EP0570467B1

EP0570467B1 - Alpine pair ski

Info

Publication number: EP0570467B1
Application number: EP92904838A
Authority: EP
Inventors: Jorgen Karlsen
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-02-07
Filing date: 1992-02-03
Publication date: 1995-01-04
Anticipated expiration: 2012-02-03
Also published as: EP0570467A1; DE69201129T2; NO910487D0; NO910487L; ATE116567T1; DE69201129D1; CA2103589A1; NO172170B; WO1992013609A1; NO172170C

Abstract

On a front section, an Alpine pair ski has a greatly increased width, and the lower edges (3a') of the sides (3a) are gradually raised on this section so that they diverge upwards in relation to each of two imaginary, straight, parallel lines (2) which constitute extensions of the lower edges (3') of the sides (3) of the rest of the main body.

Description

The invention concerns an Alpine pair ski with upturned tip and a main section with curved sides and approximately flat sliding surface. The term pair ski refers to skis which are intended for use in pairs, i.e. with one ski on each foot, as opposed to so-called monoskis, where both feet are placed on a single ski. The turning technique for pair skis is fundamentally different from that used for monoskis.
From CH 668 000 A5 a pair ski of even width is known, where a front section of the approximately flat sliding surface is bordered at the sides by two bevelled sections. The width of each of the bevelled sections normally increases steadily until they meet at the central axis of the ski at the transition between the main body and the tip. The bordered front section of the two bevelled side sections of the flat sliding surface is thereby normally approximately triangular in shape. Not only does the bevelling increase in width, but the angle of bevelling also increases towards the tip. The object is to reduce resistance during turning.
It is also normal for pair skis to be slightly wider at the front and the rear, i.e. the sides of the skis are gently curved. This helps to steer the skis through the turns with the least possible loss of kinetic energy. If the sides are curved too much, however, the skis will be difficult to control, since when they are on their edges they will cut into the snow at the front and the rear. Moreover, the grip on the snow in the middle of the ski will be reduced, which is a major disadvantage particularly on a hard cover, where everything depends on being able to skid well in the middle of the ski. For these reasons there is a limit to what can be achieved with this kind of curving of the sides.
CH 662 744 A5 describes a pair ski whose sides curve substantially inwards. As already mentioned, such skis will be difficult to control.
An embodiment of the present invention provides a ski which makes it possible to turn with the least possible loss of kinetic energy, in that it does not cut too deeply into the snow, but still permits the attainment of a good grip when skidding. In this way a faster ski can be obtained which is still easy for the performer to control.
According to the present invention there is provided an alpine pair ski as set out in claim 1. The remaining claims set out optional features.
In contrast to what is the case of CH 668 000 A5, the skis are thus considerably wider at the front end than at the middle without being difficult to control, the lower edge of each side diverging upwards and thereby being raised sufficiently from the snow to prevent it from cutting into the snow when the skis are on their edges despite the increased ski width at the front end. Thus the upward divergence of the lower edge is closely connected with the pronounced outward curve (the increased width) at the front of the ski. The ski can also be wider at the rear end and the lower edges of the sides can be raised correspondingly. When the skis are slanted or on their edges for turning, the outward curve at the front (and possibly also at the rear) will come into contact with the snow, but the lower edge will not cut into the snow to an undesirable extent. On the contrary, the outward curve will help the performer to make the turn with less skidding and thus a lesser loss of kinetic energy. Unless the skis are edged particularly severely, the outward curve at the front and possibly the rear will not prevent the (e.g. steel) edges on the central section from getting a grip. With the correct adjustment of angle and curve the skis will still be under full control, even if hard skidding is required.
The absolute width increase in millimetres is naturally dependent on the length of the front section. When this is short, the width increase will have to be in the lower part of the specified area. An interesting design is one in which the length of the front section and the width increase are in the lower range, i.e. the front section is approximately 5 cm long, while the width increase is approximately 15%.
An upward divergence of the lower edge can be achieved by bending the sliding surface on the front section slightly upwards in relation to the sliding surface on the rest of the main body. Another way of achieving upward divergence of the lower edge is to arrange for the sliding surface on the front section to be bordered at the sides by two bevelled sections. These two solutions can naturally be combined in order to achieve the necessary raising of the lower edge. When bevelled side sections are used, these should mainly lie outside the imagined, straight, parallel lines which constitute extensions of the lower edges of the sides of the rest of the main body. However, it is also possible to arrange for the width of the sliding surface on the front section to decrease towards the front in a similar way to that described in CH 668 000 A5, which, however, does not have the increased width in the front section of a ski according to the invention.
The invention will be described in more detail with reference to the drawings, which illustrate two preferred embodiments and some variations.
Fig. 1 is an embodiment viewed from above.
Fig. 2 illustrates the front section of the ski in figure 1, viewed from below.
Fig. 3 is a perspective view of the front end of the ski.
Figs. 4a, 4b and 4c are three different embodiments of the ski in fig. 2 in cross section taken along the line IV-IV.
Fig. 5 is another embodiment viewed from below.
Fig. 6 is a side view of the ski in the embodiment in fig. 5.
In fig. 1 line C-C indicates the narrowest part of the ski. Between line B-B and the rear end of the ski E-E, the ski has sides 3 with a normal inward curve (outward curve). The lower edge of each side 3 is indicated by 3'.
The ski has a mainly flat sliding surface 1 which on the front section of the ski's main body is indicated by 1a. This front section extends from B-B to line A-A, where the underside of the ski begins to curve upwards to form the tip, which ends at point F. The front section should have a length of at most 20 cm, preferably approximately 10-15 cm, but the length can also be less. The section of each side 3 relating to the front section of the ski is indicated by 3a, and the corresponding lower edges are indicated by 3a'.
In figs. 2 and 5 two imaginary parallel lines 2 are drawn constituting extensions of the lower edges 3' of the sides 3 of the main body based on the width of the ski at point B-B. The surfaces 4 between each of these straight lines 2 and the related sides 3a' of the ski from point B-B to point A-A are hatched in figs. 2 and 3, in order to indicate that these surfaces are bevelled or "slanting" in relation to the ski's sliding surface 1a. The bevelling or slanting is best illustrated by fig. 4.
In fig. 4a the bevelled surfaces 4 are shown as flat, while those in figs. 4b and 4c are shown as a concave and convex curve respectively. It may be suitable for the bevelling angle ϑ to be constant, but it is within the scope of the invention to allow it to vary between points B-B and A-A. In figs. 4a-4c the upper side of the ski is shown flat, but if the width of the bevelling 4 and the size of the angle ϑ would otherwise cause the ski to become too thin at the sides 3, it is also possible to curve the upper side upwards at the sides on those sections which are bevelled on the underside.
The result of the illustrated bevelling is that the lower edge 3a' of the sides 3a will diverge upwards in relation to the lines 2. Thereby the edge 3a' will not cut so easily into the snow when the ski is on its edge, despite the increased width of the ski between points B-B and A-A. The bevelling 4 can extend further in towards the middle of the ski than to the lines 2, but the pronounced outward curve of the ski between points B-B and A-A will make it unnecessary to let the bevelling extend so far inwards, and the embodiment illustrated in figs. 1-4 is the preferred one.
In the embodiment in figs. 5 and 6 an upward divergence of the lower edge 3a' from the related line 2 is achieved by bending the sliding surface 1a on the front section gently upwards in relation to the sliding surface 1 on the rest of the main body. Thereby no bevelling is required in order to prevent the lower edge 3a' fron cutting into the snow when the skis are on their edges during turning. The angle α between the surfaces 1 and 1a can be maintained at a few degrees.
It is, of course, possible to combine the two embodiments. Thus the angle between the sliding surface 1a and the front section and the sliding surface 1 can be too small to allow the lower edges 3a' to be raised sufficiently. Bevelling can provide the rest of the required upward divergence of each lower edge from the related line 2.
If desired the rear section of the ski (between line D-D and the rear end E-E) can be of a similar design as the front section (between lines A-A and B-B). The rear section can be less extreme with regard to outward curve and upward curve than the front section.
A normal width for an alpine ski at the front end (the root of the tip A-A in the drawing) is 75-90 mm, and the width 5-20 cm behind the front end (corresponding to line B-B) is a few millimetres less. In the case of the ski according to the invention on the other hand, the width will increase substantially more towards the front, preferably by 15-20 mm, but an increase of as little as 12 mm or as much as 60 mm is also conceivable. A preferred raising of the lower edges 3a in relation to the lines 2 will be from 2-10 mm, but higher values are conceivable.

