Alpine ski

There is provided a new and useful ski, particularly an Alpine ski, where the maximum height (radius of curvature) of the bottom camber is in the rearward portion of the ski behind the centerline of the boot placement; and the waist (minimum width of side camber) of the ski is ahead of the centerline of the boot placement such that the ski width is increasing at this centerline position.

BACKGROUND OF THE INVENTION 
This invention relates to an improved ski design and more particularly to 
an improvement in the efficiency of Downhill skis, Giant Slalom skis, 
Slalom skis and Recreational Alpine skis. 
The present ski design has developed over the years. The two key factors 
which affect the performance of a ski are the "camber" which is the 
upwardly bowed bottom surface and the "side camber" or "side cut" in which 
the forward end and rear end of the ski are wider then the center or waist 
of the ski. 
Clement, U.S. Pat. No. 2,258,046 issued Oct. 7, 1941 illustrates an early 
ski which incorporates camber. Beerli in U.S. Pat. No. 2,210,794 issued 
June 6, 1950 illustates th concept of "side camber". 
Unfortunately snow conditions and ski terrain are not uniform and vary 
dramatically. Thus skis are required to perform on conditions ranging from 
ice, hard packed powder, powder, corn snow, broken crust, etc. Skiing is 
also a difficult learned skill in which the ability of the skier is an 
important factor. 
There have been many modifications to the design of skis over the years to 
improve their performance. Most of these have been within the state of the 
art while other more novel designs have been patented. 
Some examples of the former are: 
1. The design of the side camber (side cut) has been varied to optimize the 
turning radius of the ski. The designs are noticeably different in some 
downhill and slalom skis. 
2. The placement of the boot has been moved forward and/or backward from 
the usual position on the ski. 
3. The stiffness of the ski has been varied not only of the entire ski but 
also to have different degrees of stiffness between the forward portion of 
the ski and the rearward portion of the ski. 
4. The degree of curvature and height of the "camber" (upward bowed bottom 
surface) have also been modified usually in relation to the stiffness and 
length of the ski. 
Some examples of the latter are: 
1. U.S. Pat. No. 4,377,297 which describes an alpine ski with a special 
modified side cut which has a bulge under the boot area to apply more edge 
pressure at this point of the ski during a turn. 
2. Other patents showing variation in side cut are Austrian Patent No. 
173,373 and German Patent 643,186. 
3. Canadian Pat. No. 1,148,680 is for a reverse camber (bottom bowed) ski 
which is suited for beginner skiers as it is easier to turn. 
4. U.S. Pat. No. 4,487,426 describes a ski with a reverse or relatively no 
camber combined with a convex or modified convex side camber. 
5. A number of novel ski designs have been developed such as U.S. Pat. No. 
4,085,947 which describes a rearward controlled snow ski which is 
basically a short ski with the rearward position of the ski (behind boot) 
being 20% of the ski length. 
Another significant factor to improve the capabilities of the skier and 
thus the performance of the skis has been the "forward lean" built into 
the ski boot. This has allowed the skier to shift his weight as required 
during turns while making it easier (due to the cantilever effect) to 
maintain his position relative to the fall line of the ski slope. 
Unfortunately standing on skis with this boot on level ground or walking 
causes discomfort to the skier. 
The sport of skiing requires a high degree of skill from the participant. 
To control the skis and their direction and maintain balance on a wide 
range of snow conditions the skier must shift his weight in many 
directions, apply edging and apply other forces to his skis which 
appropriately apply them to the ground (ski slope). As it is only through 
the skis that the desired forces can be applied, the ski design is 
critical to the sport. 
BRIEF SUMMARY OF THE INVENTION 
It is an object of the invention to provide a new alpine ski design which 
enhances the ability of a skier to control speed and turns and to maintain 
stability. 
It is a further object of the invention to improve the efficiency of alpine 
skis. 
