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TITLE OF THE INVENTION
RECREATIONAL VEHICLE
FIELD OF THE INVENTION
The present invention relates to recreational vehicles.
More specifically, the present invention is. concerned with a single seater
snowmobile type recreational vehicle. The present invention is also
concerned with a steering assembly for such a recreational vehicle.
BACKGROUND OF THE INVENTION
Snowmobiles are well known in the art. They usually
have a relatively long seat that allow the snowmobiles to be ridden by two
people: a driver and a passenger. This, combined with the fact that
snowmobiles are relatively wide and provided with a heavy gasoline
powered engine, make the conventional snowmobile a relatively bulky
recreational vehicle.
To overcome this bulkiness of the conventional
snowmobile, many single seater snowmobile type recreational vehicles
have been designed.
United States Patent NI° 5,474,146 issued to Yoshioka
et aL on December 12, 1995 and entitled « Snow Vehicle » describes such
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a single seater recreational vehicle. ‘r’oshioka’s snow vehicle has a
motorcycle upper structure where a steered front ski replaces the
conventional front wheel and an ern~ine-driven endless belt track
assembly replaces the rear wheel. Whine the snow vehicle described in
this document arguably offers better handling over conventional
snowmobiles since it is lighter and narrower, it also has a major
drawback: instability. Indeed, since the weight of the driver is applied to
the vehicle between the front ski and the endless track, i.e. close to the
fork, and since the vehicle’s seat is far from the ground, is it argued that
Yoshioka’s snow vehicle is inherently instable, the center of gravity being
far from the ground and towards the front of the vehicle. This instability is
increased by the fact that the endless track contacts the ground on a
relatively short portion of the entire length of the vehicle.
The following United States Patents also describe
similar single seater snowmobile type recreational vehicles having similar
drawbacks:
lumber ‘Invenfiar ‘ issue gate
4,613,006 Moss et al. September 23,
1986
5,064,208 Bibollet November 12, 1991
Des. 333,110Mogi et al. February 9, 1993
Indeed, the recreational vehicles shown in these
documents all share the common motorcycle type steering assembly that
positions the driver relatively in the front portion of the vehicle, which
leads to instability, as discussed hereinabove.
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United States Patent N° 5,568,840 issued on October
29, 1996 to Nagata et al. describes a snowmobile where the driver is
standing on a step floor. Instability is also a major drawback of Nagata’s
snowmobile since the center of gravity of the snowmobile, while in use,
is far from the ground.
OBJECTS OF THE INVENTION
An object of the present invention is therefore to provide
an improved snowmobile type recreational vehicle.
Another object of the present invention is to provide an
improved steering assembly for snowmobile type recreational vehicles.
SUMMARY OF THE INVENTION
More specifically, in accordance with the present
invention, there is provided a recreational vehicle comprising:
a longitudinal frame;
a suspension mounted to the frame;
an endless track rotat<~bly mounted to the suspension;
an engine mounted to the frame and associated to the
endless track to selectively rotate the endless track about the suspension;
a steering assembly including:
– a handlebar portion so mounted to the frame as to
pivot about a first pivot axis;
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– a fork portion so mounted to the frame as to pivot
about a second pivot axis; the fork portion having a
distal end configured and sized to receive a ski; and
– means for pivoting the fork portion about the second
pivot axis when the handlebar portion is pivoted about
the first pivot axis; the pivoting means being mounted to
both the handlebar portion and to the fork portion;
whereby the pivoting means allow the first and second pivot axis to be
longitudinally spaced apart.
According to another .aspect of the present invention,
there is provided a steering assembly for recreational vehicles including
a longitudinal frame; the steering assembly comprising:
a handlebar portion so mounted to the frame as to pivot
about a first pivot axis;
a fork portion so mounted to the frame as to pivot about
a second pivot axis; the fork portion having a distal end configured and
sized to receive a ski; and
means for pivoting the fork portion about the second
pivot axis when the handlebar portion is pivoted about the first pivot axis;
the pivoting means being mounted to both the handlebar portion and to
the fork portion;
whereby the pivoting means allow the first and second pivot axis to be
longitudinally spaced apart.
