U.S. patent number 3,758,127 [Application Number 05/140,679] was granted by the patent office on 1973-09-11 for single snow ski.
Invention is credited to William L. Bahne, Jr., Michael D. Doyle.
United States Patent |
3,758,127 |
Doyle , et al. |
September 11, 1973 |
SINGLE SNOW SKI
Abstract
A snow ski of sufficient width to hold both feet in close side
by side position in conventional bindings or boot retainers. The
ski has a stiff central body portion, with a flexible tail and an
even more flexible nose or tip, and a minimum bottom camber. The
relationship of the stiffness and flexibility is important to the
performance of the ski. Advantages of the snow ski are extreme
maneuverability, good pivot turn ability, controlled turns at all
speeds and good support on powder snow due to the large surface
area.
Inventors: |
Doyle; Michael D. (Leucadia,
CA), Bahne, Jr.; William L. (Leucadia, CA) |
Family
ID: |
22492347 |
Appl.
No.: |
05/140,679 |
Filed: |
May 6, 1971 |
Current U.S.
Class: |
280/607 |
Current CPC
Class: |
A63C
5/03 (20130101); A63C 5/12 (20130101) |
Current International
Class: |
A63C
5/03 (20060101); A63C 5/00 (20060101); A63C
5/12 (20060101); A63c 005/00 () |
Field of
Search: |
;280/11.13S,11.13L,11.13R,11.13A,11.13F,11.13W,18,19,12H
;9/31A,31B |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hersh; Benjamin
Assistant Examiner: Smith; Milton L.
Claims
Having described our invention, we now claim.
1. A single snow ski, comprising,
an enlongated body of generally flat cross section, having a
central portion, an upwardly curved forward tip and a tail portion,
the length to width ratio of said body being about 9 to 1,
said body having its greatest thickness at the central portion and
being reduced in thickness toward the tip and tail, the minimum
thickness being adjacent said tip,
retaining means on said central portion for holding a rider's feet
in close side by side relation,
and the minimum thickness adjacent said tip is approximately 37
percent of the maximum thickness of said body.
2. A single snow ski according to claim 1, wherein said body has a
longitudinally concave under surface, with a maximum camber at said
central portion on the order of one half of the maximum thickness
of the body.
3. A single snow ski according to claim 1, wherein said body is
reduced in width at said central portion, the minimum width being
on the order of 90 percent of the maximum width.
4. A single snow ski according to claim 3, wherein the maximum
width of said body is adjacent said tip.
5. A single snow ski according to claim 3, wherein the maximum
width of said body is substantially coincident with the minimum
thickness thereof.
6. A single snow ski according to claim 1, wherein the reduced
thickness of said tail is approximately 45 percent of the maximum
thickness of the body.
Description
BACKGROUND OF THE INVENTION
In the conventional technique of skiing with two skis, properly
controlled turns and other maneuvers require considerable skill and
coordination. Much body motion is used in maneuvering the body
weight being shifted for initiating and maintaining directional
control. With conventional skis which are very long and narrow, one
ski may sink deeper into the snow than the other, making balanced
control difficult. In soft or powder snow, the narrow skis tend to
sink in and run well below the surface, so that sharp turns are not
possible. To make a typical turn the skis must be unweighted by
shifting the body weight back, the skier moving toward a sitting
position and leaning forward from the waist to maintain balance.
The upper body is twisted in the direction of the turn and the
action through the legs bank the skis to carve into the snow in the
turn with the outside ski acting as a rudder. If one ski digs into
the snow or slips, a fall results. With the two skis usually going
in different directions in a fall, the skier has very little
control and injury is common.
SUMMARY OF THE INVENTION
The single ski described herein is much wider and shorter than
conventional skis and, due to its large concentrated area, rides
well on soft snow. Both feet are held in close side by side
position in any suitable type of bindings or boot retainers, the
constant secure leg position making control more positive. Tests
have shown that fast turns can be made at any speed with a minimum
of effort and body motion, and sharp pivot turns are possible as
opposed to the usually long sliding turns made with dual skis. In a
fall, the feet remain together and the skier can retain more
control over the body and limbs to avoid injury.
The performance of the single ski is not merely the result of the
short wide shape. The pattern of flexibility through the ski is
important and there is a definite configuration that is necessary
to ensure proper action. In the ideal ski, the central body portion
is very stiff, the tail is torsionally flexible and the nose or tip
is even more flexible. Very little bottom camber is used and the
ski does not need the pronounced hourglass shape used in most
conventional skis to allow a tight radius turn. The single ski has
almost straight sides for high speed stability, yet is capable of
sharp turns due to its novel design.
Conventional skis have a length to width ratio on the order of 24
to 1 and have low torsional resistance. In contrast the single ski
has a length to width ratio on the order of 9 or 10 to 1 and the
torsional resistance is important. In a turn the tail of the ski
acts as a rudder and must bite into the snow without twisting away
from the turn. The nose or tip must have enough torsional
resistance to hold a traverse across a slope, but still be able to
twist and release from the snow from a turn. A tip that is
torsionally too stiff will tend to climb or hook into a slope and,
if too soft, will twist away from the surface and not hold a
traverse. It has been found in tests that a ski which is too stiff
overall, and one which is too flexible, do not have the performance
of the properly proportioned ski described herein.