In furtherance of these objects, the invention provides a ski, particularly 
an Alpine ski, where the maximum height (radius of curvature) of the 
bottom camber is in the rearward portion of the ski behind the centerline 
of the boot placement; and the waist (minimum width of the side camber) of 
the ski is ahead of the centerline of the boot placement such that the ski 
width is increasing at this centerline position. These two disclosures in 
combination result in a ski which is much more controllable in turns on 
all snow conditions usually encountered on ski slopes. 
GENERAL DESCRIPTION 
This invention is a major improvement in ski design to meet the 
requirements of the skier to control his turns and speed and maintain his 
stability. 
This ski design also assists the skier in overcoming the forces acting 
against him such as gravity and angular forces created during the turns. 
To initiate a turn a skier must turn the skis at an angle to his current 
direction. This is accomplished by an up unweighting and by turning the 
feet at the point in time when the skis have the least downward pressure 
on them. As the pressure increases upon the skis they begin to bend and 
due to the concave sidecut move in an arc in the direction of the turn. 
Very quickly the ski achieves the amount of pressure required for the ski 
to bend to the desired arc of the turn. As the skier continues to turn, 
the pressure on his skis increases dramatically, due to the angular force 
plus pull of gravity as the skier cuts across the fall line. In order for 
the skis to retain their grip it is necessary to absorb a great deal of 
the increasing pressure (energy). This is accomplished in two ways: 
1. The skier himself can bend lower and lower to absorb the energy. 
2. The skis can bend more and more storing the increasing pressure. 
As we have noted, the skis achieve the arc of the turn in the very early 
stages. Therefore in order for the ski to bend more the skier must either 
put more weight on the front or back of the skis. 
Placing more weight on the front portion would cause the skis to plow the 
snow and would cause the skis to have a greater curvature than the desired 
radius of the turn. 
It is necessary then to apply the increasing pressure towards the tail of 
the skis. 
This does not cause the skis to overturn because from just in front of the 
boot to the back of the ski has very little sidecut (in and by itself) so 
that the further back the weight becomes, the more increased bend the tail 
of the skis must acquire to retain the curve of the turn. Therefore by 
pressuring the tails of the skis (or by letting the tail of the skis 
absorb the increasing pressure of the turn) along with a bending of the 
body the required radius or arc of the turn can be maintained. 
The difficulty in this is that towards the end of the turn the skier finds 
himself leaning back more and more. To help overcome this a stiff forward 
angled high ski boot has been developed which can act as a lever to 
pressure the tail of the skis without leaning back so far. It has been 
noted that most skiers from beginners to experts even when the assistance 
of the boot find themselves leaning too far back towards the end of a 
turn. The stored energy in the tail of the ski then releases the energy by 
returning to its previous shape thereby creating an upward push to the 
skier. This upward push helps with releasing the weight in preparation for 
the next turn. 
However the leaning back towards the end of the turn, combined with the 
forces of gravity (the angle depending on the steepness of the ski slope) 
and the angular forces created by the turn make it difficult for the skier 
to regain a balanced slightly forward position with which to initiate the 
following turn. 
During the turn the angular forces created act on the skis which can cause 
them to slide or "wash out", particularly on icy or hard packed snow 
conditions. Proficient skiers keep their edges of their skis razor sharp 
to assist them in preventing this from occuring. 
It has now been determined that a snow ski, particularly an Alpine ski, 
where the maximum height (radius of curvature) of the bottom camber is in 
the rearward portion of the ski behind the centerline of the boot 
placement, and the waist (minimum width of the side camber) of the ski is 
ahead of the centerline of the boot placement such that the ski width is 
increasing at this centerline position, is substantially more controllable 
in turns on all snow conditions usually encountered on ski slopes. 
The combination of these two factors has the following effect on the 
skier's ability to execute his turns. Substantially more energy can be 
absorbed and stored by the ski (particularly at the rear) during the turn 
without seriously affecting the arc or radius of turn desired as there is 
less pressure applied at the tip of the ski. Correspondingly it is 
possible to increase the height of the camber and/or stiffness of the ski 
without causing loss of controllability of the tips during the turn. With 
the waist forward there is greater contact with the ski slope at the 
centerline of the boot placement and rearwards. 
