The present invention relates to a ski, especially a cross-country ski. In present skis a constantly actual problem is how to provide a good hold without use of wax.

The object of the invention is to offer a new solution to this problem.

The ski according to the invention is characterized in that preferably filament parts which end obliquely in the sliding surface are positioned at least in the holding part of the ski bottom for providing a hold with¬ out the use of any wax.

The sliding surface of the holding part can be formed as a laminate structure so that the laminate layers are located adjacent each other in the direction of the sliding surface, preferably in the transverse direction, or as a moulding in which case the surface may also be assembled of a plurality of moulded parts the shape of which can be freely selected.

The laminate structure may comprise a wooden laminate in which case the cells of the wood are arranged to end obliquely in the sliding surface and provide the required hold. The utilization of wood cells in this way is not as such new but previously a continuous veneer leaf has been used which extends over the sliding surface and which suffers from the disadvantage that the wood absorbs moisture from the snow whereafter freezing takes place in the wood and the gliding is too much impaired. In the ski according to the invention the veneer leafs forming the laminate structure can be made so thin that the adhesive layers between the veneer leafs impregnate the veneers which thus do no absorb any moisture.

In addition, it is possible to insert in the adhesive layers between the veneer leafs synthetic fibre filaments running in the same direction as the wood cells

and thus ending obliquely in the sliding surface. The use of filaments for this purpose is not as such a novel idea but previously the filaments have' clearly extended from the sliding surface, the so-called sealskin principle, and the manufacturing methods have proved to be difficult. In addition, it is suggested in the Finnish Patent Specification No. 48676 to form the sliding surface of hollow cellulose fibres which can either be random or orientated in any desired manner. However, "the desired orientation" has not been discussed in more detail, and it is in no way hinted that the desired hold effect without any waxes could be achieved by orientating the fibres in a specific manner. The only object aimed at is the so-called icroporosity which aids in the adherance of the wax. Neither are the skis according to said Patent Specif cation manufactured in practice.

Alternatively, it is also possible to use a plastic laminate in which filaments are positioned in the same manner as in thewooden laminate embodiment. In the following the invention will be described in more detail with reference to the accompanying drawing.

Figure 1 is a side view of a ski.

Figure 2 is a bottom view of the ski.

Figures 3 and 4 are a bottom view and a longitudinal section, respectively, of the hold portion of one embodiment of the ski.

Figure 5 is a cross-section of a specific embodiment of the ski.

Figure 6 illustrates the manufacture of the laminate structure used for the sliding bottom of the ski.

Figure 7 is a bottom view of the hold portion of a second embodiment of the ski.

Figure 8 illustrates a combination possibility based substantially on the Figures 3 and 4. Figures 9 and 10 illustrate the manufacture of the sliding bottom from a plurality of moulded parts .

A ski is generally denoted by reference numeral 1. The front and rear parts of the ski are the so-called sliding parts, and the middle part which is important wit respect to the hold of the ski is denoted b ■ reference numeral 4.

The specific feature of the ski according to the invention is associated with the middle portion 4. The sliding surface of this portion is formed of a laminate structure 5 in which the laminate layers 6 are preferably located adjacent to each other or after each other in the transverse direction of the -sliding surface, as appears from Figure 3. The laminate structure 5 may, for example, comprise a wooden laminate. In Figure 3 the veneer leafs of the laminate are denoted by reference numeral 6 and the adhesive layers between the veneer leafs by reference numeral 7. For the sake of clarity, the adhesive layers 7 in Figure 3 are shown too thick, in practice they will in general be made considerable thinner than the veneer leafs. The points 8 marked in the adhesive layers denote filaments, preferably synthetic fibre filaments, such as nylon or glass wool _. , which end obliquely in the sliding surface. The filaments 8 are at least substantial ly parallel with the wood cells 9 indicated schematically in Figure 4. In the embodiment of the invention according to

Figure 5 a similar laminate structure 5 is also positioned in the sides of the ski. In this way an improved hold effect for steep uphills is obtained in which straddle climbing must be used. In the following the manufacture of the laminate . structure will be described with reference to Figure 6. The desired number of, for example, veneer leafs 6 and adhesive layers 7 are positioned on top of each other and the layers are pressed together while simultaneously heating whereby the veneer leafs will be impregnated with adhesive so that the wood no more will. absorb moisture.

The cells in all veneer leafs run in the same direction, which in Figure 6 is denoted by the arrow A. Of the laminate structure so formed a laminate strip 5 to be arranged in the middle portion of the sliding surface of the ski is cut, for example, by sawing obliquely so that the angle between the wood cells and the longitudinal direction of the strip 5 is about 10 to 70 . The bigger the angle is the better is the hold but, of course, sliding is at the same time impaired to some extent. Already a relatively small angle of inclination will be sufficient for an experienced skier.

