Abstract:
A collapsible boat comprising forward and aft hull sections, each of which comprising a plurality of longitudinal frame members and transverse cross members. The frame members are joined into longitudinal alignment by sliding a male end of a frame member into a complimentary female end of an adjacent frame member. The frame members are also interconnected to the cross members at a plurality of connector portions to create the forward and aft hull sections. Interlocking mechanisms are used to join together the forward and aft hull sections to define a hull framework having elongate frame members that extend longitudinally between a bow and stern and that are spaced and braced by transversely extending cross members. A variable tensioning mechanism permits variation of the elevation of the bow and stem of the framework by adjusting the overall length of the elongate frame members. The framework is insertable into a flexible water impermeable skin to create a boat with adjustable handling characteristics suitable for use in a wide variety of water conditions and environments. The water impermeable skin is provided with one or more water resistant hatch for loading and unloading of the collapsible boat, and a central cockpit opening having a removable coaming and a resealable deck slit to provide for an enlarged opening through which the forward and aft hull sections may be inserted in assembling the framework.

Description:
FIELD OF THE INVENTION 
     This invention relates to a collapsible boat in which a skin or shell of waterproof material covers a collapsible internal framework of rigid members. 
     BACKGROUND OF THE INVENTION 
     Collapsing or foldable boats such as kayaks or canoes are well known and have been commercially available for many years. The following patents, for example, disclose water craft that are designed to be collapsed from a watergoing form into a relatively compact form for storage and/or transportation: U.S. Pat. No. 389,817 to King; U.S. Pat. No. 1,649,311 to Kaechele; U.S. Pat. No. 2,415,495 to Humphreys; U.S. Pat. No. 3,123,841 to Bronner; U.S. Pat. No 3,869,743 to Brown; U.S. Pat. No, 4,004,307 to Hermann; U.S. Pat. No. 4,057,865 to Trautwein; U.S. Pat. No. 4,274,170 to Simpson; U.S. Pat. No. 4,407,216 to Masters; U.S. Pat. No. 4,480,579 to Masters; U.S. Pat. No. 4,841,899 to Fleckles; and U.S. Pat. No. 5,875,731 to Abernethy et al. 
     SUMMARY OF THE INVENTION 
     In one aspect, the invention provides a collapsible boat comprising forward and aft hull sections, each of which comprising a plurality of longitudinal frame members and transverse cross members. The frame members are joined into longitudinal alignment by sliding a male end of a frame member into a complimentary female end of an adjacent frame member. The frame members are also interconnected to the cross members at a plurality of connector portions to create the forward and aft hull sections. Interlocking mechanisms are used to join together the forward and aft hull sections to define a hull framework having elongate frame members that extend longitudinally between a bow and stern and that are spaced and braced by transversely extending cross members. A variable tensioning mechanism permits variation of the elevation of the bow and stern of the framework by adjusting the overall length of the elongate frame members. In some embodiments, the present invention accordingly provides a vessel that may be adapted to handle different water conditions by allowing the user to vary the rocker while in the boat, without having to paddle to shore to make the adjustments. The framework is insertable into a flexible water impermeable skin to create a boat with adjustable handling characteristics suitable for use in a wide variety of water conditions and environments. The water impermeable skin is provided with one or more water resistant hatches for loading and unloading of the collapsible boat, and a central cockpit opening having a removable coaming and a resealable deck slit to provide for an enlarged opening through which the forward and aft hull sections may be inserted in assembling the framework. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of a folding kayak in accordance with one embodiment of the invention. 
     FIG. 2 is side elevational view of a folding kayak of the invention, showing the internal framework. 
     FIG. 3 is a cross-sectional view along the section indicated by arrows in FIG.  2 . 
     FIG. 4 is a partially broken away cross-sectional side view of a connection between frame members, showing the members fully engaged. 
     FIG. 5 is a partially broken away cross-sectional top view of a connection between frame members, showing the members partially engaged. 
     FIG. 6 is a partially broken away cross-sectional front view of a connection between frame members, showing the members partially engaged. 
     FIG. 7 is a top plan view of a tension mechanism of the invention. 
     FIG. 8 is a cross-sectional view of a tension mechanism along the line shown by arrows in FIG.  7 . 
     FIG. 9 is a partially broken away top plan view of a cockpit opening, showing a slit in the skin of the kayak in a closed configuration. 
     FIG. 10 is a partially broken away top plan view of a cockpit opening, showing a slit in the skin of the kayak in a partially open configuration. 
     FIG. 11 is a partially broken away top plan view of a cockpit opening, showing a slit in the skin of the kayak in an open configuration. 
