Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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SNOWMOBILE
The invention refers to a snowmobile comprising a pair of glide means.
Snowmobiles with a pair of glide means are known. Some of these snowmobiles
have a wide track width and are, thus, favorable in some situations such as
when driving on
hard surfaces such as a snowmobile track, but awkward in other situations.
Other snowmobiles have a somewhat narrower track, which is better in deep-snow
conditions and when traversing hills, but then less stable in other
situations.
What is also known is single track snow vehicles. These vehicles employ one
cen-
trally placed steering ski ahead of an endless drive belt. Examples are
published in US
6,234,263, US 5,947,220, US 5,904,217, US 5,586,614 and US 5,474,146.
US 6,467,787 shows a steering mechanism for a snowmobile with a pair of glide
means. The steering mechanism enables the driver to more easily displace his
or her body
sideways as well as steering the vehicle from this position.
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The different needs of the driving conditions really call for different
snowmobiles,
which means that today either the vehicle will be good for one purpose, but
not so good for
the other, or vice versa. Alternatively, it is configured as a compromise.
In some situations, it might further be necessary or at least advantageous to
tilt the
snowmobile. However, with the type of snowmobiles with two skis, even when the
track
width is in what is now called a narrow configuration, typically down to 900
mm, the snow-
mobile is not easily tiltable. This is due to the positions of the axes around
which the snow-
mobile must be tilted. These axes each extend from one ski to the edge of the
drive belt on
each side of the snowmobile. If for instance the vehicle is making a right
turn, it must be
tilted by rotating it around the right hand side tilt axis. This involves
elevating the snowmo-
bile up. The effort (tilting moment) necessary to do this depends on the
weight of the snow-
mobile, the longitudinal position of the center of gravity, the width of both
the drive belt and
the front track between the skis as well as the resilience of the ground
surface.
Typically a snow mobile has a center of gravity quite forward, where the tilt
axes lay
well apart, meaning that a considerable effort is usually needed to tilt the
vehicle.
This means that, unlike such as when operating a motorcycle, the driver (and
pas-
senger) have to move their bodies sideways to achieve some tilting of the
vehicle. To
achieve real tilting, the driver frequently has to stand with both his feet on
the footboard on
one side of the snowmobile. This is physically rather demanding. Furthermore,
it is common
for both driver and passenger to have to move the upper parts of their bodies
sideways in
order to negotiate change of directions during all conditions.
The common type of snowmobiles with two steering skis spaced in a wide track
and
a central endless drive belt has the disadvantage of the skis not compacting
the snow be-
fore it is engaged by the drive belt, something which would have been
beneficial in deep-
snow conditions.
The known single track snowmobiles always have to be controlled by the driver
against falling (tipping over). In some driving conditions it is - as
discussed - beneficial to be
able to easily tilt the vehicle. In other conditions however, such as when
driving slowly and
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at standstill, and when driving on hard or icy tracks, the snowmobile should
be
stabilized against falling, and not have the freedom to tilt. If not such as
with single
track snowmobiles ¨ there are the following drawbacks:
The strain on a driver and on a potential passenger will be large.
Furthermore, the luggage payload will be severely limited, as a heavily loaded
snowmobile will be difficult to hold. An indication of this is found in US
6,234,263,
which describes a single track vehicle to be of "type recreational".
The steering mechanism described in US 6,467,787 allows the driver to
more easily shift his or her body sideways and then more easily control the
steering
from this position. It is clear that this will improve the control of the
vehicle when it is
subjected to a side force. However, the mechanism will still not easily enable
true
tilting of the snowmobile.
In short: The above-detailed known snowmobiles are limited by
drawbacks in those situations where a narrow track width and preferably
tiltability
would have improved the control of the snowmobile. The proposed single track
snowmobiles have the opposite problem.
In view of the above, it is an object of some embodiments of the present
invention to provide a snowmobile comprising a pair of glide means, which
snowmobile is enhanced with view to controllability.
According to one embodiment of the present invention, there is
provided a snowmobile comprising a pair of glide means, wherein a track width
of
said pair of glide means is variable and said glide means are coupled to a
chassis by
means of pendulum arms mounted to said chassis pivotably about axes transverse
to
a glide means main plane, and cardan joints for coupling said pendulum arms to
said
chassis.
