Water ski construction

Abstract

There is disclosed a water-ski construction in which there is provided an elongated element having an upper and lower surface. The lower surface is divided, in the longitudinal direction, into a fore zone, a mid-zone, and an aft-zone, the lower surface of the element being adapted for contact with water. The fore-zone is designed by a single concave surface the nature of an arrow-like depression. The mid-zone is defined by first and second concave longitudinal channels separated by a sharp edge. The longitudinal channels extend throughout the mid-zone of the ski and into the aft-zone. The mid-zone further includes a flat surface which defines and frames the outer periphery of both the fore and mid-zones of the elongated ski element, thusly defining the outer transverse extent of the longitudinal channels. The depth of the concave longitudinal channels progressively deepens at the mid-zone and lessens at both the aft and fore zones. The above set forth contour of the lower surface of the ski operates to afford enhanced control and maneuverability to the water ski.

Description

sharp flat line 40 which is formed at the intersection between the flat 38 and the upper surface 12 increases the accuracy of turning which can be accomplished in using the present ski.

An additional advantage, derivitive of the stability obtained by the combination of the above-described concave channels 22, 28 and 32 is the ability of the ski to jump often up to heights of six feet. Otherwise, the channel structure permits sufficient acceleration for jumping purposes, and the flats 38, with its clearly defined flat line 40, provides for maneuverability and stability, upon landing, after such water ski jumping has occurred.

Another inventive feature herein is the long curve, shown in FIG. 4, by which the fore-zone 20 curves upward relative to the aft-zone 26. In the prior art, the upward curve of the fore-zone relative to the aft-zone is more abrupt than that disclosed herein. The elevation of the curve is 4.0 inches over a length of the entire ski, that is, a lift of 0.7 inches per running foot of length.

With reference to FIG. 7 it is noted that the sharp V-shaped intersection defining Line 36 and the curves of channels 28 and 32 on either side thereof, is the equivalent of a V bottom on a boat and, as such, provides particular stability to the ski in its mid-zone, apart from the stability derived from the surfaces 38 above described. The configuration of FIG. 7 is also very helpful in accomplishing stable turning of the ski.

It is further noted that the point of maximum transverse bulge, this corresponding to the point of cross-section 6--6 of FIG. 2 acts to maximize the jumping capability of the ski.

It is further noted that the rapid transition from the fore zone 20 to the mid-zone 24 has, particularly, in choppy water, the effect of cutting by Line 36 into the water and, thereby, forcing of channels 28 and 32 in the water to achieve a suction-like effect, which with the surfaces 38, provide enhanced low speed stability to the ski. The deep radius of channels 28 and 32 in the mid-zone is helpful during turning in that they effectively achieve a biting effect, thusly making sharper turns much easier to execute. Typically, the radius of the channels 28 and 32 are appropriately 10 inches at the Line 6--6 of greatest transverse width.

The water ski is, in a preferred embodiment, made with a foam core such as polyurethane, covered by a thin tough skin such as a polyester resin. The weight of the ski is in the range of seven to ten pounds.

In a further embodiment, the plane of the mid-zone surfaces 38 (see FIGS. 5 and 6) may define a larger included angle relative to the plane of the upper surface 12. This will present more of a V-shaped angle of attack of the lower surface 14 into the water, thus providing enhanced stability.

Accordingly, while there has been shown and described the preferred embodiments of the present invention, it is to be understood that the invention may be embodied otherwise than is herein specifically illustrated and described and that, within such embodiments, certain changes in the detail of construction and the form and arrangement of the parts may be made without departing from the underlying idea or principles of this invention within the scope of the appended claims.

Claims

1. A water ski construction, comprising:

(a) an elongated element having an upper and lower surface, said lower surface divided along the major axis of said ski, in the longitudinal direction, into a fore zone, a mid-zone, and an aft-zone, the lower surface thereof adapted to contact water,

(b) said fore zone defining a single concave surface in the nature of an arrow-like depression, the point of the arrow of said depression directed along the major axis of said ski and in the direction of intended travel thereof,

(c)(b) said mid-zone defining first and second concave longitudinal channels separated by a sharp an edge of arcuate intersection between said first and second channels, said channels and said edge extending throughout said mid-zone and into said aft-zone, said mid-zone further including a surface which defines and frames the entire outer periphery of both said fore- and mid-zones mid-zone of said elongated element and, thereby, the outer transverse extent of said longitudinal channels, said transverse extent defining the minor axis of the ski,

(d) (c) said aft-zone including an extension of said pair of concave channels, absent said mid-zone surfaces, surface, and

(e) (d) the aft-zone tapered transversely inward to reduce, at its end, to zero the transverse width of the ski, and

(f) the radial depth of said longitudinal channels progressively deepening at the mid-zone and lessening at said aft-zone as well as at the single concave surface of said fore-zone, whereby the above-defined contour of the lower surface operates to afford enhanced control and maneuverability of the ski.

2. The water ski construction as recited in claim 1 in which the ratio of the length of said minor axis of said ski to said major axis is in the range of 0.18 to 0.30.

3. The construction as recited in claim 2 in which the length of the ski is about 66 inches and the width thereof is about 16 inches.

4. The construction as recited in claim 2 in which the ski, along its major axis, exhibits an upward slope of about 0.07 inches per running foot of length of the major axis of said ski.

5. The construction as recited in claim 2 in which the radius of curvature of each of said first and second longitudinal channels is, at the center of the mid-zone of the ski, about 10 inches.

6. The construction as recited in claim 2 where the weight of the skis is in the range of 7 to 10 lbs.

7. The ski construction as recited in claim 2 in which the ski comprises a foam core surrounded by a rugged outer skin.

8. The construction as recited in claim 7 where the weight of the skis is in the range of 7 to 10 lbs.

9. The invention according to claim 1 wherein said mid-zone edge of said intersection is lower in said water than said transverse extent. 10. The invention according to claim 1 wherein said concave longitudinal channels are of a gradually changing depth.