Note: Descriptions are shown in the official language in which they were submitted.
CA 02468333 2004-05-25
MULTI-PASSENGER SNOWMOBILE HAVING
A SEAT WITH A MOVEABLE BACK1Z»ST
[0001] This application claims the benefit of priority to U.S. Patent
Application
No. 60/472,733 filed on May 23, 2003, which is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates generally to the overall design and
construction
of a snowmobile, and more particularly to a design of a snowmobile that
improves the
driver's control over the snowmobile and the riders' comfort.
2. Description of the Related Art
[0003] Conventional snowmobiles 110 (FIG. i } share a common construction:
they
combine features and elements so that the rider (driver) 26 sits in a
generally upright position
in a location toward the rear of the snowmobile 110. When seated in this
fashion, the rider 26
sits a considerable distance behind the center of gravity 146 of the
snowmobile 110, which is
located at or in proximity to the axis of the forward-most axle 144 of the
drive track 120.
[0004] When the snowmobile 110 encounters a bump as it travels over the
ground, it
naturally tends to pivot about its center of gravity 146. Accordingly, the
fiuther the rider 26
is positioned from the center of gravity 146 of the snowmobile 110, the more
strongly the
rider 26 will feel each bump. This occurs because the snowmobile 110 acts as a
lever that
amplifies the magnitude of the forces transferred from bumps on the ground to
the rider 26.
[0005] As illustrated in FIG. 1, the positions of the handlebars, seat, and
footrests of a
conventional snowmobile 110 relative to its center of gravity 146 place the
driver 26 far
behind the center of gravity 146 of the snowmobile 110. Consequently, the
rider 26
experiences significant forces as the snowmobile 110 traverses each bump. When
a second
rider (passenger) 28 sits on the snowmobile 110 behind the driver 26 in a
second seat (2-up
rider positioning), the passenger 28 is positioned even farther away from the
snowmobile's
CA 02468333 2004-05-25
center of gravity 146 and experiences even more uncomfortable jostling when
the
snowmobile 110 encounters a bump.
(0006) While it would be desirable to add a third seat to accommodate a second
passenger (third rider), it has not been done because the riders are
positioned so far back on
the conventional snowmobile 110, that a third rider, who would be positioned
even farther
rearward on a third seat, would experience prohibitively large jostling
forces.
[0007] Accordingly, while the positioning of the driver and passenger on the
conventional snowmobile is entirely adequate for enjoying the sport of
snowmobiling, a need
has arisen for a snowmobile where the driver's and passenger's positions are
improved to
minimize the effect on the riders of the snowmobile's movement over uneven
terrain.
j0008] In addition, a desire has developed for a snowmobile that may
comfortably
accommodate two passengers in addition to the driver (3-up rider positioning).
SUMMARY OF THE INVENTION
[0009] The present invention improves upon the conventional design by
repositioning
the riders on the snowmobile and redesigning the layout of the snowmobile to
minimize the
effect of the snowmobile's movement on the driver and passenger{s) as they
pass over
uneven terrain. This improvement facilitates the addition of a third seat for
a third rider, who
experiences a reasonably comfortable ride.
[0010] One aspect of the present invention is to provide a snowmobile having a
frame, an engine disposed on the frame in front of the seat; a drive track
disposed below the
frame and connected operatively to the engine for propulsion of the
snowmobile; two skis
disposed on the frame; a steering device; and a straddle-type seat assembly
attached to the
Frame, the stxaddle--type seat comprising a first seat portion for a driver, a
second seat portion
for a first passenger, the second seat portion being disposed behind the first
seat portion, a
third seat portion for a second passenger, the third seat portion being
disposed behind the
second seat portion.
(0011 ] Another aspect of the present invention is to provides a snowmobile
further
comprising a rear idler wheel interposed between the drive track and the
frame, the rear idler
CA 02468333 2004-05-25
wheel having a rotational axis, wherein the third seat portion defines a seat
position that is
disposed forward of the rotational axis of the rear idler wheel.
[0012] Yet another aspect of the present inventions provides the second seat
portion
selectively detachable from the frame.
[0013] Another aspect of the present invention has the second and third seat
portions
permanently attached to 'each other and are selectively detachable from the
frame.
[0014] Yet another aspect of the present invention provides a backrest mounted
to the
third seat portion and the first seat portion, wherein the first seat portion
further includes a
backrest mounting pivot, and the backrest is removably mounted to the third
seat portion and
capable ofbeing removably mounting to the backrest mounting pivot on the first
seat portion.
[0015] Another aspect of the present invention is to have the first seat
portion with a
first seat surface, the second seat portion has a second seat surface that is
higher than the first
seat surface, and the third seat portion has a third seat surface that is
higher than the first seat
suxface.
[0016] Yet another aspect of the present invention provides a snowmobile
comprising
a frame; an engine disposed on the frame in front of the seat; a drive track
disposed below the
frame and connected operatively to the engine for propulsion of the
snowmobile; two skis
disposed on the frame; a steering device; and a straddle-type seat assembly
attached to the
frame, the straddle-type seat comprising a first seat portion for a driver,
the first seat portion
having a first backrest mounting point, and a backrest mounted to at least one
of the first seat
portion and the second seat portion.
[0017] Another aspect of the present invention provides the snowmobile with a
second seat portion for a first passenger, the second seat portion being
disposed behind the
first seat portion, the second seat portion having a second backrest mounting
point.
[0018] Still another aspect of the present invention provides a third seat
portion for a
second passenger, the third seat portion being disposed behind the second seat
portion, the
third seat portion having a third backrest mounting point for receiving the
backrest.
[0019] Yet another aspect of the present invention has the backrest
selectively
movable relative to the third seat portion between frst and second passenger
backrest
CA 02468333 2004-05-25
positions, the backrest is disposed above a rearward end of the third seat
portion when in the
second passenger backrest position, and the backrest is disposed above a
reazward end of the
second seat portion when in the first passenger backrest position.
[0020] Yet another aspect of the present invention provides the backrest
selectively
movable relative to the third seat portion into a driver backrest position in
which the backrest
is disposed above a rearward end of the first seat portion.
[0021] Another aspect of the present invention provides the third seat portion
detachable from the frame.
[0022] Yet another aspect of the present invention provides the backrest
attached to
the first seat portion, the backrest is movable between a driver backrest
position and a first
passenger backrest position, the backrest is disposed above a rearward end of
a first
passenger's seat portion when in the first passenger backrest position, and
the backrest is
disposed above a rearward end of the first seat portion when in the driver
backrest position.
[0023] Yet another aspect of the present invention provides a snowmobile
comprising
a frame; an engine disposed on the frame in front of the seat; a drive track
disposed below the
frame and connected operatively to the engine for propulsion of the
snowmobile; two skis
disposed on the frame; a steering device; and a straddle-type seat assembly
attached to the
frame, the straddle-type seat comprising a first seat portion for a driver, a
second seat portion
for a first passenger, the second seat portion being disposed behind the first
seat portion, a
third seat portion for a second passenger, the third seat portion being
disposed behind the
second seat portion, and left and right grab handles attached to left and
right sides of the third
seat portion.
[0024] Still another aspect of the present invention provides the snowmobile
with a
straddle-type seat assembly further comprising a first passenger hand hold
mounted to a
forward portion of the second seat portion.
[0025] Yet another aspect of the present invention shows the first passenger
hand
hold comprised of a looped strap.
CA 02468333 2004-05-25
[0026] Still another aspect of the present invention has the straddle-type
seat
assembly further comprising a first passenger hand hold mounted to a rearward
portion of the
first seat portion.
[0027] Additional and/or alternative aspects, objects, and features of
embodiments of
the present invention will be made more apparent in the description that
follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Various exemplary embodiments of the present invention will be
described
with reference to the following drawings, wherein like reference numbers
denote like
features, in which:
[0029] FIG. 1 is a side view illustration of a conventional snowmobile;
[0030] FIG. 2 is a side view illustration of a snowmobile according to a first
embodiment of the present invention;
[0031] FIG. 3 is a side view illustration of a snowmobile according to a
second
embodiment of the present invention;
[0032] FIGS. 4A and 4B show side views of a snowmobile according to a third
embodiment of the present invention;
[0033] FIG. 5 is a side view illustration of a snowmobile according to a
fourth
embodiment of the present invention;
[0034] FIGS. 6A and 6B show side view illustrations of a snowmobile according
to a
fifth embodiment of the present invention;
[0035] FIG. 7 is a side view illustration of a snowmobile according to a sixth
embodiment of the present invention;
[0036] FIG. 8 is a table comparing various dimensions of conventional
snowmobiles
and snowmobiles according to the present invention;
[0037] FIGS. 9 and 10 show the dimensions of a standard rider;
CA 02468333 2004-05-25
[0038] FIGS. 11A through 11D show the operation of a cover according to either
the
third or fifth embodiment;
[0039] FIGS. 12A through 12E show alternative seat and support arrangements
for
either the third or fifth embodiment;
[0040] FIG. 13 is a side view of a three-person snowmobile according to a
seventh
embodiment of the present invention;
[0041 ] FIG. 13A is a top view of the second seat with a portion of the seat
cut away
to illustrate internal components.
