hex or other polygonal cross-
sectional shaped axle is compression loaded with a wrapper band
which applies force at the corners of the axle. In this
embodiment, the wrapper band has interior corners corresponding
to the corners of the axle with radii of curvature larger than the
exterior radii of curvature of the axle corners and the wrapper
band is assembled essentially 45~ to the diagonal of the axle.
(3) A round, elliptical or similar cross-sectional shaped
axle is compression loaded from a wrapper band which is
relatively evenly distributed around the circumference of the axle.
The invention can be accomplished in a number of ways.
Generally, a compressive wrapper band is formed from two plates which are
shaped to conform to the shape of the axle. The conforming plates are
compressed toward each other around the axle and joined together, preferably
by welding, or alternatively by mechanical fasteners, to mzlint~in the plates in25 tension, thereby uniformly distributing compressive forces on the captured axle.
In one embodiment of the invention, the wrapper band is formed from
confronting U-shaped plates which are compressed around an axle and welded
or bolted together. The U-shaped plates have end portions adjacent to each
other and welds or mechanical fasteners join the end portions of the U-shaped
30 plates to each other. Preferably, the U-shaped plates extend about 180~ around
the axle.
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In another embodiment of the invention relating to all three forrns
of the invention, the wrapper band is formed as a single piece, either integrally
~ formed in a single piece or welded into a single piece, and stretched around the
axle, preferably while the wrapper band is heated to an elevated temperature.
S The wrapper band in this embodiment can be polygonal or round in cross
section to conform to the cross-sectional shape of the axle on which it is
mounted. In a wrapper band of polygonal cross-sectional shape, the radius of
curvature of the inner corners can be greater or less than the radius of curvature
of the outer corners of the axle. In this embodiment, the wrapper band can be
10 in the form of a uniform thickness band of steel and of uniform length formedin the same cross-sectional shape of the axle with the inner surface of the
wrapper band conforming to the outer surface of the axle.
In one embodiment relating to the first form of the invention, the
axle is polygonal, for example, square or hexagonal, in cross section, with
15 c orners, ~.nd ~he wrapper band inner surface portions are positioned near the
corners of the axle. For example, the wrapper band inner surface portions are
positioned near the tangent point between the side of the axle and the corner
radius. In another embodiment relating to the third form of the invention, the
axle is round in cross section and the wrapper band inner surface portions are in
20 contact with the axle around the entire periphery thereof. In all embodiments,
the frictional force between the wrapper band and the axle is relatively high,
sufficient to prevent relative movement of the wrapper bands with respect to theaxle under ordinary service conditions. There is ordinarily direct contact
between the .;olllplession wrapper band and the axle to m~ximi7e the frictional
25 forces between the two. There may be some instances in which a friction
enhancing coating is positioned between the wrapper band and the axle. For
example, adhesives, paint and thin film fillers can be coated onto the axle outer
surface and/or the wrapper band inner surface to increase the contact area
between the wrapper band and the axle. In order to achieve these high
30 frictional forces, the tension in the wrapper plates and the wrapper band is
preferably in excess of 15,000 psi~ preferably in excess of 25,000 psi.
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Although the invention contemplates that the frictional forces will
be sufficient to m~int~in a fixed relationship between the axle and the wrapper
band, it may be desirable in some cases to add further mechanical cormections
between the axle and the wrapper bands. For, example, the wrapper bands and,
in some cases, the axles can be pierced with through holes for receipt of a pin
or washer. When both the axle and wrapper band have apertures in register
with each other, a pin can extend through the apertures in friction fit and
prevent relative movement of the axle and wrapper band under extraordinary
circumstances. In one embodiment, a short pin is used on each side of the axle
10 and wrapper band. The short pin has a hardened, tapered end which is driven
into the hole in the axle to wedge the pin in the axle hole. Thus, the diameter
of the axle hole is slightly smaller than the diameter of the pin, except for the
tapered end portion. The tapered pin compresses the area around the axle hole
to strengthen the area. When the wrapper band alone has an apertures, a
15 washer can be placed in the aperture or apertures in tight fit and welded to the
axle. In all cases, the apertures in the wrapper band and the axle are preferably
placed at a neutral axis of the axle. The apertures in the wrapper band can be
of uniform diameter or can be of non-uniform diameter to show movement of
the axle with respect to the wrapper band.
The wrapper bands are generally of uniform thickness. However,
in one embodiment, the wrapper band has tapered or chamfered inner surfaces
at both ends thereof which correspond to the upper and lower portions of the
axle to minimi7e stress risers which may result from the compression of the
wrapper band onto the axle at the edges of the wrapper bands. The wrapper
25 bands are typically made of strips of metal plate, for example steel, and have a
width of about 2-3 inches and a thickness of about 3/4 inch. Thus, the ratio of
width to thickness of the wrapper bands is usually at least about 2 and no
greater than about 10, although in some circumstances, these ratios may vary.
The wrapper bands provide a situs for the mounting of brake
30 actuators to the suspension through appropriate mounting brackets. Thus, in
one embodiment of the invention, a brake actuator is mounted directly to a
mounting bracket which is fixed, as by welding, to a wrapper band as described
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above. The wrapper band mounting the brake actuator can be free of other
vehicle components or can mount other vehicle components such as suspension
~ system arms through ap~3r~.iate suspension brackets. In one embodiment, a
brake actuator and an arm of a suspension system through which the axle is
mounted to the frame is mounted to a wrapper band and an S-cam bearing for
the brake actuator is mounted in an opening in a suspension mounting bracket
for the suspension system. The S-cam shaft can be considerably shortened
because of the mounting of the S-cam bearing directly to the suspension
mounting bracket compared with mounting the brake actuator to a central
portion of the axle. Thus, the brake actuator can be mounted to a wrapper
band or bands which also mount a trailing arm suspension mounting bracket or
be separately mounted to the axle through a separate wrapper band.
At least one of the U-shaped plates have in a preferred
embodiment of at least the first and third forms of the invention a pair of ears,
one on each end portion thereof, for applying tension to at least one the
U-shaped plates before welding or otherwise joining the U-shaped plates
together. Further, in a preferred embodiment of at least the first and third form
of the inventionl end portions of the U-shaped plates overlap with each other
and a weld is positioned at the overlapping end portions of the U-shaped plates.In a preferred form of the invention, movable arms of the
suspension system are mounted to the axle through two wrapper bands.
Suspension brackets are mounted to the wrapper bands, preferably by welding,
and to the arms of the suspension system. The suspension systems contemplated
by the invention include trailing arm suspensions in which the arms are typically
rigid as well as leaf suspensions in which the wrapper bands are mounted to the
leaf springs through appropriate brackets.
In another embodiment of the invention, the vehicle component is
a radius rod or a track bar which is mounted to the wrapper band through an
~ opliate bracket. In other words, a wrapper band according to the invention
can have mounted thereto a track bar or radius rod tower bracket. This
wrapper band avoids the formation in the axle of stress risers which unavoidablyresult from welding a track bar or radius rod tower bracket to the axle.
