Note: Descriptions are shown in the official language in which they were submitted.
~1386~9
The present invention relates to apparatus for
preparing ski slopes, particularly ski-lift and downhill
runs as well as cross-country tracks.
Apparatus of this kind is known from the DE-OS
25 33 831. In this known apparatus called a "track device",
a connecting frame with two parallel longitudinal members is
articulated directly on a sled about a horizontal pi~ot axis
extending transversely to the direction of travel, as a
traction gear. A scraper knife with a specific (adjustable)
setting angle is suspended on the connecting frame as a
plane, and a track sled which is articulately secured to
the rear end of the connecting frame follows the scraper
knife as a compacting member.
When a slope is covered with the known device at
an angle to the line of steepest gradient (oblique slope
travel), the front sled is inclined according to the
inclination of the terrain. With this sled, however, the
scraper knife ar,d the following track sled are necessarily
also inclined. mus the plane of the track formed is always
substantially parallel to the terrain covered. This is not
always desired, particularly not for ski-lift tracks and
cross-country tracks. There the aim is that the track
~ormed - seen transversely to the direction of travel -
extends as horizontally as possible, that is to say that the
later direction of travel of the skis coincides as far as
possible with the line of the steepest gradient of the area
of the prepared track, so that the skier does not always
have to load the edges of the skis so as not to slip sideways.
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1131~6~9
In another device (DE-OS 26 27 893) which is like-
wise kno~rn, a plurality of plane members are provided which
are each articulated through a pull rod on a horizontal shaft
extending transversely to the direction of travel and which
in turn are constructed on a traction frame which is
supported on runners disposed in front of the plane members.
Here, too, the cutting edges of the planing knives are always
parallel to that plane which is determined by two adjacent
runners. Thus this device can likewise only prepare a track,
the inclination of which corresponds substantially to the
inclination of the terrain covered.
In a further known device (US-PS 3,926,262), the
traction gear is formed by two parallel longitudinal members
and this traction gear is directly articulated on a traction
vehicle about a horizontal axis extending transversely to
the direction of travel. Here, too, this has the consequence
that the broaching blade rigidly secured to the traction
gear with the following scraper blade necessarily remains
parallel to the terrain covered by the vehicleO With an
obli~ue slope travel (lateral inclination o~ the vehicle),
here, too, the prepared track would be substantially parallel
to the terrain covered.
It is an object of the present invention to obviate
or mitigate these disadvantages~
The present invention is apparatus for preparing
ski slopes, particularly ski-lift and downhill runs as well
as cross-country tracks, having at least one plane mounted
on traction gear which is articulated for free pivoting on
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~138699
a horizontal shaft disposed transversely to the direction
of travel and in front of the plane, which shaft is in turn
supported on a sled disposed in front of the plane in the
direction of travel, said shaft and with it the traction
gear and the plane being tiltable in relation to the sled
about a tilting axis substantially parallel to the direction
of travel.
As a result of the ability of the unit traction-
gear/plane to tilt in relation to the sled, during oblique
slope travel this unit can be kept by the guide rods in
that position which the resulting track is to have. The
sled, on the other hand, always bears flat against the
existing terrain.
The shaft on which the plane is articulated for
free pi~oting through the traction gear may be disposed at
the rear end of a frame which in turn is articulated on the
sled through the tilting axis disposed in the longitudinal
centre of the sled. This frame may comprise two transverse
struts which are disposed one behind the other and are
connected to one another at their free ends through
longitudinal members, which transverse struts are each
articulated in their middle on a bearing on the sled, which
bearings determine the tilting axis.
When the plane is tilted in relation to the sled
disposed in front of it about the tilting axis, then the
plane penetrates deeper into the covering of snow covered at
one side than at the other. Thus more snow is removed at
this side by the pla~e and the plane also has a greater
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~13E~6~9
resistance to overcome. In a preferred embodiment of the
invention, therefore, the plane is secured to the traction
gear through a vertical spindle about which the plane is
pivotable to both sides against the action of a spring. me
plane which normally extends with its cutting edge transversely
to the direction of travel, in this form of embodiment, is
deflected somewhat towards the rear, where the greater depth
of penetration is, about the vertical axis against the action
of the spring, that is to say where the greater resistance
has to be overcome. With this form of embodiment, it is
advisable to dispose sheet-metal guides extending substantially
at right angles to the cutting edge of the plane at the top
of the planel the purpose of which, when the plane is tilted
and consequently deflected, to displace the planed-off snow
from the one side, which is planed deeper, to the other side.