[0042] FIG. 13B is a cross-section of the second seat along A-A shown in FIG.
13A.
[0043] FIG. 13C is a bottom view of the third seat portion.
[0044] FIG. 13D is a side view of the third seat portion of FIG. 13C.
[0045] FIG. 13E is a top view of a portion of the rear of the tunnel including
mounting pins.
[0046] FIG. 14 is a side view of the snowmobile illustrated in FIG. 13 in. a
two-person
seat configuration;
[0047] FIG. 15 is a side view of the snowmobile illustrated in FIG. 13 in a
one-person
seat configuration;
[0048] FIG. 16 is a partial side view of the snowmobile illustrated in FIG.
13;
[0049] FIG. 17 is a side view of the snowmobile illustrated in FIG. 13 with
three
riders thereon; and
[0050] FIG. 18 is a side view of a three-person snowmobile according to an
eighth
embodiment of the present invention.
[0051] FIG. 19 is the commercial embodiment of the snowmobile of the present
invention.
CA 02468333 2004-05-25
[0052] FIG. 20 is a side view of the seat shown in FIG. I9 showing the
dimensions of
the various seat portions.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0053] Throughout the description of the various embodiments of the present
invention, reference will be made to various elements, the construction of
which is readily
known to those skilled in the art. Accordingly, an exhaustive description of
each and every
component is not provided. Components that are similar to components in other
embodiments will be referenced by identical reference characters but with
different prefix
digits.
[0054] The inventors of the present invention realized that it is possible to
improve
the construction of a snowmobile to alter the positioning of the riders to
considerably
improve the handling and ride of the snowmobile. By shifting the steering
device of the
snowmobile forward, the centers of gravity of the riders are likewise shifted
forward and
closer to the center of gravity of the snowmobile. As a result, the riders
experience
significantly less jostling when the snowmobile encounters uneven terrain.
Moreover, the
driver is able to maintain better control over the snowmobile.
[0055] In addition, by moving the positioning of the first and second riders
forward,
the inventors of the present invention have been able to add a third seat for
a third rider
behind the second rider, while avoiding the prohibitively large forces that a
third rider would
have experienced on a conventional snowmobile.
[0056] FIG. 8 compares various dimensions of the embodiments of the present
invention and conventional snowmobiles 110. Reference characters A-N and a
represent
variables and are commonly defined herein. 'With respect to distances, the
positive direction
is backward relative to the direction of travel of the snowmobile. Horizontal
distances are
measured wht;n the unloaded (riderless) snowmobile is positioned on level
hound. Some of
the dimensions will not apply to all of the embodiments. See FIGS. 1, 2, 3, 4A
and 7.
[0057] Distance A is measured horizontally from the axis of the forward-most
drive
axle to the center of gravity of the unloaded snowmobile. Distance B is
measured
horizontally from the steering position to the center of gravity of the
unloaded snowmobile.
Distance C is measured horizontally from the center of gravity of the unloaded
snowmobile
CA 02468333 2004-05-25
to the center of gravity of a first rider (driver). Distance D is measured
horizontally from the
center of gravity of the unloaded snowmobile to a seat position of the first
rider {driver).
Distance E is measured horizontally from the center of gravity of the first
rider to a center of
gravity of a second rider. Distance F is measured horizontally from the seat
position of the
first rider (driver) to a seat position of a second rider (first passenger).
Distance G is
measured horizontally from the center of gravity of the second rider to the
center of gravity of
a third rider (second passenger). Distance H is measured horizontally from the
second seat
position to a third seat position. Distance I is measured horizontally from
the center of
gravity of the unloaded snowmobile to a combined center of gravity of the
snowmobile and
first rider. Distance J is measured horizontally from the center of gravity of
the unloaded
snowmobile to a combined center of gravity of the snowmobile, first rider, and
second rider.
Distance K is measured horizontally from the center of gravity of the unloaded
snowmobile
to the combined center of gravity of the snowmobile and first through third
riders. Distance
L is measured horizontally from the steering position to a rearward-most seat
position.
Distance M is measured horizontally from the back end of the frame of the
snowmobile to the
back end of the second seat section. Distance N is measured horizontally from
the back end
of the frame of the snowmobile to the rear-most seat position. Angle a is
measured between
vertical and an angular position of a steering shaft of the snowmobile.
Lengths A-N are
measured in millimeters. While FIG. 8 discloses the most preferred dimensions
for each
embodiment, the range of lengths for each dimension according to the present
invention shall
be understood to be preferably within 25 mm of the stated dimension, more
preferably within
15 mm of the dimension, and even more preferably within 5 mm of the dimension.
[0058] To facilitate comparison of the present invention to the conventional
snowmobiles 110 in FIG. 8, several additional aspects of the conventional
snowmobile 110
must be identified. As shown in FIG. 1, the steering shaft 136 operatively
connects the
steering device 132 to the skis 116. The steering device 132 has a steering
position 134,
which is defined in the same manner as in the below embodiments. The driver
(first rider) 26
has a center of gravity 127, which is located slightly forward of his torso
because his arms
and legs extend forward of his body while riding the snowmobile 110, and sits
in a seat
position 152. Similarly, the first passenger (second rider) 28 has a center of
gravity 129, and
sits in a seat position 154. A combined center of gravity 170 of the
snowmobile 110 and the
first rider 26 is located behind the center of gravity 146 of the snowmobile
110 without
riders. A combined center of gravity 172 of the snowmobile 110 and first and
second riders
CA 02468333 2004-05-25
26, 28 is located farther behind the center of gravity 146 of the snowmobile
110 without any
riders.
[0059] FIG. 2 illustrates a first embodiment of the snowmobile 10. The
snowmobile
has a forward end 11 and a rearward end 13 that are defined consistently with
the travel
direction of the snowmobile 10. The snowmobile 10 includes a body 12 (d.e.,
the exterior
upper portions) and a frame 14. A motox 17, such as an internal combustion
engine, is
carried by the frame I4 at the forward end 11. In addition, two skis 16 are
attached to the
forward end 11 of the frame 14 through a suspension system 18. It should be
noted, however,
that a single centered ski would also work with the invention. A drive track
20 is disposed
under frame 14 and is connected operatively to the engine 17 for propulsion of
the
snowmobile 10.
[0060] At the front 11 of the frame 14, the snowmobile 10 includes (airings 22
that
enclose the engine I7 to protect it and to provide an external shell that can
be decorated so
that the snowmobile 10 is aesthetically pleasing. Typically, the (airings 22
comprise a hood
and a bottom pad (neither of which have been individually identified in the
drawing figures).
A windshield (not shown) may be connected to fairings 22 near the forward end
I1 of
snowmobile 10 in front of a steering device 32 to lessen the force of the air
on the first rider
(driver) 26 when the snowmobile 10 is moving.
[006I] A straddle-type seat 50 is disposed on the frame 14 behind the engine
17. The
seat SO has a first seat position 52, which is defined as a portion of the
seat 50 that is adapted
to support a center of a weight distribution of the first rider 26 on the seat
50. Because
snowmobiles typically have elongated straddle seats and are adapted to permit
riders to sit in
a variety of front-back positions, numerous seat positions will exist on any
straddle seat. The
inventors of the present invention define the term "seat position" to point
out particular
positions on the snowmobile that are adapted to function as the seat position
for a standard
rider.
[0062] FIGS. 9 and 10 illustrate the various dimensions of a standard rider of
the type
depicted throughout the drawings. The standard rider is a SOIh percentile
North-American
adult male. All lengths in FIGS. 9 and 10 are in centimeters. The middle of
each set of three
dimensions represents the standard rider. The standard rider weighs 78 kgs.
and has the body
build illustrated in FIGS. 9 and 10. The dimensions of the standard rider arc
a "ruler" by
CA 02468333 2004-05-25
which the dimensions of the various embodiments of the snowmobile of the
present invention
are measured. Riders 26, 28, 30 are standard riders.
[0063] The steering device 32, such as a handlebar, is positioned at the
forward end of
the snowmobile 10 above the engine 17. The steering device 32 has a steering
position 34,
which is defined by a center of a portion of the steering device adapted to be
held by the
hands of the rider 26. The steering position 34 is defined when the skis 16
are positioned
straight-forward. For example, if the steering device 32 comprises handlebars
(as illustrated
in FIG. 2), the steering position 34 is the center of the grips of the
handlebars.
[0064] While the steering device 32 is shown in the various figures as a
handlebar,
the steering device 32 should not be limited to just this particular
construction. It would be
understood by those skilled in the art that any suitable steering device 32
may be used for the
snowmobile 10. For example, the steering device 32 could be a steering wheel
or a yoke of
the type used in aircraft. In accordance with, the above definition of the
steering position 34,
if the steering device 32 is a steering wheel or yoke, the steering position
34 is the center of
the steering wheel or yoke.
