WO2003063975A1

WO2003063975A1 - Ski with non-waxing pattern

Info

Publication number: WO2003063975A1
Application number: PCT/NO2003/000025
Authority: WO
Inventors: Gunnar Bjertnaes
Original assignee: Madshus As
Priority date: 2002-01-28
Filing date: 2003-01-28
Publication date: 2003-08-07
Also published as: NO315787B1; NO20020438L; NO20020438D0

Abstract

The invention concerns a ski with non-waxing pattern characterised in that the pattern is gradually decreasing in depth and length on the middle underside of the ski.

Description

Ski with non-waxing pattern.

The invention relates to a ski with a no-wax pattern. More specifically, the invention relates to a specially designed pattern that is provided in the ski sole under the midsection of a cross-country ski.

The term "no-wax" ski is used to refer to a ski that has a special pattern in the sole, preferably under the midsection of the ski, whilst it has the usual glide zones at the front and the rear. The pattern may be applied under the middle portion of the ski by pressing, rolling, milling or in some other manner. Despite the name "no-wax ski", the glide zones at the front and the rear must be treated and waxed with a glide wax (glider). However, the user avoids having to employ kick wax under the midsection of the ski. The no-wax pattern is supposed provide grip by ensuring that there is sufficient friction with the snow during the kick phase.

The term "middle portion" means preferably the parts of the ski that are in contact with the snow at the time of the kick, that is to say when one of the skis is weighted by the skier's entire body weight.

Different types of no-wax skis are already known, but in general these ski types have had problems in penetrating the market. To date, no-wax skis have been intended primarily for skiers in the touring and recreational segment. The no-wax skis according to the invention are to a greater extent intended for the more active sector of the market, that is to say the racing or competitive segment.

With the no-wax ski according to the invention, an attempt will be made to overcome the prejudices which generally exist today against waxless skis.

Of the earlier no-wax skis, the most common system is the so-called "crown" pattern. In this pattern, transverse sections are milled into the sole under the central part of the ski.

Another known no-wax pattern has the form of moulded fish scales in the sole. A previously known no-wax sole consists of directionally oriented mica that is an integral part of the ski sole. The mica is intended to create sufficient friction between the skis and the snow.

A common feature of the known no-wax skis is that basically they have limited use. A no-wax ski has its optimal area of usage when the waxing conditions are generally difficult. Such difficult waxing conditions may arise when temperatures fluctuate between plus and minus degrees, i.e., fluctuating temperatures close to 0°C, often combined with falling new snow. It is especially under such conditions when wet snow alternates with dry snow that no-wax skis have proven to be particularly suitable. These conditions are generally known as "sticky snow" conditions, as it is difficult to obtain optimal glide and grip using ordinary ski waxes in this temperature range.

No- wax skis enjoy greater popularity and are used more in, for example, countries in Central Europe, than in Norway. This is partly because of historical skiing traditions, but also because both temperature and snow conditions are more variable. No-wax skis have long struggled with a poor image. This is primarily due to the fact that the no-wax skis that have been on the market have not been good enough, at least not in the more demanding competition and racing segment.

The no-wax ski according to the invention is characterised in that it is provided with a special pattern under the central zone. The ski has an irregular scale pattern that decreases gradually from the middle portion towards the glide zones at the front and the rear.

The present no-wax ski is especially characterised in that the skis are provided under the middle portion with a pattern that is irregular and decreases gradually and progressively in depth and length.

One main difference between traditional no-wax patterns and the new pattern of the invention is that traditional patterns are regular and uniform, whilst the pattern of the invention is irregular and decreases progressively in the direction of the glide soles in the front and rear portions of the ski.

The invention will be explained in more detail with the aid of the figures, wherein Fig. 1 shows a ski having the no-wax sole;

Fig. 2 is a bottom view of the no-wax ski sole; Fig. 3 is a side view of a no-wax ski.

Figure 1 shows an example of a no-wax ski sole 10 according to the invention. The no- wax area extends under the midsection of the ski, whilst the front portion 11 and the rear portion 12 of the ski are equipped with an ordinary glide sole. Moreover, the sole has a longitudinal steering groove 13 in the glide zone at the front and the rear, as in conventional waxable skis.

