Watercraft propelled with tread force

Abstract

A watercraft propelled with tread force includes a buoyant hull. A seat unit is mounted on the hull. A propulsion device is arranged to propel the hull. A manually operated apparatus is arranged to power the propulsion device. The manually operated apparatus is disposed in front of the seat unit and comprises a slide mechanism that includes a pair of pedals slideable with tread force alternately given to each one of the pedals by a rider in the seat unit.

What is claimed is:  
     
         1 . A watercraft comprising a buoyant hull, a seat unit mounted on the hull, a propulsion device arranged to propel the hull, and a manually operated apparatus arranged to power the propulsion device, the manually operated apparatus being disposed in front of the seat unit and comprising a slide mechanism including a pair of slideable pedals.  
     
     
         2 . The watercraft as set forth in  claim 1 , wherein the propulsion device includes a rotatable member, the manually operated apparatus additionally comprising a converting mechanism arranged to convert a sliding movement of the pedals to a rotational movement of the rotatable member.  
     
     
         3 . The watercraft as set forth in  claim 2 , wherein the converting mechanism includes an output shaft extending rearwardly, the propulsion device includes a propulsion shaft on which the rotatable member is mounted, both the output shaft and the propulsion shaft are coupled together in the rear of the seat unit.  
     
     
         4 . The watercraft as set forth in  claim 2  additionally comprising a power assist unit, the converting mechanism including an output shaft extending rearwardly, the propulsion device including a propulsion shaft on which the rotatable member is mounted, the power assist unit being interposed between the output shaft and the propulsion shaft.  
     
     
         5 . The watercraft as set forth in  claim 4 , wherein the power assist unit includes an electric motor, and a planetary transmission arranged to join a power of the electric motor to an output power of the converting mechanism.  
     
     
         6 . The watercraft as set forth in  claim 5 , wherein the power assist unit additionally includes a clutch to either connect or disconnect the power of the electric motor with the output power of the converting mechanism.  
     
     
         7 . The watercraft as set forth in  claim 5 , wherein the power assist mechanism is disposed in the rear of the seat unit.  
     
     
         8 . The watercraft as set forth in  claim 4  additionally comprising at least one battery to supply electric power to the motor, the battery being disposed next to the power assist unit.  
     
     
         9 . The watercraft as set forth in  claim 8 , wherein the battery is disposed on a lateral side of the power assist unit.  
     
     
         10 . The watercraft as set forth in  claim 4  additionally comprising at least two batteries to supply electric power to the motor, the power assist unit being disposed on a center plane of the hull extending fore to aft perpendicularly, each one of the batteries being disposed on each lateral side of the power assist unit.  
     
     
         11 . The watercraft as set forth in  claim 4  additionally comprising at least one battery to supply electric power to the motor, and both the power assist unit and the battery are disposed on a center plane of the hull extending fore to aft perpendicularly.  
     
     
         12 . The watercraft as set forth in  claim 2 , wherein the slide mechanism includes a pair of guide rails extending fore to aft of the hull and generally in parallel to each other, the pedals being slideable back and forth along the guide rails.  
     
     
         13 . The watercraft as set forth in  claim 12 , wherein the converting mechanism includes an output shaft and a pivot shaft connected to the output shaft, the manually operated apparatus additionally including a flexible transmitter coupled with both of the pedals and with the pivot shaft so that the pivot shaft pivots along with the sliding movement of the pedals.  
     
     
         14 . The watercraft as set forth in  claim 13 , wherein the converting mechanism additionally includes a one-way transmission arranged to couple the pivot shaft with the output shaft.  
     
     
         15 . The watercraft as set forth in  claim 14 , wherein the one-way transmission includes a combination of bevel gears with the pivot shaft and the output shaft, and a clutch unit disposed between the bevel gears and the output shaft.  
     
     
         16 . The watercraft as set forth in  claim 12 , wherein the converting mechanism includes an output shaft, and first and second pivot shafts interposing the slide mechanism therebetween, the manually operated apparatus additionally includes an endless flexible transmitter coupled with both of the pedals and wound around both of the first and second pivot shafts so that the first pivot shaft pivots with the slide movement of the pedals, the first pivot shaft being connected to the output shaft.  
     
     
         17 . The watercraft as set forth in  claim 1 , wherein the slide mechanism includes a pair of guide rails extending fore to aft of the hull and generally in parallel to each other, the pedals being slideable back and forth along the guide rails.  
     
     
         18 . The watercraft as set forth in  claim 1  additionally comprising at least one sponson linked with the hull, the sponson being moveable between a fully retracted position and a fully extended position.  
     
     
         19 . The watercraft as set forth in  claim 1 , wherein the seat unit includes a backrest, and a top end of the backrest is generally positioned lower than an uppermost surface of an upper deck of the hull.  
     
     
         20 . The watercraft as set forth in  claim 1 , wherein a location of the seat unit is adjustable between a fully forward position and a fully rearward position.  
     
     
         21 . The watercraft as set forth in  claim 1 , wherein the hull has a configuration elongated along a center plane extending fore to aft perpendicularly, the slide mechanism extends generally in parallel to the center plane, and each one of the pedals is separated from one another by the center plane.  
     
     
         22 . A watercraft comprising a hull elongated along a center plane extending fore to aft perpendicularly, a propulsion shaft journaled for rotation in the rear of the hull and extending generally on the center plane, a propeller disposed at the end of the propulsion shaft, and a manual drive unit disposed within the hull and configured to convert linear tread force to rotational force that rotates the propulsion shaft.  
     
     
         23 . The watercraft as set forth in  claim 22 , wherein the manual drive unit includes a pair of pedals slideably disposed along the center plane so that a rider can alternately push each one of the pedals with the rider's feet.  
     
     
         24 . The watercraft as set forth in  23 , wherein the manual drive unit additionally includes a pair of guide rails extending generally in parallel to the center plane, and the pedals slide along the guide rails.  
     
     
         25 . The watercraft as set forth in  claim 23 , wherein the manual drive unit additionally includes an output shaft connected to the propulsion shaft, a pivot shaft connected to the output shaft, a flexible transmitter coupled with both of the pedals and with the pivot shaft so that the pivot shaft pivots with the sliding movement of the pedals.  
     
     
         26 . The watercraft as set forth in  claim 25 , wherein the manual drive unit further includes a one-way transmission arranged to couple the pivot shaft with the output shaft.  
     
     
         27 . The watercraft as set forth in  claim 22  additionally comprising an auxiliary drive unit configured to add additional rotational force to the propulsion shaft.  
     
     
         28 . The watercraft as set forth in  claim 27 , wherein the auxiliary drive unit includes an electric motor, and a planetary transmission configured to add rotational force of the electric motor to the rotational force of the manual drive unit.  
     
     
         29 . The watercraft as set forth in  claim 22  additionally comprising at least one sponson linked with the hull, the sponson being moveable between a fully retracted position and a fully expanded position.