[0065] Moreover, the positioning of the steering device 32 above the engine 17
also
should not be considered to be limited to the position illustrated in FIG. 2.
As would be
understood by those skilled in the art, depending on the particular
arrangement of elements
for the snowmobile 10, it is possible that the steering device 32 could be
positioned higher or
lower than shown in FIG. 2 without departing from the scope and spirit of the
present
invention.
[0066] A steering shaft 36 operatively connects the steering device 32 to the
two skis
16 and is disposed over the engine I7 at an angle E from vertical. The
inventors altered the
positioning of the axis of the steering shaft 36 so that it is more steeply
sloped than steering
shafts I36 in prior art snowmobiles 110 having steering shafts over the
engine. According to
the present invention, and as illustrated in FIGS. 2 and 8, the angle s is
less than 45°. More
preferably, angle a lies between about 25 and 40°. Even more
preferably, angle E lies
between about 30 and 35°. Most preferably, angle ~ is about 33°.
[0067] There are several reasons to have a small angle s. For example, the
small
angle s is preferred because it facilitates placement of the steering position
34 in a position
CA 02468333 2004-05-25
forward of that for the conventional snowmobile 110. The forward position of
the steering
position 34 moves the riders' 26, 28 positions closer to the center of gravity
46 of the
snowmobile 10 and improves the comfort of riders 26, 28. Additionally, the
turning force
applied by the rider 26 is more directly applied to steer the snowmobile 10
when angle a is
small.
[0068] Because the steering device 32 is shifted forward, relative the to the
conventional snowmobile 110, the steering position 34 is disposed in front of
the center of
gravity 46 by a distance B. According to the first embodiment of the present
invention
shown in FIG. 2, distance B is greater than 0 and preferably between 105 mm
and 155 mm.
More preferably, distance B is between 115 rnm and 145 nun. Even more
preferably,
distance B is between 125 mm and 135 mm. Most preferably, distance B is about
130 mm.
In contrast, the steering position 134 of the conventional snowmobile 110 is
behind the center
of gravity 146 of the snowmobile (see FIGS. 1 and 8) such that distance B for
conventional
snowmobiles are -160 mm for long frames and -240 mm for short frames. Long and
short
frames will be described later.
[0069] A drive track 20, which is operatively connected to the engine 17, is
positioned below the frame 14. The drive track 20 is a continuous belt that
runs around a
number of axles including a forward-most axle 44. The continuous belt has a
136-inch
circumference in the first embodiment illustrated in FIG. 2, though the
invention is in no way
limited to a snowmobile with a particular belt size. The forward-most drive
axle 44 is
disposed behind the steering position 34 by a distance calculated as distance
B minus distance
A. According to the present invention, the forward-most drive axle 44 is
disposed behind the
steering position 34. Preferably, the distance is between 40 mm and 90 mm.
More
preferably, the distance is between 50 mxn and 80 mm. Even more preferably,
the distance is
between 60 mm and 70 mm. Most preferably, the distance is about 65 mm. In
contrast, the
steering positions 134 on conventional snowmobiles are positioned behind the
forward-most
drive 144 axle by 270 mm {see FIGS. 1 and 8).
(0070] Two footrests are positioned on either side of seat 50 to accommodate
the feet
of the riders 26, 28. The footrests extend outwardly from the frame 14. The
footrests may be
disposed in a horiaontal orientation, or alternatively, in an angled
orientation.
CA 02468333 2004-05-25
[0071 J An adjustable backrest 92 is attached to the seat 50 near the back end
of the
seat 50. Various embodiments of the backrest 92 are described throughout the
specification,
where preferred. As would be understood by those skilled in the art, the
backrest 92 need not
have only the construction shown or be located in the position depicted. In
fact, the backrest
92 need not be provided at all.
[0072) The first seat position 52 is located behind the forward-most drive
axle 44 by a
horizontal distance calculated as distance D plus distance A. According to the
present
invention, this distance is less than 590 mm and preferably between 540 mm and
590 mm.
More preferably, this distance is between 550 mm and 580 mm. Even more
preferably, this
distance is between 560 mm and 570 mm. Most preferably, this distance is about
565 mm.
In contrast, the first seat position 152 in conventional snowmobiles 110 is a
much larger 905
mm behind the forward-most drive axle 144 (see FIGS. 1 and 8).
[0073] A second seat position 54 is disposed on the seat 50 behind the first
seat
position 52 and is adapted to accommodate a second rider 28 (first passenger)
behind the
driver 26 (first rider). As the rider 26 is positioned closer to the center of
gravity 46 of the
snowmobile 10 than on a conventional snowmobile 110, the ride for the second
rider 28 on
the snowmobile IO is improved because the second rider 28 is also disposed
closer to the
center of gravity 46 of the snowmobile 10 (by comparison with a second rider
28 on a
conventional snowmobile 110). The second seat position 54 is disposed a
distance F behind
the first seat position 52. According to this embodiment, distance F is
between 315 mm and
365 mm. Preferably, distance F is between 325 mm and 355 mm. More preferably,
distance
F is between 335 mm and 345 mm. Most preferably, distance F is about 340 mm.
Consequently, the second seat position 54 of the second rider 28 is most
preferably about 840
mm behind the center of gravity 46 of snowmobile 10 (distance D plus distance
F). As
illustrated in FIG. 8, the first seat position 152 on a conventional short
frame snowmobile 110
is 875 mm behind the center of gravity 146 and 795 mm behind the center of
gravity 146 of a
conventional long frame snowmobile 110 (distance D). As the position of the
second rider 28
relative to the snowmobile's center of gravity 46 is similar to a position of
a first rider
(driver} 26 of a conventional snowmobile 110 relative to the conventional
snowmobile's
center of gravity 146, the second rider 28 on the snowmobile 10 of the present
invention
experiences forces similar to the forces experienced by the driver 26 of a
conventional
snowmobile 110.
CA 02468333 2004-05-25
[0074] In this embodiment, the first and second seat positions 52, 54 are
disposed on
the seat 50, which comprises an integral seat unit. The integral seat unit 50
may be rigidly
mounted to the snowmobile 10 or it may be removably mounted.
[0075] A center of gravity 70 of the combined weight of the snowmobile 10 and
rider
26 is disposed behind the center of gravity 46 of the snowmobile 10 without a
rider. A center
of gravity 72 of the combined weight of the snowmobile 10 and two riders 26,
28 is disposed
farther rearward of the center of gravity 46. The first rider 26 has a center
of gravity 27,
which is positioned slightly forward of the rider's 26 torso because the
rider's arms and legs
are in a forwardly-extending position. Similarly, the second rider 28 has a
center of gravity
29.
[0076] As illustrated in FIG. 8, the centers of gravity of the riders 26, 28
of the
snowmobile 10 are positioned closer to the center of gravity 46 of snowmobile
10 than in
conventional snowmobiles 110. The center of gravity 27 of the first rider 26
on the
snowmobile 10 is preferably between 325 mm and 375 mm behind the center of
gravity 46 of
the snowmobile 10, more preferably between 335 mm and 365 mm behind the center
of
gravity 46, even more preferably between 345 rnm and 355 mm behind the center
of gravity
46, and most preferably about 350 mm (distance C) behind the center of gravity
46. In
contrast, the center of gravity 127 of the first rider 26 on a conventional
snowmobile 110 is
disposed behind the center of gravity 146 of the convention snowmobile I 10 by
645 mm for
long frames and 725 mm for short frames.
[0077] The center of gravity 29 of a second rider 28 on the snowmobile 10 is
disposed behind the center of gravity 46 of the snowmobile 10 by a distance
calculated as
distance C plus distance E. This distance is preferably between 695 mm and 745
mm, more
preferably between 705 mm and 735 mm, even more preferably between ? 15 mm and
725
mm, and most preferably about 720 mm. In contrast, the center of gravity 129
of a second
rider 128 on a conventional snowmobile 110 is disposed behind the center of
gravity 146 of
the conventional snowmobile 110 by 1015 mm for short frames and by 1095 mm for
long
frames.
[0078] FIG. 3 illustrates a second embodiment of the present invention. The
snowmobile 210 of the second embodiment has a shorter frame 214 than the frame
14 of the
snowmobile 10 of the first embodiment. The frame 14 preferably has a length of
about 1913
CA 02468333 2004-05-25
mm. The frame 214 preferably has a length of about 1493 mm. The difference in
length
between the long frame and the short frame is approximately 420 mm. The long
frame
provides for two permanent seats and a larger cargo space. In addition, the
long frame is
simpler and less expensive to manufacture than the short frame as it has less
moving parts,
and less parts in general, than the short frame. The shorter frame 214,
however, provides the
driver 26 with the feeling that the snowmobile is lighter and more
maneuverable than a
snowmobile having the long frame. The short frame also reduces the polar
moment of
inertial of the snowmobile about the vertical axis. The short frame also
provides a tail
landing for the snowmobile (i.e., the short frame provides more space for a
rear idler wheel to
travel higher upon compression of the rear suspension). It should be
appreciated that the
frame 14 and the frame 214 may have lengths that differ from the preferred
embodiments
discussed above.
