Hydrofoil vehicle

Abstract

The hydrofoil vehicle has a buoyant hull to support a rider. A powering device is in the hull with a propeller therefrom. The ski assembly includes a main ski below the hull mounted on the forward and aft ends thereof. It has a pair of helper skis oppositely alongside the aft end portion of the main ski. Stabilizing fins extend below the main ski, and a rudder is used to steer.

We claim: 
     
       1. A hydrofoil vehicle, comprising: a. a bouyant hull having means to support a rider thereon,   b. a powering means mounted within said hull having a .[.propeller.]. .Iadd.propulsion .Iaddend.means extending therefrom,   c. a .[.main.]. ski mounted below said hull attached to said hull on the forward end portions and the aft end portions thereof,   d. .[.a pair of helper skis oppositely mounted with said main ski and longitudinally alongside an aft end portion of said said main ski,.].   e. rudder means operatively mounted on said .[.main.]. ski to steer the same, said rudder means comprises a .Iadd.first .Iaddend. rudder pivotally mounted above said .[.main.]. ski .Iadd.and relative thereto .Iaddend.and a second .Iadd.smaller .Iaddend.rudder pivotally mounted below said .[.main.]. ski .Iadd.and relative thereto.Iaddend., said rudders mounted on said forward end portion of said .[.main.]. ski and essentially pivot in unison around .[.the same.]. .Iadd.their respective .Iaddend.vertical axis, and   f. stabilizing fin means mounted on said .[.main.]. ski and extending .[.there below,.]. .Iadd.therebelow. .Iaddend..[.said stabilizing fin means includes a foward fin situated behind and adjacent to said second rudder..]. .[.2. The vehicle of claim, 1 wherein:   a. said main ski has an upturned forward portion,   b. said pair of helper skis have planar bottom surfaces, upturned tip portions, and extend forward from the aft end of said main ski, and   c. said stabilizing fin means additionally includes another fin at an aft   
     
     
        end portion of said main ski..]. .[.3.  The vehicle of claim 2, wherein: a. said stabilizing fin means has a plurality of fins adjacent said second rudder being aft of said second rudder in a spaced relation thereto and parallel to said main ski,   b. said stabilizing fin means has a plurality of fins at said aft end portion of said main ski in a spaced parallel relation and being parallel with said main ski,   c. said helper skis extend less than one-half the length of said main ski, and   d. said helper skis are attached to said main ski along adjacent edges   
     
     
        thereof..]. 4. The vehicle of claim .[.3.]. .Iadd.7, .Iaddend.wherein: a. said main ski has a hollow portion extending substantially the length of said main ski open at said aft end of said main ski and vented to the atmosphere at said forward end portion of said main ski,   b. said main ski has flotation material attached to the upper forward portion thereof, and   c. said powering means has said propeller means extending below said aft end portion of said main ski. .[.5. The vehicle of claim 4, wherein:   a. said hull has a streamline shape generally pointed in the forward portion thereof, having a generally narrow center portion having a seat thereon for a rider to sit straddling said hull, and having a generally wider aft end portion with the bottom surface of said aft end portion having upwardly turned forward portions, and   b. said main ski has a flat bottom surface portion at said aft end portion thereof..]. .[.6. The vehicle of claim 1, wherein said main ski has an upturned forward portion, said helper skis have planar bottom surfaces, upturned tip portions and extend forward from the aft end of said main ski..]. .Iadd. 7. The vehicle of claim 1, wherein said ski is the main ski; further including a pair of helper skis oppositely mounted with respect to said main ski and longitudinally alongside the aft portion of said main ski. .Iaddend..Iadd. 8. The vehicle of claim 1, wherein the first and second rudders are pivoted approximately at their centers about a common vertical axis, the second rudder having a substantially smaller effective area than the first rudder whereby at higher planing speeds the second rudder has a substantially comparable sensitivity to that of the first rudder at lower non-planing speeds. .Iaddend.