WO1987004361A1

WO1987004361A1 - Snow skis

Info

Publication number: WO1987004361A1
Application number: PCT/GB1987/000046
Authority: WO
Inventors: Roy Jonathan Rosser
Original assignee: Rosser Roy J
Priority date: 1986-01-27
Filing date: 1987-01-27
Publication date: 1987-07-30
Also published as: AU6893687A; EP0259361A1

Abstract

A snow ski has a horizontal sliding surface (4) and at least one edge member (30) carrying a downwardly extending edge defining portion (38) defining an ''edge'' of the ski which is adapted to dig into the snow. The edge defining portion (38) is horizontally spaced from the sliding surface (4).

Description

SNOW SKIS

The present invention relates to snow skis and is concerned with the "edges" of such skis.

Snow skis now generally comprise substantially flat elongate strips of composite plastics material whose front ends are curved upwardly. The upper surfaces of the skis carry bindings for connecting the skis to the boots of the user and the lower surfaces are flat and smooth and frequently coated with a low- friction material to facilitate sliding over snow. The lower edges of the skis are generally afforded by a metallic block or shaped profile, the outer surfaces of which are flush with the side and bottom surfaces of the skis, respectively. These blocks or profiles are regularly ground to ensure that they present sharp outer corners which constitute the so-called "edges" of the skis.

Changes in direction are accomplished primarily by use of the inner edge of the inner ski by shifting one's weight and causing the edge to dig into the snow. When "traversing", that is to say skiiing obliquely down a slope, the weight is placed primarily on the inner edge of the lowermost ski to ensure that one's movement does not include a sideways sliding component. Both turning and traversing are problematic when one is skiing on heavily compacted snow or ice since even if the edges have been recently ground they are unable to dig in to any appreciable extent. It will be appreciated that the edges are defined by two perpendicular surfaces and that even if the edges are "sharp", that is to say the two surfaces intersect at a true right angle and are not radiused, the area of the edges passing into the snow or ice increases rapidly after ^' the edges have initially penetrated the snow or ice and the resistive force increases rapidly resulting in the depth of penetration being very small when the surface of the snow is compacted or icy.

It is an object of the invention to provide a snow ski which overcomes the problems referred to above and which has an inner edge which can satisfactorily dig in to compacted snow or ice thus rendering it possible to turn and traverse satisfactorily on such a surface.

According to the present invention a snow ski includes a substantially horizontal sliding surface which, in use, slides over snow or ice, and at least one edge member extending laterally from at least one side thereof, the or each edge member carrying and preferably being integral with a downwardly extending edge defining portion defining an "edge" of the ski which is adapted to dig into the snow, e.g. when turning or traversing, the edge defining portion being horizontally spaced from the siding surface. The fact that the edge defining portion or portions, and thus also the "edge" of the ski, are horizontally spaced from the sliding surface inherently means that there is an upwardly extending space immediately inboard of the "edge", which is defined by the laterally extending portion of the edge member(s), which in turn means that an increasing depth of penetration of the "edge" into snow or ice does not encounter increasing resistance to such penetration. The edge defining portion(s) are preferably less than 3 or 2mm thick and can thus penetrate relatively deeply into even ice and thus prevent sideways slipping of the ski.

The "edge" of the ski may be continuous but in this event it may impair the longitudinal flexibility of the ski if it extends over a substantial proportion of its length. It is therefore preferred either that the "edge" extends over a minor proportion of the length of the ski or that it is discontinuous, i.e. that there is a plurality of edge members. In the latter event it is preferred that a portion of each edge member is embedded in the ski. In a particularly simple embodiment the edge members comprise screws screwed in a line into the side of the ski, the heads of which constitute the discontinuous edge of the ski. In the preferred embodiment each edge member comprises an elongate portion embedded in the body of the ski integral with a further, e.g. generally triangular, portion of which a portion is bent downwardly to constitute an edge defining portion whose downwardly facing surface extends substantially parallel to the sliding surface. It is preferred that adjacent edge defining portions overlap in the longitudinal direction of the ski.

Further features and details of the present invention will "be apparent from the following description of two specific embodiments which is given by way of example with reference to the accompanying diagrammatic drawings, in which:-

Figure 1 is a transverse sectional view through the first embodiment of ski;

Figure 2 is a plan view of the second embodiment of ski;

Figure 3 is a scrap plan view of part of the ski of Figure 2 on an enlarged scale; Figure 4 is a transverse sectional view on the line A-A in Figure 3;

Figure 5 is a scrap side view of the ski of

Figure 2;

Figure 6 is a plan view of a single edge member prior to being bent.

The ski shown in Figure 1 is of generally conventional shape and comprises an elongate rectangular section composite plastics body 2 which has a lower sliding surface 4 and along whose lower side edges two metallic bars 6 extend. The bars 6 correspond to the edge bars which are conventionally provided. Screwed to what, in use, is the inner edge of the ski by a plurality of screws or the like 8 is a regularly apertured channel section member 10, to whose outer limb a depending edge member 12 is connected by rivets 14. The lower surface of the edge member defines an "edge" 16 which is above the sliding surface 4 and horizontally spaced from it.

Under normal conditions the ski operates in the usual manner and when turning or traversing the free corner of the inner bar 6 digs into the snow. When turning on ice, the user's weight is placed on the inside of the ski to such an extent that not only does the corner of the bar 6 digs into the ice but the edge 16 does so also. By virtue of the horizontal spacing of the edge 1 β from the surface 4 and the small thickness of the edge member 12, e.g. between 1 and 2mm, the weight of the user is sufficient to press the edge 16 into ice a sufficient distance to permit it to perform the usual "edge" function adequately. The channel 10 and member 12 may be continuous and extend over a major proportion of the length of the ski. However, they are inherently relatively rigid and may thus impair the longtitudinal flexibility of the ski. Accordingly, the channel 10 and member 12 may extend over only a minor proportion of the length of the ski, preferably adjacent its centre which in any event tends to bend only slightly, in use. Alternatively, the edge 16 may be discontinuous and there may be a plurality of short spaced channels 10 and members 12.