[0079] 1n the second embodiment shown in FIG. 3, a 121 inch drive track 220 is
illustrated instead of the 136 inch track 20 of the snowmobile 10 of the first
embodiment.
The short frame 214 and the 121 inch drive track 220 reduce the rotational
inertia of
snowmobile 210 and consequently improve its handling performance. As a result
of these
differences, some of the dimensions are correspondingly altered as shown in
FIG. 8.
[0080] A steering shaft 36 operatively connects the skis 16 to the steering
device 32.
The axis of the steering shaft 36 forms an angle s with vertical that is the
same as the
orientation described in relation to the first embodiment illustrated in FIG.
2. As in the first
embodiment, the angular position of the steering shaft 36 permits placement of
the steering
position 34 in a position forward of that for the conventional snowmobile 110,
which moves
the positions of the riders 26, 28 closer to the center of gravity 246 of the
snowmobile 210
and improves the comfort of the riders 26, 28.
[0081] Because the steering device 32 is shifted forward relative to
conventional
snowmobiles 110, the forward-most drive axle 244 is disposed behind the
steering position
34 by a distance calculated as distance B minus distance A. According to the
present
embodiment, this distance is positive. Preferably, the distance is between 40
mm and 90 mx~n.
More preferably, the distance is bet<vcen 50 mm and 80 mm. Even more
preferably, the
distance is between 60 mm and 70 mm. Most preferably, the distance is about 65
mm. In
contrast, the steering positions 134 on conventional snowmobiles 110 are
positioned behind
the forward-most drive axle 144 by 270 mm (see FIGS. 1 and 8).
CA 02468333 2004-05-25
[0082] A first seat position 252 is defined on the seat 250 behind the forward-
most
drive axle 244 by a horizontal distance calculated as distance D plus distance
A. While this
distance is always positive, it is preferably between 540 mm and 590 mm. More
preferably,
this distance is between 550 mm and 580 mm. Even more preferably, this
distance is
between 560 mm and 570 mm. Most preferably, this distance is about 565 mm. In
contrast,
the first seat position 152 in conventional snowmobiles 110 is a much larger
905 mm behind
the forward-most drive axle 144 (see FIGS. l and 8).
[0083] A second seat position 254 is disposed a horizontal distance F behind
the first
seat position 252. According to this embodiment, distance F is between 315 mm
and 365 mm.
Preferably, distance F is between 325 mm and 355 mm. More preferably, distance
F is
between 335 mm and 345 mm. Most preferably, distance F is about 340 mm.
[0084] Like the seat 50 of the first embodiment, the seat 250 may comprise an
integral seat unit that may either be rigidly mounted to the snowmobile 210 or
may be
removable. Alternatively, the seat 250 may include more than one section.
[0085] A center of gravity 270 of the combined weight of the snowmobile 210
and
rider 26 is disposed behind the center of gravity 246 of the snowmobile 210
without a rider.
A center of gravity 2?2 of the combined weight of the snowmobile 210 and two
riders 26, 28
is disposed farther rearward of the center of gravity 246. The first rider 26
has a center of
gravity 227, which is positioned slightly forward of the rider's 26 torso
because the rider's
arms and legs axe in a forwardly-extending position. Similarly, the second
rider 28 has a
center of gravity 229.
[0086] The centers of gravity 227, 229 of the riders 26, 28, respectively, of
the
snowmobile 210 are positioned closer to the center of gravity 246 of
snowmobile 210 than in
conventional snowmobiles 110 (see distances C and E in FIG. 8}. The center of
gravity 227
of the first rider 26 on the snowmobile 210 is preferably between 295 mm and
345 mm
behind the center of gravity 246 of the snowmobile 210, snore preferably
between 305 mm
and 335 mm behind the center of gravity 246, even more preferably between 315
mm and
325 mm behind the center of gravity 246, and most preferably about 320 mm
behind the
center of gravity 246.
CA 02468333 2004-05-25
[0087] The center of gravity 229 of a second rider 28 on the snowmobile 210 is
disposed behind the center of gravity 246 of the snowmobile 210 by a distance
calculated as
distance C plus distance E. This distance is preferably between 665 mm and 715
mm, more
preferably between 675 mm and 705 mm, even more preferably between 685 mm and
695
mm, and most preferably about 690 mm.
[0088] FIGS. 4A and 4B illustrate a third embodiment of the present invention.
Like
the snowmobile 210 of the second embodiment, the snowmobile 310 has a short
frame 314
and a 121 inch drive track 320.
[0089] As with the previous embodiments, the axis of the steering shaft 36
forms an
angle E with vertical that is less than 45 degrees. As in the first
embodiment, the angular
position of steering shaft 36 permits placement of steering position 34 in a
position forward
of that for the conventional snowmobile 110, which moves the positions of the
riders 26, 28
closer to the center of gravity 346 of the snowmobile 310 and improves the
comfort of the
riders 26, 28.
[0090] The forward-most drive axle 344 is disposed behind the steering
position 34
by a distance calculated as distance B minus distance A. According to the
present invention,
the distance is positive. Preferably, the distance is between 40 mm and 90 mm.
More
preferably, the distance is between 50 mm and 80 mm. Even more preferably, the
distance is
between 60 mm and 70 mm. Most preferably, the distance is about 65 mm. In
contrast, the
forward-most drive axle on conventional snowmobiles is positioned in front of
the steering
position by 270 mm (see FIG. 8).
[0091] The seat 350 comprises a first seat section 350' and a second seat
section
350". In this embodiment, the second seat section 350" is removable. A cargo
space 394,
which is preferably plastic, is provided behind the first seat section 350'
beneath the second
removable seat section 350". As shown in FIGS. IlA through 11D, a cover 395
can be
attached over the cargo space 394 to enclose the cargo space 394 when the
second seat
section 350" is not attached. The cover 395 is hinged to the cargo space 394.
One or more
latches are provided to secure the cover 395 in a closed position.
[0092] A first seat position 352 is defined on the first seat section 350'
behind the
forward-most drive axle 344 by a horizontal distance calculated as distance D
plus distance
CA 02468333 2004-05-25
A. According to the present invention, this distance is less than 590 mm and
preferably
between 540 mm and 590 mm. More preferably, this distance is between SSO mm
and 580
mm. Even more preferably, this distance is between 560 mm and 570 mm. Most
preferably,
this distance is about 565 mm. In contrast, the first seat position 152 in
conventional
snowmobiles 110 is a much larger 905 mm behind the forward-most drive axle 144
(see
FIGS 1 and. 8).
[0093] A second seat position 354 is defined on the second seat section 350" a
horizontal distance F behind the first seat position 352. According to this
embodiment,
distance F is between 315 mm and 365 mm. Preferably, distance F is between 325
rnm and
355 mm. More preferably, distance F is between 335 mm and 345 mm. Most
preferably,
distance F is about 340 mm.
[0094] A support element 360 extends upwardly and rearwardly from the frame
314.
Fasteners {not shown) are used to secure the second seat 350" to the frame 314
via the
support element 360. FIG. 4B shows an enlarged side view of the removable
second seat
section 350".
[0095] A tunnel 314' forms the back end 314" of the frame 314. The drive track
320
is mounted below the tunnel 314'. A snow flap 380 extends rearwardly behind
the back end
314".
[0096] As shown in FIG. 4A, the support element 360 extends rearwardly beyond
the
back end 314" of the frame 314 to structurally support the second seat section
350" behind
the back end 314". The second seat position 354 is disposed on the second seat
section 350"
a distance N behind the back end 314" of the frame 314. For this embodiment,
distance N is
always greater than zero. Preferably, distance N is between 55 mm and 105 mm.
More
preferably, distance N is between 65 mm and 95 mm. Even more preferably,
distance N is
between 75 mm and 85 mm. Most preferably, distance N is about 80 rrun. In
contrast, the
second seat positions 154 of conventional snowmobiles 110 do not extend behind
the back
end of the frame because the second rider 28 would be prohibitively far away
from the center
of gravity 14G of the snowmobile 110. Conventional snowmobiles 110 position
the second
seat position 154 in front of the back end of the frame by 290 mm for long
frames and 120
mm for short frames (see FIGS. 1 and 8).
CA 02468333 2004-05-25
[0097] A rearward-most end of seat section 350" is disposed a distance M
behind the
back end 314" of the frame 314. Fox this embodiment, distance M is always
greater than
zero. Preferably, distance M is between 205 mm and 255 mm. More preferably,
distance M
is between 215 mm and 245 mm. Even more preferably, distance N is between 225
mm and
235 mm. Most preferably, distance M is about 230 mm. 1n contrast, the rearward-
most end
of the seat of conventional snowmobiles 110 is disposed in front of the back
end of the frame
by 50 mm for long frames and at the back end of the frame for short frames
(i.e., 0 mm, see
FIG. 8).
[0098] A center of gravity 370 of the combined weight of the snowmobile 310
and
rider 26 is disposed behind the center of gravity 346 of the snowmobile 310
without a rider.
