Abstract:
A folding boat includes a pair of stringer tube assemblies arranged for extending longitudinally when assembled and the stringer tubes of each pair of the assemblies connected by hinges to respective adjacent stringer tubes at the hinges. The stringer tubes assemblies are received within a waterproof skin. Frame members or butterfly frame members serve to connect to the assemblies of the stringer tubes within the skin to provide a frame for the waterproof skin. Fabric inflatable tubes are located within the skin, each having a seam for having the assembled stringer tubes assemblies nestled within when assembled in the frame.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is related and claims priority to U.S. Provisional Patent Application Ser. No. 61/460,190 for “Lightweight portable folding boat with inner rigid frame that assembles quickly and easily,” filed Dec. 28, 2010, the disclosure of which is specifically incorporated in its entirety by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a folding or collapsible boat that folds easily and quickly, and is light and portable for carrying. More specifically, the invention relates to a light, portable boat that folds easily and quickly within its own skin without requiring tools to assemble or disassemble the boat. The boat preferably folds into sections (e.g., thirds) making it compact, light and easy to carry and includes inflatable tubes integrated into the structure to enhance flotation and provide protection. 
       BACKGROUND OF THE INVENTION 
       [0003]    Folding or collapsible boats are generally known and many designs have been commercially available for many years. As a general rule, most of the known prior art structures are made up of a complex arrangement of stringers and formers which are joined together with latches and clamps to form a relatively loose framework in which bow and stern halves are temporarily hinged together amidships. Typically, the two halves of the framework are disconnected and when assembled, are rigidly connected together inside a skin to form the assembled boat. Such designs of folding kayaks and boats when disassembled result in a large number of disconnected pieces and require a considerable amount of time to reassemble, and a set of tools. Moreover, the assembly requires skill and care in following instructions and it is not unusual to lose an important piece of the structure when assembled. 
         [0004]    French patent publication number 2,572,050 discloses a dismantable small craft of the canoe/kayak type which includes a hull made up of a flexible envelope held in shape and in tension by a frame consisting of a set of securely fastened tubes which can be retracted, but not taken apart. However, such a structure also includes a complicated arrangement requiring a protected tube perpendicular to the length of the craft, including screw fastenings which require assembly and disassembly with tools to fold and/or assemble the boat. 
         [0005]    An alternative design is disclosed in U.S. Pat. No. 4,274,170 which discloses a framework characterized by plural longitudinal members including forward and aft member portions, forward, aft, port, and starboard chines and gunwale member portions, and forward and aft longitudinal deck members. The framework includes a cockpit structure with longitudinal members releasably interconnecting the cockpit structure with the bow and stern of the boat. The structure disclosed therein effectively permits the cockpit structure to be folded along one axis, parallel to the midportion thereof so as to bring the midportions closer together so that the kayak can be folded into a framework suitable for use as a backpack frame. Notwithstanding this folding structure, a closer review of the patents such as, for example,  FIGS. 4-8 , shows a series of screws, wing nuts and other elements which need to be connected and disconnected resulting in a structure which is not easy to assemble or disassemble. 
         [0006]    In a further development, U.S. Pat. No. 7,383,787 of one of the co-inventors herein discloses a folding boat which includes bow and stern members made up of a pair of tubes connectable to each other through a pin mechanism. A plurality of chines extend the length of the boat and are made up of connected tubes which can be disconnected amidships. Cockpit tubes serve to define a cockpit region, and are interconnected by hinges and by pin clips to allow folding along two axes approximating one-fourth of its assembled size. 
         [0007]    While constituting an improvement over the prior art, applicants have now made certain improvements and designed a new and different lightweight portable folding boat having an inner rigid frame that assembles quickly and easily. More particularly, in accordance with the invention, a user can quickly and easily assemble and disassemble the boat since all components are contained within the boat&#39;s skin. 
       SUMMARY OF THE INVENTION 
       [0008]    In accordance with the invention, traveling with a boat is made much easier. 
         [0009]    The invention further allows a user to quickly and easily assemble and disassemble the boat. 
         [0010]    The boat of the invention can be stored within a small area and allows the user to access remote areas of water with the boat. 