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Further according to the invention, a method of mounting a
vehicle component to an axle comprises the steps of: providing a bracket plate
having an inner surface portion adapted to extend around a portion of an axle
and shaped to conform to at least a portion of an external surface portion of the
5 axle; providing a wrapper plate having an inner surface adapted to extend
around a portion of the axle and having surface portions shaped to conform to
at least another external surface portion of the axle; positioning the wrapper
plate in confronting juxtaposition to said bracket plate around said axle;
compressing the bracket plate and wrapper plate towards each other to
10 compress the axle between the bracket plate and the wrapper plates; and
fastening the bracket plate to the wrapper plate while the bracket plates and
wrapper plates are compressed towards each other. Preferably, the bracket
plate and the wrapper plate are compressed towards each other at least in part
by applying a tensile force to end portions of the wrapper plates whereby the
15 axle is maintained in compression by the tensile forces in the wrapper band
after the fastening step. Further, the bracket plate and the wrapper plate have
tail end portions which overlap with each other and a weld is positioned at the
overlapping tail end portions of the wrapper plate and the bracket plate to
fasten the wrapper plate to the bracket plate. In one embodiment of the
20 invention, the wrapper plate and the bracket plate are mechanically fastened
together through threaded fasteners.
Further according to the invention, a method of mounting a
vehicle component to an axle comprises the steps of providing a hollow band
having in inner surface substantially conforming to the outer surface of the axle,
25 heating the hollow band to an elevated temperature to expand the diameter of
the inner surface thereof, forcing the hollow band onto the axle while the hollow
band is at the elevated temperature, cooling the hollow band, an ~fflxing a
vehicle component to the hollow band. The vehicle component can be fixed to
the hollow band either before or after the hollow band is pressed onto the axle.
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The wrapper band compresses the axle and is m~int~ined in a selected position
on the axle through the frictional forces between the axle and the wrapper band.- The invention provides for an assembly of an axle to a suspension,
preferably a trailing arm suspension, whereby the axle is m~int~ined in a high
S state of compression essentially sufficient to couple the axle to the axle
mounting without any welding between the axle and the wrapper band. The axle
is thus stronger because it is not welded to the mounting assembly. However,
the axle is m:~int:~ined in position on the mounting assembly and thus in a fixed
position on the trailing arm suspension frictional forces created by the
compression between the mounting assembly and the axle. The axle mounting
is lighter and stronger than previous system and further is adaptable to
automated assembly techniques. Thus, the axle mounting assembly is less
expensive to assemble, more reliable in service, longer lived and lower in weight
compared to similar strength axle mounting assemblies.
BR~EF DESCRIPTION OF THE DR~WINGS
The invention will now be described in detail with reference to the
accompanying drawings in which:
FIG. 1 is a fragmentary, side elevational view of a vehicle frame
having mounted thereon a suspension system according to the invention;
FIG. 2 is an enlarged, fragmentary side sectional view of the
suspension shown in FIG. 1;
FIG. 3 is a sectional view taken along lines 3-3 of FIG. 2;
FIG. 4 is an enlarged portion of lFIG.2;
FIG. 5 is a perspective view of a v~rapper band which is a part of
the axle mounting assembly shown in FIGS. 1 through 4;
FIG. 6 is a perspective view of an alternate embodiment of a
wrapper band used in an axle mounting assembly according to the invention;
FIG. 7 is a view like FIG. 2 of a second embodiment of the
invention adapted for use with a round axle;
FIG. 8 is a sectional view taken along lines 8-8 of FIG. 7;
FIG. 9 is an enlarged view of a portion of the axle mounting
assembly shown in FIG. 7;
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FIG. 10 is a view like FIG. 7 of a third embodiment of the
invention;
FIG. 11 is a bottom view of the axle mounting assembly shown in
FIG. 10;
FIG. 12 is a side elevational view, like FIG. 2, of a fourth
embodiment of a suspension system according to the invention and illustrating a
mounting plate assembly for a round axle;
FIG. 13 is a top view of the mounting plate assembly and a~cle
shown in FIG. 12;
FIG. 14 is a side elevational view, similar to FIG. 2, of a mounting
plate assembly for an automotive suspension system illustrating a fifth
embodiment of an axle mounting assembly according to the invention;
FIG. 15 is a front view of the axle mounting assembly shown in
FIG. 14;
FIG. 16 is a schematic view of a method of assembling the fifth
embodiment of the invention illustrated in FIGS. 14 and 15;
FIG. 17 is a side elevational view, similar to FIG. 2, of an axle
mounting assembly for an automotive suspension system illustrating a sixth
embodiment of an axle mounting assembly according to the invention;
FIG. 18 is a front view of the axle mounting assembly shown in
FIG. 17;
FIG. 19 is a partial front view of a leaf spring assembly which
incorporates an axle mounting assembly according to a seventh embodiment of
the invention;
FIG. 20 is a side elevational view, similar to FIG. 12, of a partial
axle mounting assembly for an automotive suspension system illustrating an
eighth embodiment of an axle mounting assembly according to the invention;
FIG. 21 is a front view of the axle mounting assembly sho~vn in
FIG.20;
FIG. 22 is a plan view of a component of the axle mounting
assembly illustrated in FIGS. 20 and 21;
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FIG. 23 is a side elevational view, similar to FIG. 20, of a partial
axle mounting assembly for an automotive suspension system illustrating a ninth
embodiment of the invention;
FIG. 24 is a front elevational view of the axle mounting assembly
S shown in FIG. 23;
FIG. 25 is a plan view of a component of the axle mounting
assembly shown in FIG. 23;
FIG. 26 is a side elevational view, similar to FIG. 20, of a partial
axle mounting assembly for an automotive suspension system illustrating a tenth
embodiment of the invention;
FIG. 27 is a front elevational view of the axle mounting assembly
shown in FIG. 25;
FIG. 28 is a side elevational view, similar to FIG. 20, of a partial
axle mounting assembly for an automotive suspension system illustrating an
eleventh embodiment of the invention;
FIG. 29 is a front elevational view of the axle mounting assembly
shown in FIG. 25;
FIG. 30 is a side elevational view, similar to FIG. 20, of a partial
axle mounting assembly for an automotive suspension system illustrating a
twelfth embodiment of the invention;
FIG. 31 is a side elevational view of an axle mounting assembly
according to a thirteenth embodiment of the invention;
FIG. 32 is an end elevational view as seen along lines 32-32 of
FIG. 31;
FIG. 33 is a side elevational view of an axle mounting assembly
according to a fourteenth embodiment of the invention;
FIG. 34 is a partial sectional view taken along lines 34-34 of FIG.
33;
FIG. 35 is a side elevational view of a suspension system according
to a fifteenth embodiment of the invention, illustrating the mounting of a brakeactuator to the axle mounting assembly according to the invention;
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FIG. 36 is a perspective view of the axle mounting assembly and
brake actuator illustrated in FIG. 35;
FIG. 37 is a perspective view of the axle mounting assembly
together with an ~ct~lator mounting bracket illustrated in FIGS. 35 and 36;
FIG. 38 is a perspective view of a suspension system according to
a sixteenth embodiment of the invention;
FIG. 39 is a side elevational view, partly in section, of a portion of
the suspension system illustrated in FIG. 38;
FIG. 40 is a sectional view taken along line 40-40 of FIG. 39; and
FIG. 41 is a side elevational view of a brake actuator mounted to
an axle according to a seventeenth embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and to FIG. 1 in particular, a vehicle
frame 10 has an axle 12 and ground-eng;lging wheels 14 (shown in phantom
15 lines) suspended therefrom by a suspension system 16 illustrating a first
embodiment of the invention. The front of the vehicle is to the left of the
frame as viewed in FIG. 1. Suspension system 16 includes, at each side of the
vehicle frame 10, a trailing arm 18 pivotally mounted to a hanger bracket 20
depending from frame 10. The hanger bracket 20 has a pivot pin 22 at the
20 lower end thereof for pivotally supporting the forward end of trailing arm 18.