Other objects, advantages and features of the present
invention will become more apparent upon reading of the following non
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restrictive description of preferred embodiments thereof, given by way of
example only with reference to the accompanying drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings:
Figure 1 is a side elewational view of a recreational
vehicle according to an embodiment of the preferred invention;
Figure 2 is a top plan view of the recreational vehicle of
Figure 1;
Figure 3 is a side elevational view similar to Figure 1
where the hood portion is shown in dashed lines;
Figure 4 is a side elevational view of a steering
assembly of the recreational vehicle of (Figure 1;
Figure 5 is an enlarged view, partly in section, of a
portion of the steering assembly of Figure 4;
Figure 6 is a sectional view taken along line 6-6 of
Figure 3;
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Figure 7 is a sectional view similar to Figure 6 illustrating
a second embodiment of the steering asaembly of the present invention;
and
Figure 8 is a sectional view similar to Figure 6 illustrating
a third embodiment of the steering assembly of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to Figures 1-6 of the appended drawings,
a single seater snowmobile type recreational vehicle 10 will be described.
As can be better seen in Figure 3, the vehicle 10
includes a longitudinal frame 12, a stE:ering assembly 14, a gasoline
powered engine 16 and an endless track 18 rotatably mounted to a
suspension assembly 20. As is apparent from Figure 3, the steering
assembly 14, the engine 16 and the suspension 20 are mounted to the
frame 12.
The vehicle 10 also includes a streamlined hood 22, a
gasoline tank 24, a seat 26 and two stirrups 28 and 30 (Figure 2).
The gasoline powered engine 16 is similar to a
snowmobile engine and is thus believed well known to those skilled in the
art. The engine 16 is mechanically connected to a driven portion 32 of
the suspension 20 to thereby power thE: rotation of the endless track 18
thereon. This mechanical connection is advantageously done via a cog
belt 34. Of course, other similar mechanical power transmission means,
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such as, for example, V-belts or chains, could also be used. However,
since the vehicle 10 is to be used on snow covered surtaces, the cog belt
34 is believed advantageous over other conventional mechanical power
transmission means. Furthermore, cog belts are lighter that conventional
snowmobile power transmission means and are more efficient.
It is to be noted that the engine 16 is mounted as
low as possible onto the frame 12 to thereby get the lowest possible
center of gravity of the vehicle, thereby increasing the stability thereof.
Since gasoline powered engines are believed well
known in the art, engine 16 will not be further described herein.
The purpose of the suspension 20 is obviously to
provide a smoother ride to the driver. Since it mounts the endless belt 18
to the frame, as do conventional snowmobile suspensions, it is believed
that virtually any type of conventional snowmobile suspensions could be
modified to the dimensions and requirements of the present invention. The
suspension 20 illustrated in the appended drawings could therefore be
replaced by other similar suspensions (not shown) without departing from
the spirit and nature of the present invention. A description of the
suspension 20, applied to a conventional snowmobile, can be found in laid
open Canadian patent application N° 2,191,008, filed on November 22,
1996 and entitled « Rear suspension system for a land vehicle.
It is to be noted that the endless belt 18 is relatively
long and that a meaningful portion of the belt 18 engages the ground.
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Furthermore, since the suspension 20 is mounted inside the loop created
by the endless belt 18, the radius of rotation of the belt 18 in the upper
portion of the suspension 20 is increased, which increases the centrifugal
forces created by the rotating belt 18, therefore increasing the stability of
the vehicle 10.
It is also to be noted that the endless belt 18 is flat and
narrow (about 12 inches (0.3 m) wide) and provided with long round
rubber lugs (not shown) allowing lateral traction during leaned cornering.
Turning now more specifically to Figures 4 to 6, the
steering assembly 14 will be described in greater details.
The steering assembly 14 includes a handlebar portion
36 having a stem 38 and handlebars 40, a fork portion 42 and a direction
bar 44 interconnecting the handlebar portion 36 and the fork portion 42.
As will be apparent to one skilled in the art, the direction
bar 44 allows the handlebar portion 36 to be positioned rearwardly from
the fork 42, thereby positioning the driver (not shown) of the vehicle
above the suspension 20. This position of the driver causes the center
of gravity of the vehicle 10 to be near the center of the vehicle 10 since
the weight of the driver is compensated by the weight of the engine 16.
Furthermore, since the direction bar 44 is connected at a proximate end
of the fork 42, it allows the engine to be positioned as close as possible
to the ground, thereby lowering the center of gravity of the vehicle 10.