In the embodiment of Figures 2 to 6 the "edge" is also discontinuous and the edge members are an integral part of the ski. As best seen in Figure 4, the ski comprises a core of polyurethane foam 20 surrounded by a layer 22 of glass fibre reinforced epoxy resin. The ski is faced on its upper and side surfaces by a layer 24 of ABS plastics material and on its lower surface by a layer 26 of a sliding material, in this case that sold under the Trade Mark ELECTRA 2000. On the inner edge of the ski the core 20 is provided with a recess 28 which terminates a short distance before the rear of the ski and a slightly greater distance before the front of the ski. The recess 26 accommodates a plurality of edge members 30 which are encapsulated in a layer 22. Each member comprises a flat stainless steel plate of about 1.5mm thickness of the shape seen in Figure 6, with a rectangular portion 32 integral with a generally right angled triangular portion 34, the hypotenuse of which extends at 45° to the length of the portion 32. One corner of the portion 34 is cut away thereby providing an additional vertex 36 spaced from the hypotenuse by 2.7mm. The rectangular portions 32 are embedded in the layer 22 spaced apart by a distance substantially equal to their width, i.e. about 10cm. The triangular portions 34 extend laterally beyond the inner side of the ski. Either before or after the embedding process a portion 38 parallel to the hypotenuse is bent downwardly about a bend line 40 to define an edge defining portion. The portion 38 is thus horizontally spaced from the sliding surface of the ski and its lower surface constitutes part of the "edge" of the ski which is normally- situated above the sliding surface. The portion 34 is provided with a non-stick plastics layer, such as Nylon, to prevent snow adhering to it. It will be seen from Figure 3 that the portions 34 are so shaped and arranged that they define generally triangular apertures 35 between them. In use, snow is forced upwardly through these apertures and thus does not become permanently stuck beneath the portions 34 thereby permanently clogging the channel defined by the portions 34 and 38 and the side surface of the ski.

The front end of ski is towards the top, as- seen In Figure 3, and the rectangular portions 32 of the edge members 30 are so inclined to the length of the ski that bending of the ski which occurs in use is substantially unaffected by the presence of the edge members. The shape and spacing of the portions 34 is such that the edge defining portions 38 overlap in the longitudinal direction of the ski and define narrow, parallel-sided gaps 42 which extend upwardly and frontwardly. There is thus no tendency for forward movement of the ski to result in snow being forced into the gaps 42. In use, the lower surface of the edge defining portion 38 is spaced from the snow but when turning or traversing the outer edge of each portion 38 digs into the snow or ice. The penetration of the portions 38 is limited only by their height, that is to say by contact of the horizontal portion 34 with the snow, and does not require a progressively increasing force by virtue of the fact that the portions 34 are horizontally spaced from the sliding surface.

As best seen in Figure 2, the horizontal portions 34 of the edge members 30 are accommodated within a lateral recess on the inner edge of the ski. At both ends of the recess the ski is provided with an "edge" (not shown) of conventional type. The skis illustrated are "handed", that is to say they can only be attached to the left leg. If such handedness is undesirable edge members may of course be provided along both sides of the ski. Whilst the edge members 30 have been described as separate they may of course all be integral, e.g. constitute a single .stamping, e.g. connected at the inner ends of the portions 32, and this may facilitate the manufacturing process. In this event the edge defining portions will not themselves be connected, whereby the ski will be capable of longitudinal bending. The downwardly facing surface of the portions 38, i.e. the "edge" may be covered with low friction material, such as plastics material to reduce their friction with the snow. Alternatively, the portions 38 or- even the entire edge members may be constructed of plastics material.

Claims

1. A snow ski having a substantially horizontal sliding surface and at least one edge member carrying a downwardly extending edge defining portion defining an "edge" of the ski which is adapted to dig into the snow, the edge defining portion being horizontally spaced from the sliding surface.

2. A ski as claimed in claim 1 in which the "edge" is discontinuous.

3. A ski as claimed in claim 1 or claim 2 including a plurality of edge members extending laterally from one side thereof.

4. A ski as claimed in claim 3 in which the ski includes a body of plastics material in which a portion of each edge member is embedded.

5. A ski as claimed in claim 4 in which the embedded portion of each edge member extends inwardly and frontwardly from the said one side thereof.

6. A ski as claimed in any one of claims 3 to 5 in which the edge defining portions of adjacent edge members overlap in the longitudinal direction of the ski.

7. A ski as claimed in any one of claims 3 to 5 in which each edge member comprises an elongate portion embedded in the body of the ski integral with a generally triangular portion of which a portion is bent downwardly to constitute an edge defining portion whose downwardly facing surface extends substantially parallel to the sliding surface.

8. A ski as claimed in any one of the preceeding claims in which the thickness of the edge defining portions transverse to the length of the sliding surface is less than 3mm.

9. A ski as claimed in any one of the preceeding claims in which the edge defining portions are of metal and are covered with a plastics material.

10. A ski as claimed in any one of the preceding claims in which the "edge" is situated above the sliding surface.

11. A ski as claimed in any one of the preceding claims in which the laterally extending portion of the edge member or edge members is discontinuous or defines a plurality of apertures.

12. A snow ski substantially as specifically herein described with reference to Figure 1 or Figures 2 to 6 of the accompanying drawings.