An embodiment of the prèsent invention will now
be described, by way of example, with reference to the
accompanying drawings, in which:-
Figs. 1 and 2 are respectively diagrammatic side
elevation and plan views of apparatus according to thepresent in~ention for preparing ski runs;
Fig. 2a shows, in plan view, a detail from Fig. 2;
~ igs. 3 and 4 show in front view different forms
of the rubbing edge of a scraper blade disposed following
the plane; and
Figs. 5 and 6 show the use of the apparatus shown
in Figs. 1 and 2 for preparing a track extending horizontally
in the transverse direction on an oblique slope.
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113~6~9
The apparatus shown in Figures 1 and 2 for preparing
ski tracks comprises a sled 1 which is supported on the ground,
that is to say on the track 2 to be prepared. This sled carries
a frame 3 which comprises two longitudinal members 4 extending
parallel to one another in the direction of travel A and two
` transverse struts 5 connecting the latter to one another and
V-shaped in construction. These transverse struts are secured
to the sled by means of bearings 6 which determine a tilting axis
7 substantially parallel to the direction of travel A and rising
slightly in this direction. The frame 3 can be tilted to both
sides about this tilting axis 7 with respect to the sled 1.
Fitted to the frame 3 are two parallel guide rods or shafts 8
which extend forwards in the direction of travel A and which
serve in a manner to he described later for pulling and guiding
the device. At its rear end, each shaft is secured for
adjustment in height to an attachment plate 9 fitted on the rear
transverse strut 5. This adjustment in height of the attachment
`~ point of the shafts 8 is illustrated diagrammatically in Figure 1
and designated by 10. In addition, each shaft 8 is connected to
a holder 13 for pivoting about an axis 12 by means of a collar
11, which holder is secured to the front transverse strut 5.
- When the rear end of the shaft 8 is adjusted in the attachmer.t
- plate 9, the shaft 8 is pivoted about the axis 12 and so the
inclination of the shaft is altered.
Connected to the fxame 3 is a traction gear 14 which
compxises an arm 15 extending towards the rear. At its front
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~ ` 113~36~9
`; end, this arm 15 comprises a cross arm 16 which is pivotally
connected to bearing plates 17 secuxed to the rear transverse
` strut 5. The pivotal axis 18 of the traction gear 14 determined
; by the bearing plates 17 extends at right angles to the direction
of travel A and parallel to the track 2 to be prepared, that is
to say in the horizbntal position shown in Figure 1. Let into the
arm 15 some distance behind this pivotal axis 18 is a bearing bush
39 in the bore of which extending substantially vertically a
pivot pin 40 is mounted for rotation and secured against axial
displacement by means of a nut 41. The pivo$ pin 40 is anchored
at the upper end of a downwardly directed strut 19. The strut
19 includes a centering arm 42 which is directed towards the
rear and which - see Figure 2a - engages between two compression
springs 43 which are disposed substantially horizontally and act
against one another. Thus the compression springs 43 tend to
old the centering arm 42 aligned with the arm 15. The strut 19
also carries a plane 20 which comprises an attachment arm 21
fitted to the strut 19 and articulately connected to the strut 19
. by means of a joint pin 22 and fixed in its position by a shear
pin 23 traversing the strut 19. At its free end, the attachment
~ arm 21 is provided with a knife carrier 24 which comprises an
upwardly bent edge 25 at its rear end. Secured to the front
end of the knife carrier 24 is a planing knife 26. This planing
knife, which may comprise a straight or - as shown - a toothed
~utting edge 26a, is inclined towards the rear in relation to
the vertical, that is to say it has a certain angle of attack
in relation to the plape of the track 2 to be prepared.