     FIG. 12 is a partially broken away cross-sectional view of the sealing mechanism for sealing a slit in the skin of the kayak, along the line shown by an arrow in FIG.  9 . 
     FIG. 13 is a partially broken away cross-sectional view of a coaming member and associated apparatus used to form a cockpit opening, along the line shown by an arrow in FIG.  9 . 
     FIG. 14 is a side elevational view of a kayak, showing no rocker or keel curvature. 
     FIG. 15 is a side elevational view of a kayak, showing rocker and keel curvature. 
     FIG. 16 is a side elevational view of a kayak, showing rocker and keel curvature. 
     FIG. 17 is a top plan view of a lid for a hatch. 
     FIG. 18 is a cross-sectional view showing a lid for a hatch, along the section line shown by an arrow in FIG.  17 . 
     FIG. 19 is a top plan view of a hatch opening, showing top and bottom hatch portions defining the hatch opening. 
     FIG. 20 is a cross-sectional view showing the top and bottom hatch portions defining the hatch opening, along the section line shown by an arrow in FIG.  19 . 
     FIG. 21 is a cross-sectional side view showing the hatch lid and hatch portions assembled on the hatch opening, showing the hatch lid in phantom lines in an open configuration. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, there is shown a kayak  2  and a kayak internal framework  4  constructed according to a preferred embodiment of the present invention. In FIG. 1, the framework  4  is covered by a flexible water impermeable layer or skin  6  that conforms closely to the shape of the framework. The kayak  2  has a bow  10  and a stem  12  and a central cockpit  14 . 
     Internal framework  4  comprises a forward hull section  16  and an aft hull section  18 , each hull section has elongate longitudinal members including forward and aft keel members  22  and  24 , port and starboard forward gunwale members  26  and  28  and port and starboard forward stringer members  30  and  32 . As best shown in the hull cross-section of FIG. 3, the framework also includes port and starboard aft gunwale member portions  34  and  36  and port and starboard aft stringer members  38  and  40 . 
     The longitudinal keel, gunwale and stringer members are formed from a plurality of longitudinal frame members  42  that are connected end to end at connection  44  to form the elongate longitudinal members that define forward and aft hull sections  16  and  18 , respectively, Cross members  50  extend transversely between the elongate longitudinal members at connections  44  to brace and space the longitudinal members. In the kayak configuration illustrated, forward and aft elongate deck members  52  and  54 , respectively, are also provided between forward and aft port and starboard gunwale member portions  26 , 28  and  34 , 36  to support skin  6  over the top of the framework. It will be readily apparent to those skilled in the art that the framework structure of the present invention is not limited to use in a kayak. The internal framework of the present invention can be readily designed to define the hull of other small water vessels such as a canoe. However, for the purposes of illustration only, the embodiment described is a kayak. 
     Forward and aft hull sections  16  and  18  include a bow or stem plate  56  and  58 , respectively, to which the gunwale, stringer and deck members are releasably fastened. Plates  56  and  58  are preferably rigidly attached by welding to the ends of the outermost keel member portions  22  and  24  respectively. The plates are suitably shaped to define a smoothly rounded bow and stem to the kayak beneath skin  6 . Adjacent keel, gunwale, deck and stringer member portions for connection end-to-end are preferably joined by elastic cords (not shown) so that the various member portions can remain connected by the cords when the framework is collapsed into component parts to prevent losing parts. All the longitudinal members and cross-rib members are preferably aluminum alloy tubes selected for their lightweight, strength and corrosion resistance. 
     The forward and aft hull sections  16  and  18  are joined in the cockpit region of the kayak by an interlocking mechanism  62 , or by a variable tension mechanism  64 , that joins together corresponding keel, gunwale and stringer members from the forward and aft hull sections. A variable tension mechanism  64  may be provided for all elongate frame members but it will be readily apparent to those skilled in the art that the necessary adjustments may be accomplished by three tensioning mechanisms: one between forward and aft keel members  22  and  24 , one between forward and aft starboard gunwale members  28  and  36 , and one between forward and aft starboard gunwale members  28  and  36 , and one between forward and aft port gunwale members  26  and  34 . The variable tension mechanism  64  permits variation of the elevation of the bow and stem of the framework by adjusting the overall length of the gunwale and/or the keel members as will be described. Port and starboard forward and aft stringer members  30 ,  32  and  40  may be respectively joined together by interlocking mechanism  62 . The result is an assembled framework as illustrated in FIG. 2 that defines a hull having elongate keel, gunwale and stringer members that extend longitudinally between bow  10  and stem  12  and that are spaced and braced by the transverse cross members  50 . 