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Thereby, the track width can be adjusted according to the current
situation. For example, the track width can be narrow when riding fast or when
riding
in deep snow. Such a narrow track width particularly enhances tiltability of
the
snowmobile, what is advantageous.
On the other hand, the track width can be adjusted to be wide,
particularly when riding at a low velocity or during standstill, stabilizing
the
snowmobile.
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Preferably, the track width is variable during riding. In other words, the
snowmobile
is made to react to changing riding conditions quite flexible.
Said glide means are preferably front skis.
What is provided according to a preferred embodiment of the invention is a
glide
means orientation defining rod being coupled, on the one hand, to said glide
means and, on
the other hand, pivotably coupled to a chassis, wherein a coupling of said
glide means ori-
entation defining rod to said chassis is positioned to ensure that a glide
means orientation
defined by said glide means orientation defining rod is essentially
independent of said track
width.
Thereby, what is achieved is that an adjustment of the track width is possible
during
riding, without influence on the orientation of the glide means, further
facilitating the control
of the snowmobile.
The above expression "essentially independent" means independent as far as pos-
sible with view to usual tolerances and imperfections.
Furthermore, "essentially independent" allows for - which is frequently done
in wheel
suspensions - a nominal position of the pivot point slightly away from the
neutral in order to
achieve a certain effect such as always steering slightly in or out when all
geometrical toler-
ances are coming into effect.
The glide means orientation defining rod is preferably a steering rod. In
other words,
said glide means or front skis, respectively, serve for steering the
snowmobile.
Preferably, the glide means are coupled to a chassis by means of pendulum arms
mounted to said chassis pivotably about axes transverse to a glide means main
plane.
Thus, the variation of the track width is performed by moving said pendulum
arms around
said axes, i.e. like scissors. This is a quite simple construction.
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According to a preferred embodiment of the invention, what is provided is
cardan
joints or spherical joints for coupling said pendulum arms to said chassis.
Particularly when
using cardan joints, what is achieved is that momenta around the longitudinal
axis of the
pendulum arms are absorbed, what is important particularly during cornering of
the snow-
5 mobile. In the case of spherical joints, said momenta have to be absorbed
by other means.
More preferably, one of the pivot axes of a cardan joint for coupling said
pendulum
arm to said chassis is inclined relative to a pivoting axis of a joint for
coupling an extendable
track width adjusting means to said chassis.
Preferably, said pendulum arm and said glide means orientation defining rod
are
parallel parts of a parallelogram or trapezoid mechanism. What is achieved by
this feature is
that the glide means orientation is essentially independent of the track
width.
According to a further preferred embodiment of the invention, the glide means
are
biased to a wide track configuration. In other words, the narrow track
configuration is only
realized in case that a driver performs a respective control of the
snowmobile, e.g. by
pressing a button or by actuating a lever. Releasing the button or lever,
respectively, imme-
diately results in the snowmobile being adjusted to the wide track
configuration because of
the bias. Thereby, a high level of security is achieved.
Preferably, the snowmobile has a drive means, wherein the track of at least
one of
said glide means at least partially overlaps with the track of said drive
means, in at least one
track width configuration. Thereby, the glide means serves for compacting the
snow before
the snow is engaged by the drive means, resulting in a more efficient driving
of the snow-
mobile.
To this end, what is preferred is that said one glide means track overlaps
with said
drive means track by at least 25 % of the glide means track in a narrowest
track width con-
According to a most preferred embodiment of the invention, the snowmobile com-
prises a suspension assembly for connecting said glide means to a chassis,
said suspen-
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sion assembly being adapted to allow said glide means to move transverse to
their main
planes, but in opposite directions, in order to tilt said chassis.
The above-described tiltability of the snowmobile very much enhances the
controlla-
bility and steerability of the snowmobile.
Preferably, said suspension assembly comprises a glide means orientation
defining
rod being, on the one hand, coupled to a glide means and, on the other hand,
pivotably
coupled to said chassis, wherein a coupling of said glide means orientation
defining rod to
said chassis is positioned to ensure that a glide means orientation defined by
said glide
means orientation defining rod is essentially independent of said glide means
movement
transverse to the glide means main plane.
In other words, a tilting movement does not influence the orientation of the
glide
means and, thus, needs not to be compensated by respective steering movements.
In other
words, what is provided is "zero bump steer".
