Note: Descriptions are shown in the official language in which they were submitted.
CA 02451017 2008-06-26
MODULAR SNOWMOBILE PLATFORM
RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional
Patent
Application Serial No. 60/429,536 entitled "MODULAR SNOWMOBILE PLATFORM"
which was filed on November 29, 2002. This application is also related to U.S.
Non-
Provisional Patent Application Serial Number 10/141,135, which was filed on
May 9, 2002,
now published as U.S. Publication No. 2002/0129984. This application is also
related to U.S.
Non-Provisional Patent Application Serial No. 09/877,064, filed June 11, 2001,
now issued as
U.S. Patent No. 6,446,744, claiming priority to U.S. Provisional Patent
Application Serial No.
60/246,110, filed November 7, 2000. In addition, this application relates to
U.S. Non-
Provisional Patent Application Serial No. 09/472,133, entitled "IMPROVED
VEHICLE"
filed on December 23, 1999. That application claims priority to Canadian
Patent Application
No. 2,256,944, which was filed on Dec. 23, 1998. This application also relates
to U.S. Non-
Provisional Patent Application Serial No. 09/472,134, entitled "SNOWMOBILE,"
which was
filed on Dec. 23, 1999, now published as U.S. Publication No. 2003/0201128. In
addition,
this application relates to U.S. Provisional Patent Application Serial No.
60/230,432, entitled
"A NOVEL THREE-WHEELED VEHICLE," which was filed on Sep. 6, 2000. Finally,
this
application relates to U.S. Provisional Patent Application No. 60/237,384,
which was filed on
Oct. 4, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention concerns the construction of a snowmobile. More
specifically, the present invention conceYns, first, a method for the design,
construction, and
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assembly of platform for a snowmobile and, second, the platform made according
to that
method.
2. Description of the Related Art
[00031 The basic platform for a conventional snowmobile includes three
components,
a tunnel at the rear of the snowmobile, an engine cradle connected at the
front of the tunnel,
and a front suspension connected to the engine cradle. The three components
are integrally
connected to form a unitary structure that is rigid enough to withstand the
forces impingent
thereupon during operation of the snowmobile.
[0004] In the conventional snowmobile, the tunnel is disposed above an endless
track
that propels the vehicle. The engine cradle is the structural portion of the
platform that
extends forwardly from the tunnel. and supports the engine near the front of
the vehicle. The
front suspension is the structural component integrated as a part of the
engine cradle, located
to the sides of the engine cradle. The steering skis are suspended from the
front suspension,
which includes shock absorbers that dampen the forces encountered by the skis
as the vehicle
travels over either groomed or rough terrain.
[0005) Figure 1 illustrates the construction of one conventional snowmobile
platform
10. The tunnel 12 and the engine cradle 14 are depicted in this illustration.
The tunnel 12
forms the rear portion of the platform 10 while the engine cradle 14 forms the
forward
portion of the platform 10.
[0006] The tunnel 12 is essentially an inverted, U-shaped element. The tunnel
12 has
a top portion 16, a left side portion 18, and a right side portion 20. A left
side foot board 22
extends outwardly from the left side portion 18 of the tunnel 12. A right side
foot board (not
shown) similarly extends outwardly from the right side portion 20 of the
tunnel 12.
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[0007] The rear end 24 of the engine cradle 14 is attached at the front end 26
of the
tunnel 12. The engine cradle 14 includes a bottom pan 28, a left side wall 30,
a right side
wall 32, a front portion 34, and a rear portion 36. Together, the bottom pan
28, the left side
wall 30, the right side wall 32, the front portion 34, and the rear portion 36
create a rigid
structure onto which the engine for the snowmobile is secured. A structural
upright 38 is
connected adjacent to the rear portion 36 of the engine cradle 14. The upright
38 provides
structural support for the handlebar used to steer the snowmobile.
[0008] The tunnel 12 includes openings 40 through the left side 18 and through
the
right side 20. A drive shaft (not shown) passes through the openings 40. The
drive shaft
operatively connects to the endless track positioned beneath the tunnel 12 to
propel the
vehicle. The drive shaft also operatively conriects to the engine (not shown),
which sits
above the bottom pan 28 of the engine cradle 14. As would be understood by
those skilled in
the art, motive power is transferred from the engine to the endless track via
the drive shaft.