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As can be better seen in Figures 4 and 5, the stem 38
of the handlebar portion 36 is pivotally mounted to the frame 12 via a pair
of crossbars 46, 48 to which are respectively mounted plastic bushings
52, 54. These bushings allow the step 38 to pivot about a first pivot axis
56 without undue friction. The handlebars 40 are fixedly mounted to a
proximate end 58 of the stem 38 via a conventional split fastening
assembly. Of course, other types of fastening assemblies could be used
to mount the handlebars to the pivotablE: stem.
The fork 42 is pivotally mounted to the frame 12 via a
pair of crossbars 58, 60 to which are rest>ectively fixedly mounted to pivot
plates 62, 64. The fork 42 consists of two hydraulic cylinders 66 (only
one shown) each provided with a reciprocately movable piston 68 (only
one shown) having a distal end 70 to which a single ski 72 is pivotally
mounted. The cylinders 66 are interconnected by two identical cylinder
mounting plates 74, 76. As can be better seen from Figure 6, each
mounting plates 74, 76 is formed by two elements 78, 80 provided with
respective complementary semi-circular apertures 82, 84 configured and
sized to hold the cylinders 66 therein when fasteners 86 are used to
interconnect the two elements 78, 80.
The cylinder mounting ,plate 74 is pivotally connected to
the pivot plate 62 while the cylinder mounting plate 76 is pivotally
mounted to the pivot plate 64. The fork: 42 may therefore pivot about a
second pivot axis 87, generally parallel to the first pivot axis 56.
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As will be readily apparent to one skilled in the art, the
purpose of the hydraulic cylinders 66 is to provide a front suspension to
the vehicle 10.
5 The single ski 72 is so amounted to the distal end of the
piston 70 as to pivot (see arrow 88) to follow the terrain.
Referring now back to Figure 5 of the appended
drawings, the pivotal connection between the cylinder mounting plate 74
10 and the pivot plate 62 will be described in greater details. Of course, for
concision purposes, this description will not be repeated for the pivotal
connection between the cylinder mounting plate 76 and the pivot plate 64.
As can be seen from this figure, the pivot plate 62 is
provided with an aperture 90 sized to receive a first end of a generally t-
shaped friction reducing element 92. The cylinder mounting plate 74 also
has an aperture 94 provided with a friction reducing sleeve 96 having a
flange 97 sized to receive a second end of the friction reducing element
92. A fastener 98 is used to removably secure these elements together.
The friction reducing element 92 and the friction reducing sleeve 96 are
advantageously made of a durable friction reducing material such as, for
example, Nylatron~ MOS2t »‘.
Consideration will now be given to Figure 6 to describe
the interconnection of the handlebar portion 36 to the fork portion 42 that
are linked via the direction bar 44.
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The stem 38 is provided with an arm 100 fixedly
mounted thereon. The arm 100 is provided with three adjustment
apertures 102, 104 and 106 sized to rE:ceive a fastener 107, pivotally
mounting a proximate end 108 of the bar’ 44 thereto. The proximate end
108 is shown linked to the handlebar 36 via the aperture 102 of the arm
100.
A distal end 112 of the direction bar 44 is linked to the
fork portion 42. Indeed, the cylinder mounting plate 74 includes an
aperture 110 sized to receive a fastener ‘111, pivotally mounting the distal
end 112 of the bar 44 thereto.
As can be seen from this figure, the apertures 102, 104,
106 and 110 are so positioned that the bar 44 is offset from an imaginary
line joining the two pivot axis 56 and 87,
As will be apparent to one skilled in the art, the direction
bar 44 allows the first and second pivot axis to be longitudinally spaced
apart.
The operation of the steering assembly 14 will now be
described with respect to Figures 5 and 6 of the appended drawings. It
is to be noted that the crossbars 46, 48 and the hydraulic cylinders 66 of
the fork 42 are not shown in Figure 6 for clarity purposes.
When the handlebars 40 are in the position illustrated
in Figure 5, the steering assembly 14 is in the position shown in full lines
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in Figure 6. The ski 72 is therefore longitudinally aligned with the vehicle
10.