Figure 2 is a bottom view of the no-wax ski sole 10. For the sake of simplicity, the ski sole is divided into two in the figure, but the sole joins in the area X-Y. As can be seen from the figure, the no-wax area comprises several different sections. These sections are indicated by the letters A to D. The tip 14 and the heel 15 of the ski are not shown in the figure. The no-wax pattern in the figure is scale-shaped. The radius of the curves in the scale pattern is preferably about 4 mm, but the radius may be greater or smaller. In section A, which is under the middle of the ski, the depth between the scales is greatest, but the distance between the scale tops is shortest. The scale depth in section A may be 0.5 mm, whilst the scale depth decreases gradually in the direction of the front and rear portions of the ski, so that the depth in section B may be 0.4 mm whilst in section D it may be 0.3 mm. At the same time, the distance between the scale tops increases from section A to D. In addition, the scales in section D are offset from one another unlike the other sections where the scales are preferably placed side by side.

Figure 3 is a side view of the area with the no-wax zone 10. As can be seen from the figure, the area consists of a irregular pattern, the scale pattern having a varying depth and length. The deepest pattern is under the middle of the skis, that is to say where the pressure is greatest during the kick phase. The pattern is deepest under the middle and the depth decreases section by section towards the glide zones on the front portion 11 and the rear portion 12 of the ski. In general, the depth of the pattern is d₀>d₁>d₂>d₃, where do is the depth under the middle of the ski and d₃ is the depth of the pattem close to the glide zones on the front and rear portions of the ski. The distance between the scale tops is marked on the figure by "a" and is smallest under the middle and increases gradually in sections B-D towards the front portion 11 of the ski and the rear portion 12 of the ski.

It may also be important to point out that these skis are preferably otherwise constructed in the same way as conventional competition skis, that is to say having a CAP material on the upper side. This CAP material ensures that there is a sealed sheath around the core material and protects this material from damage. The CAP material forms a sealed and continuous shell that extends from one side of the sole material up along one the side edges, then across the top and down along the other side edge to the other side of the sole material. The CAP and sole material form a continuous, impervious unit that surrounds the core material and helps to give the ski the desired camber properties.

This structural form also provides the right flexibility and other properties expected of a modem cross-country ski. Today, CAP construction is the dominant way of manufacturing a cross-county ski. A major point is that very strong side edges are obtained in this way. This is important as traditional side edges are too weak and thus are prone to breaks and flaws. This can in turn lead to cracking and delamination with subsequent damage to the core material. If water penetrates into the core, this may lead to further damage of the core material.

It should be noted that the no-wax sole according to the invention may be used on a ski regardless of whether it has a CAP construction or is made in another conventional way, but the ski with the no-wax pattern of the invention is preferably constructed using CAP technology.

It is usual for the no-wax pattern to extend across the whole width of the ski. As an alternative, the pattern may be on one side of the steering groove only. This may be appropriate for making a ski that can be used for both skating and classical skiing.

Claims

P a t e n t c l a i m s

1.

A ski having a no-wax area, characterised in that the skis are provided under the midsection with a pattern (10) that is irregular and decreases gradually and progressively in depth and in length.

2.

A no-wax ski according to claim 1 , characterised in that the no-wax pattern (10) has a variable depth in that d₀>d₁>d₂>d₃, where do is the depth under the middle of the ski and d₃ is the depth of the pattern close to the glide zones on the front and rear portions of the ski.

3. A no-wax ski according to claims 1-2, characterised in that the no-wax pattern (10) is located on both sides of the steering groove (13) or just on one side of the steering groove.

4. A no-wax ski according to claims 1-3, characterised in that the pattern has a rounded scale shape at its front edge.

5.

A no-wax ski according to claims 1-4, characterised in that the no-wax pattern (10) is made in that the ski sole is hot-rolled beforehand.

6.

A no-wax ski according to claims 1-5, characterised in that the no-wax pattern (10) is made by pressing or stamping the sole material before the sole is assembled with the core and the CAP material.

7.

A no-wax ski according to claims 1-6, characterised in that the no-wax area gradually goes over into a normal glide sole without a pattern in the front (11) and rear (12) portions of the ski.

8.

A no-wax ski according to claims 1-7, characterised in that the no-wax area covers about 1/3 of the whole ski.

9.

A no-wax ski according to claims 1-8, characterised in that the pattern is spaced in a varying and irregular manner.

10. A no- wax ski according to claims 1-9, characterised in that the ski has a camber so that the no-wax pattern (10) preferably is not in contact with the snow when the skier has distributed his body weight evenly on both skis.