The opening 40 in the left side 30 of the engine cradle 14 is also illustrated
in Figure 1. A
similar opening (not shown) also passes through the right side 32 of the
engine cradle 14.
The openings 40 in the engine cradle 14 and the openings 40 in the tunnel 12
lie in register
with one another so that the drive shaft passes through all four of the
openings when the
tunnel 12 and the engine cradle 14 are assembled together.
[0009] Figure 2 illustrates one possible embodiment of the front suspension 42
for a
conventional snowmobile. While the details of the engine cradle 14 in Figure 2
differ slightly
from those illustrated in Figure 1, those skilled in the art would appreciate
readily that the
front suspension 42 illustrated in Figure 2 may be incorporated as a part of
the platform 10
illustrated in Figure 1.
[0010] The left-hand side of the front suspension 42 is shown in Figure 2. As
would
be appreciated by those skilled in the art, the right-hand side of the front
suspension 42 is a
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mirror image of the left-hand side. The left-hand side of the front suspension
42 includes a
ski leg 44 that is rotatably coupled to a lever arm 46. The lever arm 46, in
turn, is pivotally
connected to the engine cradle 14 via a structural pivot 48. The lever arm 46
pivots up and
down as the snowmobile travels over the ground.
[0011] The forward end 50 of the lever arm 46 inch.ades a bracket 52 that
connects to
the lower end 54 of a shock absorber 56. The upper end 58 of the shock
absorber 56 connects
to a bracket 60 that is, in turn, connected to the engine cradle 14 at a
location 62 near a
forward end thereof. The shock absorber 56 dampens the forces encountered by
the ski 64
connected at the lower end of the ski leg 44.
[0012] As Figures 1 and 2 illustrate, the tunnel 12, the engine cradle 14, and
the front
suspension 42 are integrally assembled to create a rigid frame onto which the
remaining
elements of the snowmobile are attached.
[0013] In the construction of the conventional snowmobile platform 10, the
width of
the tunnel 12 and the width of the engine cradle 14 are selected as a function
of the width of
the endless track that propels the vehicle. While engine size typically varies
from one model
of snowmobile to another, the width of the endless track, and therefore the
width of the tunnel
12 and the engine cradle 14, typically remains the same regardless of the size
of the engine
employed to propel the vehicle. This is because the width of the endless track
typically
remains the same for all types of snowmobiles.
[0014] There are several engine sizes typically incorporated into conventional
snowmobiles, including 600 cc (cubic centimeters of displacement), 700 cc, and
800 cc
varieties, for example. To accommodate each of these engine sizes, the front
suspension 42
and the tunnel 12 of each platforni differs from one vehicle to another. The
front suspensions
42 differ between vehicle types to accommodate the variations in weight of the
different
engines. As a general rule, the larger the displacement volume, the heavier
the engine.
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Therefore, the front suspension needs to be more robust. The tunnels 12 vary
from one
vehicle to another to accommodate different lengths of the endless track.
[0015] While the width of the endless track typically remains the same, the
length of
the endless track can vary from one snowmobile type to another. For a racing
snowmobile,
which is designed primarily for groomed surfaces, the endless track typically
is shorter than
the endless track incorporated into a mountain snowmobile, which is designed
to operate in
ungroomed (or powder) snow. Accordingly, the tunnel 12 for a racing snowmobile
is
generally shorter than the tunnel 12 for a mountain snowmobile. In addition,
the weight of a
racing snowmobile is of critical concern because unnecessary weight slows the
vehicle,
which is antithetical to racing.
[0016] Once the platform 10 for the vehicle is designed, the chassis for the
snowmobile is designed around it. As with the platforrri 10, the chassis is
designed to
accommodate variation in the components of the vehicle.
[0017] To manufacture each new vehicle type, whether it is a racing
snowmobile, a
mountain snowmobile, or a hybrid variety, considerable engineering and
manufacturing
resources are required. Each new vehicle must be designed from the ground up.