Claims

An Alpine pair ski with upturned tip and a main body with curved sides (3) and approximately flat sliding surface (1), characterized in that a front section of the main section of at most 20 cm in length has sides (3a) whose lower edges (3a') diverge so markedly upwards in relation to the sliding surface and outwards in relation to the longitudinal axis of the skis, that (a) at the transition A-A between the main body and the tip the ski has a width which is 15-70%, preferably 15-50% and best of all 20-30% greater than the width at the transition B-B between the front section and the rest of the main body, and (b) the lower edge (3a') of each side (3a) at the transition A-A is above the plane of the sliding surface (1) of the greater part of the main body by a vertical distance which is at least 10% of the increase in width from the transition B-B to the transition A-A, preferably at least 15%, e.g. approximately 20%.
A pair ski according to claim 1,
characterized in that the front section is approximately 5 cm long and the increase in width is approximately 15%.
A pair ski according to claim 1 or 2,
characterized in that a divergence of the lower edge (3a') upwards in relation to the plane through the straight lines (2) is achieved in that the sliding surface (1a) on the front section is bent slightly upwards in relation to the sliding surface (1) on the rest of the main section.
A pair ski according to one of the previous claims, characterized in that a divergence of the lower edge (3a') upwards in relation to the plane through the straight lines (2) is achieved in that the sliding surface (1a) on the front section is bordered at the sides by two bevelled sections (4).
A pair ski according to claim 4,
characterized in that the bevelled side sections (4) lie mainly outside the straight, parallel lines (2).
A pair ski according to claim 4,
characterized in that the sliding surface (1a) on the front section has a decreasing width towards the front.