Abstract:
A personal watercraft ( 10 ) comprises a floatation platform ( 12 ) and a separate module ( 14 ) including a water propulsor driving crank mechanism ( 22 ) and a keel ( 38 ) mounting the water propulsor. The separate module ( 14 ), when mounted to the platform ( 12 ), extends at right angles to the platform with the keel ( 38 ) and propeller ( 40 ) extending below the platform ( 12 ) and the propulsor driving crank mechanism ( 22 ) extending above the platform. The separate module ( 14 ) is readily separable from the platform ( 12 ) for ease of storage and transport.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation of International Application No. PCT/CA2007/002120 filed Nov. 22, 2007, designating the United States, which itself claims priority on U.S. provisional application No. 60/866,977 filed Nov. 22, 2006, the specifications of both of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to manually operated watercrafts and particularly to a watercraft that resembles a bicycle on water. 
     BACKGROUND 
     Pedal operated, propeller driven watercrafts are well known. For instance U.S. Pat. No. 5,374,206 Gregory, 1994; U.S. Pat. No. 5,405,275 Schlangen et al, 1995; U.S. Pat. No. 5,718,611 Schlangen et al, 1998; and U.S. Pat. No. 6,146,218 White, 2000 are all bicycle type watercraft having a bicycle frame mounted between a pair of pontoons or floats. U.S. Pat. No. 6,231,408 Lekhtman is also a multi-hull watercraft with a pedal and propeller mechanism integrated therein. 
     It has been found that such watercrafts, although acceptable, are somewhat cumbersome in transport. By definition the pontoons take up a fair area in width and the nature of the bicycle frame on the floats increases the height of the vehicle. Thus it is not easy to package, ship or to handle, once in the water or for storage on land. 
     SUMMARY 
     An embodiment of the present invention comprises a personal watercraft comprising a floatation platform, having sufficient buoyancy and lateral stability to support at least one person and a separate module including a water propulsor driving crank mechanism and a keel mounting the water propulsor; the separate module when mounted to the platform extends at right angles to the platform with the keel and propulsor extending below the platform and the propulsor driving crank mechanism extending above the platform, and the separate module being readily separable from the platform for storage and transport. 
     A more specific embodiment of the invention includes a watercraft comprising a floatation platform, having a bow, stern, port and starboard sides, the platform having sufficient buoyancy and lateral stability to support at least one person and a bicycle frame. The bicycle frame extends in the longitudinal axis between the bow and the stern and the bicycle frame is readily separable from the platform for storage and transport. 
     In a specific embodiment of the present invention the floatation platform defines an opening between the bow and stern. The bicycle frame extends in the longitudinal axis between the bow and the stern and through said opening in the platform and whereby the bicycle frame is readily separable from the platform for storage and transport. 
     In a more specific embodiment of the present invention the floatation platform is a first module and the bicycle frame includes a keel adapted to extend below the hull and a propeller is operably mounted abaft the keel. The bicycle frame including the keel represents a second module wherein the first and second modules are separable for transport. 
     More specifically the keel may house the propeller shaft and pedal-mechanism for manually driving the shaft and is integral with the remainder of the bicycle frame. 
     The term propulsor or water propulsor is meant to define a water propeller, paddle system or any other propulsion system capable of being driven by a manual crank mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the watercraft; 
         FIG. 2  is a side elevation of the watercraft shown in  FIG. 1 ; 
         FIG. 3  is front elevation of the watercraft in accordance with  FIG. 1 ; 
         FIG. 4  is an exploded view of the watercraft of  FIG. 1 ; 
         FIG. 5  is a perspective of a detail of the watercraft including the bicycle and keel; 
         FIG. 6  is a partial perspective view of a further embodiment of a detail of the watercraft; and 
         FIG. 7  is a schematic view of a gearbox, within the keel. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIGS. 1 to 3  the assembled watercraft  10  includes a hull or flotation platform  12  and a bicycle frame  14  adapted to be mounted to the hull platform  12 . In the depicted embodiment, the flotation platform comprises a mono-hull; however the floatation platform could also be a multi-hull such as a catamaran or trimaran. 
     The hull  12  has a bow B, a stern S, a starboard side St and a port side P. The hull  12  includes a longitudinal slot  16  as best seen in  FIG. 4 . The slot  16  may have different shapes. The hull  12  is light weight, buoyant and has dimensions that are only sufficient, depending on the material used, to float while supporting a person mounted to the bicycle frame  14 . The hull  12  may have larger dimensions; however the speed of travel will be compromised as the wettable area is increased. The material can be any known mouldable material used for floats, and formed by blow-moulding or by a mould known as Rotomould™. The hull could also be formed with a porous core and a fibreglass skin or other buoyant material. The material must be of sufficient structural strength to support the bicycle frame in an upright position. 