From an
engineering standpoint, therefore, each new vehicle consumes a significant
number of
engineering hours because the platform 10 of the vehicle has to be designed
from scratch. In
addition, from a manufacturing standpoint, each new vehicle consumes a
significant number
of training hours, because the technicians responsible for assembling the
vehicle must be
trained to understand the construction of each new vehicle so that the vehicle
may be
assembled properly on the assembly line. The design and. manufacture of a
conventional
snowmobile, therefore, is inherently inefficient both from a design and from a
manufacturing
standpoint, because there is a considerable duplication of effort for each new
vehicle that is
designed and manufactured.
CA 02451017 2003-11-27
[0018] Accordingly, the inefficient method of designing and manufacturing
conventional snowmobiles cries out for a solution.
[0019] The prior art does not provide a solution for this inefficiency.
Summary of the Invention
[0020] Recently, Bombardier Inc. (Bombardier) of Montreal, Quebec, Canada, a
leading producer of snowmobiles, redesigned its snowrnobile in response to
consumer
demand and in an effort to update the design and construction of the vehicle.
While
designing its new vehicle, Bombardier reexamined the traditional design and
manufacturing
of snowmobiles to address the inefficiencies enumerated above.
[0021] As will be made apparent in the discussion that follows, the new design
selected by Bombardier for its new snowmobile led to a departure from
traditional design and
manufacturing techniques and, as a result, led to the development of the
present invention.
[0022] Among other aspects and benefits, the present invention provides a
novel
engineering and manufacturing method for the construction of a snowmobile
platform that
resolves many of the inefficiencies identified with the design and
manufacturing of traditional
snowmobile platforms.
[0023] In particular, it is one aspect of the present invention to provide a
method of
designing and manufacturing snowmobile platforms where the cost associated
with the
design and manufacture of the platform is greatly reduced by comparison with
the traditional
design and manufacturing technique.
[0024] Another aspect of the present invention provides a standardized design
for a
snowmobile platform.
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[0025] Still another aspect of the present invention provides a snowmobile
platform
that is modular in design. Among other things, the modular design accommodates
variation
between individual platforms while maximizing interchangeability of platform
coinponents.
[0026] Among other aspects, the present invention provides for a method of
assembling a snowmobile platform. The method entails designing and
manufacturing a
group of tunnel subassemblies comprising at least two tunnel subassemblies. In
addition, the
method includes designing and manufacturing a group of engine cradle
subassemblies
comprising at least two engine cradle subassemblies and designing and
manufacturing a
group of front suspension subassemblies comprising at least two front
suspension
subassemblies. Next, one tunnel subassembly from the group of tunnel
subassemblies, one
engine cradle subassembly from the group of engine cradle subassemblies, and
one front
suspension subassembly from the group of front suspension subassemblies are
selected.
Then, the tunnel subassembly is connected to the engine cradle subassembly at
a rear portion
thereof. Finally, the front suspension subassembly is connected to the engine
cradle
subassembly at a front portion thereof to create the snowmobile platfonn.
[0027] Another aspect of the present invention is the provision of a
snowmobile
platform. The platform includes a tunnel subassembly selected. from a group of
tunnel
subassemblies. It also includes an engine cradle subassembly, selected from a
group of
engine cradle subassemblies, attached forwardly of the tunnel subassembly. The
platform
also includes a front suspension subassembly, selected from a group of front
suspension
subassemblies, attached forwardly to the engine compartment subassembly.
[002E] Other aspects of the present invention will become apparent from the
discussion that follows.
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Description of the Drawings
[0029] Throughout the description of the present invention, reference to
common
elements will be made using the same reference numbers, in. which:
[0030] Figure 1 is an exploded, perspective illustration of a platform of a
prior art
snowmobile, illustrating the tunnel and engine cradle that form a part of the
platform;
[0031] Figure 2 is an exploded perspective illustration of the front
suspension
subassembly for the platfonn of a prior art snowmobile, such as the platform
illustrated in
Figure 1;
[0032] Figure 3 is a perspective illustration of the snowmobile that provided
the
impetus for the teachings of the present invention;
[0033] Figure 4 is a perspective illustration, from the left, rear side, of
the
snowmobile platform from the snowmobile illustrated in Figure 3;
[0034] Figure 5 is a schematic illustration of the relative dimensions
associated with
the basic elements of the snowmobile platform constructed in accordance with
the teachings
of the present invention;
[0035] Figure 6 is a schematic illustration of several variations for the
front
suspension subassembly for the snowmobile platform designed and manufactured
according
to the teachings of the present invention;
[0036] Figure 7 is a schematic illustration of several variations for the
engine cradle
subassembly for the snowmobile platform designed and manufactured according to
the
teachings of the present invention;
[0037] Figure 8 is a schematic illustration of several variations for a
snowmobile
platform, emphasizing the intercliangeability of the platform components in
accordance with
the teachings of the present invention; and
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[0038] Figure 9 is a schematic illustration of several additional variations
for the
snowmobile platform designed and manufactured according to the teachings of
the present
invention, showing two groups of possible variants of the platform, each of
which share a
common tunnel subassembly.