Trailing arm 18 comprises a hollow rectangular member for supporting the axle
12. The forward end of trailing arm 18 is pivotably mounted at pivot pin 22.
The trailing arm 18 extends rearward along the vehicle frame 10. The rear end
of the trailing arm 18 is secured to an air spring 24. Trailing arm 18 has a slight
25 downward bend intermediate between its forward and rear ends. A forward
bushed pin 26 and a rear bushed pin 28 extend through trailing arm 18 near the
slight downward bend therein for supporting an axle mounting assembly 30
while permitting limited articulation between the axle mounting assembly 30 and
the trailing arm 18. The upper portion of the air spring 24 is fixedly secured to
30 the vehicle frame 10.
In operation, vertical movement of the ground-eng~ging wheels 14
is translated through axle 12 to the axle mounting assembly 30. Vertical
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movement of axle mounting assembly 30 is translated to trailing arm 18 through
forward bushed pin 26 and rear bushed pin 28. A bushing (not shown) encases
each of the bushed pins 26,28. The limited articulation permitted between axle
mounting assembly 30 and trailing arm 18 by the bushing of forward bushed pin
26 and rear bushed pin 28 cushions the vertical movement of the trailing arm 18
and controls the roll rate of the suspension by permitting axle mounting
assembly 30 to make small vertical, rotational and conical displacements relative
to trailing arm 18.
Significant vertical displacement of axle mounting assembly 30
10 causes the vertical displacement of trailing arm 18. Vertical movement of
trailing arm 18 is permitted by the pivotal connection of the forward end of
trailing arm 18 at the pivot pin 22. The vertical movement of trailing arm 18is
cushioned and restrained by air spring 24 and a shock absorber (not shown).
The foregoing description of a trailing arm suspension is for
15 purposes of illustration and is not intended to be a limitation on the types of
suspensions on which the axle mounting assembly according to the invention can
be used. For example, the axle mounting assembly according to the invention
can be used on all different types of trailing arm suspensions, on leaf spring
suspensions, and on combinations of the two. Further, the suspensions l-tili7in~20 the axle mounting assembly according to the inventions can be used on trucks,trailers, buses and other types of heavy-duty vehicles, including off-road vehicles
as well as on-road vehicles.
The axle mounting assembly 30 comprises a pair of bracket plates
32, each of which has a plate body 34 with an upper edge 36 and a lower edge
25 38, a lower corner 40 and an upper corner 42. The lower edge 38 forms a
generally L-shape which conforms to two sides of the axle 12 with the upper
edge 36 and the lower edge 38 extending around a portion of the upper left and
lower right corners of the axle 12 as viewed in FIG. 2.
A pair of L-shaped flanges 46 extend laterally from the lower edge
30 of the bracket plate body 34 and generally conform to two sides of the axle as
shown in FIG. 2. FIG. 3 shows the flanges 46 secured to the bracket plate body
34. The L-shaped bracket plates have an end portion 48 near an upper left
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corner of the axle 12 and an end portion 44 near a lower right corner of the
axle 12, as viewed in FIG. 2. The bracket plates 32 and the flange portion 44
have a tail 50 at the lower corner 40 and a tail 52 at the upper corner. As seenin FIG. 4, the tail 50 is curved slightly. The flanges 46 and the lower edges of5 the bracket plate body 34 form edge surface portions which are shaped to
conform to the axle 12 near the corners thereo~ Specifically, the edge surface
portions bear against the flat of the axle 12 near the tangent point as illustrated
by the force arrows F shown in FIG. 2. The edge surface portions have a
radius of curvature at the corner 54 smaller than the radius of curvature of the10 corner 13 of the axle so that there is a clearance between the two surfaces so
that the forces on the axle are applied by the straight portions of the edge
surface portions. Alternatively, the flanges 46 can be formed in one piece and
welded to the lower edge of the plate body 34. In this alternative construction,the flanges by themselves would form the edge surface portions which are
15 shaped to conform to the axle 12 in the same fashion as the lower surface 36 of
the bracket plate body 34 and the L-shaped flanges 46.
An L-shaped wrapper plate 60 generally conforms to the left and
bottom sides of the axle 12 as viewed in FIG. 2 and has a vertical arm 62 which
extends up along the left side of the axle 12 (as viewed in FIG. 2) and a
20 horizontal arm 64 which extends along the lower wall of the axle 12 (as viewed
in FIG. 2). The corner 78 of the L-shaped wrapper plate 60 has a radius of
curvature smaller than the radius of curvature of the corner 13 of the axle so
that there is clearance between these two corners as illustrated in FIG. 2. Thisconstruction results in a compressive force on the axle at the sides near the
25 tangent point of the corner and the corner radius as illustrated by the forcearrows F shown in FIG. 2. A tail portion 66 on arm 64 extends beyond the tail
50. The tail portion 66 is bent upwardly at an angle to the horizontal so that
the inner edge of the tail portion 66 complements and overlaps the outer edge
of the tail 50. The left wrapper plate 60 is broken away irl FIG. 3 at an upper
30 end of arm 62 to show the flanges 48 extending laterally from a lower edge of the bracket plate body 34.
-
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The end portion 44 of the L-shaped flanges 46 is welded to the
tail portion 66 of the wrapper plate 60 through a weld 70. In like manner, the
- end portion 48 of the L-shaped flanges 48 is welded to the tail portion 68 of
wrapper plate 60 through weld 72. The welds do not touch or reach the axle so
5 that the axle can be mounted to the suspension without welds between the axle
and the mounting assembly. As shown in FIG. 3, there is a clearance between
the tail 50 and the corner 13 of the al~le 12 so that the compressive forces
applied by the L-shaped wrapper plate 60 and the lower edges surfaces of the
bracket plate body 34 and flanges 46 are substantially near the tangent point of10 the sides and corner of the axle 12 as illustrated by the force arrows F in
FIG. 2.
An ear 76 is formed on an upper outer surface of arm 62. An ear
74 is formed on an outer end portion of the arm 64. The ears 74 and 76 are
tri~n~ r in shape but can be any shape so long as they function to provide a
15 gripping abutment for applying a tensile force to the wrapper plate 60.
Alternatively, the arms 62 and 64 can be notched in lieu of the ears to form
gripping abutments for applying a tensile force to the wrapper plate 60.
The axle mounting assembly is assembled as follows:
An axle 12 is positioned against the lower edge 38 of the bracket
20 plates 32 so that the flange end portions 46 are aligned near the corners of.the
axle 12. A wrapper plate 60 is then moved into position opposite one of the
bracket plates 32. A compressive force is applied between the opposing bracket
plate 32 and wrapper plate 60 by applying a downward force against the upper
edge 36 of the bracket plate 32 and applying upward forces generally along lines25 A against the ears 74 and 76 of the wrapper plate 60. The forces A resolve into
upward and lateral forces along the arms 62 and 64 and thereby apply a tension
to the wrapper plate 60. The compressive force applied to the bracket plate 32
and wrapper plate 60 are relatively high, for example in the order of about
20,000 lbs. When the desired compressive forces are reached, the bracket plate
30 32 and the wrapper plate 60 are then joined together through welds 70 and 72.The welds, when cool, will contract and thus at least maintain the compressive
force on the axle 12. The combination of the L-shaped wrapper plate 60 and
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the flanges 46 form a wrapper band which compressibly loads the axle 12 in a
relatively uniform manner. The high level of compressive loading of the axle
through the axle mounting assembly 30 firmly positions the bracket plates on theaxle and prevents the bracket plates from laterally ~hiftin~ with respect to each
5 other and with respect to the axle 12 during use of the trailing arm suspension.
