U.S. patent number 3,650,528 [Application Number 04/882,047] was granted by the patent office on 1972-03-21 for ski-training device.
Invention is credited to Hans Natterer.
United States Patent |
3,650,528 |
Natterer |
March 21, 1972 |
SKI-TRAINING DEVICE
Abstract
A ski-training device is formed with a base, a pair of ski-like
boards pivotally mounted by their front ends on a vertical axis in
the front zone of the base and at least one flexible, resilient
traction element acting upon the middle zone of the boards over at
least two guide rollers rotatably mounted in vertical axes in the
rear zone of the base. In use of the device to obtain a realistic
feel of movement and forces experienced in technique of skiing, the
ski-like boards rotate parallel to one another out of a basic
position and are biased for return thereto by spring action.
Inventors: |
Natterer; Hans (6020 Innsbruck,
OE) |
Family
ID: |
3630969 |
Appl.
No.: |
04/882,047 |
Filed: |
December 4, 1969 |
Foreign Application Priority Data
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Dec 5, 1968 [OE] |
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A 11840/68 |
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Current U.S.
Class: |
482/71 |
Current CPC
Class: |
A63B
69/18 (20130101) |
Current International
Class: |
A63B
69/18 (20060101); A63b 069/18 () |
Field of
Search: |
;272/57B |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Pinkham; Richard C.
Assistant Examiner: Dror; Richard
Claims
What I claim is:
1. A ski-training device comprising a base, a pair of ski-like
boards pivotally mounted adjacent their front ends about
substantially vertical axes in the front zone of said base, at
least one roller at the rear end of said boards supporting the said
rear end upon the rear zone of said base, at least one elongated,
flexible resilient traction element guided over at least two guide
rollers that are rotatably mounted about substantially vertical
axes in the rear zone of said base, said traction element acting
upon said boards between their front and rear ends to bias by
spring action return of said boards to a basic position when said
boards are rotated out of said basic position, the straight line
connecting the centers of said vertical axes in the front zone of
said base being approximately parallel to the straight line
connecting the centers of said vertical axes of said guide rollers
and that portion of said traction element that lies between said
guide rollers being laterally outside the points of intersection
between straight lines projected from the centers of said vertical
axes in the front zone of said base along the longitudinal axes of
said boards onto said straight line connecting the axes of said
guide rollers.
2. A ski-training device as claimed in claim 11, wherein the guide
rollers for the traction element are adjustably arranged on said
base.
3. A ski-training device as claimed in claim 11, wherein the point
of application of the traction element on the ski-like boards is
adjustable in their longitudinal direction.
4. A ski-training device as claimed in claim 11, wherein the
ski-like boards are provided with longitudinal slots in their
middle zone in which means for tightening the ends of the traction
element are displaceable and fixable.
5. A ski-training device as claimed in claim 11, wherein a
detachable transverse clip and means for hinge connection of said
transverse clip with the ski-like boards are provided in their
middle zone between the front and rear ends of the ski-like
boards.
6. A ski-training device as claimed in claim 5, wherein means for
tightening the ends of said traction element are provided, said
means and the means for hinge connection of said transverse clip
forming an integral part.
7. A ski-training device as claimed in claim 11, wherein one single
traction element guided over guide rollers in the rear zone of the
base is provided, whose one end is tightened on one ski-like board,
the other end on the other ski-like board.
8. A ski-training device as claimed in claim 11, wherein two
traction elements guided over guide rollers in the rear zone of the
base are provided, both ends of one traction element being
tightened on one ski-like board, both ends of the other traction
element on the other ski-like board.
9. A ski-training device as claimed in claim 8, wherein both the
guide rollers of the one traction element and the guide rollers of
the other traction element are superposed on one axis.
10. A ski-training device as claimed in claim 11, wherein spring
supports are provided laterally on the bottom side of the base in
the rear zone outside.
Description
This invention relates to a ski-training device comprising a base,
a pair of ski-like boards pivotally mounted by their front ends
about substantially vertical axes in the front zone of said base
and supported over rollers by their rear ends in the rear zone of
the base, said ski-like boards rotated out of a basic position
being returned to said basic position by spring action.
Various ski-training devices are known or have been proposed which
serve for carrying out a ski-training without any snow at any
random place, especially as a home training. Though all these
devices have the purpose of imitating the real conditions of skiing
and the technique of skiing, especially of swinging, this is not
realized satisfactorily with the known ski-training devices.
It is therefore an object of the present invention to provide a
ski-training device which can be used to imitate the most important
movements of the modern technique of skiing, especially of the
parallel turn and the parallel short swing as well as of the
plough, plough turn, and stem swing, in a manner as true to reality
as possible.
