WO2000002631A1

WO2000002631A1 - Steel edge of a ski or snowboard

Info

Publication number: WO2000002631A1
Application number: PCT/SI1999/000019
Authority: WO
Inventors: Janez Stare; Luka Stare
Original assignee: Janez Stare; Luka Stare
Priority date: 1998-07-10
Filing date: 1999-07-08
Publication date: 2000-01-20
Also published as: AU4671399A; SI20009A

Abstract

A steel edge of a ski such as alpine ski, cross-country ski, off-slope ski and also a snowboard solves the problem of guiding in turns and sliding on various types of slopes, soft, hard packed or icy. The steel edge is provided on the side of an undersurface (3) with a groove (10) having in the cross-section a shape of an arch (10'), a cross-section (11) of which, that leans to a lateral surface (12) of the steel edge (1), is flat and in contact with it in a sharp angle α, with which it forms a sharp edge (13) of the steel edge (1), whereby the angle α continuously changes and amounts in the area of the central part (6) of a ski (4) approximately 45° and then continuously increases up to 90° towards a shovel (5) and a tail (7) and namely before the shovel (5) and the tail (7) when it passes to a flat surface lying in the surface of the undersurface (3) of the ski (4) or a snowboard.

Description

STEEL EDGE OF A SKI OR SNOWBOARD

The subject of the invention is a steel edge of a ski such as alpine ski, cross-country ski, off-slope ski and also a snowboard.

A technical problem solved by this invention is how to conceive steel edges of a ski which will improve the guiding of skis or a snowboard in turns whereby the steel edge may be implemented according to the invention on a new or an existing ski or a snowboard.

Guiding of a ski in turns has been assured by steel edges and by the lateral arch of a ski. Inclination of the lower and lateral steel edge surfaces have influence on the guiding of a ski in turns or on its sliding. The inclination angle of the steel edge surface on the ski undersurface lies in the area from 0 to 5°. Because the maintenance of the ski undersurface requires sharpening this angle cannot be smaller than 0° otherwise it would lie outside the plane of the undersurface. The inclination angle of the lateral surface is similar. Both surfaces form a mutual angle of approximately 90°. The sharpness of the edge in the central part of a ski contributes to a precise guiding and yet there is a wish or better a need of skiers, especially racers, for a significantly smaller sliding.

A lateral arch of a ski with a significantly smaller diameter or even a composed curve which is also very clear-cut with respect to classic skis, diminishes the effort of a skier in turns and also increases guiding capability.

There is still the problem of sliding of skis which is especially noticeable on hard packed or even icy slope. Spare-time skiers experience falls, racers lose velocity. Sliding causes additional vibrations which represent an additional burden to a skier. Slides in off-slope skiing heavily diniinish the level of safe skiing which is of utter importance in this case. A cross-country ski in gliding or in skiing in the nature outside marked ski runs would gain on its efficiency if a smaller slide were assured. The same need arises with snowboards. The described technical problem can be solved with a ski according to the invention by having at least one of its steel edges provided with a groove on the undersurface. The groove lies near the side surface of the steel edge and forms a sharp edge therewith. The groove runs along the central part of the ski with an unchanged cross- section, then continuously diminishes towards the shovel and the tail and changes into a flat undersurface before the shovel and the tail.

When skiing straight such steel edge shape offers the same skiing properties as already known steel edges, in a turn when the inner steel edge is in use, the sharp edge near the groove in the central part of the ski cuts into ski or ice. Sliding is considerably smaller. Diminished groove towards the shovel and the tail and flat undersurface of the steel edge in the area of the shovel and the tail assure easy turning manoeuvres as with known skis.

Owing to a considerably smaller sliding the same slope allows much more turns, at least twice more than with the known ski.

When skiing on various types of snow, e.g. when passing from soft to hard snow or ice, stability is much more easily kept. The sharp steel edge cuts the surface all the time and does not allow sliding which is quite heavily controllable in such passages, especially by free-time skiers who need more time to adapt to new conditions.

With sliding which consumes much energy being considerably smaller, the velocity of skiing increases. With respect to a skiing technique, a skier transmits energy to the ski and the surface when loading an individual ski, and this energy is, due to smaller sliding, used for speeding up. A skier is less tired.

A skier is subject to much less vibrations on a hard, rib-like slope and in turns because the sharp steel edge cuts into the surface and thus allows skis to be guided almost or completely without sliding. It is clear from the above-mentioned that at off-slope and extreme skiing on hard packed or icy and extremely uneven surfaces, e.g. avalanche slopes, slopes covered with stones and rocks or even in the forest among trees and bushes, guiding of skis makes an essential contribution to the quality of skiing and safety. Alpine skiing on steep slopes clearly shows that the new properties of such a steel edge contribute to the safety of a skier and increase the level of still possible skiing.

The steel edge according to the invention on a snowboard offers the same improved properties.

The invention will be described in more detail in the continuation with a description of an embodiment and the enclosed drawing, showing:

Fig. 1 ski in side view

Fig. 2 transversal cross-section along the line II-II with Fig. 1 of the ski with the steel edge according to the invention,

Fig. 3 transversal cross-section along the line III-III with Fig. 1 of the ski with the steel edge according to the invention,

Fig. 4 transversal cross-section along the line IV-IV with Fig. 1 of the ski with the steel edge according to the invention.