A center of gravity 372 of the combined weight of the snowmobile 310 and two
riders 26, 28
is disposed farther rearward of the center of gravity 346. The first rider 26
has a center of
gravity 327, which is positioned slightly forward of the rider's 26 torso
because the rider's
arms and legs are in a forwardly-extending position. Similarly, the second
rider 28 has a
center of gravity 329.
[0099] As illustrated in FIG. 8, the centers of gravity 327, 329 of the riders
26, 28 of
the snowmobile 310 are positioned closer to the center of gravity 346 of
snowmobile 3i0
than the centers of gravity 127, 129 are positioned to the center of gravity
146 in
conventional snowmobiles 110. The center of gravity 327 of the first rider 26
on the
snowmobile 310 is preferably between 295 mm and 345 mm behind the center of
gravity 346
of the snowmobile 310, more preferably between 305 and 335 mm behind the
center of
gravity 346, even more preferably between 315 and 325 mm behind the center of
gravity 346,
and most preferably about 320 mm behind the center of gravity 346.
[00100] The center of gravity 329 of a second rider 28 on the snowmobile 310
is disposed behind the center of gravity 346 of the snowmobile 310 by a
distance calculated
as distance C plus distance E. This distance is preferably between 665 mm and
715 mm,
more preferably between 675 mm and 705 mm, even more preferably between 685 mm
and
695 mm, and most preferably about 690 mm.
[00101] FIG. 5 illustrates a fourth embodiment of the present invention. Like
the snowmobile 10 of the first embodiment, the snowmobile 410 has a long frame
414 and a
i 36 inch drive track 20.
CA 02468333 2004-05-25
[00102] As with the first embodiment, the axis of the steering shaft 36 forms
an
angle s with vertical that is less than 45 degrees. Similarly, the angular
position of steering
shaft 36 permits placement of steering position 34 in a position forward of
that for the
conventional snowmobile 110, which moves the positions of the riders 26, 28
closer to the
center of gravity 446 of the snowmobile 410 and improves the comfort of the
riders 26, 28.
[00103] The forward-most drive axle 444 is disposed behind the steering
position 34 by a distance calculated as distance B minus distance A. According
to the present
invention, the forward-most drive axle 444 is disposed behind the steering
position 34.
Preferably, the distance is between 40 mm and 90 mm. More preferably, the
distance is
between 50 mm and 80 mm. Even more preferably, the distance is between 60 mm
and 70
mm. Most preferably, the distance is about 65 mm. In contrast, the steering
positions 134 on
conventional snowmobiles 110 are positioned behind the forward-most drive axle
144 by 270
mm (see FIGS. 1 and 8}.
[00104] Like the seat 50 of the first embodiment, the seat 450 of snowmobile
410 comprises an integral seat unit that may either be rigidly mounted to the
snowmobiie 410
or removable. A first seat position 452 is defined on the seat 450 behind the
forward-most
drive axle 444 by a horizontal distance calculated as distance D plus distance
A. According
to the present invention, this distance is less than 590 mm and preferably
between 540 mm
and 590 mm. More preferably, this distance is between 550 mm and 580 mm. Even
more
preferably, this distance is between 560 mm and 570 mm. Most preferably, this
distance is
about 565 mm. In contrast, the first seat position 152 in conventional
snowmobiles 110 is a
much larger 905 mm behind the forward-most drive axle (see FIG. $).
[OOI05] A second seat position 454 is disposed on the seat 450 a horizontal
distance F behind the first seat position 452. According to this embodiment,
distance F is
between 3I5 mm and 365 mm. Preferably, distance F is between 325 mm and 355
mm.
More preferably, distance F is between 335 mm and 345 mm. Most preferably,
distance F is
about 340 mm. Consequently, the seat position 454 of the second rider 28 is
most preferably
about 735 mm behind the center of gravity 446 of snowmobile 410 (distance D
plus distance
F).
[00106] A third seat position 456 is added behind the second seat position 454
on the seat 450 in order to accommodate a third rider 30. The forward
placement of the
CA 02468333 2004-05-25
steering position 34 permits a third rider 30 to ride the snowmobile 410
without experiencing
prohibitively large jostling forces. The center of gravity 431 of the third
rider 30 is
positioned behind the center of gravity of snowmobile 410 by a distance
calculated as
distance C plus distance E plus distance G, which is preferably between 900 mm
and 950
mm. The distance is more preferably between 910 mm and 940 mm. The distance is
even
more preferably between 920 mm and 930 mm. The distance is most preferably
about 925
mm. 1n contrast, the second rider 28 on the conventional snowmobile 110 is
positioned
behind the center of gravity 146 of the conventional snowmobile 110 by 1015 mm
for a long
frame and 1095 mm for a short frame (distance C plus distance E).
Consequently, the thud
rider 30 (second passenger) on snowmobile 410 is closer to the center of
gravity 446 of the
snowmobile 410 and experiences less jostling forces than a second rider 28
(first passenger)
would normally experience on a conventional snowmobile 110.
[00107] A center of gravity 470 of the combined weight of the snowmobile 410
and rider 26 is disposed behind the center of gravity 446 of the snowmobile
410 without a
rider. A center of gravity 472 of the combined weight of the snowmobile 410
and two riders
26, 28 is disposed farther rearward of the center of gravity 446 of the
riderless snowmobile
410. A center of gravity 474 of the combined weight of the snowmobile 410 and
three riders
26, 28, 30 is disposed even farther rearward of the center of gravity 446 of
the riderless
snowmobile 410. The first rider 26 has a center of gravity 427, which is
positioned slightly
forward of the rider's 26 torso because the rider's arms and legs are in a
forwardly-extending
position. Similarly, 'the second and third riders 28, 30 have centers of
gravity 429, 431,
respectively.
[00108] FIG.8 illustrates the relevant spatial relationships for the fourth
embodiment and shows that the centers of gravity of the riders 25, 28, 30 are
disposed closer
to the center of gravity 446 of the snowmobile than in conventional
snowmobiles 110.
[00109] The center of gravity 427 of the first rider 26 on the snowmobile 410
is
preferably between 220 mm and 270 mm behind the center of gravity 446 of the
snowmobile
410, more preferably between 230 mm and 260 mm behind the center of ~-avity
446, even
more preferably between 240 mm and 250 mm behind the center of gravity 446,
and most
preferably about 245 mm behind the center of gravity 446.
CA 02468333 2004-05-25
[00110] The center of gravity 429 of a second rider 28 on the snowmobile 410
is disposed behind the center of gravity 446 of the snowmobile 410 by a
distance calculated
as distance C plus distance E. This distance is preferably between 590 mm and
640 mm,
more preferably between 600 mm and 630 mm, even more preferably between 610 mm
and
620 mm, and most preferably about 615 mm.
[00111] The center of gravity 431 of the third rider 30 on the snowmobile 410
is disposed behind the center of gravity 446 of the snowmobile 410 by a
distance calculated
as distance C plus distance E plus distance G. This distance is preferably
between 900 mm
and 950 mm, more preferably between 910 mm and 940 mm, even more preferably
between
920 mm and 930 mm, and most preferably about 925 mm.
[00112] A horizontal distance H between the second seat position 454 the third
seat position 456 is preferably between 285 mm and 335 mm. Distance H is more
preferably
between 295 mm and 325 mm. Distance H is even more preferably between 305 mm
and
315 mm. Distance H is most preferably about 310 mm. A horizontal distance G
between the
center of gravity 429 of the second rider 428 and the center of gravity 431 of
the third rider
430 is about the same as distance H for this embodiment (see FIG. 8),
[00113] FIGS.6A and 6B illustrate a fifth embodiment of the present
invention. Like the snowmobile 10 of the first embodiment, snowmobile 510 has
a long
frame 514 and a 136 inch drive track 520. As in previous embodiments, the axis
of the
steering shaft 36 forms an angle s with vertical that is less than 45 degrees.
The forward-
most drive axle 544 is disposed behind the steering position 34 by a distance
calculated as
distance B minus distance A. According to this embodiment, the forward-most
drive axle 544
is disposed behind the steering position 34. Preferably, the distance is
between 40 mm and
90 mm. More preferably, the distance is between 50 mm and 80 mm. Even more
preferably,
the distance is between 60 mm and 70 mm. Most preferably, the distance is
about 65 mm.
[00114] Similar to the seat 350 of the snowmobile 310 of the third
embodiment, seat 550 is formed by a first seat section 550' and a second seat
section 550".
The second seat section 550" is removable. When the second seat section 550"
is removed, a
cover 395 (as illustrated in FIGS. 1 lA-D and discussed with respect to the
third embodiment)
may be used to cover a cargo space 594 that is located beneath the second seat
section 550"
and behind the first seat section 550'.
CA 02468333 2004-05-25
[00115] A first seat position 552 is defined on the first seat section 550'
behind
the forward-most drive axle 544 by a horizontal distance calculated as
distance D plus
distance A. According to the present invention, this distance is less than 590
mm and
preferably between 540 mm and 590 mm. More preferably, this distance is
between 550 mxxx
and 580 mm. Even more preferably, this distance is between 560 mm and 570 mm.