The primary object of this invention is to provide a new and
improved single snow ski.
Another object of the invention is to provide a new and improved
single snow ski on which both feet are held in close side by side
relation.
Another object of this invention is to provide a new and improved
single snow ski with a wide body, having a stiff central portion
and flexible tip and tail portions in a particular relationship of
flexibility for optimum performance.
A further object of this invention is to provide a new and improved
single snow ski which is more easily controlled and safer to use
than conventional dual skis.
Other objects and many advantages of this invention will become
more apparent upon a reading of the following detailed description
and an examination of the drawing, wherein like reference numerals
designate like parts throughout and in which:
FIG. 1 is a top plan view of the ski.
FIG. 2 is a side elevation view thereof.
FIG. 3 is a bottom plan view thereof.
FIG. 4 is an enlarged sectional view taken on line 4--4 of FIG.
2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The ski comprises an elongated body 10 with a central portion 12,
and an upwardly curved nose or tip 14 and a tail 16. The ski is
preferably constructed from longitudinal laminated strips 18, of
wood or the like, enclosed in a skin 20 of fiberglass reinforced
plastic. Along each side edge 22 is a reinforcing angle 24, having
a flange 26 secured in any suitable manner to the underside of body
10, and a downwardly extending rib 28 which provides the wear
resistant edge of the ski. Between the ribs 28, the underside of
the ski has a running surface 30 of polyethylene, or similar
plastic material, having a pair of parallel longitudinal grooves 32
extending substantially the full length of the body. Grooves 32
allow the ski to unstick from the snow more readily and reduce
friction in running. A single groove or more than two grooves could
be used if necessary. The tail end of the ski is cut substantially
square and is preferably protected by a reinforcing strip 40 of
metal or the like. The general structure of the ski, as illustrated
in FIG. 4, is well known in various forms and is not necessarily
limited to the arrangement and materials described.
In plan form the ski is shorter than a conventional ski and
approximately two and a half times the width. While the exact
dimensions may vary to suit the rider and the required performance
characteristics the basic proportions of a tested efficient ski are
given as typical. For an overall length of 75 inches, the body has
its maximum width of 8.31 inches at the beginning of the upward
curve of tip 14, marked as point A in FIGS. 1 and 2. At the tail
16, at point C, the width is 7.94 inches and at point B,
substantially at the center of the body, the width is reduced to
7.62 inches. There is thus a very slight hourglass configuration to
the body, far less than used in a conventional ski, the narrowest
width being about 90 percent of the maximum width.
In side view, the body has its greatest thickness of 0.84 inch at
point B, and tapers to 0.31 at point A and 0.38 at point 16. The
minimum thickness is thus essentially coincident with the maximum
width of the body, to provide the required properties of
flexibility. Expressed as proportions, the minimum thickness at the
tip is about 37 percent and the reduced thickness at the tail is
about 45 percent of the maximum thickness.
The body has a longitudinally concave under surface with a small
bottom camber of 0.375 inch with reference to a ground line 34 at
point B, as opposed to a camber of up to an inch in a conventional
ski. As a proportion, the bottom camber is less than half of the
maximum thickness of the ski. It is emphasized that the exact
dimensions are only typical and are given merely to indicate the
unique configuration of the single ski relative to the conventional
type.
The rider's feet are held in side by side position on the cenral
portion of the body by any suitable bindings or boot retainers,
represented in broken line as toe grips 36 and heel clamps 38. Many
different bindings and quick release fittings are available, and
suitable securing means can be incorporated in the ski structure
where needed.
The thickest portion of the body, at the center, has the greatest
rigidity, the thickness being gradually reduced toward the tip and
tail. If the tip and tail are too stiff, the ski will tend to dig
into the snow and not release readily, so the ends are made quite
flexible. In addition to the taper, the flexibility can be
controlled, both longitudinally and torsionally by the orientation
and density of the glass fiber reinforcing material, the technique
being well known. While the actual proportions of flexibility and
stiffness will depend somewhat on the weight of the rider, it has
been found that the tip should be about 20 percent more flexible
than the tail and the torsional resistance of the tail should be
about 45 percent more than the tip. The tail needs to be stiffer
than the tip to act as a rudder in a turn, but must have sufficient
flexibility to provide a positive release from the snow at the
beginning of a turn. In the ski described, the combination of the
stiff center body and the flexible tail causes an actual upward and
forward spring as the ski is unweighted when starting a turn. The
tip must be sufficiently flexible to ride up or float on deep snow
and to twist in a turning action, both being important with the
wide, large area ski. Minimum bottom camber allows turning without
undue unweighting action by the body, and provides more stability
at high speed.
The single ski is simple to ride with both feet held together on a
single platform, and there is no tendency for the feet to separate
and get out of control in extreme maneuvers. Very tight pivot turns
can be made at any speed without loss of stability, tests showing
that the turning radius can be as little as one third of that
possible with conventional dual skis. The wide area enables the ski
to plane effectively and ride high in soft snow, which also
facilitates maneuvering. In a fall the risk of injury is greatly
reduced, since the feet do not fly in different directions, each
with a long unweildy ski attached.
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