Note: Descriptions are shown in the official language in which they were submitted.
CA 02433115 2006-05-01
A Retrofit Suspension System for a Vehicle
FIELD OF THE INVENTION
The present invention relates to suspension systems for commercial vehicles.
BACKGROUND OF THE INVENTION
Several suspension systems have been developed which improve the ability of a
vehicle's rear wheels to track the front wheels of the vehicle as it takes a
turn around a sharp
corner. For example, U.S. Patent No. 5,220,972 issued to the present inventor
on June 22, 1993
(hereinafter the '972 Patent) discloses a suspension system for permitting the
self-tracking of
rear axles by the use of angled torsion rods coupled with means for permitting
non-powered
lateral deflection of the suspension type employed on the vehicle. With the
suspension system
of the '972 Patent, the rear tires rotate closely along the line of travel of
the front tires such that
the rear tires track around the corner thereby allowing the driver to safely
negotiate a turn
without having to use two lanes of traffic. Such conventional suspension
systems although
operable with significant success may not be cost effective to manufacture and
install on all
types of vehicles.
1
CA 02433115 2003-06-23
OBJECTS OF THE INVENTION
One object of the present invention to provide a kit to easily and cost
effectively retrofit
old vehicles with a suspension system that cause the rear tires to rotate
closely along the line of
travel of the front tires such that the rear tires track around the corner
thereby allowing the driver
to safely negotiate a turn without having to use two lanes of traffic.
SUMMARY OF THE INVENTION
The present invention is a suspension system for use with a trailer or truck
having a frame
and front and rear axles. In one embodiment, the suspension system comprises a
front hanger
having a lower portion, a bearing portion, and an upper portion engaged with
the frame. The
suspension system further comprises a hanger assembly having a lower portion,
an upper portion
engaged with the frame and a rocker arm having first and second bearing
portions. The
suspension system further comprises a rear hanger engaged with the frame and
having a bearing
portion. The suspension system further comprises a first saddle engaged with
the front axle and a
second saddle engaged with the rear axle. The suspension system further
comprises a leaf spring
having a first end portion engaged with the bearing portion of the front
hanger and a second end
portion engaged with the first bearing portion of the rocker arm. The
suspension system further
comprises a torque bar having a first end portion engaged with the front
hanger and a second end
portion engaged with the first saddle of the front axle. The suspension system
further comprises a
leaf spring assembly comprising an upper leaf spring having a first end
portion engaged with the
second bearing portion of the rocker arm and a second end portion engaged with
the bearing
portion of the rear hanger. The first and second end portions of the upper
leaf spring have a width
that is substantially less than the width of the second bearing portion of the
rocker arm and the
2
CA 02433115 2003-06-23
bearing portion of the rear hanger. The suspension system further comprises a
torque bar
assembly having a first end portion engaged with the hanger and rocker
assembly and a second
end portion engaged with the second saddle of the rear axle.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of the invention will be more fully
understood with
reference to the accompanying drawings in which:
Fig. 1 is a plan view of a two axle vehicle (such as a trailer) retrofitted
with the
suspension system of the present invention;
Fig. 2 is an exploded view of section 2-2 of Fig. 1;
Fig. 3 is an exploded view of section 3-3 of Fig. 1;
Fig. 4 is an exploded view of section 4-4 of Fig. 1;
Fig. 5 is plan view of the two axle vehicle retrofitted with the suspension
system of the
present invention;
Fig. 6 is a plan view of a torque rod and bolt kit of the present invention;
Fig. 7 is an exploded view of the torque rod and bolt kit of the present
invention;
Fig. 8 is a side elevation view of the leaf spring of the present invention;
and
Fig. 9 is an exploded view of the leaf spring of the pres.ent invention.
Fig. 10 is a plan view of a three axle vehicle having retrofitted with the
suspension system
of the present invention;
Fig. 11 is an exploded view of section 11-11 of Fig. 10;
Fig. 12 is an exploded view of section 12-12 of Fig. 10;
Fig. 13 is an exploded view of section 13-13 of Fig. 10;
3
CA 02433115 2003-06-23
Fig. 14 is an exploded view of section 14-14; and
Fig. 15 is plan view of the three axle vehicle retrofitted with the suspension
system of the
present invention.