It is the purpose of the invention to imitate not only the cited
movements of the technique of skiing, but also the forces required
in a manner as true to reality as possible.
This is realized according to the invention by at least one
elongated, flexible, and resilient traction element acting upon the
middle zone of said ski-like boards between their front and rear
ends, said traction element being guided over at least two guide
rollers pivotally mounted about substantially vertical axes in the
rear zone of said base, the straight line connecting said guide
rollers being at least approximately parallel to the straight line
connecting the front axes of rotation of said pair of ski-like
boards and lying laterally outside the points of intersection
between the straight line projected from the front axes of rotation
of said pair of ski-like boards onto said straight line connecting
said guide rollers.
Further details of the invention and various embodiments are
hereinafter described with reference to the accompanying
drawings.
FIG. 1 is a diagrammatic view,
FIG. 2 is a top view,
FIG. 3 is a rear view, and
FIG. 4 is a side view of an embodiment of a ski-training device
according to the invention.
FIG. 5 is a diagrammatic view of an embodiment according to FIG.
1.
FIG. 6 is a variant of a detail of the device according to FIGS. 1
to 4 in side view.
FIG. 7 is a variant of another detail of the device according to
FIGS. 1 to 4 in top view.
FIG. 8 is a top view of another embodiment of the invention.
FIG. 9 is a diagrammatic view other than in FIG. 5.
FIG. 10 is a top view, and
FIG. 11 is a rear view of still another embodiment of the
invention.
FIG. 12 is a diagrammatic view of a known device.
FIG. 13 represents a curve of the characteristic features of
various ski-training devices.
The ski-training device according to the embodiment in FIGS. 1 to 4
comprises a base consisting of a front plate 1, a rear plate 2 and
two lateral frame parts 3, 4 connecting both the plates 1, 2. The
front plate 1 rests directly on the floor, the rear plate 2 over
spring supports 5, 6 located in the outer side zones of the rear
plate 2.
A pair of ski-like boards 7, 8 are pivotally mounted about
substantially vertical axes by their front ends in the front zone
of said base, i.e., in the front plate 1, by means of the pivot
pins 9, 10. The rear ends of the ski-like boards 7,8 are supported
on the rear zone of the base, i.e., on the rear plate 2 over
rollers 11, 12 mounted in forked bearing 13, 14 connected to the
ski-like boards 7, 8.
The pair of ski-like boards 7, 8 are provided with a nonslide
coating 15 of about a foot length and, if necessary, with lining
rails 16 and 17, 18 in the rear zone. The lateral lining rails 16
and 18 may have slots through which straps or rubber bands for
tightening the feet or shoes can be passed.
The pair of ski-like boards 7, 8 can also be held parallel by a
detachable transverse clip 19. The transverse clip 19 and the
ski-like boards 7, 8 are in hinge connection so that the ski-like
boards are not impeded in their rotation about the axes of the
bolts 9, 10. The device may also be used without any transverse
clip 19. The transverse clip 19 must be removed when ploughing,
plough turn movements, etc., are trained.
In the middle zone of the ski-like boards 7, 8, both ends of an
elongated, flexible, resilient, rope-like traction element 20, for
example an expander spring rope, are attached. The resilient
traction element 20 is guided, under tension, over guide rollers
pivotally mounted about substantially vertical axes in the rear
plate 2. The straight line 23 connecting the guide rollers 21, 22
is at least approximately parallel to the straight line 24 of the
front axes of rotation of the ski-like boards 7, 8 and laterally,
the guide rollers lie outside the points of intersection between
the straight line projected from the front axes of rotation of the
ski-like boards 7, 8 onto the straight line 23 connecting the guide
rollers.
FIGS. 1 to 4 show the device in basic position. The training begins
in this position. The ski-like boards 7, 8 are rotated in parallel
towards one side by rotational heel push in connection with a
downward movement in the ankle and knee joints. At the end of the
sideways rotation, for example as soon as the stop (on the frame 3,
4) has been reached, this is followed by an upward movement in the
ankle and knee joints; the traction element 20 subject to an
additional tension during the movement of rotation again causes the
ski-like boards 7, 8 to return in direction of the basic position
(midposition). This return movement can be passed over immediately
to a movement of rotation of the ski-like boards 7, 8 towards the
other side, again by rotational heel push and a downward movement
in the ankle and knee joints. A rhythmic movement of pendulum is
produced by these repetitive processes.
FIG. 5 shows in diagrammatic view the basic position of the
ski-like boards in rotation in a device according to FIGS. 1 to 4;
besides, the change in course of the traction element 20 during the
movement of rotation is shown.