Most
preforabIy, this distance is about 565 mm.
[00116] A second seat position 554 is disposed on the first seat section 550'
a
horizontal distance F behind the first seat position 552. According to this
embodiment,
distance F is between 265 mm and 315 rnm. Preferably, distance F is between
275 mm and
305 mm. More preferably, distance F is between 285 mm and 295 mm. Most
preferably,
distance F is about 290 mm.
(00117] A third seat position 556 is positioned on the second seat section
550"
behind the second seat position 554 by a horizontal distance H, which is
preferably between
320 mm and 370 mm_ Distance H is more preferably between 330 mm and 360 mm.
Distance H is even more preferably between 340 mm and 350 mm. Distance H is
most
preferably about 345 mm.
[00118] A tunnel 514' forms the back end 514" of the frame 514. The drive
track 520 is mounted below the tunnel 514'. A snow flap 580 extends rearwardly
behind the
back end 514".
[00119] As in the third embodiment, a support element 560 extends upwardly
and rearwardly from the back end 514" of the frame 514 to provide support for
the second
seat section 550". The third seat position 556 and back end of the third seat
position 556
extend behind the back end 5I4" of the frame 514 by distances N and M,
respectively.
Distance N is always positive and preferably between 35 mm and 85 mm. Distance
N is
more preferably between 45 mm and 75 mm. Distance N is even more preferably
between 55
mm and 65 mm. Distance N is most preferably about 60 mrn, Distance M is always
positive
and preferably between 265 mm and 315 mm. Distance M is more preferably
between 275
mm and 305 mm. Distance M is even more preferably between 285 mm and 295 mm.
Distance M is most preferably about 290 mm.
CA 02468333 2004-05-25
[00120] A center of gravity 570 of the combined weight of the snowmobile 410
and rider 26 is disposed behind the center of gravity 546 of the snowmobile
510 without a
rider. A center of gravity 572 of the combined weight of the snowmobile 510
and two riders
26, 28 is disposed farther rearward of the center of gravity 546 of the
riderless snowmobile
510. A center of gravity 574 of the combined weight of the snowmobile 510 and
three riders
26, 28, 30 is disposed even farther rearward of the center of gravity 546 of
the riderless
snowmobile 410. The first rider 26 has a center of gravity 527, which is
positioned slightly
forward of the rider's 26 torso because the rider's arms and legs are in a
forwardly-extending
position. Similarly, the second and third riders 28, 30 have centers of
gravity 529, 531,
respectively.
[00121] FIG.8 illustrates the relevant spatial relationships for the fifth
embodiment and illustrates that the centers of gravity of the riders 26, 28,
30 are disposed
closer to the center of gravity 546 of the snowmobile 510 than in the
conventional
snowmobiles 110.
[00122] The center of gravity 527 of the first rider 26 on the snowmobile 510
is
preferably between 220 mm and 270 mm behind the center of gravity 546 of the
snowmobile
510, more preferably between 230 mm and 260 mm behind the center of gravity
546, even
more preferably between 240 mm and 250 mm behind the center of gravity 546,
and most
preferably about 245 mm behind the center of gravity 546.
[00123] The center of gravity 529 of a second rider 28 on the snowmobile 510
is disposed behind the center of gravity 546 of the snowmobile 510 by a
distance calculated
as distance C plus distance )1. This distance is preferably between 590 mm and
640 mm,
more preferably between 600 mm and 630 mm, even more preferably between 610 mm
and
620 mm, and most preferably about 615 mm.
[00124] The center of gravity 531 of the third rider 30 on the snowmobile 510
is disposed behind the center of gravity 546 of the snowmobile 510 by a
distance calculated
as distance C plus distance E plus distance G. This distance is preferably
between 935 mm
and 985 mm, more preferably between 945 mm and 975 mm, even more preferably
between
955 mm and 965 mm, and most preferably about 960 mm.
CA 02468333 2004-05-25
[00125] It should be noted that while the third and fifth embodiments include
a
removable back seat that simply attaches to the support element 360, 560,
other ways of
creating a removable seat section, which are known by those of ordinary skill
in the art, are
also intended to be included in the invention. For example, a second seat
section might be
slidable along a longitudinal track such that a third seat could be inserted
like a leaf of a table
between the first and second seats. Similarly, a backrest might be slidably
mounted to a
longitudinal track behind a first seat and pemit the insertion of second
and/or third seats
between the first seat and the backrest.
[00126] Furthermore, while the third and fifth. embodiments illustrate
particular
embodiments of the second seat sections 350, 550 and support pieces 360, 560,
numerous
other embodiments of such components, which would be apparent to those skilled
in the art,
could also be utilized and are intended to be included in the present
invention. For example,
FIGS. 12A through 12E illustrate several alternative seats having first seat
sections 650',
750', 850', 950', 1050', second seat sections 650", 750", 850", 950", 1050",
and support
pieces 660, 760, 860, 960, 1060.
[00127] FIG. 7 illustrates a sixth embodiment of the snowmobile 610. The
snowmobile 610 of the sixth embodiment may have a short or long frame 614 and
a snow
flap 680 extending from the back end of the frame 614. The snowmobile 610 has
a 136 inch
drive track 620.
[00128] As with the previous embodiments, the axis of the steering shaft 36
forms an angle s with vertical that is less than 45 degxees. As in the first
embodiment, the
angular position of steering shaft 36 permits placement of steering position
34 in a position
forward of that for the conventional snowmobile 110, which moves the position
of the driver
26 closer to the center of gravity 646 of the snowmobile 610 and improves the
comfort of the
driver 26.
[OOI29] The forward-most drive axle 644 is disposed behind the steering
position 34 by a distance calculated as distance B minus distance A. According
to the present
invention, the distance is positive. Preferably, the distance is between 40 mm
and 90 mm.
More preferably, the distance is between 50 mm and 80 mm. Even more
preferably, the
distance is between 60 mm and 70 mm. Most preferably, the distance is about 65
mm. In
CA 02468333 2004-05-25
contrast, the forward-most drive axle 144 on conventional snowmobiles 110 is
positioned in
front of the steering position 134 by 270 mm (see FIG_ 8).
[00130] The snowmobile 610 has a seat 650 configured for a single rider 26 (1-
up rider positioning) that defines a seat position 652. The seat position 652
is behind the
forward-most drive axle 644 by a horizontal distance calculated as distance D
plus distance
A. According to the present invention, this distance is less than 590 mm and
preferably
between 540 mm and 590 mm. More preferably, this distance is between 550 rnm
and 580
mm. Even more preferabiy, this distance is between 560 mm and 570 mm. Most
preferably,
this distance is about 565 mm. In contrast, the first seat position 152 in
conventional
snowmobiles 110 is a much larger 905 mm behind the forward-most drive axle 144
(see
FIGS. 1 and 8).
[00131 ] As illustrated in FIG. 7, the center of gravity 627 of the rider 26
of the
snowmobile 610 is positioned closer to the center of gravity 646 of the
snowmobile 610 than
in conventional snowmobiles I10. The center of gravity 627 of the rider 26 on
the
snowmobile 610 is preferably between 295 mm and 345 mm behind the center of
gravity 646
of the snowmobile 610, more preferably between 305-mm and 335 mm behind the
center of
gravity 646, even more preferably between 315 mm and 325 mm behind the center
of gravity
646, and most preferably about 320 mm behind the center of gravity 646.
[00132] FIGS. 13-17 illustrate an additional alternative embodiment of the
present invention, which is similar to the embodiment illustrated in FIG. 6A.
Like the
snowmobile 510 illustrated in FIG. 6A, the snowmobile 1100 is designed to
accommodate up
to three riders (a driver and first and second passengers). Accordingly, a
three-person
straddle-type seat assembly 1110 is mounted to a frame 1120 of the snowmobile
1100.
[00133] FIGS. 13 and i7 illustrate a first configuration of the seat assembly
1110, which is specifically designed to accommodate 3 riders. The straddle
type seat
assembly 1110 comprises distinct first, second, and third seat portions 1I30,
1140, 1150 for
the driver, first passenger, and second passenger, respectively. The seat
portions 1130, 1140,
1150 define seat positions 1130a, 1140a, I150a, respectively for the driver
and the two
passengers.
CA 02468333 2004-05-25
[00134] The seat position 1150a of the second passenger is disposed forward of
an axis 1152 of a rear idler wheel 1154 of an endless track 1156 of the
snowmobile 1100. By
placing the seat position 1154a forward of the rear idler wheel 1154, the skis
of the
snowmobile 1100 and the second passenger are disposed on the same side of the
"see-saw"
fulcrum created by the rear idler wheel 1154 so that the second passenger's
weight does not
lift the steering skis or impair the steerability of the snowmobile 1100. In
conventional
snowmobiles, on the other hand, if a third rider attempts to squeeze onto a
snowmobile, his
weight would be positioned behind the rear idler wheel and, disadvantageously,
would tend
to lift the skis frown the ground or reduce the steering force applied by the
skis.