     Referring to FIG. 4,  5  and  6 , there is shown a detail view of a typical connection  44  for joining various longitudinal frame members end to end and to transverse cross members  50 . Each connection  44  comprises an end of a first portion  70  of a frame member having a male end  72  and an adjacent end of a second portion  74  of an adjacent frame member having a complementary opening or female end  76  to receive the male end therein. The cross members  50  have a plurality of connector portions  80  spaced around the periphery of the cross member&#39;s peripheral edge  82 . The connector portions  80  of the cross member  50  comprises a projection  84  having a shaft  86  and an enlarged end  88  which may be inserted into a first opening  90  in the second portion  74  of frame members  42 . Cross member  50  is secured to frame member  42  by inserting the projection  84  into a first opening  90  and then inserting male end  72  of an adjacent frame member Into the female end  76  in direction  77  so that the male end of the adjacent frame member engages the enlarged end  88  of projection  84 . The male end  72  may be provided with a longitudinal slot dimension to fit around shaft  86  so as to engage enlarged end  88  more fully. In the preferred embodiment, it is necessary to lock together the male and female portions of each connection  44  to reduce the possibility of the frame members becoming unintentionally separated from each other. In FIGS. 4 and 5, a locking mechanism is illustrated comprising a second opening  92  in female end and a depressible protrusion or button  94  on the male end that is spring biased  96  to protrude outwardly from the male end. When male end  72  is inserted into female end  76 , button  94  extends into second opening  92  to lock the male and female ends together on alignment of second opening  92  and button  94 . 
     Referring to FIGS. 7 and 8, there is shown the variable tension mechanism  64  of the present invention. Tension mechanism  64  is telescoping so that it is insertable between and connectable to forward and aft longitudinal members. Tension mechanism  64  includes a telescoping member  100  comprising an outer tube  102  with a first end  104  and a second end  106  that is insertable into the female end of a frame member from the forward or aft hull sections that extends into the central cockpit region  60  of the framework. Telescoping member  100  also includes an inner tube  108  slideable within the outer tube and extending from the first end  104  of the outer tube  102 , and having an end  110  being insertable into the female end of an adjacent frame member from the forward or aft hull sections that extends into the central cockpit region  60  of the framework. Such female end of frame members from forward or aft frame sections is provided with a stop, the structure of which would be apparent to a person skilled in the art, to limit the distance that ends  104  and  110  may be inserted into the female end. A rod  112 , preferably formed with a ratcheted surface  114 , is movably disposed within the outer tube of the telescoping member and having one end  116  connected to the inner tube  108 . An actuator in the form of a guide  120  is provided about rod  112  and connected to the outer tube  102  by an arm  122 . A lever  124  is connected to the arm  122  by pivot  126 . Lever  124  includes a pin  128  and a dog  130  that is engageable with the ratcheted surface  114  of the rod  112  to move the rod and inner tube in the direction  132  to extend the telescopic member  100 . As lever  124  is raised in direction  134  about the pivot  126 , the pin  128  pushes the top portion of dog  130  in direction  132  which engages the ratcheted surface of the rod forcing the rod in direction  132 . Rod  112  is free to move in direction  132  through opening  144  in locking member  140 . When lever  124  is lowered in a direction opposite to direction  134 , spring  142  acts on the locking member  140  causing it to pivot such that opening  144  is misaligned with rod  112  and the opening engages the ratcheted surface  114  thereby acting as a lock on the rod preventing the rod from moving counter to direction  132 . As the lever  124  is lowered, spring  146  acts on dog  130  which slips back on the rod to its starting position. To disengage locking member  140  to allow the telescoping member  100  to shorten, locking member  140  has a handle  148  by which the locking member is pivoted to align hole  144  with rod  112  such that member  140  is disengaged from the ratcheted surface. When the handle  148  is moved in direction  149 , rod  112  is thereby allowed to move in a direction opposite of direction  132 . 