After one set of a bracket plate and a wrapper plate is welded in the foregoing
manner, the second set of a bracket plate and a wrapper plate is then welded
together to form a second wrapper band on the axle and complete the assembly
of the axle mounting assembly to the axle 12. The bracket plates can then be
10 mounted to the trailing arm through the bushed pins 26 and 28.
As shown in FIGS. 2 and 3, the wrapper plate 60 applies a
compressive force to the sides of the axle near the tangent point of the flat and
corner radius of the axle 12. The wrapper is preloaded onto the axle and then
welded together. The radius of the inside corner 54 of L-shaped flange 46 is
15 smaller than the radius of the outside corner 13 of the axle 12 to provide
clearance between the two corner surfaces. Likewise, the radius of the inside
corner 78 of the L-shaped wrapper plate 60 is smaller than the radius of the
outside corner 13 of the axle 12 to provide clearance between the two corner
radius surfaces. The same relationship exists bet~veen the other corners of the
20 wrapper and the axle.
The manner of welding the L-shaped flange 46 to the L-shaped
wrapper plate 60 can vary so long as the weld does not contact the axle. The
axle mounting can be one or more bands as desired to connect each trailing arm
or other suspension to the axle. The axle connection can be used for many
25 types of suspensions in addition to the suspension shown in FIGS. 1-6. For
example, the axle connection of the invention can be used to connect axles to
leaf spring suspensions as well as top mount and underslung trailing arm and
combination leaf spring and trailing arm suspensions.
As an alternate procedure, the bracket plates 32 can first be
30 mounted to the trailing arm 18 through the bushed pins 26 and 28 and the axle
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and L-shaped wrapper plates can be assembled to the bracket plate, applying
compressive pressure to the bracket plate and/or the trailing arm and the
wrapper plate as described above.
The ~shaped wrapper plate 60 is generally el-~ng~te~l in shape
and has a width a~ploxil"~tely the distance between the ends of the flanges 44,
46 and 48. Thus, there is a substantial contact between the wrapper plate 60
and the axle 12, thereby providing a relatively high frictional force between the
two
FIG 6 illustrates the alternate embodiment of the L-shaped
wrapper plate. The alternate wrapper plate 80 is L-shaped in configuration and
has wide flange portions 82, 84 and 86 separated by webs 88 and 89. The
L-shaped wrapper plate illustrated in FIG 6 is substantially the same as the
wrapper plate 60 except that there are narrowed web portions 88 and 89
between the flange portions 82, 84 and 86 The flange portions 82, 84 and 86
are adapted to be positioned against the corresponding corners in the upper left,
lower left and lower right (as viewed in FIG. 2) of the axle 12
Reference is now made to FIGS 7, 8 and 9 which show a second
embodiment of the invention wherein an axle mounting assembly is adapted for
mounting a round axle 90 A pair of bracket plates 92 are adapted to be
mounted to a trailing arm 18 of a trailing arm suspension through bushed pins
26 and 28 in the same fashion as bracket plates 32 The bracket plates 92,
however, have a different shape, each being formed with a plate body 94 having
an upper edge 96 and a lower flange 98 The lower flange 98 is arcuate shaped,
having a lower arcuate surface 100 which conforms to the shape of the outer
surface of the axle 90 and an upper surface which is fixed to the lower portion
of the plate body 94 The lower flange 98 further has, as shown in FIG 9, a
terrninal tail 104 at a lower right portion (as viewed in FIG 7) and further has a
terminal tail 106 at a lower left portion (as viewed in FIG. 7). The flange 98 is
preferably formed integral with the plate body 94 by casting or forging on the
~ 30 lower portion of the bracket plate body 94 perpendicular thereto Alternatively,
the lower flange can be formed as a separate plate and welded to the lower
portion of the plate body 94.
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A pair of U-shaped wrapper plates 110 are mounted to an
opposite side of the axle 90 in juxtaposition to the bracket plates 92. Each of
the U-shaped wrapper plates 110 has an a lower central bite portion 112, a rightleg 114 and a left leg 116 which collectively define an arcuate upper surface 120
5 which conrol,lls to the outer surface of the axle 90. The central bite portion 112
has an arcuate lower edge 118. A notch 126 is formed in the right leg 114 and
a notch 128 is formed in the left leg 116. A tail 130 is formed in the right leg114 in overlapping relationship to the right tail 104 of flange 98. In like
manner, a tail 132 is formed in the left leg and is in overlapping relationship to
10 the left tail 106 of flange 98. A tri~n~ r ear 134 is welded to the right leg 114
and a triangular ear 136 is welded to the left leg 116. A weld bead 138 joins
the tail 130 to the tail 104 of flange 98. In like manner, a weld bead 140 joinsthe tail 132 to the left tail 106 of the flange 98.
A tri~n~ r gusset plate 122 is welded to one side of the
15 U-shaped wrapper plate 110 through a weld 125 and extends along the axle 90
at a neutral axle thereof. A weld 124 secures the gusset plate 122 to the axle 90
along a neutral axis of the axle 90. The welded gusset plate will increase the
slip resistance of the axle 90 with respect to the axle mounting.
The round axle mounting assembly is assembled in substantially
20 the same manner as the square axle mounting assembly 30 identified above.
The bracket plates 92 are positioned on the round axle and the U-shaped plates
110 are position in juxtaposed relationship thereto. A compressive force is
applied to the U-shaped plates 110 and to the bracket plates 92 of the same
order as the compressive force applied to the axle mounting assembly 30. Force
25 is applied to the ears 134 and 136 until such time as an appl-o~"iate compressive
force is reached. The bracket plates 92 are welded to the U-shaped plates 110
through the fillet welds 138 and 140. The compressive force is then released butthe axle remains under compression by the axle mounting assembly. Optionally,
the central portions of the arcuate surfaces 100 and 120 can be slightly recessed
30 to permit a slight flexing of the top and bottom of the axle with respect to the
lower flanges 98 and the U-shaped plates in service. The triangular gusset
plates are then welded to the axle.
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Referring now to FIGS. 10 and 11, there is shown a third
embodiment of the invention wherein an axle mounting assembly is provided for
. a hexagonal axle 148. The axle 148 is hexagonal in cross section, having six
sides and six corners.
S The axle mounting assembly comprises a bracket plate 150 having
a plate body 152, an upper edge 154, a lower edge 156 and lower corners 158
and 160. Bushed openings 162 are provided in conventional fashion in the plate
body 152.
A pair of semicircular flanges 164 are welded to each side of the
10 plate body. A brace flange 166 extends upwardly from a lower left side of thesemicircular flange 164 toward the left bushed opening 162 as viewed in FIG.
10. A similar flange of mirror image construction is mounted to the other side
of plate body 152. The semicircular flanges 164 have a central inner surface 168which is spaced from the upper surface of the axle 148 and has an upper left
15 pressur~ su~fzce 170, ar. upper right p.essure sd~laee 172, a lowel lefL pressure
surface 174 and a lower right pressure surface 176, all in bearing relationship to
the hexagonal axle near the corners thereof.