Description of Embodiment(s) of the Invention
[0039) Figure 3 illustrates one possible embodiment of a snowmobile 100
designed
and constructed in accordance with the teachings of the present invention. The
snowmobile
100 has a front end 102 and a rear end 104. The front end 102 is provided with
one or more
fairing elements 106, including a bottom pan 108, a side panel 110, and a
motor cover 112
As would be understood by those skilled in the art, the front end 102 of the
snowmobile 100
houses the engine (not shown) beneath the fairing elements 106. A front
suspension 114 is
connected at the front end 102 of the snowmobile 100. As with the prior art
snowmobile, two
skis 116 are suspended from the front suspension 114.
[0040] The endless track 118 that is operatively cormected to the engine is
disposed
beneath the rear end 104 of the snowmobile 100. A seat 120 is positioned
generally above
the endless track 118. A windshield 122 is disposed atop the fairing elements
106 at the front
end 102 of the snowmobile 100. A handlebar (not shown) is positioned behind
the
windshield 122. The handlebar is operatively connected to the skis 116 so that
the
snowmobile 100 may be turned during operation.
[0041] The front suspension 114 of the snowmobile 100 differs from the front
suspension 42 on the prior art snowmobile ilh:istrated in ],"igures 1 and 2 in
at least one
significant respect. In particular, the front suspension 114 is a double A-arm
suspension,
much like the type of suspension incorporated into automobiles. Shock
absorbers 124
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connect between the A-arms 126 of the front suspension 114 and the frame of
the
snowmobile 100 to dampen the iorces experienced by the snowmobile 100 during
operation.
[0042] Figure 4 illustrates, from the rear left side, the platform 128
designed for the
snowmobile 100 illustrated in Figure 3. The platform 128 includes a tunnel
subassembly 130
with a rear end 132 and a front end 134. The tunnel subassembly 130 comprises
an inverted
U-shaped tunnel 136 having a top portion 138 and left and right sides 140, 142
extending
downwardly from the top portion 138. A left footboard 144 extends outwardly
from the
bottom of the left side 140 of the tunnel 136. Similarly, a right footboard
146 extends
outwardly from the bottom of the right side 142 of the tunnel 136. A radiator
148 is
incorporated into the top portion 138 of the tunnel 136 and is a part of the
tunnel subassembly
128 illustrated in this figure. The radiator 148, which fluidly connects to
the engine to cool
the engine, is positioned to receive snow thrown thereupon by the endless
track 118
positioned beneath the tunnel 136.
[0043] Figure 4 also illustrates another aspect of the tunnel 136. In
particular, the
tunnel 136 has a left-hand portion 141 and a right-hand portion 143. As
illustrated, the left-
hand portion 141 and the right-hand portion 143 are connected to either side
of the radiator
148. So constructed, the left-hand portion 141 and the right-hand portion 143
may be
separated from the radiator 148 and replaced with wider or narrower
replacements to widen
or narrow the width of the tunnel 136.
[0044] As would be appreciated by those skilled in the art, the radiator 148
need not
be included in the tunnel 136. If the radiator is omitted, the left-hand
portion 141 and the
right-hand portion 143 would join one another at a seam roughly at the center
of the tunnel
136. With such a construction, the left-hand portion 141 could be separated
from the right-
hand portion 143 so that the two portions could be replaced with wider or
narrower left-hand
CA 02451017 2003-11-27
and right-hand portions 141, 143. Accordingly, the width of the tunnel 136
could be made
wider or made narrower, depending upon the width required. for the platform
128.