         [0011]    The boat includes numerous advantages, among which is that it folds into a small package, in one example about 36 inches by about 15 inches by about 6 inches, making it very portable. 
         [0012]    Yet still another advantage is that it is easy and quick to assemble and disassemble because all of the components are contained within the boat skin. Assembly time can be as short as about three (3) to about four (4) minutes. 
         [0013]    In accordance with another aspect there are provided internal flotation tubes which may also act as shock absorbers so that the internal rigid frame and user are isolated from obstacles the boat could bump into in the water. 
         [0014]    Yet still further, coaming is provided designed to wrap closely around the user or to be unzipped allowing greater access to the inside of the boat. 
         [0015]    Even still further, multiple hinges are provided which allow the boat to be folded with the frame inside the boat skin without pinching its waterproof fabric skin. The boat is light, for example, in the range of about 11 to 14 pounds, resulting from use of lightweight and durable waterproof fabrics and high quality rigid tubing. 
         [0016]    In accordance with another advantage of the invention, a rigid internal frame is provided which gives the user a firm surface for entering or exiting the boat and allows accessories such as fishing rods, drinks, cameras, motor holders or the like to be firmly secured to the boat. Yet still further, the internal parts can be easily removed to allow for repair. The combination of rigid and inflatable tubing allows for proper alignment and tensioning of the waterproof fabric skin around the frame and no tools are needed to assemble the boat, but an air pump, such as a portable air pump, can be used to hasten assembly. 
         [0017]    The invention is a folding boat which preferably includes all components within a waterproof skin which can be easily assembled in a matter of minutes. The folding boat includes a pair of a plurality of stringer tubes arranged for extending longitudinally when assembled, and connected by hinges to respective adjacent stringer tubes at the hinges. A waterproof skin is provided for having the stringer tubes assembled therein as a frame. In one embodiment, bow tubes serve to connect one of the pair of stringer tubes assemblies to the other of the pair at a bow of the boat within the skin, and stern tubes serve to connect one of the pair of stringer tubes assemblies to the other of the pair at a stern of the boat within the skin. Frame members are provided for connecting to the pairs of the stringer tubes assemblies at spaced locations within the skin when assembled. Fabric inflatable tubes are provided within the skin, and each having a seam for having each one of the pair of plurality of stringer tubes nestled within the seam when assembled in the frame. 
         [0018]    In a more specific aspect, the plurality of stringer tubes assemblies have the tubes thereof connected by hinges located so that the boat can be folded into sections, for example into thirds. Sleeves are provided at the ends of the individual stringer tubes of the assemblies for connecting and locking the stringer tubes together. A shock cord is tensioned inside the stringer tubes to maintain the sleeves line. 
         [0019]    In a more specific aspect, frame sleeves are provided for holding the frame members, and the frame members comprise two frame members spaced from each other and received in a corresponding frame sleeve, and extend transverse across the boat spaced from each other, and shaped to facilitate shedding water from the top of the skin, for example, the frame members may be shaped to give a rounded shape at the top of the skin. 
         [0020]    In another embodiment the invention provides a folding boat. The folding boat preferably including a pair of a plurality of stringer tubes assemblies, having individual stringer tubes, arranged for extending longitudinally when assembled, and each stringer tube of the assemblies connected by hinges to a respective adjacent stringer tube, at the hinges; a waterproof skin for having the stringer tubes assemblies assembled therein as a frame; butterfly frame members for connecting the pairs of the stringer tubes assemblies to each other when assembled; inflatable tubes for being arranged within the skin and each having a seam for having each of the pair of plurality of stringer tubes assemblies nestled within when assembled in the frame; and may further include center stems. 
         [0021]    The butterfly frame members may be spaced apart from each other (e.g., positioned one toward the bow and one positioned toward the stern), and extend transverse across the boat. Further, the center stems may be connected to the butterfly frame members and may be deployed at the bow and stern during assembly to increase the overall boat length. The butterfly frame members may have an opening for allowing a user to pass items into the bow or stern. The butterfly frame members may function as a hinge between the pairs of the stringer tubes assemblies, allowing the pairs of the stringer tubes assemblies to fold side to side. 