A U-shaped plate 180 is positioned beneath the axle 148 and has a
pair of integrally formed ears 182 for applying pressure to the wrapper band
20 during assembly of the wrapper band to the bracket plate 150. The U-shaped
plate has an upper left pressure surface 184, an upper right pressure surface
186, a lower left pressure surface 190, a lower right pressure surface 192, a
bottom left pressure surface 196 and a bottom right pressure surface 198, all inbearing relationship to the hexagonal axle near the corners thereo~ A left weld
25 192 and a right weld 194 secure the U-shaped plate 180 to the bracket plate
150. The welds 192 and 194 do not extend to the axle 148. The compressive
pres~ule applied by the semicircular flange 164 and the U-shaped plate 180 is
~ applied to the side walls of the axle 148 adjacent to but not at the corners in a
manner similar to the compressive forces applied to axle 12 by the axle
mounting assembly illustrated in FIGS. 1-4 and described above.
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Reference is now made to FIGS. 12 and 13 which show a fourth
embodiment of the invention. Like numerals have been used to design~te like
parts. A bracket plate 92 comprises a plate body 94 having an upper edge 96.
A semicircular flange 202 is welded to each side of the plate body 94. A brace
5 flange 204 extends upwardly from a lower left side of the semicircular flange
202 (as viewed in FIG. 12) toward a left bushed opening 226. A right bushed
opening 226 is also provided on the plate body 94 in conventional fashion. The
semicircular flanges 202 have a lower inside surface 206 which is arcuately
shaped to conform to the outer surface of the axle.
A U-shaped plate 212 is mounted beneath the round axle 90 and
has a pair of integral ears 214 formed therein for applying an upward force to
the outer portions of the U-shaped plate 212 for applying tension thereto in theassembly of the axle mounting assembly in a manner discussed above. The
U-shaped plate has an inner surface 216 which is arcuately shaped to conform
15 to the shape of the outer surface of the axle 90. A left weld 222 and a rightweld 224 secure the U-shaped plate 212 to the bracket plate 92. As in the other
embodiments, a relatively high force is applied to the upper edge 96 of the plate
body 94 and/or to the flanges 202 on one side of the axle and substantial forcesare likewise provided at the ears 214 on the U-shaped plate 212 to compress the
20 axle prior to welding the U-shaped plate 212 to the bracket plate 92 through the
welds 222 and 224. The semicircular flanges 202 and U-shaped plate 212 apply
a relatively evenly distributed compressive force to the axle 90 through the
arcuate surfaces 206 and 216, respectively.
Referring now to FIGS. 14 and 15, there is shown a fifth
25 embodiment of an axle mounting assembly according to the invention. A
bracket plate 230 mounts a hollow rectangular prismatic wrapper band 232.
The wrapper band 232 can be welded to plate 230 as an integral piece which
extends on either side of plate 230 or can be integrally formed with the plate
230 by casting or by forging. The wrapper band 232 has eight inner pressure
30 surfaces 234 which bear against and compress a square axle 12. These pressuresurfaces 234 load the axle near the tangent point of the flat sides and corner
radius of the axle 12. As shown in FIG. 14, the radius of curvature of the
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inside corner 235 is smaller than the radius of curvature of the outside corner 13
of the axle 12 so that there is clearance between the two radius surfaces. The
- wrapper band 232 further has on each side a central wave portion 236 which
assists in flexing of the walls of the wrapper band. There are typically four ofS the wrapper bands 232, two at each end of the axle to attach the wrapper bands
to a suspension. The square axle can also be loaded on the corners. This
concept also applies to other axle shapes such as hexagonal and round shapes.
The bracket plate 230 has a pair of mounting holes 231 through
which the bracket plate and thus the axle 12 can be mounted to a suspension
system, such as a trailing arm suspension or any other type of suspension. An
S-cam bearing mounting flange 237iS formed on the bracket plate 230 and has
an opening 238 therein for mounting an S-cam (not shown) to the bracket plate
230. The mounting flange 237 provides support for the S-cam bearing of the
brake actuator. The brake chamber bracket can also be attached to the
wlappe, band 232 or io Ihe bracket piates and eiiminzltes the need to weld the
actuator mounting bracket to the axle.
The wrapper band 232iS press fit onto the axle 12 and can be
preheated to aid in shrinking it onto the axle. Thus, the wrapper band 232
compresses the axle 12 at the eight pressure surfaces.
Referring now to FIG. 16, there is shown a method of assembling
the bracket plate 230 and wrapper band 232 onto an axle 12. The axle 12 iS
mounted on a support 244. The adapter plate 230 and the wrapper band 232
are heated to an elevated temperature to expand the same. The bracket plate
and wrapper band are heated as high as possible without rh~nging the crystal
structure of the metal which is preferably steel or ductile iron. The temperature
typically is below the austenitic range for the steel which is used for the bracket
plate and wrapper band. The thus-heated bracket plate 230 and wrapper band
232 are placed in a fixture 240 which is mounted to a press 242. The press
forces the hollow rectangular prismatic wrapper band 232 onto the axle 12 and
into a properly aligned position. Four such bracket plates and wrapper bands
are forced onto an axle 12 to complete the assembly.
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Whereas the embodiment shown in FIGS. 14-16 illustrates a
square axle and a square prismatic wrapper band, the axle can be round,
rectangular, hexagonal, D shape, oval, octagonal or any other common shape in
cross section and the wrapper band can conform to the shape of the axle in a
S manner analogous to the square axle and square prismatic wrapper bands 32
illustrated in FIGS. 14 and 15.
Although the invention has been described with respect to one
trailing arm in a suspension, it is to be understood that each suspension inç~ les
a pair of trailing arms, one on each side of the vehicle. Thus, there are four
10 axle mounting assemblies on each axle, two on each end, with one mounting
assembly on each side of a trailing arm 18. Further, whereas the invention has
been described with reference to an axle mounting assembly for round, square
and hexagonal axles, the invention is equally applicable to axle mounting
assemblies for other shape axles. For example, the invention is also believed to15 be suitable for axles which are octagonal in cross section. Assembly of
octagonal axle support assemblies would follow the same procedure as for axles
which are square, round or hexagonal in cross section. The invention is
applicable to axles of all cross-sectional shapes.
Referring now to FIGS. 17 and 18, there is shown a sixth
20 embodiment of a axle mounting assembly according to the invention. A pair of
mounting plates 250 have mounting holes 252 for mounting the plates to a
trailing arm suspension or to another type of suspension. The mounting plates
250 have a U-shaped opening 254 in which is received the upper portion of a
wrapper band 256. The wrapper band 256 comprises a U-shaped upper portion
25 258 and a U-shaped bottom portion 264 which are fitted together at ends 260
and 266, respectively, and welded together at the ends 260 and 266 through
welds 272. The U-shaped upper portion has inside corners 262 which have a
radius of curvature greater than the radius of curvature of the external corners13 of the rectangular or square axle 12. Likewise, the inside corners 270 of the30 U-shaped bottom portion 264 have a radius of curvature greater than the radius
of curvature of the external corners 13 of the axle 12. Thus, there is some
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clearance between the straight sides and bite portions of the U-shaped upper
portion 258 and the U-shaped bottom portion 264 and the sides of the axle 12.
The wrapper band is mounted to the axle through compressive
forces which are applied to the U-shaped upper portion 258 and the U-shaped
5 bottom portion 264 at the arrows illustrated in Fig. 17 before the welding
operation. The welds are made while the U-shaped upper portion 258 and the
U-shaped bottom portion 264 are compressed towards each other so that the
axle 12 is in compression. After the welds cool, the preloading in the axle
remains with the sides of the U-shaped upper and bottom portions 258 and 264
10 which have a high tensile loading. Further, the shrinkage of the welds further
increases the compressive forces on the axle by the wrapper band 256. As
illustrated, the compressive forces on the axle 12 are applied at the corners 13of the axle by the corners 262 and 270 of the wrapper band 256.