DETAI[..ED DESCRIPTION OF THE INVENTION
Referring to Figs. 1-5, wherein the suspension system 10 of the present
invention is
shown retrofitted to a commercial trailer 12 having a frame 81 and first and
second rear axles 14
and 16. Axles 14 and 16 each have a whee120 mounted to each end thereof by a
hub (not
shown). The system 10 generally comprises a torque bar asserribly 22 and a
leaf spring assembly
24 mounted to first rear axle 14 by a saddle 23 and a torque bar 26 and a leaf
spring 28 mounted
to the second rear axle 16 by a saddle 27. The system 10 further comprises a
front hanger 30
having a first end portion 32 securely connected to the frame 81 by
conventional means such as
welding. The front hanger 30 further comprises a second end portion 34 and a
bearing surface 36.
The leaf spring 28 has first and second end portions 38 and 40 and a median or
bearing portion
42. The torque bar 26 has first and second end portions 39 and 41. The second
end portion 40 of
the leaf spring 28 is in bearing contact with the bearing surface; 36 and
extends outward and
upward therefrom. The second end portion 39 of the torque bar is securely
connected to the
second end portion 34-of the front hanger 30. The system 10 fiirther comprises
a hanger assembly
48 having a rocker arm 52 rotatably connected to a hanger 50. The rocker arm
52 comprises a
first bearing surface 54 and a second bearing surface 56. The hanger 50
comprises a lower
portion 53 and an upper portion 55 securely connected to the fi-ame 81 by
conventional means
such as welding. The first end portion 38 of the leaf spring 28 is in bearing
contact with the
bearing surface 56 and extends outward and upward therefrom. The second end
portion 41 of the
4
CA 02433115 2006-05-01
torque rod 26 is securely connected to the saddle 27 by conventional means
such as U-bolts and
nuts. The system 10 further comprises a rear hanger 58 having an upper portion
60 securely
connected to the frame 81 and a lower portion 62 and a bearing surface 55. The
bearing surface
55 has a width Wl. The leaf spring assembly 24 generally comprises a first end
portion 64, a
median portion 66, and a second end portion 68. The torque bar assembly 22
generally
comprises a first end portion 70 and a second end portion 72. The median
portion 66 is
engaged to the saddle 23 and axle 14 by conventional means such as a U-bolt
assembly 74. The
second end portion 68 of the leaf spring assembly 24 is in bearing contact
with the bearing
surface 54 of the rocker arm 52 and extends outward and downward therefrom.
The first end
portion 64 of the leaf spring assembly 24 is in bearing contact with the
bearing surface 55 of the
rear hanger 58 and extends outward and downward therefrom. The first end
portion 70 of the
torque bar assembly 22 is securely connected to the lower end portion 53 of
the hangar 50 while
the second end portion 72 is securely connected to the saddle 23.
Referring to Figs. 6 and 7, where the torque bar assembly 22 generally
comprises a
torque bar 80 having a first threaded end portion 82 and a second threaded end
portion 84.
The torque bar assembly 22 further comprises a first outer mounting fitting 86
securely and
rigidly connected to the first end portion 82. The torque bar assembly 22
further comprises a
second outer mounting portion 88 securely and rigidly connected to the second
end portion 84.
The torque bar assembly 22 further comprises an inner mounting portion 90
disposed and
moveably encapsulated by an encapsulation medium 92 within the outer mounting
portion 86.
The torque bar assembly 22 further comprises an inner mounting portion 94
disposed and
moveably encapsulated by an encapsulation material 96 within the outer
mounting portion 88.
5
CA 02433115 2003-06-23
Encapsulation mediums 92 and 96 is preferably a polymer based material that
allows a small
amount of movement between the inner mounting portions 90 and 94 and the outer
mounting
portions 86 and 88, respectively. In the non biased state, the inner portions
90 and 94 are at an
angle Al of 27.5 degrees with respect to the centerline C of the torque rod
80. The torque bar
assembly 22 further comprises a pair of safety washers 98 and 100 mounted at
opposite ends of
the inner mounting portion 94. The torque bar assembly 22 further comprises a
first cylindrical
spacer 102 having a thru hole 104 and a second cylindrical spacer 106 having a
thru hole 108.