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`` 113E~ti99
; Secured to the rear end of the arm 15 is a scraper
blade 28 which is pivotable about an axis 27 parallel to the
pi~otal axis 18 of the arm 15. The scraper blade 28 lies with
its rubbing edge 29 on the ground, that is to say on the track 2.
The inclination of the scraper blade 28 and hence also the height
of its rubbing edge 29 with respect to the planing knife 26 can
- be altered by means of an adjusting device. This adjusting device
` 30 comprises a screw tube 31 which is articulately connected at
one end, by means of a bearing eye 32 to the scraper blade 28.
Engaged in this screw tube 38 is a threaded spindle 33 which is
mounted in a bearing 34 secured to the arm 15. In order to turn
the threaded spindle 33, this is pro~ided with a crank 35 at its
free end. By turning the stationary threaded spindle 33, the
screw tube is adjusted in the longitudinal direction of the
~` 15 spindle 33 which leads to a pivoting of the scraper blade 28
- about the pivotal axis 27. Thus the scraper blade 28 is held in
its particular pi~oted position by means of this adjusting device
30.
The rubbing edge 21 of the scraper blade 28 can be
straight as shown in Figures 1 and 2. It is also possible,
however, to construct or profile this rubbing edge 29 otherwise.
As Figure 3 shows, which illustrates diagrammatically the under
part of the scraper blade 2~ in front view, projections 36
- projecting from the rubbing edge 29 can be provided at the
under side of the rubbing edge 29 which serve o form ski tracks
113869~
when the devices shown in Figures 1 and 2 are pulled. It is
naturally possible to provide more than two such projections 36
to form a plurality of ski tracks lying side by side.
In order to pro~ide the whole device with a lateral
guide means, guide runners 37 which project at both sides beyond
the rubbing edge 29 may be pro~ided on the scraper blade 28,
as Figure 4 shows, which guide runners, when the apparatus is
pulled, dig into the snow at the side of the track to be prepared
and prevent slipping away sideways. The use and mode of operation
of the device described is as follows:
First, if necessary, the inclination of the scraper
blade 28 and possibly also the shafts 8 is adjusted. By means
of hooks 8a fitted at their front end, the shafts 8 are suspended,
for example in the loop of a towing lift~ An operator present
between the guide rods, guides the device and determines the
tilting position of the frame 3 and of the traction gear connected
to this with respect ~o the sled 1. During the towing of the
device, the plane 20 digs into the snow as a result of the angle
of attack of the planing knife 26, tears up the layer of snow
and mixes the deeper layers of snow with the used uppermost
layer. Since the plane 20 is freely pivotable about the pivot
axis 18 through the traction gear 14, the arm 15 is pivoted
downwards by this digging in of the plane 20. This pivotal
movement of the arm 15 is transmitted to the scraper blade 28
rigidly connected to this, which as a result is pressed with
its rubbing edge 29 against the track 2. Thus as a result of the
penetration of the plane 20 a downwardly directed component of
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113~699
force results which is transmitted ~ia the arm 15 to the scraper
blade 28 as mentioned. As a result of the pressure which the
scraper blade 28 exerts on the now loosened layer of snow, this
is compacted again. In addition, the scraper blade 28 with its
rubbing edge 29 causes a levelling of the prepared track. In
addition, the scraper blade 28 ser~es as a baffle plate for the
lumps of snow broken away by the planing knife 26, sliding away
over the knife carrier 24 and thrown up by the bent up edge 25,
which lumps Lmpinge on the scraper blade 28 and are broken up.
Because the scraper blade 28 is pressed against the track by the
plane 20 digging in, the scraper blade ensures to some extent as
a spatula a satisfactory compacting of the loosened snow without
the scraper blade 28 having to be made particularly heavy for
this purpose. On the other hand, assurance is also provided that
the scraper blade 28 presses with it~ rubbing edge with a certain
pressure on the track 2, so that a satisfactory distribution of
the snow accumulating in front of the scraper blade is
ensured for the necessary levelling. The risk that the scraper
blade might slide away over an accumulation of snow without
exerting a distributing action is largely avoided in this manner.