A steel edge 1 is positioned on lateral edges 2 of an undersurface 3 of a ski 4 consisting of a shovel 5, a central part 6 and a tail 7 whereby the steel edge 1 runs along the entire length of lateral edges 2.

The steel edge 1 is placed in the ski 4 in a known manner with its thinner inner band 8 in a way that a sliding layer 9 of the ski covers it and thus binds into a ski. On the side of the undersurface 3 the visible part of the steel edge 1 is provided with a groove 10 having in the transversal cross-section preferably a form of a semi-circle, the inclined cross-section 11 of which leans to a lateral surface 12 of the steel edge 1 and is straight and in contact with it in a sharp edge 13. The angle α between the inclined cross-section 11 of the groove 10 and the lateral surface 12 of the steel edge 1 continuously changes and amounts in the area of the central part 6 of the ski approximately 45°, then increases towards the shovel 5 and the tail 7 up to 90° when it changes into a straight surface of the steel edge lying in the area of the undersurface 3 of the ski 4.

With respect to different purposes of a ski the lengths of cross-sections of the groove 10 in the central part 6, where the groove is even and deepest, and those of cross- sections in direction of the shovel 5 and the tail 7, where it continuously diminishes, vary. The length of cross-sections on the shovel and the tail without a groove has influence on the easiness of taming, the length of the central cross-section of the groove with the largest cross-section has influence on the degree of fitting to snow and ice.

An arch shaped cross-section of the groove allows turbulence of the cut snow in the groove. The size of the cross-section of the groove can thus be subject of special tests for the adaptation of optimal properties with regard to the purpose of the ski and type of snow.

The sharp edge 13 or a sharp angle in the cross-section of the steel edge 1 has one more advantage, namely if it is used during normal skiing or even if a ski is serrated because having been damaged on a hard object, normally stones, it does not lose its property with respect to good guiding of a ski in a turn and to the prevention of sliding as was the case with the known steel edges. The steel edges thus do not need to be sharpened often, which increase the life durability of the steel edges. Severe damage with serration which cannot be corrected by sharpening does not diminish the property of a ski to such an extent as with the known steel edge.

The steel edge according to the invention is shaped by sharpening with profile grinder in dimensions determined for the type and purpose of a ski. Sharpening can also be performed on a ready made ski. The invention can therefore be applied also on old skis at a workshop. A grinding device to this purpose can be manufactured with known means and in a known way on the basis of given data about the geometry of the groove.

Knowing the described essence of the invention it is understandable that a person skilled in the art can design other shapes of the groove than that described in the embodiment without circumventing the essence of the invention defined in the attached patent claims.

Claims

1. A steel edge (1) of a ski or a snowboard placed on at least one lateral edge (2) of an undersurface (3) of a ski (4), or a snowboard, consisting of a shovel (5), a central part (6) and a tail (7), characterised in that on one side of the undersurface (3) there is a groove (10) having in the cross-section the shape of an arch (10'), the transversal cross-section (11) of which, that leans to the side surface (12) of the steel edge (1), is flat and in contact with it in a sharp angle α, with which it forms a sharp edge (13) of the steel edge (1).

2. The steel edge according to claim 1, characterised in that the angle α continuously changes and amounts in the area of the central part (6) of the ski (4) approximately 45°, then it continuously increases towards the shovel (5) and the tail (7) up to 90° and before the shovel (5) and the tail (7) when it changes into a flat surface lying in the area of the undersurface (3) of the ski (4) or a snowboard.

3. The steel edge according to claim 1, characterised in that the cross-section consists of optional straight sections.

4. The steel edge according to claim 1, characterised in that the groove (10) is provided in the steel edge (1) while being manufactured, during the manufacture of skis, or later in a ready made ski.

AMENDED CLAIMS

[received by t e International Bureau on 7 December 1999 (07.12.99) ; original claim 2 cancel led ; original claim 1 amended ; claims 3 and 4 renumbered as claims 2 and 3 ( 1 page) ]

1. A steel edge (1) of a ski or a snowboard placed on at least one lateral edge (2) of an undersurface (3) of a ski (4) or a snowboard, consisting of a shovel (5), a central part (6) and a tail (7), whereat on one side of the undersurface (3) there is a groove (10) having in the cross-section the shape of an arch (10'), the transversal cross-section (11) of which, that leans to the side surface (12) of the steel edge (1), is flat and in contact with it in a sharp angle α, with which it forms a sharp edge (13) of the steel edge (1), characterised in that the angle α continuously changes and in the area of the central part (6) of the ski (4) amounts to approximately 45°, then it continuously increases towards the shovel (5) and the tail (7) up to 90°, whereat before the shovel (5) and the tail (7) it changes into a flat surface lying in the area of the undersurface (3) of the ski (4) or a snowboard.

2. The steel edge according to claim 1, characterised in that the cross-section consists of optional straight sections.

3. The steel edge according to claim 1, characterised in that the groove (10) is provided in the steel edge (1) while being manufactured, during the manufacture of skis, or later in a ready made ski.