U.S. patent number 3,918,114 [Application Number 05/471,861] was granted by the patent office on 1975-11-11 for water skis.
Invention is credited to Bruno Schmitt.
United States Patent |
3,918,114 |
Schmitt |
November 11, 1975 |
Water skis
Abstract
A water ski having enhanced stability when compared to the prior
art results from the formation, at the sole of the ski, of a
plurality of grooves which extend inwardly from each end a portion
of the length of the ski. The grooves are angled with respect to
the main axis of the ski so as to deflect water passing under the
trailing end of the ski toward the trajectory axis of the
skier.
Inventors: |
Schmitt; Bruno (38170
Seyssinet-Pariset, FR) |
Family
ID: |
9127392 |
Appl.
No.: |
05/471,861 |
Filed: |
May 21, 1974 |
Foreign Application Priority Data
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Nov 7, 1973 [FR] |
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73.39500 |
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Current U.S.
Class: |
441/68; 441/79;
280/609 |
Current CPC
Class: |
B63B
32/30 (20200201); B63B 32/20 (20200201) |
Current International
Class: |
B63B
35/81 (20060101); B63B 35/73 (20060101); A63C
005/04 () |
Field of
Search: |
;9/31R,31A,31AA,31E
;280/11.13S ;D34/40,14D ;114/66.5R,56,63 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Taper-Flite," Nash Manufacturing, Inc., Fort Worth, Tx., Mar.
1968..
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Primary Examiner: Blix; Trygve M.
Assistant Examiner: Kazenske; Edward R.
Claims
What is claimed is:
1. In water ski, the ski comprising an elongated body having an
upper foot supporting side and an oppositely disposed base and
normally leading and trailing edges, the improvement
comprising:
a first plurality of grooves in the base of the ski, said grooves
extending inwardly from the normally trailing edge of the ski at an
oblique angle with respect to the longitudinal axis of the ski in
such a manner as to deflect water passing therethrough toward the
trajectory of the ski, said grooves terminating intermediate the
length of the ski.
2. The ski of claim 1 wherein said grooves converge toward the
longitudinal axis of the ski and toward the normally trailing
edge.
3. The ski of claim 1 further comprising:
a second plurality of grooves in the base of the ski, said grooves
of said second plurality extending inwardly from the normally
leading edge of the ski at an oblique angle with respect to the
longitudinal axis of the ski, the grooves of said second plurality
terminating intermediate the length of the ski and short of the
inner termination of the grooves of said first plurality, water
passing through the grooves adjacent the instantaneously trailing
edge of the ski being deflected toward the trajectory of the
ski.
4. The ski of claim 3 wherein said grooves of said first and second
pluralities are convergent toward the longitudinal axis of the ski
and respectively toward the normally trailing and leading edges of
the ski.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to water skis. More particularly,
this invention is directed to improving the stability of water skis
employed in competition. Accordingly, the general objects of the
present invention are to provide novel and improved apparatus and
methods of such character.
2. Description of the Prior Art
In international water ski competition the participants are
required to perform a number of maneuvers when they are both facing
and have their backs to the tow boat. The ability to and necessity
of skiing backwardly dictates that the skis be symmetrical with
respect to a plane perpendicular to their main axis. Such
symmetrical skis are known in the art.
While previously available water skis have numerous attributes,
there is a long standing desire in the art for improvements in the
stability of the skis.
SUMMARY OF THE INVENTION
The present invention comprises a novel and improved water ski
design which is characterized by enhanced stability when compared
to the prior art. In accordance with the invention the bottom
surface of each ski is provided with a number of grooves. These
grooves preferably extend inwardly from both ends of the ski along
a portion of the length of the ski only. Also the grooves define
notches preferably oriented in such a manner as to deflect the
water passing under the ski toward the trajectory axis of the
skier. This desired deflection is accomplished by use of grooves
which converge, toward the respective ends of the ski, toward the
main axis of the ski. Thus, in a preferred embodiment, the grooves
formed on the bottom of the ski converge toward the outside of the
main axis of the ski.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be better understood and its numerous
objects and advantages will become apparent to those skilled in the
art by reference to the accompanying drawing wherein:
FIG. 1 is a bottom plan view of a water ski in accordance with the
present invention; and
FIG. 2 is a cross-sectional side elevation view of the ski of FIG.
1 taken along line B-B of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawing, and particularly to FIG. 1, for
purposes of explanation it will be presumed that the end of the
ski, indicated generally at 10, indicated A is the normally leading
or forward facing end whereas the end indicated A' is normally the
trailing edge of the ski. Thus, as the skier is pulled he will
normally advance in the direction A'--A and the end A' of the ski
will be in the water while the end A will have a tendency to lift
itself out of the water. Of course, when the skier does a
180.degree. revolution, the ski will move through the water in the
direction A--A' and end A will be immersed while end A' will be
slightly out of the water.
In the disclosed embodiment the ski has been provided with six
grooves at each end; the grooves at the ends A and A' respectively
being indicated by reference numerals 12, 14, 16, 18, 20, 22 and
12', 14', 16', 18', 20', 22'. These grooves converge toward the
respective ends of the ski; i.e., respectively in the directions A
and A'; and also toward the main axis of the ski which is indicated
by a broken line. It is to be understood that, while six grooves
appear for most skis to offer the optimum performance improvement,
it is possible to use more or less than six grooves and the grooves
may be larger or smaller, longer or shorter or shallower or deeper
than shown in the accompanying drawing without departing from the
spirit and scope of the invention. Additionally, while optimum
performance is obtained by the use of grooves which are angled with
respect to the main axis of the ski, it is also possible to employ
parallel grooves.
Movement of the ski through the water creates a plurality of
streams which, in the disclosed embodiment, converge toward the
main axis of the ski at the end which is in the water. The grooves
at the other side of the ski; i.e., at the leading end which is
normally raised above the surface of the water; have practically no
effect on the performance of the ski.
In the preceding discussion is was presumed that the ski was
operating on a surface that was relatively smooth. In the case of a
body of water with a rough surface the trailing edge of the ski
will periodically leave the water. These short time duration losses
of the stabilizing effect of the grooves of the present invention
have been found not to detract from the overall improved
performance of a ski in accordance with the present invention.
As shown in FIG. 2, the desirable stabilization enhancement of the
present invention is preferably achieved by the formation of
grooves in the sole 24 of the ski. The grooves could also be
defined by attaching half-round staves in any suitable manner to
the sole of the ski. It has, however, been found that protruding
parts such as staves produce, at the leading edge of the ski,
eddies which produce a braking effect. Accordingly, the arrangement
of FIG. 2 is preferred.
While a preferred embodiment has been shown and described, various
modifications and substitutions may be made thereto without
departing from the spirit and scope of the invention. Accordingly,
it is to be understood that the present invention has been
described by way of illustration and not limitation.
* * * * *