If the handlebars 40 are rotated left (see arrow 114) so
that the arm 100 is positioned as illustrated in dashed lines, the direction
bar 44 will be pulled therefore causing ‘the counterclockwise rotation of
the cylinder mounting plate 74 (see arrow 116). This rotation of the
cylinder mounting plate 74 will cause the fork 44, hence the ski 72, to be
rotated left.
Of course, if the handlebars 40 are rotated right (not
shown) the bar 44 will be pushed therefore causing the clockwise rotation
of the cylinder mounting plate 74 (not shown). A right rotation of the fork
44 and of the ski 72 will therefore result.
As can be also seen from Figure 6, the apertures 104
and 106 of the arm 100 are adjusting apE~rtures allowing the user to adjust
the deflection of the handlebars 40 required to produce a known
deflection of the ski 72 by modifying they distance between the first pivot
axis 56 and the pivotal connection between the bar 44 and the arm 100.
Indeed, the deflection a required to pivot the cylinder mounting plate 74,
as illustrated in dashed lines when the proximate end 108 is connected
to aperture 102, is increased to (i if the proximate end 108 is connected
to aperture 104, and to a if the proximate end 108 is connected to
aperture 106.
While it is not illustrated in the appended figures, similar
adjustment apertures (not shown) could be provided in the cylinder
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mounting plate 74 to modify the distancE~ between the second pivot axis
87 and the pivotal connection between the bar 44 and the cylinder
mounting plate 74.
It is also to be noted that while the direction bar 44 is
shown in the appended figures as being a non adjustable bar, it could
advantageously be designed as a length adjustable direction bar to allow
minute adjustments to be made to precisely adjust the angle of the
handlebar to the angle of the fork portion.
Turning now to Figure 7 of the appended drawings,
which is a sectional view similar to Figure 6, a steering assembly 200
according to a second embodiment of the present invention will be
described.
The steering assembly 200 is very similar to the steering
assembly 14 shown in Figure 6. The only difference between these two
steering assemblies concerns the link between the fork portion 42 and the
handlebar portion 36. Indeed, the direction bar 44 of the steering
assembly 14 has been replaced by a cog belt assembly 202 including a
stem pulley 204, a fork pulley 206 and a. cog belt 208. Since the pulleys
204 and 206 are respectively fixedly mounted to the stem 38 and to the
cylinder mounting plate 74, rotation of the handlebar will cause a similar
rotation of the fork assembly, as will easily be understood by one skilled
in the art.
It is to be noted that the cog belt assembly 202 could be
replaced by a chain assembly (not shown) where the cog belt 208 would
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be replaced by a chain and the pulleys would be replaced by dented
wheels.
Turning now to FigurE: 8 of the appended drawings,
which is a sectional view similar to Figure 6, a steering assembly 300
according to a third embodiment of the present invention will be
described.
The steering assembly 300 is very similar to the steering
assembly 14 shown in Figure 6. The only difference between these two
steering assemblies concerns the link between the fork portion 42 and the
handlebar portion 36. Indeed, the direction bar 44 of the steering
assembly 14 has been replaced by a cog rail/pinion assembly 302
comprising a pinion 304, a cog rail 306 and a direction bar 308.
The pinion 304 is fixedly mounted to the stem 38 to
thereby pivot about the first pivot axis 56.
The cog rail 306 is slidably mounted to the frame 12 via
a bracket 310 secured to the crossbar ~48 (not shown in this figure).
The direction bar 308 has a proximate end pivotally
mounted to the end of the cog rail 306 and a distal end pivotally mounted
to the cylinder mounting plate 74.
As will be easily understood by one skilled in the art, the
pivoting action of the stem 38 will cause the longitudinal displacement of
the cog rail 306, which, in turn, will force the direction bar 308 to pull or
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to push onto the cylinder mounting plai:e 74 therefore pivoting the fork
portion 42 about the second pivot axis 87.
It is to be noted that thf~ amount of pivoting of the stem
5 38 required to cause a predetermined pivoting of the fork portion 42 is
determined by the diameter of the pinion 304.
It is to be noted that while the recreational vehicle 10 is
shown and described as being a single seater, it would within the reach
10 of one skilled in the art to design a two seater recreational vehicle
similar
to the recreational vehicle 10.
Although the present invention has been described
hereinabove by way of preferred embodiments thereof, it can be modified,
15 without departing from the spirit and n<~ture of the subject invention as
defined in the appended claims.
English