         [0022]    The butterfly members may each further include a pair of hinge sleeves that rotate around vertical stringer tube stanchions for connection to the stringer tubes. The butterfly members may each further include a vertical axle at its center, wherein the vertical axle may further include vertical axle sleeves that rotate about it, and wherein the butterfly members may further include attachment points for the center stems, wherein the attachment points may include center stem sleeves positioned at the top and bottom of the vertical axle. 
         [0023]    These and other advantages and features that characterize the invention are set forth in the claims and annexed hereto and forming a part hereof. However, for a better understanding of the invention and of the advantages and objectives obtained through its use, reference should be made to the Drawings, and to the accompanying descriptive matter, in which there are described exemplary embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is a perspective view of a fully assembled boat in accordance with the invention, providing a view through the coaming, showing in partial view internal parts thereof. 
           [0025]      FIG. 2  is a perspective view showing the boat&#39;s folding edges. 
           [0026]      FIG. 3  is a side view of a fully assembled boat. 
           [0027]      FIG. 4  are two perspective views of one set of stringer hinges showing the shock cords thereof in dashed lines within the stringer tubes, with the hinges shown in both open and closed conditions. 
           [0028]      FIG. 5  is a perspective view of the stringer tubes positioned within the inflatable tubes with the waterproof fabric skin removed. 
           [0029]      FIG. 6  is a perspective view of the frame sleeve and frame member, and a partial view of the frame member rotating into position between stringer tubes. 
           [0030]      FIG. 7  is a perspective view of the stringer tubes interconnected to bow and stern tubes, and folded longitudinally. 
           [0031]      FIG. 8  is a perspective view of a frame member of the type used in the invention. 
           [0032]      FIG. 9  is a perspective view of a butterfly frame member in an opened configuration. 
           [0033]      FIG. 10  is a perspective view of butterfly frame member in a closed configuration. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    In order to facilitate an understanding of the description of the invention, and for ease of reference, the following listing of parts and corresponding numbers is provided:  10 —waterproof fabric skin;  15 —stringer tubes;  17 —tubing connectors;  20 —fabric inflatable tubes;  22 —inflatable tube air valves;  25 —frame members;  30 —frame sleeves;  35 —stringer hinges;  37 —hinge inner sleeves;  38 —hinge outer sleeves;  40 —shock cords;  45 —sleeve tang;  50 —sleeve bolt;  55 —sleeve tang rivets;  60 —inflatable tubes with stringer ties;  70 —bow stern tube hinge;  75 —coaming;  80 —bow tubes and stern tubes;  90 —butterfly frame;  100 —latch pin;  105 —hinge sleeves;  110 —vertical stringer tube stanchion;  115 —vertical axle;  120 —vertical axle sleeves;  125 —center stem;  130 —center stem sleeves; and  135 —spring pin. 
         [0035]    As shown in  FIGS. 1 ,  4 ,  5 ,  6 ,  7 ,  9 , and  10 , the stringer tubes  15  assemblies of the invention are made up of lightweight hollow tubing such as carbon fiber, aluminum, or other suitable material. The stringer tubes  15  assemblies are assembled longitudinally within a waterproof fabric skin  10  as shown in  FIGS. 1 and 5 . The stringer tubes  15  and frame members  25  are connected, and are held in place by tubing connectors  17 , and may also use common rivets. 
         [0036]    As shown in  FIGS. 4-7 , multiple hinges are employed with the stringer tubes  15  assemblies. Stringer hinges  35  provide a means for the stringer tubes  15  to fold 180 degrees without pinching the waterproof fabric skin  10 . The stringer hinges  35  are located such that the boat can be folded into sections, e.g., into thirds as shown in  FIG. 2 . The stringer hinges  35  are made up of a hinge inner sleeve  37  and a hinge outer sleeve  38  as shown in  FIG. 4 . Shock cord  40  is tensioned within the individual stringer tubes  15  of the assemblies and the stringer hinges  35  to maintain the sleeves  37  and  38  aligned in place. 
