Note: Descriptions are shown in the official language in which they were submitted.
CA 02535925 2006-02-10
' 1
SNOW SURFACE COMPACTOR AND TRACKING DBVICE
[0001] The present invention relates to a snow surface compactor in accordance
with the 'preamble of main
claim 1 and a tracking device to be used on a snow surface compactor.
[0002] Snow surface compactors are used f~ preparing snow surfaces, especially
for winter sports. In this
connection, the preparation of the related snow surfaces, where said snow
surfaces are smoothed and
compacted is also relevant. The terns 'snow surfaces' refers to (ski) tracks,
cross-country ski trails, sld jumps,
freestyle facilities such as half pipes ar fun parks.
[0003] The most usual design form of such a snow surface compactor comprises a
snow blower that is pulled
by a track crawler, where partially multi-ember heavy plates made of rubber,
plastic, or steel are attached
to the snow blower. Thus in case of these snow surface compactors, first the
lumps of snow and ice are
broken up into smaller pieces by the snow blower and consequently smoothed and
compacted by the effect
of the weight of the plates that are pulled over the snow surface. Since these
plates lie on the snow and
compress the related snow surface only by their weight, this type of
compaction is referred to as static
' compaction.
[0004] As opposed to these statically compacting snow surface compactors,
there are also dynamically acting
snow surface compactors in recent times that can be used in addition to or
even completely without the snow
blower. In these dynamic snow surface compactors, a plate is made to oscillate
by an exciter device. The
periodic vibration of the plate compresses the related snow surface and
compacts it more strongly than is the
case with plates made of rubber, plastic or steel that work purely statically.
-
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The stableness of a track or trail prepared using a dynamic snow surface
compactor is markedly greater than
that of conventionally preparCd snow surfaces.
[0005] This increases the comfort of the user of the related snow surfaces and
involves significant cost
advantages in the grooming of the tracks or trails since the snow surfaces no
longer have to be prepared so
often in case of an even surface quality. The known dynamic snow surface
compactors are already
successfully in use. However, there is a wish to still further increase the
running smoothness and the
application area of the snow surface compactor. .
[0006] Therefore, the object of the present invention is to create a dynamic
snow surface compactor whose
running smoothness as c~pared to the solutions disclosed so far is further
improved and that has a wider
area of application.
[0007] The object is achieved by the snow surface compactor pursuant to claim
1. Advantageous
embodiments are descn'bed in the dependent claims.
[0008] Thus the snow surface compactor according to the present invention is a
dynamically acting
compactor that comprises a base plate. The base plate can be made to osallatc
by an exciter device and it
acts flatly on the snow to be compacted. The base plate in tum comprises a
front region that is located to the
front in the working direction of the snow surface compactor and is bent
upwards. In addition, the base plate
has a reinforcing swcture. It is particularly advantageous if the reinforcing
structure is an especially light
and stiff cell structure. Furthermore, the snow surface compactor comprises a
suspension device for attaching
to a tractor, which is vibration-damped as far as possible so that the
vibrations from the snow surface
compactor are not transferred onto the tractor.
[0009] The snow surface compactor according to the present invention differs
from the compactors known
from prior art particularly in that the exciter device is arranged in the
wa~rking direction behind the center of
gravity of the snow surface compactor. Due to this, the oscillation amplitude
is increased towards the rear
edge of the snow surface compacta~r and the compacting effect is strengthened.
[0010] This property has great advantages particularly when compacting greater
quantities of snow and
fresh-fallen snow. While the dynamic snow surface compactors known from prior
art can dig into the snow
or tend to stagger or tilt, the snow surface compactor according to the
present invention slides over the snow
in a safe and stable manner. Therefore, the snow surface can be prepared with
greater speed than was known
so far.