[0045] An engine cradle subassembly 150 connects to the front end 134 of the
tunnel
subassembly 128. The engine cradle subassembly 150 includes, among other
elements, a
bottom pan 152, a left wall 154, a right wall 156, a front wall 158, and a
rear wall (not
shown). An opening 160 is disposed through both the left wall 154 and the
right wall 156 of
the engine cradle assembly 150. The drive shaft (not showri) of the snowmobile
100 extends
through the opening 160. The drive shaft connects between the erigine and the
endless track
118 to transmit motive power from the engine to the endless track 118.
[0046] As Figure 4 illustrates, the left side wall 154 and the right side wall
156 of the
engine cradle subassembly 150 do not need to have the same construction. In
particular, the
left side wall 154 has an open construction, which permits ready access to the
engine placed
within the engine cradle subassembly 150. The right side wall 156, on the
other hand, has a
closed construction that reflects heat generated by the engine back into the
engine cradle
subassembly 150. Accordingly, the right side wall 156 helps to manage heat
losses from the
engine during operation of the snowmobile. Other constructions for the left
side wall 154 and
the right side wall 156 are also possible, including a closed construction
with removable
sections to facilitate access to the engine when the engine is tnaintained or
serviced.
[0047] In another embodiment, it is contemplated that the tunnel subassembly
130
and the engine cradle subassembly 150 may be manufactured together as an
integral
component of the platform 128. If so manufactured, the left side 140 of the
tunnel and the
left wall 154 of the engine cradle could be manufactured as a single, unitary
left side wall.
The right side 142 and the right wall 156 could be similarly combined. If the
platforrn 128
were to be constructed in this fashion, the left-hand wall and the right-hand
wall would
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extend the entire length of the engine cradle subassembly 150 and the tunnel
subassembly
130.
[0048] As shown in Figure 4, a front suspension subassembly 162 is connected
to and
extends forwardly from the engine cradle subassembly 150. The front suspension
subassembly 162 includes a V-shaped gnember 164 that is attached to the engine
cradle
subassembly 150. Right and left side walls 166, 168 extend upwardly and are
integrated with
or connected to the V-shaped member 164. The shock absorbers 124 and two A-
arms 126
extend outwardly from either side of the front suspension subassembly 162 to
support the skis
116 on either side of the snowmobile 100.
[0049] An upper frame subassembly 170 is connected to the platform 128 above
the
tunnel subassembly 130, the engine cradle subassembly 150, and the front
suspension
subassembly 162. The upper fraane subassembly 170 provides additional
structural rigidity to
the platform 128. The upper frame subassembly 170 includes two rear supports
172, a
middle support 174, and two forward supports 176. Together, the rear supports
172, middle
support 174, and forward supports 176 for a pyramid-shaped structure that is
connected to the
tunnel subassembly 130, the engine cradle subassembly 150, and the front
suspension
subassembly 162. Alternatively, the middle support 174 may be omitted, where
appropriate.
The upper frame subassembly 170 defines an apex 178, which supports the
steering
handlebar for the snowmobile 100.
[0050] The construction of the platform 128 differs i:rom the platform 10 of
the prior
art in at least one significant respect. In particular, the platform 128 is
designed and
constructed so that the front suspension subassembly 162 connects to the front
of the engine
cradle subassembly 150. For the prior art platform 10, the front suspension 42
was
positioned beside or beneath the engine cradle 14, was housed by the engine
cradle 14, or was
constructed as a part of the engine cradle 14.
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[0051] The change in the construction of the snowrnobile 100 to combine the
tunnel
subassembly 130, the engine cradle subassembly 150, and the front suspension
subassembly
162 together to construct the platform 128 illustrated in Figure 4 provides
numerous
advantages, one of which resulted in the development of the present invention.
[0052] In particular, the present invention capitalizes upon the fact that the
platform
128 is designed and constructed from the tunnel subassembly 130, the engine
cradle
subassembly 150 and the front suspension subassembly 162. In addition, the
present
invention also capitalizes on the split construction of the tunnel 136, which
has left-hand
portions 141 and right-hand portions 143 with a varying width. With such a
construction, it
is possible to mix and match components to accommodate different riding styles
of
snowmobiles, a construction methodology previously unavailable to the
snowmobile
manufacturer.