Said glide means orientation defining rod is preferably a steering rod. In
other words,
the snowmobile is preferably steerable by respectively controlling the
position of said glide
means, which might be front skis.
Said suspension assembly preferably comprises a pendulum arm for coupling a
glide means to said chassis. This is a very simple solution for attaching said
glide means to
the chassis.
What is even more preferred is that said coupling of said glide means
orientation
defining rod to said chassis is positioned approximately on a rotating pivot
through a joint for
coupling said pendulum arm to said chassis. Thereby, said coupling of said
glide means
orientation defining rod to said chassis is positioned in a "neutral area".
What is meant by
"approximately" is that the position might vary with view to usual tolerances
and imperfec-
tions. Furthermore, the exact optimum position depends on various
circumstances and on
the overall geometry of the glide means suspension.
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According to a preferred embodiment of the invention, a line through a joint
for cou-
pling said pendulum arm to said chassis and through a joint for coupling said
glide means
orientation defining rod to said chassis is inclined relative to a horizontal
line perpendicular
to a lengthwise direction of the snowmobile. Thereby, glide means movements in
the verti-
cal direction change the angle of the main plane of said glide means, what is
to some extent
useful, particularly when the track is adjusted to be wide. The same applies
to a depend-
ency of said main plane angle from the track widths.
Preferably, said line through said joint for coupling said pendulum arm to
said chas-
sis and through said joint for coupling said glide means orientation defining
rod to said
chassis goes through a joint for coupling an extendable track width adjusting
means to said
chassis.
More preferred, an inclination angle as seen from above is 4 to 30 degrees and
an
inclination angle as seen from the front of the snowmobile is 0 to 5 degrees.
Preferably, a force acting against said movement of said glide means is
variable. In
other words, a force acting against tilting of the snowmobile is variable.
This is particularly
advantageous with view to the fact that a tilting should be more easily
performed when rid-
ing at high speed, whereas it should be not so easily be performed
particularly during
standstill. During standstill, a tilting might be completely prevented.
According to a preferred embodiment of the invention, the force acting against
said
movement of said glide means and, thereby, against tilting is dependent on the
track width.
Particularly, easy tilting should be possible in a narrow track configuration,
whereas a tilting
should not be so easy in a wide track configuration.
To achieve this, preferably an angular position of a means applying said force
rela-
tive to said suspension is dependent on the track width. This is a
mechanically quite simple
solution.
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According to a preferred embodiment of the invention, a height of a front part
of the
snowmobile is dependent on the track width. Thereby, further advantages are
achieved with
view to the controllability of the snowmobile.
Preferably, said glide means are coupled to a suspension assembly by joint
means,
said joint means allowing said glide means to pivot around axes parallel to
the main plane
of said glide means, but not around an axis transverse to said main plane.
These features
result in an improved stability of the snowmobile during riding on uneven and
bumpy sur-
faces.
In order to further enhance stability, preferably said glide means is biased
around an
axis parallel to its lengthwise direction into a position parallel to a main
plane of the snow-
mobile. In other words, said glide means is always urged to return in a
position parallel to
the main plane of the snowmobile and, thereby, into a position parallel to a
horizontal plane
when standing on horizontal ground, to further stabilize the snowmobile.
A very simple solution according to the invention includes that a biasing
force results
from torsion.
As is to be taken from the above explanations, the invention provides
preferably for
a front ski suspension with a track which is varied according to the
conditions during riding.
Furthermore, the track may be extremely narrow when it is in the narrow
configuration. This
greatly enhances tilting at will by the driver. Furthermore, the skis - when
in a very narrow
track - will compact the snow before it is engaged by a driving belt.
Conversely, the track may be very wide when it is in the wide track
configuration.
This enhances stability against falling (tipping over).
The several purposes of the invention are thus to allow a new type of
snowmobile to
be driven according to the needs of the conditions. This will make the
operation of the
snowmobile easier as well as reduce the strain on the driver - as well as on a
potential pas-
senger. This would improve the safety of the operation of the snowmobile.
Furthermore, it is
the purpose of some embodiments of the invention to increase the traction of
the drive belt
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in deep-snow conditions. This will improve the operation and increase the
usefulness of the
snowmobile. Another purpose of some embodiments of the invention is to enable
a snow-
mobile in a cost-efficient manner. This is done by providing a simple and
effective mecha-
nism to achieve the purpose.