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[0011] It is advantageous if a predominant part of the base plate of the snow
surface compactor is bent. Thus
when compared with a compactor having an even base plate, the snow surface
compactor stands on a very
narrow strip. In other words, its ground contact area is very small. This
results in a concentration of the
compacting forces on the relatively narrow contact strip. The compaction
performance is particularly
concentrated in this case. This has great advantages especially when breaking
up and disintegrating ice
surfaces.
[0012] Furthermore, the snow surface compactor can swing properly into its
best working position and
comprises a base plate that is constantly bent up towards the front at the
usual inclination angles. Thus the
snow surface compactor can slide over snow accumulation without tilting or
getting buried in it even in case
of a lowered front region, strong inclination changes or very deep bumps in
the ground. The snow surface
compactor can thus be used independently of its attack angle against the snow
cover that is to be compacted.
The improved operating characteristics of the snow surface compactor markedly
increase its areas of
application.
[0013] A predominant part of the base plate is expediently bent with a
constant curve. This facilitates the
production and manufacture of the snow surface compactor since it is then
possible to use conventional,
circularly bent sheet metals or tools. It is particularly advantageous if the
part of the base plate that is bent
with a constant curve stretches at Ieast over two-thirds of the cross-
sectional width of the snow surface
compactor. Thus it is possible to manufacture a relatively large portion of
the snow surface compactor from
uniformly bent components or sheet metals.
[0014] In a preferred embodiment of the snow surface compactor, the base plate
comprises at least two
variably strongly bent regions, where the region located in the working
direction at the back has a larger
bending radius and stretches at the most over a third of the cross-sectional
width of the snow surface
compactor. Thus the rear region of the base plate is less strongly bent than
the region located at the front. As
a result, the snow surface compactor does not tilt over backwards so easily
and simultaneously comprises a
large region with a stronger curvature that positively influences, the sliding
properties of the snow surface
compactor on bumpy grounds. The specific relation between flatter and stronger
curvature results in the best
possible compromise between concentrated compacting forces, tilt resistance,
and effective compacting
surface.
[0015] At least one tracking element is preferably arranged on the snow
surface compactor for profiling the
snow surface. This tracking element can be massive profile rails that are
grooved, for example on their lower
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side and are attached to the rear end of the snow surface compactor
transversely to the working direction.
The snow surface compactor thus creates a grooved structure in fhe compacted
snow surface.
[0016] It is particularly advantageous to use the snow surface compactor
according to the present invention
when preparing cross-country tracks such as even skating tracks or classic
cross-country trails having
parallel tracks. There, the compaction of the snow surface that is
substantially stronger compared to the static
compactors creates better support for the skis and ski poles of the skiers.
The skiers can thus move forward
more comfortably and more effectively due to which the cross-country tracks
that have been prepared with
the snow surface compactor according to the present invention enjoy maximum
popularity.
[0017] For preparing a cross-country trail for the classic telemark
technology, at least two tracking elements
that stretch in their length essentially in the working direction, are
arranged in pairs and parallelly at a
distance from one another on the snow surface compactor. The tracking elements
then have at least a width
that is somewhat broader than a cross~ountry ski, a height that corresponds to
the height of a cross-country
ski and a substantially even lower side. The tracking elements are arranged in
at a distance from one another
that corresponds to an inner distance of approximately 20 cm.
[0018] It is preferred if the tracking element is arranged on the lower side
of the base plate. This is the side of
the base plate that is turned towards the snow to be compacted. The tracking
element is expediently attached
to the base plate such that it can be detached. Examples of suitable
attachment means for this purpose are
screws or clamps.
[0019] Ia an advantageous embodiment the tracking element is attached to the
snow surface compactor with
a tracking element holder. This tracking element holder comprises conveniently
a rigid holding arm that can
deviate as far as possible.