Referring now to FIG. 19, there is shown a seventh embodiment
15 of the invention wherein an axle mounting assembly as shown in FIGS. 17 and
18 is mounted to a leaf spring suspension. Like numerals have been used to
described like parts in FIGS. 17 through 19. The leaf spring suspension is
shown only in partial form, showing the spring suspension end 280 comprising
leaf springs 282, 284 and 286 and an end cap 288. An elastomeric pad 290 is
20 positioned between the cap and the leaf spring 284. The leaf spring 286 has an
opening 292 in which is mounted a pin 294 in conventional fashion. The
wrapper band 256 is substantially identical with the wrapper band disclosed in
FIGS. 17 and 18 but does not have the mounting plates 250. Instead, it is
mounted to the end cap 288 with bolts. The wrapper band 256 is assembled to
25 the axle in the same manner as described above with respect to FIGS. 17 and
18. After assembly of the wrapper band to the axle, the wrapper band is then
bolted to the end cap 288.
~ Reference is now made to FIGS. 20, 21 and 22 which show an
eighth embodiment of the invention and like numerals have been used to
30 designate like parts. An axle 300 has circular openings 302 on a horizontal
centerline or neutral axis of the axle. A wrapper band comprises an upper
U-shaped plate 304 and a lower U-shaped plate 312 which are welded together
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at lower edges 306 and upper edges 314 of the upper and lower U-shaped plates
304 and 312, respectively, through welds 318. The upper U-shaped plate 304
has a chamfered relief area 310 near each longitudinal edge which provides a
slight relief to the axle at the lateral edges of the upper U-shaped plate 304. In
5 a similar manner, the lower U-shaped plate 312 has a chamfered relief area 322at the lateral edges thereof. The chamfered relief areas 322 are positioned
adjacent the bottom of the axle 300. The chamfered relief areas 310 are
positioned at the top of the axle. These chamfered areas prevent stress risers in
the axle which may result from the lateral edges of the U-shaped plates 304 and
10 312 during vertical bending of the axle. The chamfered areas are desirable insome instances but they are not essential for the invention. The upper and
lower U-shaped plates 304 and 312, respectively, are compressed in the same
manner as described above with respect to the other embodiments for the
welding operation. After the welding operation and after cooling of the welds,
15 the wrapper band compresses the axle and distributes the compressive forces
substantially uniformly around the axle. Typically, the compressive force is
sufficient to prevent the wrapper band from sliding on the axle. The wrapper
band is then attached to a suspension system in a manner described above. As
in the embodiment of Figs. 7-9, ears 134 and 136 are provided on the lower
20 U-shaped plate 312 to assist in applying the compressive forces to the upper and
lower U-shaped plates 312 and 304.
It may be desirable in some cases to incorporate a safety
mech~ni~m to make certain that the axle does not move with respect to the
wrapper bands. In the embodiment illustrated in FIGS. 20 through 22, the
25 upper U-shaped plate 304 is provided with a circular opening 308 which is in
register with one of the circular openings 302. The lower U-shaped plate 312
has an opening 316 which is in register with the other of the circular openings
302 in the axle 300. A drive pin 320 has an exterior diameter substantially
equal to the interior diameter of the circular openings 302, the circular opening
30 308 and the circular opening 316. After assembly of the wrapper plate to the
axle 300, the drive pin 320 is driven through the openings 316, 302 and 308 and
remains fixed in this position during the service life of the axle. The pin
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effectively prevents any rotational as well as longitudinal movement of the axlewith respect to the wrapper band in the event that the axle experiences any
3 llml.cll~l torsional or longitudinal forces which tend to overcome the frictional
forces between the wrapper band and the axle.
Referring now to FIGS. 23 through 25, there is shown a ninth
embodiment of the invention where like numerals have been used to de~i~n~te
like parts. A wrapper mounting band 330 comprises an upper U-shaped plate
332 and a lower U-shaped plate 338 which are joined together at lower edges
334 and upper edges 340 through welds 318 in the same manner as described
above with respect to the previous embodiment. The upper U-shaped plate 332
has chamfered relief areas 337 which are positioned at the top of the axle 300.
Likewise, the lower U-shaped plate 338 has chamfered relief areas 344 which
are positioned at the bottom of the axle 300. As in the previous embotliment,
the axle 300 has circular openings 302.
The upper U-shaped plate 332 has an oblong opening 336 in
register with one of the opening 302 in the axle 300. Likewise, the lower
U-shaped plate 338 has an oblong opening 342 in register with the other of the
circular openings 302 in the axle 300. Oblong openings 336 and 342 have a
greater diameter in a circumferential direction rather than an axial direction as
illustrated in FIG. 24. The axial diameter of the openings 336 and 342 is
essentially identical with the diameter of the circular openings 302 in the axle300. A unitary drive pin (not shown) can be positioned through the openings
342, 302 and 336 as a safety feature to prevent any inadvertent lateral
movement of the axle 300 with respect to the wrapper mounting cylinder 330. A
tapered drive pin 321, shorter than the integral drive pin 320 of the embodimentshown in Figs. 20-22, is positioned in each of the sides of the axle 300 and is
wedged in the openings 302, thereby compressing the metal around the openings
~ 302, and extend through the oblong openings 336 and 338. The diameter of the
drive pin increases from the tapered end to a diameter slightly greater than thediameter of the openings 302. The oblong openings 336 and 342 provide a
clearance between the upper and lower surfaces of the drive pins and the
wrapper mounting cylinder 330. Thus, a slight amount of proportional
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movement between the axle 300 and the wrapper mounting cylinder 330 is
possible with this embodiment of the invention. Preferably, the drive pins 321
are welded to the upper and lower U-shaped plates 332 and 338 at the
respective oblong openings 336 and 342, respectively.
As in the previous embodiments, the U-shaped plates 332 and 338
are preloaded onto the axle 300 before the welding operation using the ears 136
and 138 on the lower U-shaped plate 138 and using the upper edge 96 of the
bracket plate 92. The resulting wrapper mounting band 330 exerts a substantial
compressive force on the axle 300 to maintain the fixed mounting relationship
10 between the axle 300 and the wrapper mounting cylinder 330 during the service life of the axle.
Referring now to FIGS. 26 and 27, there is shown a tenth
embodiment in which like numerals have been used to describe like parts. In
this embodiment, an axle 90 has a cylindrical wrapper identical with the wrapper15 disclosed in FIGS. 20 through 22. The U-shaped plates 304 and 312 are
preloaded onto the axle 90 in the same fashion as they are preloaded onto the
axle 300 in the embodiment of FIGS. 20 through 22 and are welded during the
preloading to compress the U-shaped plates 304 and 312 around the axle 90. In
the embodiment shown in FIGS. 26 and 27, a washer 350 is snugly positioned in
20 each of the openings 316 and 308 and is welded to axle 90 through a plug weld352. The washer and plug weld perform substantially the same function as the
drive pin in embodiment of FIGS. 20 through 22 in that they prevent
inadvertent translation of the axle 90 with respect to the wrapper band. The
washer and weld are not essential to the operation of the invention but merely
25 provide a safety feature which may be desirable in certain applications to avoid
any relative movement between the wrapper band and the axle due to
extraordinary forces on the axle with respect to the wrapper band.