The force required to move the pair of ski-like boards 7, 8 out of
the basic position is composed of the force required to give the
resilient tension element 20 an additional tension and the force
required to overcome the frictional forces. Frictional forces are
produced, above all, between the rollers 11, 12 and the rear plate
2, in the bearing of the pivot pins 9, 10, in the bearing of the
guide rollers 21, 22 and between the resilient tension element 20
and the guide rollers 21, 22.
The ski-like boards 7, 8 are stabilized in the basic position,
above all, due to the frictional forces. This stabilizing effect
may be reinforced, for example, by increasing the frictional
resistance of the guide rollers 21, 22. As shown in FIG. 6, this is
realized by means of a soft helical spring 27 pressing onto the
guide roller 21 or 22 from the top and adjustable by a wing nut 28.
A similar effect is produced by locating further rollers 29, 30 for
guiding the traction element 20 on the rear plate 2, as shown in
FIG. 7, in addition to the guide rollers 21, 22. Apart from the
frictional forces to overcome and the force required to tension the
traction element, a further influence is exerted on the force
required by the training person to rotate the ski-like boards 7, 8
in the case of a base resting on spring supports 5, 6. An equal
weighting of the pair of ski-like boards 7, 8 brings with it an
equal weighting of both spring supports 5, 6 so that the rear plate
2 and the surface of the ski-like boards 7, 8 are horizontal. As
soon as the ski-like boards 7, 8 are rotated toward one side by
rotational heel push in connection with a downward movement in the
ankle and knee joints, the corresponding spring support 5 or 6 is
subject to more stress. This causes a tilting of the rear plate 2
and permits an easier rolling-off of the rollers 11, 12 in
direction of rotation of the ski-like boards 7, 8.
In the embodiment according to FIGS. 1 to 4 the tension of the
resilient traction element 20 may be modified by removing or adding
chain links at the end of the traction element 20.
As seen in FIG. 8, the tension of the resilient traction element 20
can also be adjusted, for example by shifting the point of
application on the ski-like boards 7, 8 or by shifting the guide
rollers 21, 20 laterally. For this purpose slots 31, 32 are
provided in the ski-like boards 7, 8 in which means for tightening
the ends of the resilient traction element 20, if necessary
together with the transverse clip 19, can be adjusted and fixed,
for example by means of wing nuts. The guide rollers 21, 22 are
also attached to the frame supports 3', 4' which are provided with
a plurality of thread bolts 33 on both sides. Each of the frame
supports 3' and 4' is put on a thread bolt 33 and secured by wing
nuts.
The invention is not limited to the trapezoidal arrangement of the
resilient traction element 20 shown in FIGS. 1, 2, 5 and 8. FIG. 9
is a diagrammatic view of an arrangement of the traction element 20
with crossed ropes (for example in a device according to FIGS. 1 to
4).
It is also possible to attach more traction elements, for example
two traction elements 20' and 20", as seen in FIGS. 10 and 11, to
the pair of ski-like boards 7, 8. In this case, two guide rollers
21', 21" and 22', 22" rotatable about a common axis are located at
the left and at the right of the ski-like boards 7, 8 in the rear
zone of the base, for example in the rear plate 2.
The arrangement of the traction elements 20' and 20" according to
FIG. 10 is appropriate for training parallel skiing (with
transverse clip 19) and ploughing, plough turns, etc., (without
transverse clip 19).
With regard to the forces required during lateral rotation of the
ski-like boards 7, 8 the ski-training devices of the invention have
a typical feature; the differences in this feature between an
arrangement of the traction element 20, for example according to
FIG. 5 (trapezoidal arrangement of a traction element) and an
arrangement of two traction elements 20', 20" according to FIG. 10
(two traction elements in triangle arrangement)--when the ski-like
boards 7, 8 are moved in parallel--are relatively small. The
characteristic features of the various embodiments according to the
invention differ considerably as against other known embodiments,
for example an embodiment in which the ski-like boards 7, 8 are
held in basic position by lateral tension springs 34, 35 guided
directly to the frame parts 3, 4, as shown in FIG. 12.
This difference in the features is illustrated in FIG. 13 by the
force-angle curves, curve A corresponding to the known embodiment
according to FIG. 12, curve B to the embodiment according to FIG.
5, curve C to the embodiment according to FIG. 10. In FIG. 13 the
spring force F is represented in the abscissa, the angle of
deflection .alpha. of the parallel ski-like boards in the ordinate.
The nonlinear course of the curves B and C is a better illustration
of the real forces in a parallel swing than the course of the curve
A. Moreover, the heavy irregularity of the curve A (deflection
through about 15.degree.) caused by a complete unweighting of one
of the springs 34, 34' (FIG. 12) is not conform to the real
conditions.
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