SPECIFICATION

[0001] Invented is a fin which pertains to water planing devices, namely, a surfboard (a wave riding vehicle). The invented fin (located in the center rear position) works in conjunction with side fins, which are in most cases, already existing on the surfboard. This new technology could, however, lend itself to custom placed side fins to achieve a different result. The invented fin is a vertical foil, with two bilaterally attached horizontal foils toward the vertical fin tip. These foils are forward leaned, to control the water flowing between said horizontal foil, the vertical foil, the surfboard surface and the opposing side fin configuration. This creates two chambers (semi enclosed) of water passing under the rear section of said surfboard. The fin is constructed of, but not limited to, fiberglass or carbon fiber. First the vertical fin is constructed, currently in a mold, then set into a jig, where the horizontal foils are attached at a desired angle. The horizontal foils are also made of fiberglass or carbon fiber, and they also may be handcrafted or molded pieces. The horizontal foils are affixed to the vertical foil using a common bonding method (in surfboard manufacturing), using fiberglass rope at the seams, and laying fiberglass cloth over the rope and overlapping onto the desired adhered surfaces. The result is an inverted “T” shaped fin. This fin, when installed in the center rear position of a common modern three fin surfboard, will result in two semi controlled chambers of water passing under the rear section of said surfboard. Furthermore, if this invented fin were to travel backward it would provide lift, because of the reverse travel of the forward leaned horizontal foils. This characteristic lends itself to the ability to attach the same or similar fin configurations to both ends of the underside of a surfboard and achieve a surfboard that may be indiscriminately ridden without regard to nose and tail or front and rear. The forward mounted fin will provide lift, while the rearward mounted fin will provide down force.

REFERENCES CITED

U.S. Patent Documents

[0002] 1

Foreign Patent Documents

[0003] 2

BACKGROUND OF THE INVENTION

[0004] The present invention is related to water planing devices herein referred to as a surfboard, and particularly a surfboard having hydrodynamic fin properties, which provide the surfboard with controlled chambers of water at the underside rear section of said surfboard, as well as providing lift should the hydrodynamic fin travel backward. This fin may be used as a replacement for the center rear fin of a common modern multi-fin surfboard, to achieve this chambering effect with negative lift properties. Furthermore, this fin when traveling backwards provides lift, should the surfer re-enter the breaking wave backward, with less incidence of submerging the tail of the backward traveling surfboard. These properties allow said fin to be positioned, with the complementing side fin configurations, at both ends of a surf or planar type board, to achieve a surfboard capable of generating speed, on a breaking wave, with either end being used as the tail or rear section. Inherently surfboards generate their speed using the fin configuration at the rear of the surfboard. the forward mounted fin will then be traveling backwards, with the reverse traveling foils providing lift to the forward section of said surfboard. A previous patent with down force technology, U.S. Pat. No. 4,320,546, is a surfboard. This patent describes down force technology in the same area of the surfboard, however, is not using a side fin configuration to create a variable between the center fin and a vertical side fin. The side fin configuration with horizontal foils in place on the center rear fin, does not create a complete enclosure, but the effects of chambering the water under the surfboard are obvious when used and adjusted with different fin sizes, profiles, angles, and placements. Furthermore, no patent researched uses the same or similar type fin on the front and rear of a surfboard to achieve a lift and down force effects simultaneously.

SUMMARY OF THE INVENTION

[0005] The invention comprises of a surfboard, having a planing hull, and a unique fin configuration characterized by a configuration consisting of at least three vertical foils; one foil located on each side toward the rear underside section and one vertical foil located further rearward in the center. This center rear vertical foil is constructed with two symmetrically placed horizontal foils located toward the fin tip. These horizontal foils are forward leaned to provide down force to the forward traveling surfboard, as well as lift for the tail, should the surfboard travel backward. This allows for the configuration to be applied to both ends of a surfboard, if desired, to achieve an omni-directional surfboard, or one that will be able to turn one hundred eighty degrees and continue to surf forward without loss of fin propulsion. If a surfer decides to replace the center rear fin of a common multi-fin surfboard, with the hydrodynamic fin, the benefits will be extra grip of the existing side fins as well as having a foil that maintains verticality while the surfboard is executing a turn. Furthermore, the hydrodynamic fin's profile is lower than that of a standard common vertical foil. This gives the surfboard a looser feel without sacrificing speed or maneuverability and also facilitates in tail-first re-entries, by providing positive lift due to the reverse traveling forward leaned horizontal foils.