Thrust Assembly For Personal Watercraft

Abstract

A personal watercraft includes a floatation member, a thrust assembly, a steering assembly, and a braking assembly. The assemblies may be actuated either mechanically or electrically. The thrust assembly is human powered, solar powered, or electric powered. The thrust, steering, and braking assemblies can be added after-market to an existing stand-up paddle board (SUP), or built into one or a plurality of SUPs during initial manufacturing. When the thrust assembly is human powered, it is leg or arm powered. When the thrust assembly is leg powered, the legs can move backward and forward in a sliding motion, up and down in a stomping fashion, or move in a loop trajectory. When the thrust assembly is arm powered, the arms can move forward/backward together or separately. The thrust assembly includes one or a plurality of paddles or flippers that are positioned to the side or under the SUP.

What is claimed is: 
     
         1 . A thrust assembly for a standup paddle board (SUP) with a single hull, said thrust assembly comprising:
 a foot support for supporting a foot; and   a thrust member for applying force to water and propelling said SUP when said foot support is moved;   wherein said thrust member includes a flexible-thrust portion and is for attaching to said foot support by a foot-thrust attachment structure configured for extending over a right, left, front, or rear side edge of said SUP for positioning said thrust member in water and at least mostly under said SUP.   
     
     
         2 . The thrust assembly according to  claim 1  further comprising a cantilever-thrust member including a rigid-cantilever portion extending from said flexible-thrust portion, said cantilever-thrust member having a cantilever-distal end at a distal end of said rigid-cantilever portion, and having a flexible-distal end at a distal end of said flexible-thrust portion;
 wherein said foot-thrust attachment structure and said cantilever-thrust member share an articulated joint positioned between said cantilever-distal end and said flexible-distal end; and 
 wherein said cantilever-thrust member is for rotating about said articulated joint for increasing speed of movement of said flexible-distal end for increasing thrust when said foot support nears a bottom or top of its movement range. 
 
     
     
         3 . The thrust assembly according to  claim 2  further comprising a joint-limiting structure;
 wherein said articulated joint includes a first link and a second link for rotating relative to each other about a joint axis; 
 wherein said foot-thrust attachment structure includes said first link, and said cantilever-thrust member includes said second link; 
 wherein at least one of said first link and said second link includes said joint-limiting structure; and 
 wherein said joint-limiting structure is for limiting said second link from rotating more than a maximum angle relative to said first link about said joint axis. 
 
     
     
         4 . The thrust assembly according to  claim 2  further comprising a cantilever-limiting structure for limiting said cantilever-distal end from moving more than a maximum distance from said SUP. 
     
     
         5 . The thrust assembly according to  claim 1 , wherein said flexible-thrust portion includes a flexible flipper. 
     
     
         6 . The thrust assembly according to  claim 2 , wherein said cantilever-distal end includes a wheel, a rotary structure, or a sliding pad. 
     
     
         7 . The thrust assembly according to  claim 3 , wherein said joint-limiting structure includes at least one limiting structure from the from the group consisting of
 (a) a flexible tendon, wherein ends of said tendon are attached to said links; whereby the length of said tendon limits said joint angle;   (b) a pin-slot joint including a slotted link; wherein one end of the slotted link is rotatably connected to said first link, and said second link is adapted with a pin for sliding in a slot in said slotted link; wherein said pin in said second link cannot slide past the end of said slot; whereby the length of said slot limits said joint angle; and   (c) a rigid pin; wherein one end of said pin is attached to one of said links with ability to pivot, and the other end of the pin passes through a hole in the other said link, and possess a structure on the end of the pin that prevents the pin from coming out of the hole; whereby the length of said pin limits said joint angle.   
     
     
         8 . The thrust assembly according to  claim 4 , wherein said cantilever-limiting structure includes at least one limiting structure from the from the group consisting of
 (a) a flexible tendon; wherein one end of said tendon is attached to said SUP, and the other end of said tendon is attached to said cantilever-distal end; whereby the length of said tendon limits the distance the cantilever-distal end can deviate from said SUP; and   (b) a pin-slot joint including a slotted link; wherein one end of the slotted link is rotatably connected to said SUP, and said cantilever-distal end is adapted with a pin for sliding in a slot in said slotted link, wherein said pin in said cantilever-distal end cannot slide past the end of said slot; whereby the length of said slot limits the distance the cantilever-distal end can deviate from said SUP.   
     
     
         9 . The thrust assembly according to  claim 1  further comprising a multi-component mounting structure configured for removable attachment of said multi-component mounting structure to said SUP;
 wherein said SUP is a standard SUP, said removable attachment does not require permanently modifying said standard SUP, a forward portion of said foot support is rotatably attached to said multi-component mounting structure, and a rearward portion of said foot support is attached to said foot-thrust attachment structure. 
 