     When assembling the collapsible kayak of the present invention, the forward and aft hull sections  16  and  18  are constructed initially and inserted into the ends of skin  6  as illustrated in FIG.  1 . Referring to FIG. 9 through 13, skin  6  has a central cockpit opening  200  and a deck slit  202  extending from the cockpit opening  200  to allow for enlargement of the cockpit opening to permit the hull sections to be inserted into the skin. The skin  204  adjacent the cockpit opening  200  has a collar  206  attached thereto with an enlarged edge  208 . The comers  210  and  212  located where the deck slit  202  converges with the cockpit opening have fasteners  214  and  216  that are connectable with one another. As well, the skin  218  adjacent the deck slit has sealing portions  220  and  222  with enlarged edges. Once the forward and aft hull sections are inserted into skin  6 , the corresponding forward and aft keel members, gunwale members and stringer members of each hull section are connected by interlocking mechanism  62  or variable tension mechanism  64 , as the case may be. The variable tension mechanism  64  is maintained in place by the inwardly acting longitudinal forces resulting from the tension of the skin  6  acting on the framework  4 . A rigid annular coaming member  224  is then inserted into the cockpit opening  200 . The coaming member  224  has a central body  226  dimensioned for a close fit within the cockpit opening, and top and bottom portions  228  and  230  radiating outwardly from the central body such that a cross section of the coaming member generally defines a “U”-shape and forms a channel  232  around the periphery of the coaming member. The collar  206  is drawn around the channel  232  of the coaming member  224  and fasteners  214  and  216  are drawn towards each other and connected. The sealing portions  220  and  222  are drawn together and a sealing mechanism, in the preferred embodiment, an elongated member  234  having a longitudinal channel  236  and inwardly extending flange portions  238  and  240  along the length of the channel, is slid over the sealing portions to engage the enlarged edges and maintain them in contact with each other to form a waterproof seal. 
     The variable tension mechanisms operate to change the length of the keel, gunwale or stringer members. As the gunwale length shortens, the bow  10  and stern  12  of the boat rise thus increasing the rocker or curvature of the keel. The shorter the gunwale length, the higher the bow  10  and stern  12  and the greater the rocker. FIG. 14 shows a kayak with no rocker or keel curvature which is appropriate for flat water conditions to assist in keeping the kayak travelling in a straight line. FIGS. 15 and 16 show different rocker positions with an increasingly curved keel. In general, the greater the curvature or rocker of the keel, the greater the turning ability of the kayak hull. Furthermore, by lengthening or shortening one gunwale member in relation to the other gunwale member the lateral curvature of the kayak may be adjusted to give the kayak a tendency to yaw to one side. The ability to adjust the yaw of a kayak is advantageous in compensating for the tendency of the kayak to drift laterally in a cross-wind or cross-current. 
     Also provided in the present invention is one or more hatches  250  in the skin to allow for more convenient loading of gear into the hull of the kayak. Referring to FIGS. 17 through 21, the deck portion of the skin  6  has a hatch opening  252 . Around the hatch opening  252  is an annular top hatch portion  254  having a material contact surface  256  dimensioned for conformable contact with the outer surface  258  of the skin adjacent the hatch opening. On the inner surface  260  of the skin  6  is an annular bottom hatch portion  262  dimensioned for a conformable fit with the contact surface  256  of the top hatch portion  254  and the inner surface  260  of the skin adjacent to the hatch opening  252 . The top and bottom hatch portions  254  and  262  with the skin  6  sandwiched therebetween are connected to one another by a plurality of connectors  264  extending between the top hatch portion and the bottom hatch portion. The top batch portion  254  also has a lid end  266  opposite the contact surface  256  that has a flange  268  extending radially therefrom such that a cross section of the top hatch portion tends to resemble an inverted “L”. The hatch  250  also includes a lid  270  dimensioned for a conformable and generally waterproof fit over the top hatch portion  254  and having an engaging end  272  with a flange  274  extending downwardly and inwardly which engages the flange  268  on the top hatch portion  254 . The lid  270  also has a locking end  276  opposite the engaging end and having a locking mechanism comprising an actuator such as a dial  280  seated in a depression  282  in the lid and a portion  284  of the dial  280  extending through a hole  286  in the lid to engage a latch portion  290  that is movably mounted on the inner surface of the lid. The actuator engages the latch causing it to move between a first position in which the latch portion does not impede the removal of the lid from the hatch, and a second position in which the latch portion engages the hatch so as to impede the removal of the lid from the hatch. Also, in the preferred embodiment, the latch portion  290  has a leading edge that tapers to a thicker trailing edge so that the leading edge engages the hatch prior to the trailing edge as the latch portion is moved from first position to second position thereby gradually increasing the locking tension on the lid. 
     Although the present invention has been described in some detail by way of example for purposes of clarity and understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Many adaptations and modifications may be made within the scope of the invention in accordance with the common general knowledge of those skilled in this art. Such modifications include the substitution of known equivalents for any aspect of the invention in order to achieve the same result in substantially the same way. Numeric ranges are inclusive of the numbers defining the range. In the claims, the word “comprising” is used as an open-ended term, substantially equivalent to the phrase “including, but not limited to”.