[0020] The tracking element holder expediently comprises an adjusting means
for adjusting the position
and/or adjusting the track depth of the tracking element. Thus in this
embodiment of the snow surface
compactor, tracks of varying depth can be created in the. snow. The adjusting
means can be, for example,
mechanical adjusting means such as screws that are guided into oblong holes,
clamping screws, spanner nuts
and the like. It is also expedient if the adjusting means is driven
hydraulically. Thus, for example, a hydraulic
cylinder can be used for adjusting the tracking element holder. Then it is
possible to omit an expensive
manual adjustment of the adjusting means or an adjustment that can be
inconvenient for the operating
personnel in bad weather.
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[0021] The tracking element is preferably attached to the deviating holding
arm and can deviate into a
working position that is located behind the base plate in the working
direction. Thus the tracking element can
be mounted on the snow surface compactor, but can be brought into a rest
position in which it is not pressed
into the snow to be compacted and thus leaves no tracks behind. It is thus
easily possible to use the snow
surface compactor both for profiling as well as for smoothing snow. surfaces.
The snow surface compactor
can also be used both for tracking telemark tracks and skating tracks without
necessitating a reassembly or
disassembly of the tracking element for this purpose. Skating tracks are
usually 2 m to 3 m broad, smooth;
even snow surfaces, while telemark tracks refer to surfaces that are
structured with parallel grooves.
[0022] It is expedient if the tracking element is a pivoted wheel. The
advantage of this embodiment of the
tracking element is that it can rotate simultaneously with the snow to be
compacted and causes low friction.
Alternatively, the tracking element can also be a pivoted roller that is
profiled with annular elevations and/or
depressions. The advantage of this embodiment is that between the elevations,
the tracking clement
contributes to a further smoothing of the compacted snow while the elevafions
of the roller press the tracks
into the snow. The roller can also consist of several disks or roller
segments. The advantage of this is that the
profile of the tracking element can easily be adjusted individually by
inserting the variably thick roller parts
on top of one another.
[0023] In an alternative embodiment of the snow surface compactor, the
tracking element holder comprises a
flexible strip- to which at least one tracking element is attached. The term
"flexible" here refers to a property
that is well adjusted to the shape of the base plate of the snow surface
compactor. The tracking element-
holder is thus not mounted on instead below the snow surface compactor and
must be easy to bend due to the
curvature of the base plate. The strip is expedicatly a plastic mat where even
metal sheet strips or fabric
sheets can be used. The strip comprises at least one holding means and a
clamping means for attaching the
tracking element-holder to the snow surface compactor. The holding means in
the simplest embodiment is a
claw or a bracket that can be hooked onto one end of the snow surface
compactor. On its other side that is
expediently located at the front in the working direction, the strip comprises
at least one clamping means that
can be a clamping screw. With the help of the clamping means, the strip is
pulled tautly and pressed on the
base plate of the snow surface compactor. On the outer side of the strip, the
tracking element is attached that
can thus be clamped easily and removably on the lower side of the base plate.
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[0024] The strip can be expediently clamped using the tracking elements lying
outside on a profiling rail that
is attached to the base plate. This means, that the strip itself is either
attached to the profiling rail or is guided
over the profiling rail.
[0025] The tracking element preferably stretches in its length over about a
third of the cross-sectional width
of the snow surface compactor. The advantage of this embodiment is that by
twisting the snow surface
compactor, the tracking elements are turned into a position in which they no
longer press into the compacted
snow any. Thus by twisting the snow surface compactor, it is possible to
change the surface structure created
by it in the snow surface. Firstly, the driver of the tractor can twist the
snow surface compactor into a
~~position in which the tracking elements are not pressed into the snow so
that the result is a smooth working
surface. Alternatively, he twists the snow surface compactor such that the
rear end is lowered and the
tracking elements are pressed into the snow. The snow surface compactor then
creates a classic trail structure
or the like in the snow.