The above purposes are preferably achieved by providing a suspension mechanism
which varies the track of two front skis. The mechanism is suspended on
springs and
dampers which are effective in the narrow and wide track configurations as
well as in all
intermediate positions in between.
The ratio between tilting angle and vertical (referring to the snowmobile)
movement
of the skis, thus suspension springs, thus resistance against tilting,
preferably varies with
the track. This means that when the skis are in the narrow track positions,
tilting is achieved
by one ski going up and the other one going down (referring to the
snowmobile). The skis
are preferably steerable in all track configurations, and the steered
direction is not noticea-
bly influenced by the track width itself. This means that a change of track
during speed does
not influence the direction into which the snowmobile is steered.
Cost effectiveness of the invention is preferably achieved by providing a
mechanism
which may readily be adapted to current snowmobiles. Furthermore, the
mechanism itself
preferably consists of a minimum of parts, and standard mechanical elements
such as
bearings, joints and tubes are used to a large extent.
Cost effectiveness of the invention may preferably also be achieved by
utilizing a
pressurized oil lubrication system to be found on some snowmobile engines to
actuate the
variation of the track.
International patent application PCT/IB 02/05833, filed by the applicant of
the pres-
ent application on December 20, 2002, refers to a wheeled vehicle, which
vehicle is quite
similar in construction of a suspension assembly of the wheels as compared to
the suspen-
sion assembly of the glide means or skis, respectively, of the present
invention, so that ref-
erence is made here to all the disclosure of PCT/1B 02/05833.
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The following is a detailed description of preferred embodiments of the
invention,
referring to the drawings, in which
figure la is a
schematic perspective view of a preferred
5
embodiment of a snowmobile according to the
invention,
figure lb is a front view of said mobile at
standstill,
10 figure lc is the
same view as figure 1 b, but in a tilted
condition,
figure 2 is a
schematic view of the front ski suspension
assembly,
figure 3 is a view of the right
hand side of the assembly
according to figure 2, as seen from above,
figure 4 is a
schematic front view meant for explaining
the movements when tilting,
figure 5 is a perspective view showing details of attach-
ing a front ski to a front ski suspension assem-
bly,
figure 6 is 2 front views meant
for explaining the effects
of track width adjustment, and
figure 7 is
the same view as figure 3, but of another em-
bodiment.
Figure 1a shows a perspective view of a snowmobile according to a preferred em-
bodiment of the invention, with a centrally placed drive belt A and two
steered front skis 5,5
configured in a narrow track. The snowmobile is tiltable, as shown in the
front view accord-
ing to figure lc. Figure lb shows the snowmobile with a wide track
configuration, when it is
not easily tiltable, and safe against falling (tipping over).
Figure 2 shows details of a sprung and damped steerable suspension assembly
with
a variable track.
The skis 5 are pivotally attached to steering pivots 3 which can be swivelled
in
bearing supports in housings in pendulum arms 1. Steering arms 4 are rigidly
fixed to the
steering pivots, and are actuated through steering rods 6. Said steering rods
6 are con-
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nected to steering swivel 8. Pendulum arms 1 are fixed to a sub-frame 2
through cardan
joints 7. Supported on said sub-frame 2 on spherical joints, extendable
elements 9 control
pendulum arms 1 through joints 15 (figure 3). If said extendable elements 9
are attached to
pendulum arms 1 by precise and stiff revolution joints, spherical joints 11
may alternatively
be used to attach said pendulum arms 1 to sub-frame 2, instead of cardan
joints 7, cf. the
lower right part of figure 2. Suspension spring and damper units 13 control
the vertical (seen
in the direction of the snowmobile) movements of pendulum arms 1 by being
attached to
said pendulum arms 1 as well as to the chassis (not shown) of the snowmobile
by spherical
joints.
Figure 3 shows a top view of the details of the right hand side of the
mechanism in
both the narrow and wide track positions. The dotted lines indicate the ski,
pendulum arm
and steering linkage in the outer (wide track) position.
Pivot axis 14 goes through joints 7 (or 11, depending on which type is used)
and
spherical joints 15 of said extendable elements 9. Joints 16 between steering
swivel 8 and
steering rods 6 are spherical or of the cardan type, and the joint center is
placed to ap-
proximately intersect axis 14 when the steering mechanism is in the straight
ahead position.
