WO2003047707A2 - Ski - Google Patents

Abstract

A ski (10) design for both advanced and beginner skiers with a reverse camber, a convex bottom surface (18), and the width of the ski (10) in the middle portion (24) is larger than the width of the ski (10) at either the front portion (20) or the rear portion (22).

Description

SKI

BACKGROUND

1. Cross Reference to Related Applications

This application claims priority from U.S. Provisional Application Serial Number 60/338,731 filed December 4, 2001 and the corresponding U.S. application filed December 4, 2002 (serial number to be assigned; attorney reference 02719.0003.NPUS00), which are hereby incorporated by reference in their entirety.

2. Field of the Present Invention

The present invention relates to snow skis, and more particularly to snow skis which are adapted to be used in powder snow ski conditions.

3. Description of the Related Art

Most conventional snow skis have several consistent geometric parameters. These include "camber", which describes the non-planar shape of the ski bottom surface from a side view. Camber is always "positive" by the definition of being concave in an unloaded condition relative to the snow surface. Under vertical loads, the ski loses camber, becomes flat or planar with no camber, or reverses camber to create a convex shape of the ski bottom surface from a side view. This reverse or "negative" camber, is what becomes the desired bent shape of the ski in use that creates the arc for a carved turn or what creates lift in the ski for floatation in loose snow or powder snow. While camber is viewed as necessary in the ski at rest, the negative camber condition is the actual in-use condition, except on flat and hard snow or ice where the ski cannot bend into negative camber due to resistance of the snow surface. Unloaded and at rest a ski will touch a flat surface only at the ends of the running surface along a line parallel to the ground.

"Sidecut" in a ski typically has been considered a positive concave side shape as viewed from the top of the ski. This concave geometric shape works together with camber to facilitate the reverse camber condition when a ski is put on edge for a turn. As the ski goes from flat to angled on edge, the wider tip and tail, usually at or close to the contact points of the running surface, dig into the snow surface more than the narrower waist or center section of the ski. This causes the tip and tail to bend up to force the ski into a negative camber condition. This creates the arc in the ski that the ski cuts into the snow to carve a turn.

When viewed from the top, such a prior art ski typically has a wider tip and wider tail than the narrower waist or center section of the ski. Additionally, prior art skis typically have a wider tip than tail creating a positive "taper angle", the angle between the ski centerline and a line drawn from the top to the tail. This configuration is typically best adapted to skiing on snow having a hard surface, typical in climates with high humidity, such as the northeastern United States.

However, in areas where low humidity prevails, such the western mountains of the United States, snow tends to accumulate without a great deal of moisture. The result is a deep base of powder snow without a hard surface. Powder snow presents a different challenge to a skier when compared to hard surface skiing. Powder tends to exhibit fluid dynamics similar to water and a ski tends to "float" as it moves through powder snow exhibiting lift and drag characteristics. Moreover, because powder snow is "soft," a ski typically does not contact a hard reference surface. As a result, turning in powder is more difficult because a typical ski will not be able to take advantage of the cutting surfaces inherent in present skis which utilize the wide tip and tail surfaces to transfer lateral forces to the ground during turning.

Byway of example, U.S. Pat. No. 4,343,485 issued to Johnston, et al., discloses a design of a ski where there is negative camber at rest. Johnston et al., disclose various teaching techniques, one of which is having beginners use relatively short skis (e.g. three'feet long). As a skier becomes more proficient, he (or she) graduates to a longer ski until ultimately the ski could be as long as about six feet. The ski design in Johnson et al. is particularly adapted for use as an instructional ski which would be useful in teaching a beginning skier, yet would not create an undesirable pattern of moguls on a ski slope. However, the preferred embodiment of the ski according to Johnston includes positive side camber and placement of the ski boot slightly to the rear of the center of the ski. Although this configuration may be beneficial for skiing on hard snow surfaces, this configuration has been found to difficult to maneuver in powder snow.

Further, U.S. Pat. No. 4,487,426 issued to Nishizawa, discloses a ski design which is adapted for use by less proficient skiers. More specifically, it is one object of this design to provide skis which permit easy turning with "simple skiing skill", even for those having relatively weak leg strength. In this particular design there are shown a number of configurations, where there is "reverse camber" and/or "reverse sidecut" (i.e. where the ski has a greater width at the middle portion than that at the end portions). However, the embodiments disclosed by Nishizawa do not contemplate skiing in powder snow, which is typically considered appropriate for advanced skiers.

Li light of the forgoing there is a need for a ski that provides stability, control and maneuverability in powder snow.