[0026] The tracking element is expediently bent in the working direction with
a height that reduces in the
working direction. Thus it is well adjusted to the outer shape of the snow
surface compactor. Furthermore, it
is advantageous if the tracking element is a rigid body that has a top side
which is shaped corresponding to
the outer shape of the base plate and/or the shape of the profiling rail. Thus
it can be easily placed outside on
the base plate and in case of existing permanently screwed profiling rails, it
can be easily placed on these
rails.
[0027] The tracking element advantageously has a convex or Y-shaped lower side
that pushes away the snow
to be compacted to the sides so that a locally increased compacting value is
not generated in the surfaces
touched by the tracking element.
[0028] The object of the present invention is also achieved by a tracking
device for use on a snow surface
compactor with a tracking element and a tracking element-holder as described
earlier.
[0029] The present invention is explained in more detail in the following
description on the basis of a
drawing, which schematically illustrates:
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Fig. l a cross-section of a first embodiment of the snow surface compactor
according to the present
invention;
Fig. 2 a cross-section of a second embodiment of the snow surface compactor
according to the present
invention with a wheel-shaped tracking element;
Fig. 3 the second embodiment illustrated in fig. 2 of the snow surface
compactor according to the present
invention in a working position that is angled for trail tracking;
Fig..4 a third embodiment of the snow surface compactor according to the
present invention with a
hydraulically deviating tracking element-holder;
Fig. 5 the third embodiment of the snow surface compactor according to the
present invention illustrated in
figure 4 with a tracking eleaarnt that is folded up for creating an even snow
surface;
Fig. 6 a fourth embodiment of the snow surface compactor according to the
present invention with tracking
elements that are attached to a plastic mat and are clamped below the base
plate in a working position to
create an even snow surface; and
Fig. 7 the cross-section of the fourth embodiment illustrated in figure 6 in a
working position that is angled
for preparing the trails.
[0030] As indicated in figure 1 with the arrow A, the illustrated snow surface
compactor is pulled in a
working direction A over the snow to be compacted. Thus, in this illustration,
the left side is the backside
and the right side is the front side of the snow surface compactor 1. In order
to avoid getting twisted on
uneven surfaces or digging into loose snow, the snow surface compactor 1 has a
bent base plate 3 that is
pulled strongly upwards especially in the front region. Furthermore, the snow
surface compactor has a
suspension device 4 for being attached to a tractor that runs ahead and that
is usually a track-crawler. The
base plate 3 is stiffened with a reinforcing structure 5. The reinforcing
structure 5 consists of longitudinal
walls 6 that stretch in the working direction and are provided partly with
holes or recesses 7 for weight
reduction. Transverse walls 8 run transversely to the longitudinal walls so
that the reinforcing structure forms
a cell structure on the whole. This reinforcing structure is covered upwards
partly by cover sheet 9 especially
in the front region of the snow surface compactor so that no snow can
penetrate into the reinforcing structure.
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[0031] The special feature of the snow surface compactor 1 according to the
present invention is that the
exciter device 2 is arranged behind the center of gravity S. The exciter
device 2 is a customary unbalance
exciter with semi-circular imbalances that are seated parallel to and at a
distance from one other on a rotary
shaft 10 that stretches transversely to the working direction A. By fuming
this imbalance exciter shaft 10, the
snow surface compactor 1 is made to oscillate and acts particularly with the
rear region of its base plate 3
flatly on the snow that is located below the snow surface compactor 1. The
exciter device 2 sits in a trough-
shaped exciter housing 11 that is closed with a removable lid 12 and is thus
protected against damages
caused by the deposited snow.:
[0032] The base plate 3 has a three-part design. A first segment 13 located to
the front in the working
direction A is an even, straight plate to which a middle segment 14 is
connected that is bent with a first
constant bending radius 15. Connected to the second base plate segment 14 is
the third base plate segment 15
that starts in the embodiment illustrated here below the center point of the
exciter shaft 10 and stretches up to
the end of the base plate 3 that is located in the working direction A at the
back. The third base plate segment
15 is bent less strongly than the second base plate segment 14. In the
embodiment illustrated here, the second
bending radius 17 with around 1.4 m is about twice as big as the first bending
radius 15 with 0.73 m. Both
the bent base plate seg~nts 14, 15 are thus bent up circularly where even
other bending radii or bending
progressions can also be used.