The scraper blade 28 supported on the track 2 also prevents the
plane from penetrating too deeply into the track to be prepared
so that the depth of penetration of the plane 20 is limited by
the scraper blade 28. By adjusting the inclination of the
scraper blade 28, the height of the rubbing edge 29 with respect
to the plane 20 and hence also the depth of penetration of the
plane can be altered - as already mentioned.
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113~ ?9
,
The free pivotability of the plane 20 with respect to
the sled 1 has the advantage that the plane 20 does not necessarily
have to follow the movements of the sled 1 in every respect. The
plane 20 is therefore in a position, in the event of humps in the
track to be prepared, to cut off the peaks of these humps
effecti~ely so that such irregularities can be entirely or at
- least mostly eliminated in one operation.
If the scraper blade 28 is provided with track-forming
projections 36 on its rubber edge 28, as already explained with
10 reference to Figure 3, then in the course of compacting and
levelling the track, one or more ski tracks can be formed which
is of particular interest for cross-country tracks.
The operator is in a position, by raising and lowering
both shafts 8, to alter their inclination with respect to the
track 2. As a r~sult, the height of the pivot axis 18 with
respect to the track is also altered which leads to a
corresponding alteration in the angle of attack of the planing
knife and hence the depth of penetration of the plane 20. It
is also possible for the operator to adapt the depth of
penetration of the plane to the state of the unprepared track
found during the journey, as reguired. By lateral tilting of
the frame 3 about the tilting axis 7, that is to say by pressing
down the one and/or raising the other shaft 8, the position of
the planing knife 26 with respect to the sled 1 can likewise be
altered. This is of importance when - as clearly shown in Figure
5 - a horizontal track 39 has to be produced in the transverse
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113E~699
direction on an obLi~ue slope~ The sled 1 resting flat on the
terrain co~ered assumes the inclination of the terrain coYered,
as shown in Figure 6. The traction gear 14 and hence the plane
20 and the scraper blade on the other hand can be held in a
horizontal position by tilting about the tilting axis 7 so that
a track is prepared, the lateral inclination of which does not
depend on the lateral inclination of the terrain covered.
Now if, as described above, the plane 20 (and hence
the scraper blade 28) is tilted with respect to the sled 1 by
means of the shaft 8, then the plane 20 penetrates deeper into
the layer of snow at one side than at the other. Therefore
a greater resistance is also opposed to the plane 20 at this
side. Since the pIane 20 with the strut 19 is rotatable to a
limited extent through the vertical pivot pin 40 and against
the action of the compression springs 43, in this case it is
deflected somewhat towards the rear at that side where there is
the greater depth of penetration. The outlines of the plane 20
in such a deflected position is illustrated in chain lines in
Figure 2a. Secured to the upper side of the knife carrier 24
are sheet-metal guides 44 which are substantially at right angles
to the cutting edge of the plane and the purpose of which is to
push the snow broken away from the side with the greater depth
of penetration of the plane towards the other side, before
levelling action of the scraper blade 28 begins. So long as the
plane 20 is not deflected, however, these sheet-metal guides
contribute to the straight guiding of the plane 20 (somewhat like
the runners 37).
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113E~9
Instead of, pu~ the de~ice by means of a towing
lift as described, this car, also be pulled by a towing vehicle.
In this case, other suitable trailer members should be used
instead of the shafts, the attachment points of which on the
towing vehicle are adjustable indi~idually in height.
In another embodiment of the device, the scraper
blade 28 is not adjustable in its inclination. In order to
adjust the depth of penetration of the plane 20, however, the
scraper blade 28 is displaceable in height in the direction of
the arrow C ~Figure 1), as illustrated in broken lines in Figure
1. For this purpose, the strut 19 can be mounted on the arm 15
for adjustment in the direction of the arrow C and be held in
its particular position by means of a locking device.
The device described is suitable not only for
preparing ski-lift tracks but can also be used - according to
width - for preparing downhill runs and cross-country tracks.
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