     
     
         10 . The thrust assembly according to  claim 9  further comprising a lever for braking said SUP or for controlling said thrust member;
 wherein for braking, said lever rotating down at least a portion of a brake fin for increasing drag. 
 
     
     
         11 . The thrust assembly according to  claim 10  further comprising said brake fin configured for removable attachment to a rear-fin slot of said SUP;
 wherein at least a portion of said brake fin is for rotating down to slow movement of said SUP. 
 
     
     
         12 . The thrust assembly according to  claim 9  further comprising a handle for steering or braking said SUP, or for controlling said thrust member; and
 wherein said handle includes a wireless control for controlling an electric actuator. 
 
     
     
         13 . The thrust assembly according to  claim 12  further comprising a rotatable rudder configured for removable attachment to a rear-fin slot of said SUP;
 wherein said rudder is for steering by said handle. 
 
     
     
         14 . The thrust assembly according to  claim 1 ; wherein said attachment structure includes a U-shaped structure for extending over said side edge of said SUP, whereby said foot support is positioned above or on top of said SUP, and said thrust member is positioned under at least a portion of said SUP. 
     
     
         15 . The thrust assembly according to  claim 9 ,
 wherein a portion of said U-shaped structure is configured for extending underwater toward the centerline of said SUP; and   wherein said thrust member includes a flexible flipper.   
     
     
         16 . The thrust assembly according to  claim 1  further comprising:
 a single pulley or four-bar mechanism; 
 a left foot support for supporting a left foot; and 
 a left thrust member for applying force against said water and propelling said SUP when said left foot support is moved; 
 wherein said foot support is for supporting a right foot; 
 wherein each of said thrust members includes a flexible flipper; 
 wherein said thrust assembly is for constraining said foot supports to move down and up in opposite directions to each other, where moving one of said foot supports down moves the corresponding said thrust member down to propel said SUP and moves the other said foot support and corresponding thrust member up; and 
 wherein said single pulley or four-bar mechanism is for said constraining. 
 
     
     
         17 . The thrust assembly according to  claim 2 ;
 wherein said attachment structure includes a U-shaped structure for extending over said side edge of said SUP, whereby said foot support is positioned above or on top of said SUP, and said thrust member is positioned under at least a portion of said SUP;   wherein a portion of said U-shaped structure is configured for extending underwater toward the centerline of said SUP; and   wherein said thrust member includes a flexible flipper.   
     
     
         18 . A standup paddle board (SUP) comprising:
 a single SUP hull;   a right thrust assembly including:   a right foot support for supporting a right foot; and   a right thrust member for applying force to water and propelling said SUP when said right foot support is moved;   wherein said right thrust member includes a flexible-thrust portion and is for attaching to said right foot support by a right attachment structure configured for extending over a right side edge of said SUP for positioning said right thrust member in water and at least mostly under said SUP; and   wherein said right attachment structure further includes a right articulated joint;   a left thrust assembly including:   a left foot support for supporting a left foot; and   a left thrust member for applying force to water and propelling said SUP when said left foot support is moved;   wherein said left thrust member includes a flexible-thrust portion and is for attaching to said left foot support by a left attachment structure configured for extending over a left side edge of said SUP for positioning said left thrust member in water and at least mostly under said SUP; and   wherein said left attachment structure further includes a left articulated joint; and   a single pulley or four-bar mechanism for constraining said right and left foot supports to move down and up in opposite directions to each other, where moving one of said foot supports down moves the corresponding said thrust member down to propel said SUP and moves the other said foot support and corresponding thrust member up.   
     
     
         19 . A thrust assembly for a standup paddle board (SUP) comprising:
 a foot support for supporting a foot;   a thrust member including a flexible-thrust portion, said thrust member for applying force to water and propelling said SUP when said foot support is moved;   a foot-thrust attachment structure for attaching said foot support to said thrust member;   a cantilever-thrust member including a rigid-cantilever portion extending from said flexible-thrust portion, said cantilever-thrust member having a cantilever-distal end at a distal end of said rigid-cantilever portion, and having a flexible-distal end at a distal end of said flexible-thrust portion;   a cantilever-limiting structure for limiting said cantilever-distal end from moving more than a maximum distance from said SUP;   wherein said foot-thrust attachment structure and said cantilever-thrust member share an articulated joint positioned between said cantilever-distal end and said flexible-distal end; and   wherein said cantilever-thrust member is for rotating about said articulated joint for increasing speed of movement of said flexible-distal end for increasing thrust.   
     
     
         20 . The thrust assembly according to  claim 19  further comprising a joint-limiting structure;
 wherein said articulated joint includes a first link and a second link for rotating relative to each other about a joint axis; 
 wherein said foot-thrust attachment structure includes said first link, and said cantilever-thrust member includes said second link; 
 wherein said joint-limiting structure includes at least one of said first link and said second link; and 
 wherein said joint-limiting structure is for limiting said second link from rotating more than a maximum angle relative to said first link about said joint axis.