[0033] The projections of the base plates 13, 14, 16 on a base result in the
partial cross-sectional widths 38,
39, 40. The total cross-sectional width B of the snow surface compactor 1 thus
corresponds to the sum of the
partial cross-sectional widths 38, 39, 40, and amounts to 0.974 m with a
working width of around 2.5 m to 3
m in the embodiment illustrated here. The sum of the partial cross-sectional
widths 38 and 39 is greater than
2/3 of the total cross-sectional width B of the snow surface compactor 1. In
addition, both the exciter device
2 as well as the plate segment 16 are seated visibly in the rear third B/3 of
the snow surface compactor 1
where the exciter shaft axis 10 is at a distance of around 0.23 m from the
rear edge of the snow surface
compactor 1.
[0034] A wear protection device 18 is located below the base plate 3. Said
wear protection device 18 consists
of a plastic plate that is clamped on the base plate 3 ~in this embodiment.
The wear protection device 18 is
hooked on to the rear end of the base plate 3 in a hook 19 and is locked in
position by means of a screw 20
on the front end of the base plate 3. A profiling rail 21 is mounted on the
rear end of the wear protection
device 18. This profiling rail comprises a wavy profile on its lower side and
stretches over the width of the
base plate 3. Due to the wavy structure of the profiling rail 21, the snow
surface compactor 1 creates a
rippled structure in the compacted snow.
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[0035] The suspension device 4 is a bow-shaped plate that is welded with the
reinforcing swcture and that
comprises two damping elements 22 on each of its sides. The snow surface
compactor can be attached to
these damping elements 22 on the holding arm (not illustrated) of the tractor
in a torque-proof manner and is
vibration-damped. Thus by fuming the holding arm of the tractor, the snow
surface compactor 1 can be
deviated around an axis stretching transversely to its working direction.
[0036] A cross-section of a second embodiment of the snow surface compactor l
according to the present
invention is illustrated in figure 2 that is intended for the preparation of a
classic trail. A tracking device 37 is
attached to the snow surface compactor 1 for this purpose. This tracking
device consists of two parallel
tracking elements 23 that are mounted at a distance of 20 cm from one another
for profiling the snow surface
31 and that are attached on the snow surface compactor 1 using two tracking
element holders 24. The
tracking elements 23 are aligned such that they are seated at the rear end of
the snow surface compactor 1.
Due to the cross-sectional illustration of figure 1, however, the second
tracking element and/or the second
tracking ele~nt-holder are hidden and cannot be seen.
[0037] The tracking elements 23 in the embodiment illustrated here are metal
disk wheels that are attached in
a torque-proof manner to the tracking element-holders 24. The individual
tracking element-holder 24
consists of a deviating stiff holding arm 25 that in tum consists of two T-
shaped plates, which are screwed
against one another by means of spacers. The T-shaped holding arm 25 is
pivoted on one end on the snow
surface compactor 1 in a holder 26. On its other end, the holding arm 25 is
loosely connected to a rod 27.
The rod .27 comprises an oblong hole 28 on its end that is. opposite to the
holding arm 25. The rod 27 can be
attached to a second holder 29 thmugh this oblong hole 28 such that it 27~can
be adjusted in its longitudinal
direction. The holder 29 is attached in tum to the reinforcing structure 5.