[00135] Second seat portion 1140 is shown in greater detail in FIGS 13A and
13B. Seat portion 1140 comprises a base 1141, preferably made from plastic or
light weight
metal and a foam 1143 placed on top of the base 1141. The top portion of foam
1143 defines
seat position 1140a where a rider will be seated, A flexible, preferably
waterproof cover will
cover the foam 1143 and attach to the base 1141 to hold the foam and base
together as a
single unit. Base 1141 further includes tongues 1142 extending forwardly from
the front of
the base 1141. Tongues 1142 are used to secure seat 1140 to the first seat
portion 1130 as
will be described in greater detail below. Base 1141 also includes cavities
1146 situated
toward the rear of the base 1141. Cavities 1146 serve to accept tongues 1152
of seat 1150
shown in FIGS. 13C and 13D. In the preferred embodiment, two cavities are used
to accept
two tongues of the seat placed behind it, if will be appreciated that one or
more than two
tongues and cavities could be used.
[00136] Best seen in FIG. 13E the tunnel 1120 has two holders 1162, one on
the right-hand side of the tunnel and one on the left-hand side of the tmmel,
to accept tongues
1142 and/or 1152 of the second and third seat portions 1140 and/or 1 I50
respectively. The
two forward-most holders 1162 are preferably situated on the tmmel 1120 such
that they
coincide with the rear bottom comers of the first seat portion 1130 and second
seat portion
l I40 best shown in FIG. 13. When the second seat portion 1140 is to be
attached to the
snowmobile 1100, the bottom surface 1145 of second seat portion 1140 is placed
on top of
frame/tunnel 1120 such that the tongues 1142 are aligned with the two forward-
most holders
1162. The seat 1140 is then pushed forward until surface 1144 of the second
seat portion
1140 contacts the f rst seat portion 1130. The bottom surface 1145 of the
second seat portion
1140 further includes cavities 1146 which accept the rear-most holders 1162
and permit the
CA 02468333 2004-05-25
second seat portion 1140 to lie flat onto the tunnel 1120. In order to prevent
the second seat
portion from moving rearward relative to the first seat portion, a third seat
portion 1150 is
attached to top of the tunnel 1120 behind the second seat portion 1140 as will
be described in
greater detail below.
[00137] Also shown in FIG. 13E are pins 1164 which are used to attach the
third seat portion 1150 to the tunnel 1120 in a manner described below. The
preferred
embodiment uses two laterally spaced pins to attach the seat in each of the
two positions, i.e.
when the third seat portion 1150 is placed directly behind the first seat
portion 1 I30, the two
forward-most pins 1164 are used, when the third. seat portion 1150 is placed
behind the
second seat portion 1140, which is itself placed behind the first seat portion
1130, the two
rear-most pins 1164 are used. It would be appreciated that one or more than
two pins could
he used to secure the seat portion to the tunnel. The pins 1164 have a
circular shaft (not
shown) with an enlarged head portion 1166. The pins 1164 are preferably placed
in
indentations 1168 within the tunnel 1120 such that the enlarged heads 1166 do
not protrude
beyond the upper surface of the tunnel and interfere with any cargo placed in
that area when
the seat portions are not being used. A cargo rack 1170 is also placed on the
tunnel 1120 to
prevent cargo from falling off the tunnel 1120. The wail 1170 could also be
used to support
additional accessories or the passenger hand grips 1200 such as is shown in
FIG. 14.
[00138] FIGS. 13C and 13D illustrate further aspects of the third seat portion
1150. Third seat portion 1150 comprises a base 1153, preferably made of
plastic or a
lightweight metal, and foam 1154 placed above the base 1153. A flexible,
preferably
waterproof cover will cover the foam 1154 and attach to the base 1153 to hold
the foam and
base as a single unit. The top surface of foam 1154 defines the seating
surface 1150b. As
discussed above, third seat portion 1150 also includes two tongues 1152
extending forwardly
from the base 1153. Base 1153 further includes two apertures 1154 toward the
rear bottom
corners of the base 1153 as can be seen in FIGS 13C and 13D. Apertures 1154
are provided
to accept mounting pins 1164 shown in FIG. 13E.
[00139] Base 1153 also includes a latch mechanism for holding and releasing
the third seat portion 1150 to the turu~el 1120. The latch mechanism uses a
strap 1155,
extending from the rear of the seat 1150 and connected to a piece of wire
1156, which, when
the seat is installed onto the tunnel 1120, engages the enlarged portions 1166
of the mounting
pins 1164 preventing the seat from being pulled away from the tunnel 1120.
Wire 1156 is
CA 02468333 2004-05-25
shaped such that it passed through at least a portion of the aperture 1154.
When strap 1155 is
pulled, the wire is flexed away from the apezture 1154, disengaging the pins
1164 and
allowing the seat to be removed from the tunnel.
(00140] It is to be understood, that, in order to install the third seat
portion 1150
to the top of the tunnel 1120 behind the second seat portion 1140, or behind
the first seat
portion 1130, one would slightly tip the seat toward the front, insert the
tongues 1152 into
cavities 1162 and proceed to push the rear of the seat toward the tunnel until
pins 1164 are
inserted into apertures 1154 and wire 1156 has flexed and passed over the
enlarged top
portion 1166 of the pins 1164 securing the seat to the tunnel 1120. The second
seat portion
1140, when in used, relies on its tongues 1142 inserted into the two forward-
most cavities
1162 and the tight fit with between the first seat portion and the third seat
portion to keep it in
place. As would be appreciated by one skilled in the art, a similar attachment
system
including the pins and flexible wire explained for the third seat portion 1150
could be used to
attach the second seat portion 1140 to the tunnel 1120 without deviating from
the present
invention.
[00141] In the preferred embodiment, the second seat portion 1140 can only be
installed if the third seat portion 1150 has been removed from the tunnel
1120. It is
contemplated that the second seat portion, without the tongues 1142, could be
used and
simply inserted between the first seat portion 1130 and the third seat portion
1150 (also
without tongues 1152) and rely on a tight fit between the two seats to prevent
the second seat
portion 1140 from being inadvertently removed from the tunnel 1120.
[00142] Base 1153 of the third seat portion 1150 further includes rubber
bumpers 1 I57. Bumpers I 157 make contact with the top surface of the tunnel
1120 when the
third seat portion 1150 is attached to the tunnel 1120. Bumpers 1157 are sized
such that they
era compressed between the seat and the tunnel once the seat is installed onto
the tunnel, thus
pushing the seat vertically away form the tunnel creating constant contact
between the wire
1156 and the enlarged portion 1166 of pins 1164, eliminating any small
vertical movements
between the seat and the tunnel when the rider is not seated on the seat. It
would be
understood that the force created by the bumpers 1157 would be insufficient to
cause the
third seat portion to be inadvertently forced away from the tunnel.
CA 02468333 2004-05-25
[00143] To facilitate comfortable seating of all three riders, a surface 1130b
of
a seat defned by the first seat portion 1130 is preferably disposed below a
surface 1140b of a
seat defined by the second seat portion 1140. The surface 1140b is preferably
disposed
below or at the same height as a surface 1150b of a seat of the third seat
portion 1150.
[00144] FIG. 13D also shows backrest assembly 1210 mounted to the third seat
portion 1150 through the mounting points 1240. Mounting points 1240 allaw the
backrest
assembly 1210 to pivot with respect to the third seat portion 1150 in the
direction of the
arrows. A lever, 1241, when rotated counterclockwise, engages a release
mechanism (not
shown) which allows the spring to bias the backrest 1220 toward the front.
When lever 1241
is rotated clockwise, the release mechanism prevents further movement of the
backrest 1220
relative to the third seat portion 1150. This allows the passenger to adjust
the positioning of
the backrest 1220 to a comfortable position. Lever 1241 may also be spring
biased to a
position which prevents the backrest 1220 from any movement with respect to
the third seat
portion 1150.
[00145] FIG. 14 illustrates a second configwation of the seat assembly 1110,
which is designed to accommodate 2 riders, (a driver and one passenger). As
may be
appreciated from the discussion that follows, the second configwation of the
seat assembly
11 ZO presents a variation on the configuration depicted in FIG. 13.
[00146] So that these two configurations are possible, each seat portion 1130,
1140, 1150 is individually mounted to the frame 1120. The first seat portion
1130 is mounted
to the frame 1120. The second seat portion 1140 is selectively detachable from
the frame
1120. The third seat portion 1150 is movably attached to the frame 1120 for
selective
positioning in a rearward position (see FIG. 13) and a forward position (see
FIG, 14).
Accordingly, when the second seat portion 1140 is detached from the snowmobile
1100, the
third seat portion 1 I50 may be selectively moved forward to abut against the
first seat portion
1130. In this second seat assembly 1110 configuration, the driver is supported
by the first
seat portion 1130 and a first passenger is supported by the third seat portion
1150. For this
configuration, a storage space 1160 is provided behind the third seat portion
1150 and above
the frame 1120 in the space created by moving the third seat portion 1150
forward.