         [0037]    As shown in  FIG. 4 , two hinge outer sleeves  38  can be moved amidships over hinge inner sleeve  37  to allow the stringer tubes  15  assemblies bend 180 degrees. Two of the hinge inner sleeves  37  may be secured (e.g., pinned) within the stringer tubes  15  ends at each joint section. A third hinge inner sleeve  37  floats between the two hinge inner sleeves  37  that are secured utilizing shock cord  40  inside the sleeves to maintain alignment. The two hinge outer sleeves  38  can slide over the hinge inner sleeves  37 . 
         [0038]    When the hinge outer sleeves  38  are advanced away from amidships or in a locked position, the stringer tubes  15  assemblies are rigid longitudinally, as shown in  FIGS. 5 and 6 . Bow tubes  80  and stern tubes  80  are connected to the stringer tubes  15  through the bow stern tube hinges  70 . These hinges serve to connect the two set of stringer tubes  15  together at the bow and stern of the boat. Bow stern tube hinge  70  is an inner sleeve which is secured (e.g., pinned) inside the ends of the stringer tube  15  and protrudes into the bow tube  80  and stern tube  80  ends. Shock cords  40  serves to hold the bow tube  80  and the stern tube  80  tight to the stringer tube  15  ends. In this manner, when assembled, the stringer tubes  15  assemblies are allowed to swing into a vertical position as shown in  FIGS. 6 and 7 . 
         [0039]    The invention may also include frame members  25 , as shown in  FIG. 8 . Frame members  25  serve to hold the stringer tubes  15  assemblies when assembled in a nearly vertical alignment. As shown in  FIG. 6 , frame members  25  are inserted into frame sleeves  30 . The frame sleeves  30  is attached to the sleeve tangs  45  by sleeve bolts  50 , or other suitable mechanism, and is secured (e.g., pinned) to the lower section of the stringer tubes  15  assemblies with, for example, sleeve tang rivets  55 , or other suitable mechanism, as more clearly shown in the partial view of  FIG. 6 . 
         [0040]    When frame members  25  are inserted into the frame sleeves  30 , they may be rotated into a vertical position and attached to the upper portion of the stringer tube  15  assembly through tubing connectors  17 , as shown in  FIG. 5 . The frame members  25  are constructed to allow the user to pass or retrieve objects into the bow or stern through the center thereof. Frame members  25  may have a rounded top portion to facilitate the boat to shed water when it comes over the bow or stern, before it reaches the coaming  75 . 
         [0041]    The bottom portion of the stringer tubes  15  assemblies, when assembled, rests in a seam between the pair of fabric inflatable tubes  20  and held in place, such as by, a small diameter shock cord, ties, or other suitable means, identified as inflatable tube stringer ties  60 , and at various intervals where needed to perform the required function. This is more clearly shown in  FIG. 5 . Each set of fabric inflatable tubes  20  are tapered proportionately to best fill out and shape the waterproof fabric skin  10  when inflated with air or other gas. 
         [0042]    Thus, when assembled, as shown in  FIG. 1 , the stringer tubes  15  assemblies are nested inside the fabric inflatable tubes  20  seam, with the frame members  25  installed inside the waterproof fabric skin  10 . As shown in  FIG. 1 , the fabric inflatable tubes  20  have been filled with air through inflatable tube air valves  22 . As air is added, the waterproof fabric skin  10  is pushed outward and away from the internal stringer tubes  15  assemblies and stretched taut. A seat (not shown) may be positioned between the fabric inflatable tubes  20  in the bottom of the boat through the coaming  75 . 
         [0043]    The boat may be carried in unassembled form in a backpack (not shown). Once removed the boat may be unfolded as shown in  FIG. 2  and laid flat on the ground. The user then reaches through the coaming  75  to enter the interior of the boat and slide the hinge outer sleeves  38  away from amidships over the hinge inner sleeve  37 . Once all stringer hinges  35 , typically numbering eight, are extended, the stringer tubes  15  are collectively assembled in a rigid form for the length of the boat. The stringer tubes  15  assemblies can now be positioned into a nearly vertical position within the waterproof fabric skin  10  and the bow tubes  80  and stern tubes  80  remain horizontal. The user then takes one frame member  25  and inserts it through the coaming  75  into the frame sleeves  30  as shown in  FIG. 6 . The frame member  25  is then positioned into a vertical position where it is secured in place by tubing connectors  17  to the upper portion of the stringer tubes  15  assemblies. This is accomplished preferably by stepping into the boat through the coaming  75 . The other frame member  25  is installed in a similar manner. 