SUMMARY OF THE INVENTION

The design of the ski of the present invention is particularly adapted for use in most all conditions, but is especially advantageous for use in powder snow, and especially in deep powder snow. The ski is well adapted to be used by both the beginner and the accomplished skier. For powder floatation and maneuverability, in a preferred form, the tail width can be less than the tip width to enhance bias of the lower running surface forward to enhance floatation. Also in the preferred embodiment, since the widest point of the ski is underfoot, the ski also provides better balance. The ski floats and carves so easily that an accomplished skier can easily spin 360 degrees around the vertical axis while in an overall forward motion. This maneuverability allows the skier to perform tricks more easily.

Additional features and advantages of the invention will be set forth in the description as follows, and in part will be apparent from the description or may be learned by practicing the invention. The objectives and other advantages of the invention will be realized and attained by the method and apparatus particularly pointed out in the written description and the claims hereof together with the appended drawings. To achieve these and other advantages, and in accordance with the purpose of the invention, as embodied and broadly described in general and in a first aspect the invention features a ski with a front portion, a middle portion and a back portion, having a top surface, right and left side surfaces and a bottom surface having a convex curved configuration, where the distance between the right and left side surfaces at the middle portion is larger than the distance between the right and left surfaces at the front portion and the distance between the right and left surfaces at the back portion. This embodiment may also include at least one of the right and left side surfaces having at least one curve or at least one linear segment.

Other embodiments may include a ski where the distance between the right and left side surfaces at the front portion does not equal the distance between the right and left surfaces at the back portion. Further, the distance between the right and left side surfaces at the front portion may be greater than the distance between the right and left surfaces at the back portion width.

Still other embodiments may include a ski where the distance between the right and left side surfaces at the mid portion is about 90 mm and about 180 mm. The ski may also have a distance between the right and left side surfaces at the front portion between about 80 mm and about 180 mm. The ski may also include a distance between the right and left side surfaces at the rear portion between about 70 mm and about 160 mm.

Another embodiment may include a ski having a front portion being separated from the reference surface up to about 60 mm. The ski may also include a rear portion separated from the reference surface up to about 50 mm.

The above advantages and features are of representative embodiments only, and are presented only to assist in understanding the invention. It should be understood that they are not to be considered limitations on the invention as defined by the claims, or limitations on equivalents to the claims. Additional features and advantages of the invention will become apparent from the drawings, the following description, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, it is believed the same will be better understood from the following description taken in conjunction with the accompanying drawings, which illustrate, in a non-limiting fashion, the best mode presently contemplated for carrying out the present invention, and in which like reference numerals designate like parts throughout the figures, wherein:

FIG. 1 is a side view of the ski according to one embodiment of the invention;

FIG. 2 is a plan of the ski in FIG. 1 according to one embodiment of the invention;

FIG. 3 is a side view of the ski according to another embodiment of the invention; and

FIG. 4 is a plan of the ski in FIG. 3 according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1 and 2, ski 10 can be seen to comprise a tip 12, a tail 14, and a main ski portion 16 extending between the tip and the tail. The main ski portion 16 has a lower running surface 18 which extends between a front location 20 at the back end of the tip 12 to a rear location 22 at the front end of the tail 14.

For purposes of further description, there is a mid location 24 located between the forward and rear locations 20 and 22. As shown herein, this mid location 24 is a short distance from the actual center location that is halfway between the front and rear locations 20 and 22, and this mid location 24 approximates a center location (or near-center location) where the middle part of the skier's boots may be located. Obviously, this mid location 24 can vary, depending upon such things as the preference of the skier, the configuration of the ski 10, etc.

Also, for purposes of description and analysis, the forward ski section 26 can be considered as having a front forward subsection 30 which comprises approximately the front half of the forward ski section 26, and a back forward subsection 32 which comprises approximately the back half of the front section 26, with the line location that divides these two subsections 30 and 32 being indicated at 34. hi like manner, the rear section 28 can be considered as being substantially divided into two subsections, namely a front rear subsection 36 and a back rear subsection 38 of the equal length, with these having a division line 40.

Reference is a first made to FIG. 1, where there is shown ski 10 in its rest position (i.e. not bearing any load) on a flat horizontal surface 42 which functions in FIG. 1 as a reference surface. It can be seen that at a central location of the ski 10 (at its center of gravity which would be at or near to location 24) the lower running surface 18 engages the reference surface 42. At the front location 20, it can be seen that the running surface is separated by a short distance from the reference surface, and this space is indicated at 44. In like manner, it can be seen that the running surface 18 at the rear location 22 is separated from the planar reference surface 42 by a distance (i.e. gap) indicated at 46. Thus, it can be seen that the ski 10 has "reverse camber" in that when ski 10 is in its rest position, the lower running surface 18 has, with respect to the reference plane 42, a slightly convex curved configuration.