[0053] Figure 5 illustrates the basic design and constn.iction concept that
underlies the
present invention. In particular, the connection of a tunnel assembly 180, an
engine cradle
subassembly 182, and a front suspension subassembly 184 is illustrated. The
three
subassemblies are connected in the same order as the platform 128 illustrated
in Figure 4 to
create a platform 198. Since these subassernblies may not share the same
structural
components as the platform 128, different reference numbers are being used to
identify these
subassemblies.
[0054] As illustrated in Figure 5, the tunrrel subassernbly 180 has a length
186 and a
width 188. Similarly, the engine cradle subassembly 182 has a length 190 and a
width 192.
The front suspension subassembly 184 also has a length 194 and a width 196.
The width of
the platform 198 is defined by the largest width of the three subassemblies
180, 182, 184. In
this particular example, the width 188 of the tunnel subassembly 180 defines
the greatest
lateral dimension for the platfoim 198. It is expected that the tunnel
subassembly 180
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CA 02451017 2003-11-27
typically will be the widest of the three components. However, given the
variability that the
present invention offers, this need not always be the case.
[0055] Figure 6 illustrates schematically for different front suspension
subassemblies:
(1) a small platform front suspension subassembly 200, (2) a large platform
front suspension
subassembly 202, (3) a deep snow front suspension subassembly 204, and (4) a
trail front
suspension subassembly 206. Each of these front suspension subassemblies
differ from one
another according to the riding conditions anticipated. For example, the large
platform front
suspension subassembly 202 will be structurally more robust than the small
platform front
suspension subassembly 200.
[0056] Figure 7 schematically illustrates four different engine cradle
subassemblies:
(1) a small engine cradle subassembly 208, (2) a medium engine cradle
subassembly 210, (3)
a large engine cradle subassembly 212, and (4) an extra-large engine cradle
subassembly 214.
The small engine cradle subassembly 208 is designed and constructed to support
a small
engine, which includes a two-stroke, one-cylinder engine or a 277 cc-FC
engine, for example.
The medium engine cradle 210 is designed and constructed to accommodate a
medium-sized
engine such as a two-stroke 500 cc-FC engine, a similar engine with a larger
displacement, or
an LC engine with up to an 800 cc displacement, for example. The large engine
cradle
subassembly 212 is designed and constructed to accommodate large-sized engines
including,
among other varieties, both two-stroke and four-stroke engines with a
displacement of 995 cc
and up. It is also contemplated that the large engine cradle subassembly 212
may
accommodate an in-line, four-stroke engine. The extra-large engine cradle
subassembly 214
is designed and constructed to accommodate extra-large engines including, for
example, a
four-stroke, V-type 400 cc engine, a four-stroke, V-type 1400 cc engine, or an
engine of the
same size with a displacement between 400 cc and 1400 cc.
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[0057] As would be understood by those skilled in the art, the specific engine
varieties identified above are meant to be illustrative of the types of
engines contemplated for
placement into the particular engine cradle subassembly mentioned. The engines
listed,
however, are not meant to limit the invention. It is contemplated, for
example, that a small
engine cradle subassembly 208 may accommodate any other type of engine
therein.
Moreover, the designations "small," "medium," "large," and "extra-large" are
meant to be
illustrative of the variety of engine cradle subassemblies that may be
designed and
constructed according to the teachings of the present invention.
[0058] Two specific examples of different engine cradle subassemblies are
provided
below for illustrative purposes. As indicated above, these examples are meant
to be
illustrative only and are not meant to limit the scope of the present
invention.
Engine Cradle Subassembly for a Two-Stroke 600 cc Engine
Width 44 inches
Length 40 inches
Depth 20 inches
Sides one side open, one side closed
Front Engine Mounts 2 vertical rubber mounts
Rear Engine Mounts 2 vertical rubber mounts
Engine Cradle Subassembly for a V-Type 1000 cc Engine
Width 48 inches
Length 44 inches
Depth 30 inches
Sides both sides closed
Front Engine Mounts 2 horizontal i-ubber mounts
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Rear Engine Mounts T 2 vertical plate rubber mounts
[0059] As illustrated in Figure 8, the tunnel subassembly 180 also may be
designed
and constructed to have a variety of widths 188 and lengths 186. For example,
a short tunnel
subassembly 216 is contemplated for use with a small snowmobile, such as a
racing vehicle.