It is understood that when in this position, any vertical movements of the
skis 5, thus of
pendulum arms 1, are not influencing the steered straight ahead direction of
skis 5. To use
a common expression used in the field of wheeled vehicle suspensions, the
mechanism has
"zero bump steer". This applies to all track configurations of the mechanism.
Said extendable elements 9 control the track. When they are governed to be
short,
the mechanism has a narrow track. When they are governed to be long, the track
is wide.
It is understood that said extendable elements 9 may be actuators controlled
by
electricity or cylinder and piston assemblies controlled by fluid or
compressed air. It is fur-
thermore understood that said elements may contain springs which act against
the ele-
ments being compressed, in other words tend to keep them extended.
Pendulum arms 1 and steering rods 6, together with steering arms 4 and the dis-
tance between joints 7 (or 11) and 16 configures or nearly configures a
parallelogram
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mechanism. Alternatively, a trapezoid mechanism can be used. It can be shown
that the
mechanism can be deployed with a practical geometry which provides parallel
skis 5 in both
the narrow and wide track configurations, as well as parallelism or near
parallelism in the
positions in between.
The preferred use of the mechanism is to either drive the snowmobile with a
wide or
narrow track, the positions in between being transitional, effected in as
little as one second
or a little more. It is therefore understood that a slight out of parallelism
in this phase will
have but a minor, temporary and hardly noticeable influence on the steered
direction.
The bending moments which are built up in the mechanism due to side forces on
skis 5 are taken up as torsion in pendulum arms 1 and are transmitted to sub-
frame 2
through cardan joints 7. Cardan joints 7 themselves allow angular movements
around their
two principal axes alone or in combination, so that pendulum arms are free to
swivel in all
directions but not rotate. Alternatively fixing pendulum arms 1 to sub-frame 2
through ball
joints 11 and supporting them against rotation by means of precise and sturdy
pin joints to
extendable elements 9 will alternatively provide the same load-carrying
effect.
A typical drive belt width today is 380 mm, and skis 5 typically have a width
of 180
mm. With these skis, it is possible to have a narrow track of 200 mm between
the center
planes of the skis. It is now realized that this lines up well with drive belt
A both for tilting as
well as for the skis compressing deep and loose snow before it is engaged by
drive belt A.
Figure 4 shows how the vertical ski movements induced by tilting vary
according to
the width of the track between skis 5. This clearly shows the usefulness of
varying the track
according to the need of the situation:
When in a narrow track configuration, the snowmobile may be tilted against the
sus-
pension springs, with one ski being forced up and the other down. The vertical
movements
needed for this are small, so that tilting is facilitated. Again, here
"vertical movements" are
understood to be in the vertical direction of the snowmobile when standing on
horizontal
ground. The vertical movements is this track position are denounced al and a2
in figure 4,
and it is clear that they are so small that they are well within the normal
vertical suspension
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movements of the mechanism. In figure 4, 19 denounces a ground plane which the
vertical
movements refer to.
Should the snow furthermore be so deep and loose that it does not provide
ample
resistance onto the skis, the body of the snowmobile will float somewhat on
the snow. Now
a combination of vertical ski movements and simply tilting the vehicle is the
case. Both
modes are greatly facilitated by having the narrow track configuration. It is
here noted that
tilting against the force of a sprung suspension means tilting against a
resisting moment.
This resistance is useful for helping leveling the snowmobile back to an
upright position af-
ter tilting.
Conversely, the great vertical movements needed for tilting in the wide track
position
of the skis effectively secure the snowmobile against tilting, in other words
stabilize the
snowmobile so it cannot easily tip over. Here, b1 and b2 denounce the vertical
movements
in this position. It can be shown that these movements by far exceed the
limits of the
movements of a suspension, and thus cannot take place. In other words, the
snowmobile
must be lifted up to be tilted.
It is understood that the natural or regular track configuration of the
snowmobile is
the wide track. The snowmobile is parked in the wide track configuration, and
ridden in the
wide track condition, similar to conventional snowmobiles, until the driver
decides that he or
she wants to drive in the narrow track condition. The respective change over
may then be
achieved by the driver actuating and holding a button or lever on the steering
handlebar.
The transition from the wide track to the narrow track takes a second or so.