[0038] By loosening the screw 30 that is guided in the oblong hole 28, the
tracking element 23 and/or the
holding arm 25 with the tracking element 23 can be deviated around the pivot
point 26, Thus it is easily
possible to adjust the tracking element 23 in its elevation with respect to
the snow surface compactor 1. If the
tracking element 23 is to be lowered, the screw 30 is Ioosencd and the rod 28
is pushed against the working
direction A towards the back Due to this, the tracking element 23 lowers below
the base plate 3. In the
working position of the snow surface compactor 1 illustrated in figure 2, the
tracking clement is located in a
neutral position. This means that the tracking element 23 is not pressed into
the snow 31. The snow surface
compactor 1 is angled such that its rear region and/or the rear edge is
raised. Thus the tracking element 23 as
CA 02535925 2006-02-10
well as the profiling rail do not come into contact with the snow surface 31.
The surface structure created by
the snow surface compactor 1 in the snow surface 31 is smooth due to the
smooth lower side of the wear
protection mat 18.
[0039] Should the tracking element 23 be used, the snow surface compactor 1 is
easily tilted and/or twisted
slightly backwards so that the tracking element 23 that is rigidly mounted on
the tracking element holder 24,
is pressed into the snow 31. The twisting action of the snow surface compactor
1 takes place by a twisting or
angling of the holding arm (not illustrated) of the tractor.
[0040] If the tractor islnot able to twist the snow surface compactor 1 in its
angular position Qansversely to
the working direction A, then it is expedient if the rod 27 is replaced by a
hydraulic cylinder 32 as illustrated
in figure 4. By activating the hydraulic cylinder 32, the holding arm 25 is
deviated around the first
attachment point 26. Thus it is easily possible to lower or to raise the
tracking element 23 without changing
the position of the snow surface compactor 1.
[0041] A fourth embodiment of the snow surface compactor 1 according to the
present invention is
illustrated in figure 6 in which the tracking element holder 24 consists of a
flexible plastic mat. This soft
plastic mat is provided with wedge-shaped tracking elements 23 on its end. The
tracking element holder 24
penetrates the tracking element 23 and comprises a holding hook 33 on the end
located at the back in the
working direction. At the end of the snow surface compactor 1 that is located
at the front in the walking
direction, a U shaped profile 34 is placed on the fiont edge of the snow
surface compactor 1. A spanner nut
35 is attached on one side of this U-profile 34 on the outer side. Said
spanner nut 35 is attached on its other
side to the tracking element holder 24. With the help of tk~ spanner nut 35 it
is thus possible to clamp the
tracking element holder 24 on the lowar side of the snow surface compactor.
[0042] The tracking element holder 24 illustrated here serves for tracking an
individual trail. Therefore, it is
somewhat kuoader than an individual trail track, thus approx. 30 em to 50 cm
wide. Should, for example, two
trail tracks be tracked next to one another and simultaneously, a second
tracking element holder is clamped
easily next to the holder illustrated here on the base plate 3. The tracking
element holders 24 are thus also
narrower than. the wear protection device 18 that covers the entire working
width, wluch stretches
transversely to the working direction A. The individual tracking element
holders 24 are directky clamped on
the continuous wear protection device 18. Thus the base plate 3 does not wear
out near the tracking element
holders 24.
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[0043] l3xactly as in case of the embodiment illustrated in figures 2 and 3,
even in this embodiment of the
snow surface compactor 1, the profiling of the snow surface 31 can be selected
by the angular position of the
snow surface compactor 1. Should the tracking elements 23 be pressed into the
snow, only the adjusting
angle of the snow surface compactor needs to be changed. If the snow surface
compactor is twisted such that
its rear end is pressed into the snow, the tracking element 23 arranged in the
rear end region is automatically
pressed into the snow surface 31. Should the rear end region be raised, the
snow surface 31 is compacted
essentially with the smooth middle segment 14 of the base plate 3 and a smooth
snow surface 31 is created.
Due to the base plate 3 that is almost continuously bent over the entire cmss-
sectional width, it is thus also
possiblo when wing the flexible tracking element holder 24, to change the
surface structure created in the
snow 31 without attaching or having to attach the tracking devices 37 with
traclting ele~nt holders 24 and
tracking elements 23 for this purpose.