Referring now to FIGS. 28 and 29, there is shown an eleventh
embodiment of the invention in which like numerals have been used to describe
30 like parts. In FIG. 28, a round axle has a wrapper mounting cylinder 330 of the
same construction illustrated in FIGS. 23 through 25. In the embodiment shown
in FIG. 28, a washer 350 is positioned within each of the oblong holes 342 and
,
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336 and is welded to the axle through a plug weld 352 as in the embodiment of
F~GS. 26 and 27. In this embodiment, the oblong holes 342 and 336 provide a
me~cure of clearance between the upper and lower portions of the washer 350
and the wrapper mounting cylinder 330. The wrapper band 330 is mounted to
~ 5 the axle 90 in the same fashion as the wrapper band 330 is mounted to the axle
300 as described above with respect to FIGS. 23 through 25.
Referring now to FIG. 30, there is shown another form of a
wrapper band and round axle according to the invention. In this embodiment,
the axle 90 has a wrapper band 360 formed from an upper U-shaped plate 362
having lower edges 364 and a lower U-shaped plate 366 having upper edges 368.
The upper and lower U-shaped plates 362, 364 conform to the shape of the axle
90 and are compressed together before joining the two U-shaped plates together
through welds 370 at the lower edges 364 and the upper edges 368. The upper
U-shaped plate has a chamfered relief area 372 at both ends in the same
manner as shown in FIG. 22 to relieve stress on the axle upper portion at the
edges of the U-shaped plate. Likewise, the lower U-shaped plate 366 has a
chamfered relief area 374 at each end to relieve stress on the axle bottom
portion at the edges of the plate 366. The wrapper band of this embodiment
functions essentially the same as the wrapper bands shown in the previous
embodiments to compress and retain the axle in a relatively fixed relationship
with respect to the wrapper band during normal service of the axle on a
suspension system without welding of the axle bracket or wrapper band to the
axle.
The invention contemplates the development of frictional forces
between the wrapper bands and the axles sufficient to fix the axles to the
wrapper bands and to the suspension arms without welding on the axle. Thus, it
is contemplated that these frictional forces will be generated with metal-to-metal
contact and without any intervening layers, for example, rubber. However, it is
within the scope of the invention to use an adhesion promoting compound or
filler, such as Loktite, which is an anaerobic liquid which cures in air to promote
adhesion between the confronting metal surfaces. A primer paint can also be
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used. These compounds may increase the coefficient of friction between the
cont~ctin,~ metal surfaces of the wrapper band and axle.
The invention contemplates the use of an axle shape which is t
round, slightly elliptical or egg-shaped. A slight elliptical configuration can be
5 imparted to the axle by compressing the axle slightly or in the forming process.
The slight elliptical configuration to the axle can assist in preventing the axle
from rotating about its longitudinal axis with respect to the wrapper band. An
axle which is egg-shaped in cross section would have the same result.
The axles typically have a uniform wall thickness. However, the
10 invention also can be used for mounting axles which have non-uniform wall
thicknesses. For example, when an axle is made in two parts and welded
together at the side, the upper portion of the axle may have a thinner wall
thickness than the lower portion. Axles of this configuration can be mounted on
suspension systems in accordance with the invention.
The invention also contemplates that the wrapper band can be
made in a "C" shape instead of in two pieces. The confronting edges of the "C"
can be joined after assembly of the wrapper band to the axle and drawing the
edges of the "C" shaped band together by welding or mechanical fasteners.
The invention has been described in part with respect to a
20 wrapper band formed of two parts welded together in tension along common
axially extending confronting edges. Although welding alone is a preferred form
of joining the parts of a wrapper band, the two parts can be joined in tension by
mechanical fasteners such as bolts which extend through ears on the parts. Stillfurther, the two parts can be joined together by a combination of mechanical
25 fasteners and welding.
Referring now to FIGS. 31 and 32, there is illustrated an
embodiment of the invention in which the two portions of the wrapper band are
joined together by mechanical fasteners. A bracket plate 380 has an S-cam
mounting flange 382 with an aperture 384 and mounting apertures 386, the
30 latter of which are used to mount the bracket plate 380 to a trailing arm
suspension in the manner illustrated in FIGS. 1-3. The bracket plate 380
further has an upper U-shaped flange 388 with a lower semicylindrical surface
,
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390 in contact with the outer surface of axle 90. A pair of U-shaped plates 392
are mounted to the front and back portions of the bracket plate 380 and have a
central portion 394 with openings 396 and end flanges 398. In FIG. 31, the end
flange on the left-hand side of the bracket plate 380 is broken away to show the5 openings 396 in one of the plates 392.
A lower bracket plate 402 has a lower U-shaped flange 404 with a
semicylindrical surface 406. The semicylindrical surfaces 406 and 390 are in
contact with the outer surface of the axle 90. A pair of U-shaped plates 408 aremounted in inverse position to the front and back edges of the bracket plate 40210 and have a central portion 410 with a pair of bolt openings 414. End flanges
416 and 418 are formed on the outer ends of the central portion 410. Bolts 420
extend through the openings 414 and 392 and draw the U-shaped plates 392 and
408 tightly together by threading a nut 422 on the ends of each of the bolts 420.
As illustrated in FIG. 31, the central portions 394 and 410 of the
15 U-shaped plates 392 and 408, respectively, are spaced from each other as are
the ends of the U-shaped flanges 388 and 404. Thus, as the bolts 420 are
tightened, the U-shaped flanges 388 and 404 are tightened onto the outer
surface of the axle 90 to compress the axle 90 and to frictionally mount the
bracket plate 380 and the bracket plate 402 to the axle 90. The bolts are
20 tightened sufficiently so that the axle will be held torsionally and axially by the
U-shaped flanges 388 and 404 during service operation of the axle.
The axle mounting assembly illustrated in FIGS. 31 and 32 are
mounted to a trailing arm suspension, for example, of the type illustrated in
FIGS. 1-3. Two of the axle mounting assemblies are mounted onto each axle 90
25 at each trailing arm 18 (FIGS. 1-3). Four such axle mounting assemblies are
mounted onto each axle with two axle mounting assemblies mounted onto each
trailing arm.
FIGS. 33 and 34 illustrate yet another embodiment of the
invention in which the two portions of the wrapper band are mechanically
30 secured together to frictionally join the axle mounting bracket to the axle. With
reference now to FIGS. 33 and 34, where like numerals have been used to
describe like parts, bracket plate 380 of substantially identical nature to the
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bracket plate 380 shown in FIGS. 32 and 31 has an S-cam mounting flange 382
with an aperture 384 and mounting apertures 386 and 387. An upper U-shaped
flange 388 has a semicylindrical lower surface which is in frictional contact with
an outer surface of the axle 90. The bracket plate 380 further has a pair of
5 openings (not shown) adjacent the ends of the upper U-shaped flange 388 for
receipt of bolts described hereinafter.
A U-shaped outer band 430 has ends 431 and 432 with holes (not
shown) to receive bolts 433 to bolt the outer band 430 to the axle plate 380.
The bolts 433 extend through the openings (not shown) in the bracket plate 380.
An inner band 434 has ramped surfaces 435 and 436 and a
semicylindrical surface 437, the latter of which is in frictional contact with the
outer surface of the axle 90. Wedges 438 having upper ramped surfaces 439 are
U-shaped in nature and are positioned adjacent the ramped surfaces 435 and
436 of the inner band 434 as illustrated in FIG. 34. Bolts 440 having nuts 441
15 extend between the wedges 438 and the outer band 430 to force the surface 437of the inner band 434 into frictional contact with the outer surface of the axle90. Further, tightening of the bolts 440 results in tension in the outer band 430
which in turn will apply uniform compressive forces along the surface 437 of theinner band 434. At the same time, the U-shaped flange 388 is drawn in tension
20 and com~resses the semicylindrical surface 390 against the outer surface of the
axle 90. In this manner, the axle is compressively clamped between the upper
U-shaped flange 388 and the lower inner band 434.