The snowmobile
now stays with the narrow track for as long as the button or lever,
respectively, is held, and
will immediately go back to the wide track condition, when the button or
lever, respectively,
is released. This mode of operation is a parallel to the frequently used
method of controlling
accelerators of snowmobiles, thus will intuitively fit well together with
this.
Namely, if something unforeseen happens when riding with a narrow track, such
as
for example the driver or a passenger falling off the machine, both the
accelerator and the
track controlling button or lever will then be released. The engine speed will
get down, the
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drive transmission will be disengaged and the track will go to the wide
position, enabling the
snowmobile to come to rest in an upright position.
Figure 5 shows a useful enhancement of the ski attachment. Here, reference nu-
meral 20 refers to a wedged-shaped yoke which is fixed to a torsion spring 24,
which latter
is pivotally attached to the ski body by two bearing blocks 22. In effect we
here have a joint
with cardan-like action. Torsion spring 24 is rotatably fixed to ski 5 by
means of an anchor
block 23. The effect of this is that the orientation of ski 5 may to some
extent be allowed to
adapt to the situation, such as when driving on a surface which is not very
resilient, never-
theless tilting is still called for.
This may come in combination with using a drive belt A which is adapted for
more
easily allowing tilting such as for example through having more resilient
edges. The angular
freedom of the attachment may be limited by - for example - limiting surfaces
21 which stop
further rotation when they hit ski 5. These stops may be cushioned by layers
of rubber. The
figure shows one preferred embodiment. However, it is clear that there are
many alternative
solutions such as placing the torsion spring by a pin and having rubber
springs attached to
the wedge block and so on.
Figure 6 shows yet another useful improvement of the suspension: It is
beneficial to
have soft suspension springs when the skis are in the narrow track to
facilitate the tilting
movements of the skis. Conversely, it is beneficial to have somewhat stiffer
suspension
springs in the wide track position to secure the vehicle against
tilting/leaning out of the
curve.
As shown on the left hand side half-figures, this can be solved by positioning
spring
and damper units 13 so that they have a lower effective ratio between own
movements and
the vertical (seen in the direction of the vehicle) movements of skis 5 when
they are in the
narrow track. When the skis are in the wide track, said ratio is higher. The
effects of this are
soft suspension springs in the narrow track position, and harder suspension
springs in the
wide track position.
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In other words, the angular position of spring and damper units 13 relative to
the
suspension assembly and, thus, relative to skis 5 is dependent on the track
width.
Another effect of this spring and suspension geometry is that the front part
of the
5 snowmobile will sit nearer to the ground in the narrow track
configuration, but is raised in
the wide track configuration.
The needs of the different driving conditions may however in some cases be
oppo-
site: A large clearance to the ground may be wanted in deep-snow conditions
where the
10 narrow track is most likely to be used, whereas a low center of gravity
is wanted in the wide
track positions where stability against leaning out of curves are wanted. The
right hand side
half-figures of figure 6 show how this can be solved by lengthening and
shortening the sus-
pension spring and damper units according to the needs. This may for example
be done
through hydraulic means, as indicated by flexible tubes 25.
If said extendable elements 9 shown in Figures 2 and 3 are of a hydraulic
type, said
suspension units may conveniently be coupled to the same control system.
Figure 7 shows a ski suspension and steering mechanism with the pendulum arms
pivoting around axes 26 which are at an angle a (13.5 ) to a horizontal line
perpendicular to
the lengthwise direction of the skis (or of the snowmobile). It is understood
that - seen in a
front view of the snowmobile - a similar deviation of the axes compared to a
horizontal di-
rection may also be applied. Now it is understood that the ski movements in
the vertical
direction of the snowmobile change the angle of the main plane of the skis -
as seen in a
front view of the snowmobile - due to the pivoting action around axis 26. It
can be shown
that this effect may to some extent be useful, particularly in the wide track
position of the
skis. Now it is furthermore understood that if the fixing of the pendulum arm
to the chassis
of the snowmobile is by means of a cardan joint, the orientation of the axes
of said joint may
differ from axis 26. It is clear that this will then determine the angular
orientation of the main
plane of the skis - as seen in a front view of the vehicle - during vertical
ski movements -
independent of the orientation of axis 26. This again enables the ski
suspension to be kine-
matically optimized for all track widths and vertical movement combinations.
