US3061846A - Water ski - Google Patents

Description

W. R. BLAKE Nov. 6, 1962 WATER SKI W/Y/l'dfn R. Blake 1N VEN TOR.

United States Patent f 3,061,846 WATER SKI William R. Blake, 907 East Ave., Baxter Springs, Kans. Filed Aug. 5, 1959, Ser. No. 831,799 4 Claims. (Cl. 9-310) This invention relates to water skis and more particularly to a reinforced plastic water ski.

An object of the invention is to provide a water ski of unique design. Briefly, the prow or nose of the ski incorporates a reflex curve upward from the planing surface and at an elevation where other ski designs terminate. The design in accordance with this invention recurves and the body of the ski projects forward and upward at approximately a 10 angle, although the angularity may be varied within practical limits. Accordingly, there is a very important inflection area at the place in the reflex curvature where the curvature changes from concave to convex.

The contours of this section of the prow are flared, for instance, like the prow section of some boats. This flaring provides a laterally stabilizing effect on the forward part of the ski, tending to hold the direction of the ski in a constant path when the user is proceeding through waves, wakes or other rough water.

Further, the reflex curve, when viewed as a profile, tends to provide laminar water flow over the top of the prow in moments of unavoidable submersion, for instance through wakes, etc., in contrast to a turbulent vortex-type flow which exists in previous designs where the nose merely sweeps up along a radius and terminates on this radius. Laminar flow over the ski top theoretically is more conductive to maximum lift than turbulent flow, and swamping is considerably less likely.

Accordingly, a further object of the invention is to provide a ski which is hydrodynamically more stable than previous skis and which provides for considerably more enjoyment in the use thereof.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawing forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a top view of the ski constructed in accordance with the invention;

FIGURE 2 is a side view of the ski in FIGURE 1;

FIGURE 3 is a bottom view of the ski in FIGURE 1;

FIGURE 4 is a front view of the ski;

FIGURE 5 is a rear elevational view of the ski; and

FIGURE 6 is an enlarged sectional view taken substantially on the line 6-6 of FIGURE 2.

In the accompanying drawings there is illustrated a ski 10 which exemplifies the principles of the invention. This ski has a body 12 made of plastic, although the principles of the invention can be practiced in connection with skis of other construction. Mentioned as a preference, the flotation core or body provides beam strength and rigidity by adopting a plastic laminate sandwich construction with the core and skin of reinforced plastic integrally molded into a one-piece construction.

Foot receiving device 14 is shown in dotted lines in FIGURE 1 and this is conventional. There is a depression 16 in body 12 aft of the foot receiving device, and a stabilizing fin 18 located on the longitudinal axis of the body and depending downwardly from the bottom of depression 16. This fin is short in comparison with the length of the ski body and functions as a keel.

Prow 20 has a tapered tip when viewed in plan, and the prow configuration is most important. It is a wave breaker prow in contrast to other ski designs. The prow ice is symmetrical about a longitudinal axis of the ski body and has a lower reflex curve surface 22 at the forward end of the longitudinal center line. The curvature 34 is convex downward and is in the direction upward from the planing surface 26. At or near an elevation where other designs terminate the curvature of the new design passes through an inflection area 32 recurving and becoming concave downward. The forward end of the prow 20 projects forward and upward at an angle of approximately 10 degrees (FIG. 2) measured from a horizontal plane. The recurved area 22 terminates in the leading edge 33 of the ski body.

The side contours of this section of the prow are dished inward and flared, there being flared surfaces 28 and 30 (FIG. 6) commencing at the forward tip of the prow on opposite sides of the upward curvature and terminating forward of the rear end of the reflex curvature. The flared surfaces 28 and 30 are upwardly and outwardly flared and provide a lateral stabilizing effect on the forward part of the ski tending to hold the direction of the ski in a constant path when the user proceeds through waves, wakes and other disturbances.

As shown best in FIGURE 2 and in FIGURE 4 there is an inflection area 32 between the forward section of the convex downward curvature 34 and the rear section of the re-curved (concave downward) curvature 22. This inflection area 32 may be smoothly faired, or abruptly stepped as illustrated in FIGURE 2 to further assist in providing maximum lift. The use and operation of the ski has been previously discussed. Accordingly, further description is unnecessary.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A water ski comprising a ski body, said ski body having a lower planing surface and a prow, said prow curving smoothly forwardly and upwardly and including a lower reflex curvature surface from the tip thereof and merging into said planing surface, said prow being tapered in plan and toward the tip thereof, said prow also having laterally spaced upwardly and outwardly flared opposite side marginal portions extending from the region of the tip rearwardly of the ski body and forming upwardly and outwardly curving concave lower surfaces providing lateral stability on the forward part of the ski.

2. A water ski comprising a ski body, said ski body having a lower planing surface and a prow, said prow curving smoothly forwardly and upwardly and including a lower reflex curvature surface from the tip thereof and merging into said planing surface, said prow being tapered in plan and toward the tip thereof, said prow also having laterally spaced upwardly and outwardly flared opposite side marginal portions extending from the region of the tip rearwardly of the ski body and forming upwardly and outwardly curving concave lower surfaces providing lateral stability on the forward part of the ski, an inflection area in said reflex curvature surface and at approximately the line of division between the forward portion and the rear portion of said reflex curvature surface.

3. A water ski comprising a ski body, said ski body having a lower planing surface and a prow, said prow curving smoothly forwardly and upwardly and including a lower reflex curvature surface from the tip thereof and merging into said planing surface, said prow being tapered in plan and toward the tip thereof, said prow also having laterally spaced upwardly and outwardly flared opposite side marginal portions extending from the region of the tip rearwardly of the ski body and forming upwardly and outwardly curving concave lower surfaces providing lateral stability on the forward part of the ski, an inflection area in said reflex curvature surface and at approximately the line of division between the forward portion and the rear portion of said reflex curvature surface, a keel at the aft part of said ski body, and means connected with the ski body by which to receive the foot of a person.

4. A ski restricted exclusively for use on water, said ski comprising a ski body having a lower planing surface and a prow, said prow curving smoothly forward and upwardly and incorporating a reflex curvature at the bottom thereof and an inflection area in said reflex curvature, said prow also having transversely spaced upwardly and outwardly flared opposite side marginal portions on 4 each side of the longitudinal center line of the ski body and commencing in the region of the tip of the prow and forming outwardly curving concave lower surfaces terminating at a place between the forward and rear ends of the reflex curvature.

References Cited in the file of this patent UNITED STATES PATENTS 2,126,152 Suits Aug. 9, 1938 2,374,229 Newham Apr. 24, 1945 2,382,150 Hartman Aug. 14, 1945 2,866,210 Romig Dec. 30, 1958 2,915,031 Johnston Dec. 1, 1959 2,940,409 Chaffee June 14, 1960 FOREIGN PATENTS 212,221 Switzerland Feb. 3, 1941

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