The torque bar assembly 22 further comprises a bolt 110 having a threaded end
portion 112. The
bolt I 10 is adapted to pass through the washer 98, the inner mounting member
94, the washer
100, the spacer 102, an opening 114 of hanger 50, the spacer 106, an opening
116 of hanger 50
and secure the entire assembly together by a nut 118. The torque bar assembly
22 further
comprises a flange portion 120 having side portions 120 and 122 securely and
rigidly connected
by, for example, welding to the spacer 102 and a side wall 124 of the hanger
50, respectfully. The
flange portion 120 is provided to give added strength to the torque bar
assembly 22.
Referring to Figs. 8 and 9, where the leaf spring assembly 24 is shown
generally
comprising end portion 64, median or bearing portion 66, and end portion 68 as
previously
identified. The leaf spring assembly 24 generally comprises an upper leaf
spring 130, a middle
leaf spring 132 and a lower leaf spring 134. Each of the leaf springs 130,
132, and 134 have a
median portion 136 and a thru hole 138. Leaf springs 130, 132, and 134 are
securely fastened
together conventional means such as a bolt 140 and nut 142. The median portion
136 of the
upper leaf spring 130 has a width W1 (3.0 inches) and end portions 64 and 68
have a width W2.
It is critical that width W2 be 1.0 inches less than W1 to allow= for movement
of the end portions
6
CA 02433115 2003-06-23
64 or 68 within the bearing surface or channels 55 and 54, respectfully. The
width OV 1 of the
median portion of the upper leaf spring 130 is about 3.0 inches. The upper
leaf spring 130 has
tapered portions 144 and 146 which decrease from width W1 of the median
portion 136 to the
width W2 of the end portions 64 and 68. The middle leaf spririg 132 has first
and second end
portion 148 and 150 having a width W4. The middle leaf spring 132 further
comprises tapered
portions 152 and 154 which decrease from width W3 of the median portion 136 to
the width W4
of the end portions 148 and 150. The width W3 of the median portion of middle
leaf spring 132
is substantially the same as the width W1 of the median portion 136 of the
upper leaf spring 130.
The width W4 of the end portions 148 and 150 are substantially the same but
not greater than the
width of the tapered portions 144 and 146. Springs 130, 132, and 134 each have
a thickness of
about 0.750 inches. The tapered portions 152 and 154 have the same decreasing
width as tapered
portions 144 and 146 of upper leaf spring 130. The lower leaf spring 134
comprises a first and
second end portion 156 and 158 having a substantially uniforcri width WS which
is substantially
the same but not larger than the width W3 of the middle leaf spring 132 and
width W 1 of the
upper leaf spring 130. Upon assembly of the leaf springs 130, 132, and 134,
the leaf spring
assembly 22 maintains the necessary elasticity andlor flexural properties
while allowing for
movement of end porti-ons 64 and 68 within the bearing surfaces or channels 55
and 56,
respectfully. Leaf springs 130, 132, and 134 are preferably made from steel
and manufactured
from machine and/or casting processes.
Referring to Figs. 10-15, where a second embodiment of the suspension system
10 is
shown engaged with a vehicle such as a trailer having three axles: axles 14
and 16 and a third
axle 170. The suspension system 10 comprises front and rear hangers 30 and 58
and hanger
7
CA 02433115 2003-06-23
assembly 48, as heretofore described. The suspension system 10 further
comprises a saddle 190
disposed upon the third axle 170 and a second hanger assembly 172 having a
rocker arm 176
rotatably connected to a hanger 174. The rocker arm 176 comprises a first
bearing surface 188
and a second bearing surface 190. The hanger 174 comprises a lower portion 180
and an upper
portion 178 securely connected to the frame 14 by conventional means such as
welding.. The first
end portion 38 of the leaf spring 28 is in bearing contact with the bearing
surface 188 and
extends outward and upward therefrom. The second end portion 41 of the torque
bar 26 is
securely connected to the saddle 196 by conventional means such as U Bolts and
nuts.
The suspension system of the present invention has been shown in connection
with two
and three axle vehicle. The present invention , however, may be easily
configured for used with
vehicle having more than three axles.
The foregoing description is intended primarily for purposes of illustration.
This
invention may be embodied in other forms or carried out in other ways without
departing from
the spirit or scope of the invention. Modifications and variations still
falling within the spirit or
the scope of the invention will be readily apparent to those of skill in the
art.
8