         [0044]    With the internal tubing structure now in place, the inflatable tube air valves  22  are located and used to fill the fabric inflatable tubes  20  with air or other gas by means of an air pump, although it can be done by simply blowing into the tube physically with one&#39;s mouth. As air or gas enters the fabric inflatable tubes  20 , the internal tubing structure assumes a rigid configuration thereby forcing the waterproof fabric skin  10  to expand and conform to a desired shape. The seat (not shown) can then be placed between the inflatable tubes inside the bottom of the boat and the boat is ready to be placed and used in the water. The inflated fabric inflatable tubes  20  serve to isolate the rigid internal tubing structure from the waterproof fabric skin  10  and protects the user and internal rigid frame from underwater obstacles such as rocks and logs, and provides for flotation should the boat capsize. Accessories may be attached to the internal tubing structure. 
         [0045]    As may be appreciated and already discussed, the coaming  75  may be designed to allow the user to zip the closure tight to the body to keep water out or unzip to allow free access to the inside of the boat. The coaming may be part of, or attached to waterproof fabric skin  10  by any suitable methods, such as, those well known in the art. 
         [0046]    In another embodiment, frame members  25 , and the associated connections to the stringer tubes  15 , (i.e. frame sleeves  30 ; tubing connectors  17 ; sleeve tang  45 ; sleeve bolt  50 ), may be altered in shape or form to allow greater ease of installation. In one embodiment, butterfly frame members  90 , as shown in  FIGS. 9 and 10 , may be installed inside the boat to stringer tubes  15  as an alternative to frame members  25 . In one example, butterfly frames  90  may be permanently installed inside the boat to stringer tubes  15 . By removing the bow stern tube hinges  70  and the bow tube  80  and stern tube  80 , as shown in  FIG. 6 , the butterfly frame functions as a hinge between stringer tubes  15 , allowing the stringer tubes  15  to fold in a side to side fashion. The butterfly frames  90  may be secured into the assembled position with a latch pin  100 , for example, or other suitable securing mechanism. Butterfly frame members  90  may include a pair of hinge sleeves  105  that rotates about vertical stringer tube stanchions  110  to form a connection to the stringer tubes  15 . At the center of the butterfly frame members  90  a vertical axle  115  allows vertical axle sleeves  120  to also rotate about it. The latch pin  100  is preferably installed through a hole that passes thru the vertical axle  115  and vertical axle sleeves  120  to secure the butterfly frames  90  into the assembled position and is removed for disassembly. Boat assembly time is significantly decreased with the use of the butterfly frames  90 , as compared to frame members  25 , as now all parts of the boat are now permanently installed inside the outer waterproof fabric skin  10 . 
         [0047]    With the butterfly frames  90  in use and the bow tube  80  and stern tube  80  removed, as shown in  FIG. 9 , center stems  125  may be added to the bow and/or stern with attachment points via center stem sleeves  130  to the top and bottom of the vertical axle  115 . The center stem  125  in this configuration is pushed toward the bow and/or stern during deployment of the butterfly frames  90  and secured in place by, for example, spring pins  135 , or other suitable type of mechanical fastener. This feature allows the boat length to be extended at the bow and stern during assembly. The center stems  125  are retracted toward amidships during disassembly while the butterfly frames  90  are being folded. 
         [0048]      FIG. 10  shows butterfly frame  90  in a closed or folded position. 
         [0049]    While the invention has been described in great detail, it may be appreciated that certain modifications may be made. For example, the shape of the boat may be modified to allow for greater white water performance. 
         [0050]    Further, a greater number of internal hinges could be used to either make the boat fold into an even smaller shape, or to extend the overall length of the boat. Different materials, sizes, and interconnections can be used for all components. Slight adjustments may be made to the outer skin to allow the use of the boat to function as a rescue sled for water or snow. 
         [0051]    While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of the applicants to restrict, or any way limit the scope of the appended claims to such detail. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, of the illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants&#39; general inventive concept.