Lift-propulsion system for a watercraft and watercraft having same

Abstract

A lift-propulsion assembly and a watercraft. The watercraft includes a buoyant body having upper and lower surfaces on respective upper and lower sides thereof; a lift-propulsion system including a mast connected to the buoyant body, the mast having a proximal end and a distal end, the mast extending from the lower side of the buoyant body; and the lift-propulsion assembly. The assembly includes an assembly frame connected to the distal end of the mast; a propulsion unit for providing thrust to the watercraft, the propulsion unit being connected to the assembly frame; a hydrofoil for providing lift to the watercraft, the hydrofoil being selectively connected to the assembly frame; and a manually-operable attachment system connecting the hydrofoil to the assembly frame.

What is claimed is: 
     
         1 . A watercraft, comprising:
 a buoyant body having upper and lower surfaces on respective upper and lower sides thereof;   a lift-propulsion system comprising:
 a mast connected to the buoyant body, the mast having a proximal end and a distal end, the mast extending from the lower side of the buoyant body; and 
 a lift-propulsion assembly comprising:
 an assembly frame connected to the distal end of the mast; 
 a propulsion unit for providing thrust to the watercraft, the propulsion unit being connected to the assembly frame; 
 a hydrofoil for providing lift to the watercraft, the hydrofoil being selectively connected to the assembly frame; and 
 a manually-operable attachment system connecting the hydrofoil to the assembly frame. 
 
   
     
     
         2 . The watercraft of  claim 1 , wherein:
 the assembly frame comprises one of a male tapered portion and a female tapered portion;   the hydrofoil comprises an other one of the male tapered portion and the female tapered portion; and   the male tapered portion is engaged in the female tapered portion when the hydrofoil is connected to the assembly frame.   
     
     
         3 . The watercraft of  claim 2 , wherein the male tapered portion and the female tapered portion extend and taper along a longitudinal direction of the watercraft. 
     
     
         4 . The watercraft of  claim 1 , wherein:
 the attachment system comprises a rigid connection member connected to a one of the assembly frame and the hydrofoil; and   the hydrofoil is selectively maintained connected to the assembly frame at least in part by engagement of the rigid connection member with an other one of the assembly frame and the hydrofoil.   
     
     
         5 . The watercraft of  claim 4 , wherein:
 the rigid connection member is connected to and extends from the assembly frame; and   the hydrofoil is selectively maintained connected to the assembly frame by engagement of the rigid connection member with the hydrofoil.   
     
     
         6 . The watercraft of  claim 1 , wherein:
 the attachment system comprises a locking element connected to a one of the assembly frame and the hydrofoil;   the locking element is selectively rotatable between a locked position and an unlocked position; and   the hydrofoil is selectively maintained connected to the assembly frame at least in part by engagement of the locking element with an other one of the assembly frame and the hydrofoil.   
     
     
         7 . The watercraft of  claim 6 , wherein:
 the locking element is pivotally connected to the hydrofoil; and   the hydrofoil is selectively maintained connected to the assembly frame by engagement of the locking element with the assembly frame.   
     
     
         8 . The watercraft of  claim 7 , wherein:
 the locking element comprises:
 an element body defining a slot therein, and 
 a handle portion connected to the element body; and 
   the hydrofoil is selectively maintained in connection to the assembly frame by an operator rotating the locking element to the locked position.   
     
     
         9 . The watercraft of  claim 1 , wherein:
 the attachment system comprises:
 a rigid connection member connected to the assembly frame, and 
 a locking element pivotally connected to the hydrofoil; and 
   the hydrofoil is selectively maintained connected to the assembly frame at least in part by engagement of the locking element with rigid connection member.   
     
     
         10 . The watercraft of  claim 9 , wherein:
 the locking element comprises:
 an element body defining a slot therein, and 
 a handle portion connected to the element body; and 
   the rigid connection member comprises:
 a stem, and 
 a distal end portion connected to the stem, the distal end portion having a greater width than the stem. 
   
     
     
         11 . The watercraft of  claim 10 , wherein:
 at least a first portion of the slot is wider than a width of the distal end portion, permitting the distal end portion to pass through the first portion; and   at least a second portion of the slot, opposite the first portion, is wider than a diameter of the stem and narrower than the width of the distal end portion, preventing the distal end portion from passing through the second portion.   
     
     
         12 . The watercraft of  claim 11 , wherein:
 the locking element is selectively rotatable between at least an unlocked position and a locked position;   in the unlocked position, the first portion of the slot is aligned with the rigid connecting member, such that the hydrofoil is selectively removable from the assembly frame; and   in the locked position, with the rigid connecting member being engaged with the locking element, the second portion of the slot is aligned with the rigid connecting member, such that the hydrofoil is prevented from being removed from the assembly frame.   
     
     
         13 . The watercraft of  claim 10 , wherein the handle portion is accessible on a lower side of the hydrofoil. 
     
     
         14 . The watercraft of  claim 10 , wherein, when the rigid connecting member is inserted in the locking element, the stem passes through the slot. 
     
     
         15 . The watercraft of  claim 12 , wherein the locking element is rotatable about an axis perpendicular to a bottom surface of the hydrofoil between the locked position and the unlocked position. 
     
     
         16 . The watercraft of  claim 1 , wherein:
 the hydrofoil is a front hydrofoil; and   the lift-propulsion assembly further comprises a rear hydrofoil connected to the assembly frame, the rear hydrofoil being disposed rearward of the front hydrofoil when the front hydrofoil is selectively connected to the assembly frame.   
     
     
         17 . The watercraft of  claim 1 , wherein the lift-propulsion assembly further comprises an electric motor for driving the propulsion unit. 
     
     
         18 . The watercraft of  claim 1 , wherein the lift-propulsion system further comprises an electrical assembly supported by the buoyant body, the electrical assembly comprising:
 a battery for powering the electric motor; and   an inverter in electrical communication between the battery and the electric motor.   
     
     
         19 . The watercraft of  claim 1 , wherein the propulsion unit comprises one of a propeller and an impeller. 
     
     
         20 . A lift-propulsion system for a watercraft, comprising:
 a mast connected to a buoyant body of the watercraft, the mast having a proximal end and a distal end, the mast extending from a lower side of the buoyant body; and   a lift-propulsion assembly comprising:
 an assembly frame connected to the distal end of the mast; 
 a propulsion unit for providing thrust to the watercraft, the propulsion unit being connected to the assembly frame; 
 a hydrofoil for providing lift to the watercraft, the hydrofoil being selectively connected to the assembly frame; and 
 a manually-operable attachment system connecting the hydrofoil to the assembly frame.