[00147] FIG. 15 illustrates a third seat assembly 1110 configuration, which is
designed to accommodate one rider. In addition to being movably attached to
the frame
CA 02468333 2004-05-25
1120, the third seat portion 1150 is also detachably mounted to the frame
1120. Accordingly,
when both the second and third seat portions l I40, 1150 are detached, the
seat assembly
1100 provides support for one rider via the first seat portion 1130. A large
storage space
1170 is provided behind the first seat portion and above the frame 1120 in the
space that is no
longer occupied by the second and third seat portions 1140, 1150.
[00148] As illustrated in FIGS. 13 and 17, various hand holds are preferably
provided on the seat assembly 1110 to help the riders secure themselves in
their positions on
the snowmobile 1100. The driver remains secure on the seat assembly 1110
because he holds
the steering device 11$0 (such as handlebars) with his/her hands.
[00149] The first passenger holds onto a looped strap 1190 that is mounted to
the second seat portion 1140. When the first passenger rests on the second
seat portion 1140,
the looped strap 1190 is disposed between his/her legs and is positioned to
enable the first
passenger to hold onto the looped strap i 190 with his/her hands. In the
illustrated
embodiment, the looped strap 1190 comprises a looped piece of fabric webbing.
However,
various other types of hand holds could alternatively be provided for the
first passenger. For
example, flexible rubber or plastic handles could be mounted to the forward
middle portion
of the second seat portion 1140. Alternatively, grab handles) could be formed
in the second
seat portion 1140. Hand holds for the first passenger could alternatively be
attached to or
formed in a back end of the first seat portion 1130.
[OOI50] Since the looped strap 1190 is mounted on the second seat portion
1140, detachment of the second seat portion 1140 from the snowmobile 1100 also
detaches
the looped strap 1190 from the snowmobile 1100. Of course, in the alternative,
the looped
strap 1190 could be attached to the rear of the first seat portion 1130
without deviating from
the scope of the present invention.
[00151] In the embodiment illustrated in FIG. 17, left and right grab handles
1200 (only the left grab handle is shown) mount to the left and right sides of
the third seat
portion 1150. The grab handles 1200 extend upwardly above the surface 1150b of
the seat of
the third seat portion 1150 to enable the second passenger to easily grab the
handles 1200
with his/her hands without having to strain his/her arms. The grab handles
preferably
comprise blow-molded plastic or rubber that is relatively flexible. Such grab
handles are
preferably of the type described in U.S. Patent Application No. 10/361,682,
filed February
CA 02468333 2004-05-25
11, 2003, titled "QUICK RELEASE PASSENGER SEAT WITH FLEXIBLE GRAB
HANDLE", which is incorporated by reference herein in its entirety. In the
alternative, as
would be appreciated by those skilled in the art, the grab handles 1200 may
not be attached to
the third seat portion 1150. Alternatively, a strap, such as the looped strap
1190, may be
attached thereto.
[00152) As illustrated in FIGS. 13, 13D, and 14, a backrest assembly 1210
mounts to the third seat portion 1150. The backrest assembly 1210 includes a
cushioned
backrest 1220 connected to an adjustable backrest mount 1230. The third seat
portion 1150
includes backrest mounting points 1240 on its left and right sides. The
backrest mount 1230
has left and right arms that extend downwardly from the cushioned backrest
1220 and are
constructed and arranged to adjustably and detachably mount to the backrest
mounting points
1240 of the third seat portion 1150. As illustrated in FIG. 16, the backrest
mount 1230
selectively pivotally connects to the mounting points 1240 to enable the
position of the
backrest 1220 to be adjusted. The backrest mount 1230 may include one or more
internal
backrest 1220 adjustment mechanisms, e.g., pivotal connections, telescopic
connections, ete.
The backrest assembly 1210 can therefore be adjusted for use by the fzrst or
second
passenger.
[00153] While only the extreme positions of the backrest assembly 1210 are
illustrated, the backrest assembly 1210 is preferably selectively positionable
in a variety of
intermediate and more extreme positions. For example, as illustrated in dotted
lines in FIG.
13, the backrest assembly 1210 may be attached to the third seat portion 1150
and pivoted
forward enough that the driver may use the backrest 1220 for back support.
Similarly, as
illustrated in dotted lines in FIG. 14, when the second seat portion 1140 is
removed, the
backrest assembly 1210 may also be adjusted to provide back support for the
driver sitting on
the first seat portion 1130.
[00154] As illustrated in FIGS. 13, 15, and 16, the first seat portion 1130
also
has left and right backrest mounting points 1250. As illustrated in FIG. 15,
when the third
seat portion 1150 is not used, the backrest assembly 1210 may be detached from
the
mounting points 1240 and attached to the mounting points 1250 so that the back
rest 1220
may be used by the driver. As illustrated in FIG. 16, when attached to the
mounting points
1250, the backrest assembly 1210 may also be pivoted rearwardly enough to
provide back
CA 02468333 2004-05-25
support to a first passenger. Also illustrated in FIG. 16, backrest assembly
1250 selectively
pivotally connects to the backrest mounting points 1260 on the second seat
portion 1 I40.
[00155] Although the second and third seat portions 1140, 1150 in this
embodiment are independently detachable from the frame, various other seat
assembly
configurations are within the scope of the present invention. For example, all
three seat
portions 1130, I 140, 1150 could be integrally formed or permanently attached
to each other.
Such a combination of seat portions 1130, 1140, 1150 could be permanently
attached to the
frame or removably attached to the frame. Alternatively, the first and second
seat portions
1130, 1140 could be integrally formed with each other such that just the third
seat portion
1150 would be detachable.
[00156] FIG. 18 illustrates yet another alterxaative embodiment of a
snowmobile
according to the present invention. The snowmobile 1300 is identical to the
snowmobile
1100 illustrated in FIG. 13 except for an alternative seat assembly 1310. The
seat assembly
1310 is identical to the seat assembly 1110 illustrated in FIG. 13 except that
the second and
third seat portions 1140, 1150 are integrally formed with (or otherwise
permanently attached
to) each other. The second and third seat portions 1140, 1150 can therefore be
simultaneously detached from frame 1120 to create a storage space behind the
first seat
portion 1130. To use the seat assembly 1310 in a two rider configuration, the
combined
second and third seat portions 1140, 1150 are removed and a separate
additional third seat
portion 1150 is attached to the frame 1120 behind the first seat portion (see
FIG. 14).
[00157] FIG. 19 shows a commercial embodiment of the present invention.
Snowmobile 1300 is very similar to snowmobile 1100 shown in FIG. 14.
Snowmobile 1300
has a frame 1320, an engine 1317 disposed an the frame 1320, a drive track
1321 disposed
below the frame 1320 and operatively connected to the engine 1317. A straddle-
type seat
assembly 1310 is disposed on the frame 1320 rearward of the engine 1317 and
two front skis
1316 are disposed forward of the engine 1317. Handlebars 1332 are operatively
connect to
the rivo front skis 1316 for steering the snowmobile 1300.
[00158] The straddle-type seat assembly 1310 is very similar to that of seat
assembly 1110 shown in FIGS. 13-18 in that it comprises a first seat portion
1330, a second
seat portion 1340 and a third seat portion 1350. Seat assembly 1310 also
includes a back rest
1320 pivotally connected to the third seat portion 1350. Backrest 1322
pivotally connects to
CA 02468333 2004-05-25
the third seat portion 1350 in the same manner as described above with respect
to backrest
1220 and third seat portion 1150. Backrest 1322 is spring biased {not shown)
toward the
front of the seat as described above with respect to backrest 1220. As also
shown in FIG. 19,
handgrips 1301 and wind deflectors 1302 are provided on left and right sides
of the third seat
portion 1350. Cargo boxes 1303 may also be attached to the right and left
sides of the third
seat portion 1350 to provide extra storage space when travelling with all
three seat portions.
[00159] FIG. 19 shows the preferred dimensions of the first, second and third
seat portions 1330, 1340, and 1350 respectively. First seat portion 1330 is
approximately
764mm +/- 50mm in length. The second seat portion is approximately 207 mom +/-
50mm in
length and the third seat portion is approximately 398mm in length. The first
seating portion
has a first seating position 1330a, which is approximately 478mm +/- 50mm from
the
steering position 1334. The second seat portion has a second seating position
1340a which is
approximately 380mm +/- 50mm behind the first seating position 1330a and the
third seat
portion 1350 has a third seat position 1350a which is approximately 300mm +/-
50mm
behind the second seating position 1340a. The total length of the seat
assembly 1310
comprising first, second and third seat portions 1330, 1340, and 1350 is
1369mm +/- 150mm.
[00160] While the invention has been described with reference to the various
exemplary embodiments outlined above, it will be understood by those skilled
in the art that
various changes may be made and equivalents may be substituted for elements
thereof
without departing from the spirit and scope of the present invention. In
addition, many
modifications may be made to adapt a particular situation, component, or
material to the
teachings of the present invention without departing from its teachings as
claimed.
