Abstract:
The modular boat has an improved assembly which is more compact when disassembled and is more solid when assembled. The boat comprises two side cockpit members, a transverse bow member, a transverse stern member and a middle member covering an opening between the side members. The side members each provide a middle portion of a hull with the bow portion and stern portion of each hull being provided by the bow member and the stern member respectively.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a modular boat. More particularly the present invention relates to a modular catamaran or twin hull boat. 
     BACKGROUND OF THE INVENTION 
     Collapsible and modular water crafts are known in the art for the purposes of providing small pleasure craft able to be transported more easily in a disassembled form and reassembled before use. It is known to provide hull constructions in which independent floating hull sections are assembled to form a larger continuous hull as is disclosed in the June 1954 issue of Popular Science at page 121 and in Dutch patent publication NL 7,802,634. It is also known in British patent publication GB 2,119,721 to build a catamaran in which bow and stern portions of each pontoon or hull are connected together to form a pair of floats. The floats are then interconnected by a member which supports a seat. 
     In the prior art configurations, the modules making up the boat are not very compact as individual units, and transport of the boat before assembly requires the transport of one or more elements of relatively large dimensions. 
     SUMMARY OF THE INVENTION 
     The present invention provides a modular twin hull boat for two persons in which each hull is formed of three portions, namely a middle portion, a bow portion and a stern portion, the three portions being connectable together to provide a continuous hull. When the middle portion includes a cockpit by providing the hull in three portions, the boat is given good buoyancy while reducing the length of the middle portion to as little as the required length for receiving the person in the cockpit, with the bow and stern portions add greater buoyancy. 
     According to the invention there is provided a modular twin hull boat for two persons comprising two elongate side members each providing a middle portion of a hull, bow means connectable to a bow side of the side members for providing a bow portion of the hull continuous with the middle portion, stern means connectable to a stern side of the side members for providing a stern portion of the hull continuous with the middle portion, and means for connecting the side members together and to the bow means and the stern means with the side members parallel and separated. 
     Preferably, the side members include a cockpit for receiving a person, and the connecting means provided between the side members and the stern means include an upper flange provided on the side members for engagingly resting on a lower flange of the stern means, so that the buoyancy of the stern means causes the upper and lower flanges to engage one another. According to another preferred feature of the invention, the bow means and the stern means each comprise integral members including an upper transverse member, a length of said transverse members and a length of the two side members being approximately equal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood by way of the following non-limiting detailed description of a preferred embodiment with reference to the drawings in which: 
     FIG. 1 is a side view of a pedal boat according to the preferred embodiment; 
     FIG. 2 is an exploded view of the side bow and stern float members according to the preferred embodiment; 
     FIG. 3 is a detailed view of the connecting dovetail joint between one side member and the stern member; 
     FIG. 4 is a perspective view of the assembled twin hull with the middle member being installed; and 
     FIG. 5 is a detailed lengthwise section illustrating the attachment of the middle member to the stern member. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the preferred embodiment, the modular twin hull boat (10) is made up of three basic modules (FIG. 1), namely a middle side member (22), a bow member (20) and a stern member (24) which together form two unitary hulls (12). The boat (10) is a leisure pedal boat, and a middle member (14) is provided which can house pedals and a paddle system (not shown). As shown in FIG. 2, each side member (22) includes a seat (16) and a pedal footwell provided inside a cockpit of each side member (22). A twin dovetail connection (30) is provided for connecting the stern side of the side members (22) to stern member (24), and similarly a bow side of side members (22) is connected to bow member (20). 
     As shown in FIG. 3, the dovetail connection includes upper dovetail tenons (32&#39;) fitting into upper dovetail mortises (34&#39;) and lower dovetail tenons (32) fitting into lower dovetail mortises (34). In this way, tenons (32&#39;) rest upon tenons (32) as member (22) is plugged vertically onto member (24). Tenons (32&#39;) act as an upper flange and tenons (32) act as a lower flange such that the upper flange rests upon the lower flange in such a way that the buoyancy of member (24) causes the lower flanges to engage the upper flanges. A side connecting member (36) is placed through an appropriate bore (40) provided in members (22) and (24) which keeps the upper and lower flanges together once fastened by bottom bolt (38). Similar connection means are provided for connecting the side members (22) to bow member (20) except that the mortises (34) of member (22) are on top. 
     With reference to FIGS. 4 and 5, one can see that hulls (12) are interconnected by bow member (20) and stern member (24) with an opening (26) provided therebetween. The opening (26) between members (20) and (24) is covered by member (14) which has a rearward projection (42) which engages from underneath a recess in an upper member interconnecting the two hull portions of member (24), and member (14) also has side edges (44) which rest on upper lips (46) of the inner sides of members (22). 
     When assembling boat (10), stern member (24) is placed first on the ground and side members (22) are connected thereto. Middle member (14) is placed with projection (42) inserted into the recess of stern member (24) and lowered so that side grooves (44) fit over rounded edges (46). Bow member (20) is then placed over members (22) and (14), with projection (42&#39;) being received by a recess (not shown) in bow member (20). 
     With fasteners (36) and (38) connected at the bow, the boat (10) is assembled. To make the interconnection more solid, fasteners (36) and (38) are provided at the stern, and a bolt interconnecting member (14) to bow member (20) may be provided for a central connection. 
     It can be appreciated that the specific arrangement according to the preferred embodiment provides a solidly connected assembly with a minimum number of components. 
     The upper members of bow member (20) and stern member (24) have flat upper deck surfaces which can be used as a small deck surface or raft for swimmers. 
     All of members (14) (22) (20) and (24) can be molded from plastic using blow molding or rote-molding techniques whereby the members are watertight floats as individual components. In the preferred embodiment, the length, width and height of members (14) (20) (22) and (24) are approximately equal such that boat (10) can be shipped in five boxes of approximately the same size and shape, or the modular components can be more densely packed in a larger shipping container. 
     Although the connection (30) has been illustrated in the preferred embodiment as comprising dual dovetail joints, it is to be understood that other connections are possible. For example, the upper dovetail tenons may be replaced by a single upper flange contacting a single lower flange (32) provided that another connector such as member (36) or the like is used to keep members (22) and (24) fastened together. Although the members (20) and (24) are shown to include upper deck surfaces interconnecting the hulls (12) together, it would be possible to interconnect hulls (12) by means of another member such as middle member (14) alone.