This coupled with the additional energy stored in the ski reduces the 
tendency of the ski to slide or "wash out". The increased absorption of 
energy at the rearward portion of the ski also allows the skier to remain 
more upright and balanced over his skis. When the skier is completing his 
turn and the ski returns to its original shape this energy as it is behind 
the centerline of the boot is applied upwards and forward thereby 
assisting the skier to be in the proper position to initiate the next turn 
.

While the invention will be described in conjunction with illustrated 
embodiments, it will be understood that it is not intended to limit the 
invention to such embodiments. On the contrary, it is intended to cover 
all alternatives, modifications and equivalents as may be included within 
the spirit and scope of the invention as defined by the appended claims. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the following description, similar features in the drawings have been 
given similar reference numerals. 
Referring to FIG. 1 which is the plan view of a conventional ski it can be 
seen that the waist B of the ski is within the area of the centerline c of 
the boot placement. Referring to FIG. 2 which is the side elevation of a 
conventional ski it can be seen that the maximum height A of the bottom 
camber is located approximately at the midpoint of the planar surface 
where the forward portion of the ski touches that surface and the rearward 
portion of the ski touches that surface when the ski is placed on that 
surface. 
FIGS. 3 and 4 show the two features of the ski design that when combined 
result in a ski which is substantially superior in performance and 
efficiency. FIG. 3 shows the position of the waist B forward of the 
centerline of the boot placement so that the width of the ski is 
increasing (rearwards) at this centerline. FIG. 4 shows the maximum height 
A of the bottom camber behind (rearward) the centerline of the boot 
placement. 
To more clearly illustrate the improved ski of the present invention the 
following is an example of a ski which would be utilized by a proficient 
skier in the execution of his sport of slalom skiing. 
A comparison is made to a typical prior art slalom ski. It is recognized 
that these measurements are not fixed and can be varied (and are varied on 
a prior art ski) depending on many factors such as the length, stiffness 
and composition of the skis. Measurements involving length use the tail of 
the ski as the datum. 
______________________________________ 
Prior Art Ski 
Improved Ski 
FIGS. 1 and 2 
FIGS. 3 and 4 
______________________________________ 
Length of Ski 205.0 cm 205.0 cm 
Width at a 8.8 cm 8.8 cm 
Width at b 6.8 cm 6.8 cm 
Width at c 6.8 cm 6.8 cm 
Width at d 7.8 cm 8.3 cm 
Length from tail at a 
190.0 cm 190.0 cm 
Length from tail at b 
96.0 cm 112.0 cm 
Length from tail at c 
64.0 cm 102.0 cm 
Length from tail at d 
7.0 cm 7.0 cm 
Length from tail at A 
98.5 cm 75.0 cm 
Length from tail at 
85.5 cm 85.5 cm 
Boot centerline 
Height at A 1.1 cm 1.8 cm 
______________________________________ 
The repositioning of the waist B and of the maximum height A of the bottom 
camber produced a performance which was superior to the conventional ski 
in field trials. 
It was found in arriving at optimum design during field trials of this 
embodiment of the improved skis that the increased width at d and the 
increased height at A as compared to the example of the prior art ski gave 
some improvement of performance. 
This specific example of the invention illustrates the best known mode for 
practicing this invention. 
Thus it is apparent that the invention provides an alpine ski that fully 
satisfies the objects, aims and advantages set forth above. While the 
invention has been described in conjunction with specific embodiments 
thereof, it is evident that many alternatives, modifications and 
variations will be apparent to those skilled in the art in light of the 
foregoing description. Accordingly, it is intended to embrace all such 
alternatives, modficiations and variations as fall within the spirit and 
broad scope of the invention.