Self stabilizing monowing hydrofoil

Abstract

This invention relates generally to hydrofoils. More specifically, this invention relates to a monowing hydrofoil that provides inherent pitch stability during use. The monowing hydrofoil utilizes one or more mast interfaces to facilitate its removable, and optionally angularly adjustable, engagement to a mast.

We claim: 
     
         1 . A monowing hydrofoil comprising:
 a body defining a central portion and two rear-swept wing portions between forward and trailing edges, the central portion defining a front lateral line at the forward edge, each rear-swept wing portion swept rearwardly of the forward lateral line by between about 20 degrees and 45 degrees, the body having a distance between the leading edge and trailing edge defining a chord;   an upwardly-swept central extension rearwardly extending from the central portion and laterally into each rear-swept wing portion; and   a mast interface located on the central portion.   
     
     
         2 . The monowing hydrofoil of  claim 1  wherein the upwardly-swept central extension terminates in a rear lateral straight line at the trailing edge. 
     
     
         3 . The monowing hydrofoil of  claim 2  wherein the rear lateral straight line is about parallel with the front lateral straight line. 
     
     
         4 . The monowing hydrofoil of  claim 3  wherein the central portion defines a negative mean camber line of between about 1% and 6% aft of about 70% of the chord from the leading edge. 
     
     
         5 . The monowing hydrofoil of  claim 4  wherein the central portion defines a positive mean camber line and a thickness of about 30 mm at about 20% of the chord from the leading edge. 
     
     
         6 . The monowing hydrofoil of  claim 5  wherein the rear lateral straight line is located about 80 mm rearwardly of the central portion and is angled between about 9 degrees and 13 degrees from a horizontal axis. 
     
     
         7 . The monowing hydrofoil of  claim 5  wherein the trailing edge is located between about 20 mm and 170 mm rearwardly of the central portion and defines a curved line at the trailing edge. 
     
     
         8 . The monowing hydrofoil of  claim 5  wherein the trailing edge is located between about 20 mm and 170 mm rearwardly of the central portion and defines an angular line at the trailing edge. 
     
     
         9 . The monowing hydrofoil of  claim 6  wherein the rear-swept wing portions define wing tips having a Hoerner cross section. 
     
     
         10 . The monowing hydrofoil of  claim 1  wherein the mast interface comprises a stantion defined on the central portion, the stantion removably engageable with a lower end of a mast. 
     
     
         11 . The monowing hydrofoil of  claim 1  wherein the mast interface comprises a cavity defined in the central portion, the cavity removably engageable with a lower end of a mast. 
     
     
         12 . The monowing hydrofoil of  claim 10  further comprising a washer located between the stantion and the lower end of the mast. 
     
     
         13 . The monowing of  claim 11  further comprising an interface housing located at the lower end of the mast, said housing removably engageable with the cavity. 
     
     
         14 . The monowing of  claim 11 , further comprising at least one collar removably engageable with the lower end of the mast, the collar and lower end of the mast removably engageable with the cavity. 
     
     
         15 . The monowing of  claim 14 , wherein the at least one collar defines a mast abutment and a lower collar surface, the lower surface having an angle from the mast abutment of between about 0 degrees and 90 degrees, said lower collar surface removably engageable with a collar abutment of the cavity, said mast abutment removably engageable with the lower end of the mast. 
     
     
         16 . The monowing of  claim 14 , wherein the at least one collar is interchangeably selected from a plurality of collars, each collar of said plurality defining a mast abutment and a lower collar surface, the lower collar surface having an angle from the mast abutment of between about 0 degrees and 90 degrees, said lower collar surface removably engageable with a collar abutment of the cavity, said mast abutment removably engageable with the lower end of the mast. 
     
     
         17 . The monowing of  claim 14  further comprising a set screw and wherein the collar defines opposing ovoid inner side portions and the lower end of the mast defines opposing ovoid outer side walls, said side portions configured for frictional engagement with said side walls, said set screw configured to displace the collar and mast lower end in relation to one another to increase said frictional engagement. 
     
     
         18 . The monowing of  claim 14  further comprising an anode located between the body and the collar. 
     
     
         19 . The monowing hydrofoil of  claim 9  wherein the mast interface comprises a stantion defined on the central portion, the stantion removably engageable with a lower end of a mast. 
     
     
         20 . The monowing hydrofoil of  claim 9  wherein the mast interface comprises a cavity defined in the central portion and further comprising at least one collar defining a mast abutment and a lower collar surface, the lower collar surface having an angle from the mast abutment of between about 0 degrees and 90 degrees, said lower collar surface removably engageable with a collar abutment of the cavity, said mast abutment removably engageable with the lower end of the mast.