     The bicycle frame  14  is mounted to a beam  42  that is adapted to fit in the slot  16  of the hull  12 . If the slot  16  has a different shape than the elongated slot shown in the drawings, the bicycle frame  14  and beam  42  will have a corresponding shape. The beam  42  will include fasteners (not shown) to lock the bicycle frame  14  in a fixed position to the hull  12  when assembled. The bicycle frame  14  includes a post  32  mounting a cantilevered beam  15  extending aft, above and parallel to the beam  42  as well as a tubular base member  43  attached to the beam  42 . A brace  34  may be provided between the column  32  and the beam  15 , as shown. A seat  18  is mounted to a carriage  18   a  that slides on track  18   c  that is fixed to the beam  15 . A backrest  19  is mounted to the carriage  18   a  by means of a vertical support  36 . Thus the seat  18  can slide on the beam  15  in order to adjust the position of the seat  18 . 
     The forward portion of beam  15  mounts a bushing  20   a  that supports steering column  20  for rotation about the axis of the bushing  20   a . A handle bar  28  is fixed to the upper reaches of the steering column  20 . In the present embodiment the steering column  20  is made up of a pair of parallel tubes as shown. 
     Referring to  FIGS. 4 and 7 , a further cantilevered beam  30  extends forward of the column  32  and mounts a pedal assembly  22 . The frame also includes a base tube  43  for added structural support, which extends rearwardly from the column  32  and is mounted to beam  42 . The pedal assembly includes a sprocket  24  and a chain  26 . The chain  26  drives a sprocket  37  in the gearbox  49  formed in the keel  38 . An elongated bore  62  extends within the keel from the gearbox  49  to the propeller  40 . A worm and sprocket gear combination  50  is associated with the sprocket  37  to drive the shafts  51 ,  54  and  56 . The segmented shafts  51 ,  54  and  56  are joined by universal joints  52  and  55 . A plastic bearing  60  completes the support for the shaft. In this case the pedal assembly  22  is mounted on the upper part of the bicycle frame but it could also form part of the keel. 
     It is also contemplated that instead of an elongated slot, a bore could extend through the hull  12 . The bicycle module could be in the form of a vertical pod mounted on a rotatable plate seated on the hull  12  over the bore. Thus the steering of the watercraft could be provided by the person operating the watercraft by simply rotating to the new direction of movement desired. 
     The upper part of the bicycle frame  14  may be made of lightweight metal tubing such as extruded aluminium, or other well known materials for constructing road-bicycle frames. 
     The keel  38  is one piece with the beam  42  and is adapted to extend below the hull  12  as shown in  FIG. 2 . The keel  38  and beam  42  may be moulded as one-piece by thermoforming, by a Rotomould™ process or other inflatable based technology. In the present embodiment the keel  38  is moulded fibreglass. A rudder  39  is pivotally mounted to the beam  42  as shown in  FIGS. 2 and 5 . As shown in  FIG. 5 , the rudder  39  is controlled by Bowden cables  21  extending between a sprocket  42  and the steering column  20 . 
     As can be seen in  FIGS. 4 and 5  the bicycle frame  14  including the keel  38  is an integral unit. As shown in  FIG. 4 , the bicycle frame  14  including the keel  38  is presented as a one-piece, narrow module, which can be inserted through the slot  16  in the hull  12 . During shipping, the two modules: the bicycle frame  14  and the hull  12  are packaged independently to occupy minimum volume. The two modules are easily assembled for use, by merely placing the hull  12  in shallow water and then inserting the bicycle frame  14  through the slot and fastening the beam  42  to the hull  12  when it is coincident with the slot. When it is required to transport the watercraft  10  after use, the bicycle frame  14  module is removed and stored in the luggage space of a vehicle while the hull  12  module may be strapped to the roof of the vehicle. To reduce the possibility of the propeller  40  interfering when the bicycle frame  14  module is being removed, an arrow  44  or other indicator may be located near the pedal crankshaft  22   a  to coincide with the alignment of the propeller with the keel to allow removal of the module  14  through the slot  16 . 
     In another embodiment, as shown in  FIG. 6 , the sprocket  137  includes parallel sidewalls  137   a  to prevent the chain from derailing. 
     The embodiments of the invention described above are intended to be exemplary. Those skilled in the art will therefore appreciate that the forgoing description is illustrative only, and that various alternatives and modifications can be devised without departing from the spirit of the present invention. Accordingly, the present is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.