Typically, there are two such mounting assemblies at each of the
trailing arms in a manner illustrated in FIG. 3, and there are typically two
25 trailing arms on each suspension. Thus, there are four such axle mounting
assemblies illustrated in FIGS. 33 and 34 on each axle.
The invention also contemplates the attachment of brake ~ctu~tQr
components to the axle mounting plates to avoid mounting of the brake
components directly to the axle. The mounting bracket for the actuator
30 chamber can be mounted to the axle mounting assembly. Mounting of the
S-cam bearing and the actuator mounting bracket to the axle mounting assembly
will avoid welding of the brake actuator mounting bracket to the axle itself and
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shortens the S-cam shaft, thereby saving weight and cost as well as reducing a
potential crack initiation site on the axle.
Reference is now made to FIGS. 35-37 which show an axle
mounting assembly according to the invention and a brake actuator mounted to
the axle mounting assembly. Like numerals have been used to designate like
parts. The suspension system is the same as illustrated in FIGS. 1-3. A
conventional shock absorber 450 is pivotably mounted at one end to the frame
10 and at another end to the trailing arm 18. The bracket plate 380 is mounted
to the trailing arm through bushed pins 26 and 28. An upper U-shaped wrapper
10 plate 362 having lower edges 364 is welded to the bracket plate 380 through
suitable welds 474 (FIG. 37). The welds 474 appear on both sides of the
bracket plate. As see in FIG. 37, the upper U-shaped plate 362 extends
laterally from each side of the bracket plate 380 to provide a semicircular
surface 365 to bear against the outer surface of the round axle 90. A lower
15 U-shaped plate 366 having upper edges 368 has a semicylindrical inner surface369 (FIG. 37) which bears against the outer surface of the mount axle 90. The
upper and lower U-shaped plates 362 and 366 are joined through a weld 370
after being pressed together in a manner described above to apply compression
to the axle 90.
As illustrated in FIGS. 36 and 37, there are two axle mounting
assemblies at each of the trailing arms. A brake actuator chamber bracket 452
is mounted to each of the lower U-shaped plates 360 in a pair of axle
assemblies as illustrated in FIGS. 36 and 37. The brake actuator chamber
bracket 452 comprises a pair of triangular side plates 466 and a rect~n~ r end
25 plate 468. A central opening 470 and a pair of bolt openings 472 are formed in
the rect~ngnl~r end plate 468. A brake actuator chamber 454 is mounted to the
brake actuator chamber bracket 452 through bolts ~not shown) which extend
through the bolt openings 474 in the rect~ngll~r end plate 468. An actuator rod
455 extends from the brake actuator chamber and is connected to a slack
30 adjuster 456 which in turn mounts a crank arm 458. An S-cam shaft 460 is
rigidly connected to and is rotatably driven by the crank arm 458. The S-cam
shaft mounts an S-cam 464 and is journaled in an S-cam bearing 462. The
-
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S-cam bearing 462 is mounted to the bracket plate 380 through bolts 465 which
extend through bolt openings 385 in the bracket plate 380. The brake ~ct~ tor
comprising the brake chamber 454, the actuator rod 457, the slack adjuster 456,
the crank arm 458, the S-cam shaft 460 and the S-cam 464 are all conventional
and operate a brake on a wheel in conventional fashion. However, the
mounting of the S-cam bearing and the brake chamber 454 to the axle mounting
assembly is new and avoids welding of these components to an axle.
Reference is now made to FIGS. 38-40 which show yet another
embodiment of the invention. FIGS. 38-~0 show a suspension system as
10 disclosed in US-A 5,366,237 but with the axle mounting assembly according to
the invention in lieu of the axle mounting assembly disclosed in that patent. Inparticular, the suspension system comprises a pair of frame brackets 480 each ofwhich mounts a trailing arm 482 through a pivot assembly 484 of the type
disclosed in US-A 4,166,640. Each of the trailing arms 482 has an axle opening
15 486 in each side thereof so that an axle extends directly through the trailing
arm. The trailing arm 482 further mounts an air spring 490 and also mounts a
brake actuator comprising a brake actuator chamber 492 having an actuator rod
493, a crank arm 494, an S-cam 498 which is journaled in an S-cam bearing 496,
mounted to the trailing arm 482. The mounting of the brake actuator to the
20 trailing arm is further disclosed in US-A 5,366,237.
According to the invention, the axle mounting assembly illustrated
in FIG. 30, for example, is used to mount the axle 90 to the trailing arms 482.
Thus, the upper U-shaped plate 362 and the lower U-shaped plate 366 are
welded to the sides of the trailing arm through weld beads 500.
Referring now to FIG. 41, there is shown a spring brake actuator
chamber 454 mounted to an axle 90 shown in phantom lines. Like numeral
have been used to de~ign~te like parts. The embodiment shown in FIG. 41 is
very similar to the embodiment shown in FIGS 36 and 37 except that the spring
brake actuator chamber is mounted to an upper side of the axle 90 through a
30 wrapper band which is not attached to a suspension but exists independently of
the suspension. An upper U-shaped plate 362 provides a semicircular surface
365 to bear against the outer surface of the round axle 90. A lower U-shaped
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plate 366 having upper edges 368 has a semicylindrical inner surface 369 which
bears against the outer surface of the axle 90. The upper and lower U-shaped
plates 362 and 366 are joined through welds 370 after being pressed together in
a manner described above to apply compression to the axle 90. A brake ~ct~l~tor
S chamber bracket 452 is mounted to the upper U-shaped plate 360. The brake
actuator chamber bracket 452 comprises a pair of tri~n~ r side plates 466 and
a rect~ng~ r end plate 468. A central opening 470 and a pair of bolt openings
472 (FIG. 37) are formed in the rectangular end plate 468. The brake actuator
chamber 454 is mounted to the brake actuator chamber bracket 452 through
10 bolts (not shown) which extend through the bolt openings 474 in the rect~ng~ r
end plate 468. An actuator rod 455 extends from the brake actuator chamber
and is connected to a slack adjuster 456 which in turn is connected to a crank
arm 458. The crank arm 458 is rotatably mounted in a cam bracket 510 through
an S-cam shaft 460 whereby the S-cam shaft is rotatably driven by the crank arm
15 458. The S-cam shaft mounts an S-cam 464 (FIG.37) and is journaled in an
S-cam bearing (not shown~. The brake actuator comprising the brake chamber
454, the actuator rod 45~, the slack adjuster 456, the crank arm 458, the S-cam
shaft 460 and the S-cam 464 are all conventional and operate a brake on a
wheel in conventional fashion. However, the mounting of the brake chamber
20 454 to the wrapper band formed by the upper and lower U-shaped plates, 362,
366, respectively, is new and avoids welding of these components to an axle.
A tower for mounting a radius rod to an axle can be mounted to
the axle through a wrapper band or bands in the same fashion as the brake
actuator is mounted to the axle as shown in FIG. 41. A conventional tower can
25 be welded to the wrapper band 360 through a bracket which conforms to the
exterior surface of the upper U-shaped plate 362. Otherwise the tower
mounting is conventional. However, the use of the wrapper band 360 to mount
a tower to the axle avoids welding of the tower directly to an axle as is
conventional.
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Reasonable variation and modification are possible within the
scope of the foregoing disclosure and drawings without departing from the spiritof the invention which is defined in the appended claims.