With reference to FIG. 2, there are three primary width dimensions shown, namely, a front width dimension 48 at the forward location 20, a mid width dimension 50 at the location 24, and a rear width dimension 52 at the rear location 22. hi a preferred embodiment, at mid location 50, the width is greater than both the forward width dimension 48 and the rear width dimension 52. Thus, this configuration can be described as having "reverse sidecut", with the side of the ski having a convex shape as viewed from the top of the ski. The side contour of the ski can have various configurations, such as being a simple arc, a combination of several arcs, a simple no-linear curve, a combination of the above, including linear segments. Also, the front width dimension 48 and the rear width dimension 58 can differ from one another, and in one preferred embodiment, the width dimension 48 is slightly greater than the rear width dimension 52.

It should be understood that while FIGS. 1 and 2 represent generally the configuration of this first embodiment of the present invention, these are not drawn precisely to scale. However, these representations of FIGS. 1 and 2 reasonably illustrate the basic configuration of this first embodiment. In one embodiment incorporating the design features of the present invention, the front width dimension 48 is 120mm, the mid width dimension 50 is about 125mm, and the rear width dimension 52 is 115mm. The two side edges 54 follow smooth, curved contours and can (as indicated immediately above) have the precise configuration of the curves be combinations of various curve or linear portions.

Also, in this preferred configuration, the camber of the ski 10 is such that the forward gap 44 is approximately 20mm, and the rear gap 46 is approximately 12mm. The length of the ski could have various dimensions, depending on various factors, including, but not limited to, the height of the skier, the proficiency of the skier, and other factors, but this length dimension could vary, for example, between 120 to 210 centimeters including the tip and tail length and, of course, could go beyond those length limits (either shorter or longer). Preferably, the length, including the tip and tail length is between 180 and 190 centimeters. The length of the lower running surface 18, is preferably between 150 and 160 centimeters. For the embodiment described above the overall length is 186 centimeters and the running surface length is 156 centimeters.

The flexural stiffness of the ski (i.e., a resistance to bending upwardly along its longitudinal axis) will vary depending upon various factors, including, but not limited to, the size of the skier, and other factors.

The embodiment which is described above was constructed to evaluate the performance of this type of ski in powder, as well as its overall performance in other snow conditions. As indicated above, the ski functions very well in powder snow and also very well in relatively deep powder snow. Further, as indicated above, the ski would "float" wliile on the powder snow and also execute turns effectively.

Thus, the specific dimensional relationships may be optimized to improve performance for specific types of use. For example, if a person is using this ski for a "trick" acrobatic, or "stunt" skiing, where unusual maneuvers are being performed, the relative dimensions of the front, middle, and rear portions, could vary from one another to a substantially greater extent, or possibly a moderately greater extent. Conceivably, the mid width dimension 50 could be substantially greater than either or both of the front and rear dimensions 48 and 52, one of these dimensions could be modified substantially.

Also, a skier who is anticipated skiing through powder, but wants to achieve greater skiing speeds (which would require less resistance), the dimensions 48, 50, and 52 maybe relatively nearer to one another. Alternatively, if the person is more concerned about making sharp turns or sliding sideways to the fall line of the ski slope, the front and/or rear dimensions 48 and 52 could vary to a greater extent from one another.

The dimensions could be further optimized so that there would be a balance of favorable design features which would be something of a compromise between achieving reasonable speeds and also turning ability. Further, there may be design compromises depending upon expected snow conditions in certain areas (the probability of powder snow and also the frequency of deep powder snow in certain ski areas).

Additionally, the preferred embodiment may be optimized based upon a combination of the various forces that are exerted upon the ski (particularly in powder snow, whether a moderate-depth or deep powder snow), such as the distribution of the forces exerted by the snow against the ski surface, the forces exerted simply by the weight of the skier, and also those forces exerted by the skier exerting a substantial downward force against the ski in executing a turn. Accordingly, it can be anticipated that the width dimensions given above will vary, as the proportions of the width dimensions will vary relative to one another. It is also anticipated that the forward width dimension 48 would vary upwardly preferably, but not limited to, in 1-mm increments (from 120mm, 122mm, 123mm, etc., ... 150mm). Preferably the forward width dimension 48 is about 120mm, however, forward width dimension can be up to, for example, 180mm or above. In like manner, the width dimension 48 could diminish in value preferably, but not limited to, in 1-mm increments from the 120mm value (i.e. 119mm, 118mm...90mm) down to 90mm, and even to for example, 80mm or below.

In like manner, the mid width value 50 could vary preferably, but not limited to, in 1- mm increments up to as high as 150mm, or even to values up to 180mm or above. Also, the values could vary from 125mm preferably, but not limited to, in 1-mm increments down to 90mm or lower. Further, the rear width 52 could vary preferably, but not limited to, in 1-mm increments to 160mm or above. Also, the values could vary from 115mm preferably, but not limited to, in 1-mm increments to 70mm or lower.