When the laminate strips are cut in the manner indicated in Figure 6 by reference numeral 5, a bottom of the type of Figure 3 will be obtained. Alternatively, it is also possible to cut the laminate strips in the manner denoted by reference numeral 10 in Figure 6, in which case a bottom of the type of Figure 7 will be obtained. In this case the filaments end in the sliding surface in an angle 6. Of cource, the laminate strip can be cut obliquely also in other ways so as to obtain, for example, strips in which the laminate layers are located' obliquely adjacent each other, as indicated in Figure 8 by reference numerals 15 and 16. ^v

It is of course possible to freely combine laminate strips cut in different manners. This is illustrated by Figure 8, in which the sliding surface consists of a plurality of laminate strips 11 to 20 whereby the longitudinally, transversely and obliquely running lines represent laminate layers. There are, of course, a great number of variation possibilities. For drawing technical reasons, the laminate constructions in the Figures 3 to 8 have been presented quite roughly; in practice, a very smooth sliding surface is obtained so that it is hard to perceive any roughness when, for example, moving a hand along the surface towards the back end in each particular case.

OMP

In order that the adhesive would be able to impregnate the veneer leafs thoroughly, it is advisable to use veneer leafs of a maximum thickness of about 1 mm. The thickness of the laminate strip 5 (or 10) is, on the other hand, in general about 1 to 2 mm.

Preferably filaments 8, which are also parallel wit the arrow A, can be positioned in the adhesive layers. An additional improvement of the hold is obtained by means of such, for example, nylon filaments or glass wool fibres.

Although the so impregnated wooden sliding surface is clearly better than the wooden sliding surfaces known so far, it may possibly with the time absorb some moisture when skiing under so called zero conditions . In order to avoid this, also a second embodiment is suggested in which a part of the veneer leafs or all of them are replaced by plastic layers between which filaments 8 of the above described type are interposed.

In principle, the manufacture can take place in the same manner. The plastic layers are heated and pressed together whereby they will melt into a practically fully homogenic mass with the exception of the filaments which, however, are completely bound in the structure formed, which in this patent application, on the basis of the manufacturing method, is included in the term "laminate structure". The ends of the filaments ending in the sliding surface produce the required hold. The plastic can be of any quality which is commonly used in sliding surfaces of skis, e.g. polyethylene. For the filaments 8, mainly two main types are suggested which are represented, for example, by nylon and glass wool fibre. Nylon in general is more resistant to wear than the plastic qualities coming into question whereby, as the plastic is worn, a very small "piling" is gradually left in the surface. Glass wool fibres, on the other hand, are brittle and any ends penetrating out of the sliding

PI

surface will break whereby very small suction cups are formed. By using simultaneously both filaments of nylon type and filaments of glass wool fibre type, both a small piling and small suction cups among it are thus produced. If polyethylene is considered to be too soft and to wear off too rapidly, an adhesive layer of, for*example so-called Araldit glue, can be applied to its surface. When said glue is heated with a means such as a smoothing iron, a harder sliding surface is obtained. Alternative- ly, it is possible to use instead of plastic, for example, nylon in which case the filaments 8 must of course be selected so that they do not melt into the nylon when this is heated and pressed.

A still further alternative manufacturing method is moulding, in which a molten plastic or nylon mass is moulded on top of the filaments which have been inserted in place in advance. The sliding surface can in this case of course be moulded in one piece but, alternatively, also the sliding surface can be assembled of plurality of moulded parts, which manufacturing method is illustrate in the Figures 9 and 10.

For example, a rod 21 of circular cross-section can be moulded inside which the longitudinal filaments 8 are positioned. Discs 22 obtaining an ellipse shape are cut obliquely from the rod, and the sliding surface is assembled of these discs. The parts 23 remaining between the discs may be of any known sliding surface material. The cross-sectional shape of the rod 21 can be freely selected, and it may, for example, have the shape of a letter. In this way, even a text can be included in the sliding surface, i.e. the ski manufacturer can mark the sliding surface of the ski according to the invention in the same way as has earlier been done in all known sliding bottoms. In the embodiment illustrated in Figure 3 the laminate structure 5 covers practically the entire width

OMP

of the sliding surface of the ski. This need not necessarily be the case, for example, in the central part or the outer edge can simply be left a conventional sliding surface, even more than is shown in Figure 5. The same applies, of course, also to the sliding surface made according to the principle of Figure 10. A resin adhesive, for example so-called Araldit glue and so- called Resinol glue, can be used for the adhesive layers. Any known structure can be used for the body of the ski, and also the sliding surfaces 2 and 3 are known per se. The orientation and even distribution of the filaments 8 can be produced, for example, by using comb-like means at each end of the laminate structure to be formed. Filaments 8 ending in the sliding bottom have been shown very schematically and spaced-apart in the drawing, for example, in Figures 4, 6, 9 and 10. In reality, the number of these filaments is quite great, their amount, for example in the rod of Figure 9 can be about 10 to about 50 % by weight. For example, the adhesive layers 7 -of the laminate structure, may also contain the above- mentioned quantity of filaments .