FIELD OF INVENTION
This invention relates to a fin for a water ski; and in particular to a fin for a slalom water ski.
BACKGROUND OF THE INVENTION
Standard slalom water ski fins, which have been in use for more than thirty years have four or five holes in the bottom and back to avoid sudden losses of traction at the tail of the ski due to cavitation. This method of water flow management requires a large fin for strong acceleration across a slalom course. In fact, the standard slalom fin is so large that it makes turning a ski difficult.
An object of the present invention is to provide a slalom ski fin which solves the turning problem without compromising maximum acceleration of a ski.
SUMMARY OF THE INVENTION
Accordingly, the present invention relates to a water ski fin comprising a planar body having a top end, mounting elements on said top end for mounting the fin on a water ski, a convex leading edge, a trailing edge and a bottom rear corner connecting the leading edge to the trailing edge; and one slot proximate said leading edge of the body, said slot including an arcuate leading edge having the same curvature as the leading edge of the body and a wave-shaped trailing edge including alternating projections formed by crests and troughs.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described below in greater detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention, and wherein:
FIG. 1 is a side view of one embodiment of a slalom ski fin in accordance with the present invention;
FIG. 2 is a side view of a second embodiment of a slalom ski fin in accordance with the invention;
FIG. 3 is a side view of a third embodiment of a slalom ski fin in accordance with the invention;
FIG. 4 is a side view of a fourth embodiment of a slalom ski fin in accordance with the invention;
FIG. 5 is a side view of a fifth embodiment of a slalom ski fin in accordance with the invention; and
FIG. 6 is a side view of the ski fin of FIG. 2 overlying a standard water ski fin.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, one embodiment of the water ski fin includes a thin, planar body 1 having a top edge 2, a convex leading edge 3 flowing into a bottom, rear corner 4, and a concave rear or trailing edge 5. Notches 7 and 8 in the top edge 2 separate front and rear ears 9 and 10, respectively from a large central projection 11 which contains a window 12. The fingers 9 and 10, the projection 11 and the window 12, which are standard on most tournament water ski fins, define mounting elements used to mount the fin in the trailing end of a ski. A pair of holes 14 and 15 are used to mount adjustable wings (not shown) on the body 1.
In the following description of FIGS. 1 to 5, the same reference numbers have been used to identify the same or similar elements of the fins.
In the fin of FIG. 1, water flow from the front to the back of the fin is controlled by an elongated, arcuate slot 16 extending parallel to the leading edge 3. The slot 16 has a smooth, arcuate leading edge 17, which has a similar curvature, i.e., is generally parallel to the leading edge 3 of the fin, and a wavy rear edge 18. The wavy rear edge 18 is defined by alternating wave-like projections shown as crests 19 and troughs 20. The projections 19 manage water flow patterns on the low pressure side of the fin body 1. Thus, the fin of the present invention controls water flow dynamics primarily from the front of the fin, significantly reducing drag and unwanted lift.
The second embodiment of the invention which is shown in FIG. 2 includes a pair of slots 22 and 23 extending generally parallel to the leading edge 3 of the fin. The slot 22 similar in shape and orientation to the slot 16 in the first embodiment of the fin, but the slot 22 is shorter than the slot 16, including a wavy trailing edge 18 with fewer projections 19 and grooves 20. The second slot 23 is located rearwardly and below the slot 22. The slot 23 includes a leading, bottom edge 25 generally parallel to the leading edge 3 of the fin body 1, and a top edge 26 with a single projection 27.
As shown in FIG. 3, the third embodiment of the invention includes a slot 28, the arcuate leading edge 29 of which is not parallel to the leading edge 3 of the body 1. The slot 28 is closer to the vertical than the slot 16 or 22, i.e., the top end 31 of the slot 28 is farther away from the edge 3 than its bottom end 32.
The embodiment of the invention shown in FIG. 4 includes a slot 28 similar to the same slot in FIG. 3, and a second slot 34 beneath and rearwardly of the slot 28. The slot 34 is generally comma-shaped and includes a convex leading edge 35 and a trailing edge 36 with a single projection 37. The top end 38 of the slot 34 is farther from the leading edge 3 of the fin than the trailing edge 39.
The fifth embodiment of the invention shown in FIG. 5 includes a plurality of holes 41 extending in a row not necessarily parallel to but proximate the leading edge 3 of the fin body 1. The holes 41, which may or may not be equidistant apart perform the same function as the projections in the other embodiments of the invention.
FIG. 6 shows the fin of FIG. 4 overlying a standard slalom ski fin 43. Because of its unique forward slot and projection design, the fin of the present invention can be made smaller than a standard tournament ski fin without compromising its ability to make the ski accelerate. The turning of a ski equipped with a smaller fin is easier than the turning of a ski with a standard fin.
Patent Application
20200172208