These dimensions 48, 50, and 52 could possibly all be increased from those dimensions of the initial preferred embodiment described herein in a somewhat uniform manner, or in somewhat different proportions, due to the various factors indicated above. Alternatively, some could increase and others increase. Or, of course, they could all decrease in some manner.

The quarter length dimensions 56 and 58 would generally vary in accordance with the width dimensions of their adjacent dimension locations. For example, the dimension of 56 would depend in large part on the dimensions at the forward location 48 and the mid location 50. But the amount of increase or decrease of the dimension 56 would vary depending upon the contours of the adjacent side edges 54. For example, the rate of increase in width from location 48 to the location 56 could be greater due to a greater angle of alignment from the lengthwise axis, and then the side edge portion 56 between the dimension locations 34 and 24 could be at possibly a very little slant or even be parallel to the lengthwise axis of the ski. The same could be true of the rear dimension 58, relative to the dimension locations 50 and 52.

Also, the camber of the ski 10 can vary from that indicated above depending upon various factors, as recited previously. Thus, these values (20mm at the forward gap location 44 and the 12mm at the rear gap location 22), could vary from about zero preferably, but not limited to, in 1-mm increments (e.g. 1mm, 2mm...20mm for the forward gap 20 and 1-mm increments up to the 12mm gap at 46). Also, the camber could be greater than the embodiment shown and described in FIG.l, and the size of the gap 44 could increase preferably, but not limited to, in 1-mm increments from the value of 20mm, as described above, up to 60mm. In like manner, the gap at 46 could vary preferably, but not limited to, in 1-mm increments to values above 12mm up to 50mm or higher. Some of these outer limits may depend upon the manner in which the ski is used, such as where very high performance is desired in certain extreme conditions, or in rather unusual conditions, where certain aspects are to be emphasized. For example, for a stunt or acrobatic skiing, these relative dimensions could be quite different.

In some situations, it might even be possible that the configuration of the side edges 54 would be substantially straight, but with reverse camber, with the side edges 54 being parallel to the lengthwise axis of the ski, or even with the possibility that these could converge toward the tail 14, or alternatively conceivably converge toward the tip 12. In some situations, it may be possible that one of the width dimensions 48 or 52 would be greater than the width dimension 50. For example, it may be that the forward width dimension 48 may be made wider for some purpose, such as optimizing the engagement of the forward ski portion with the snow. Further, it could be that the central width dimension 50 could be less than both of the width dimension 48 and 52 in the event that, for some design considerations, these two width dimensions 48 and 52 could be larger for some special applications.

FIGS. 3 and 4 show an alternative embodiment with the tail of the ski having an alternative upturn. In other respects, substantially the same design considerations and parameters as discussed with reference to FIGS. 1 and 2 apply.

For the convenience of the reader, the above description has focused on a representative sample of all possible embodiments, a sample that teaches the principles of the invention and conveys the best mode contemplated for carrying it out. The description has not attempted to exhaustively enumerate all possible variations. Further undescribed alternative embodiments are possible. It will be appreciated that many of those undescribed embodiments are within the literal scope of the following claims, and others are equivalent.

Claims

CLAIMSWhat is claimed is:

1. A ski with a front portion, a middle portion and a back portion, comprising:

a top surface; a right side surface; a left side surface; and a bottom surface, the bottom surface having a convex curved configuration; wherein the distance between said right and left side surfaces at the middle portion is larger than the distance between said right and left surfaces at the front portion and the distance between said right and left surfaces at the back portion.

2. The ski according to claim 1 wherein at least one of said right and left side surfaces include at least one curve.

3. The ski according to claim 2 wherein at least one of said right and left side surfaces includes at least one linear segment.

4. The ski according to claim 1 wherein the distance between said right and left side surfaces at the front portion does not equal the distance between said right and left surfaces at the back portion.

5. The ski according to claim 4 wherein the distance between said right and left side surfaces at the front portion is greater than the distance between said right and left surfaces at the back portion width.

6. The ski according to claim 1 wherein the distance between said right and left side surfaces at the mid portion is between about 90 mm and about 180 mm.

7. The ski according to claim 1 wherein the distance between said right and left side surfaces at the front portion is between about 80 mm and about 180 mm.

8. The ski according to claim 1 wherein the distance between said right and left side surfaces at the rear portion is between about 70 mm and about 160 mm.

9. The ski according to claim 1 wherein the front portion is separated from the reference surface up to about 60 mm.

10. The ski according to claim 1 wherein the rear portion is separated from the reference surface up to about 50 mm.