Conversely, a long tunnel subassembly 218 is contemplated for use with a
mountain
snowmobile, for example.
[0060] As the foregoing should make apparent, there can be considerable
variation
from one type of each of the three subassembl'res to another. Accordingly, the
method for the
design and construction of a snowmobile platform of the present invention
involves the
following. First, a multiplicity of tunnel subassemblies are designed and
constructed to meet
predeterrnined structural and operating characteristics. Second, a number of
engine cradle
assemblies are designed and constructed to meet predetermined structural and
operating
characteristics. Third, a number of front suspension subassemblies are
designed and
constructed to meet predetermined structural and operating characteristics.
Next, one from
each of the tunnel subassemblies, engine cradle subassemblies, and front
suspension
subassemblies are selected. The three selected subassemblies are then
assembled together to
form a platform for a particular snowmobile. Then, where additional frame
rigidity is
deemed appropriate, an upper frame subassembly is attac:hed to the completed
platform.
Once assembled, the remaining components of the snowmobile are assembled onto
the
platform.
[0061] Figure 8 provides one example of the variability of the design and
manufacturing method of the present invention. In the example provided in
Figure 8, the
front suspension subassembly is selected as a constant variable in the
construction of a
platform 220. As illustrated, the trail front suspension subaissembly 206 has
been selected.
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Four variations on the platform 220 are illustrated. The first variation
includes a medium
engine cradle subassembly 210 to accommodate a two-stroke 400 cc direct
injection internal
combustion engine. That engine cradle subassembly 210 is then combined with a
short
tunnel subassembly 216, which is common for a small snowmobile used for
racing, for
example. The second variation combines the trail front suspension subassembly
206 with the
medium engine cradle subassembly 210 and a long tunnel subassembly 218, such
as that
commonly provided for a mountain snowmobile. The third variation combines the
trail front
suspension subassembly 206 with the extra-large engine cradle subassembly 214
capable of
accommodating a four-stroke, V-type, 855 cc internal combustion engine. A
short tunnel
subassembly 216 is connected to these components to from the platform 220. The
fourth
variation combines the trail front suspension subassembly 206 with the extra-
large engine
cradle subassembly 214 and the long tunnel subassembly 218.
[0062] Figure 9 illustrates other variations in the construction of a platform
222. In
this example, the tunnel, which is selected as a long tunnel subassembly 218,
is combined
with any of the engine cradle subassemblies 208, 210, 212, 214 and front
suspension
subassemblies 200, 202, 204, 206 as may be appropriate for the snowmobile
being created.
[0063] As would be appreciated by those skilled in the art, the permutations
available
for the construction of a snowmobile platform using just the components listed
above is
considerable. With two tunnel subassembly variations, four engine cradle
subassembly
variations, and four front suspension subassembly variations, there are thirty-
two different
platforms that may be created. Naturally, if the number of tunnel
subassemblies, engine
cradle subassemblies, and front suspension subassemblies designed and
constructed as a part
of the group of potential subassemblies is increased, the number of variations
in pl.atforms
can be increased further still.
17
CA 02451017 2003-11-27
[0064] With this in mind, the snowmobile manufacturer may decrease, in some
instance greatly decrease, the cost associated with the design and
construction of snowmobile
platforms. Rather than designing each platform from scratch for each new
snowmobile,
which has been the practice in the prior art, the snowmobile manufacturer
needs only design
and construct one of the three subassemblies needed for the new vehicle. The
remaining two
subassemblies for the platform may be chosen from front suspension
subassemblies and
tunnel subassemblies previously designed. In addition, manufacturing costs may
be reduced,
because the knowledge and training required for assembly line professionals
may be reduced.
Other advantages also may be realized by practicing the present invention.
[0065] The embodiments of the present invention that are described above are
meant
to be illustrative of the present invention only. The embodiments illustrated
and described
are not meant to limit the present invention solely to the embodiments
described. Those
skilled in the art would readily appreciate the unlimited potential of the
present invention.
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