Abstract:
A collapsible boat hull  10  has a pair of bottom panels  12, 14  with a first continuous hinge along an inner edge thereof  16  and a second continuous hinge  17, 19  along each outer edge thereof connecting to respective side panels  18, 20 . A flexible material  30  forms the hinge line, supported either side by a support material  36, 38 . The flexible hinge accommodates curvature of the panels when the hull is erected to its boat shape. The support material can be glass fibre or polymeric material, such as polyethylene, PVC or polypropylene. The hinge can be ‘W’ shape in cross section and can form a ridge  40  into the boat, and can be bonded to the respective panels e.g. by glass fibre to the panels. Hinge strengtheners/protectors can be provided, such as additional ribs  52, 54  bonded to or integral to the hinge protective material.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a hinge arrangement between panels of a collapsible boat hull. 
         [0002]    The present invention also relates to a collapsible boat hull incorporating such hinge arrangement(s). 
       BACKGROUND TO THE INVENTION 
       [0003]    It is known to provide collapsible boat hulls, comprising a pair of hingedly interconnected bottom panels and a pair of side panels hinged to the bottom panels. Such boats can be collapsed and folded along the hinging edges of the panels into a substantially flat configuration. 
         [0004]    Typically collapsible boat hulls are also provided with a stern member functioning as a transom, a bow member, and seats which are mounted onto the boat hull when the boat hull is in an erected configuration. 
         [0005]    It is important that the junction between the boat hull and the bow member, and the boat hull and the stern member, are leak-proof. Provision is generally also made to mount an outboard motor on the stern member. 
         [0006]    Some collapsible boat hulls are provided with rigid stern members, while others are provided with diaphragms that can accommodate rigid panels, which rigidify and stabilise the diaphragm when an outboard motor is mounted thereon. 
         [0007]    Further, the collapsible boat hulls of the prior art, when arranged in their erected configuration, are generally flexible rather than rigid, leading to poor handling in the water. 
         [0008]    Some collapsible boats have a hull formed of a waterproof(ed) flexible fabric membrane stretched covering a framework to form the hull. 
         [0009]    Other collapsible boat hulls use panels that are slotted together and have seals between panels, with some form of strapping or looking mechanism holding the panels together. 
         [0010]    Yet other collapsible boat hulls have some form of foldable hinges between side and bottom panels of the hull to allow what is essentially a one piece hull to erect for use and be folded down for transport and storage. Such hulls avoid the problems associated with having to join panels together in situ and ensure that the seals do not leak in use. Such hulls also avoid the risk of puncture associated with all fabric hull skins. 
         [0011]    However, such hinges need to be sufficiently robust to withstand use when the boat is propelled and used in the water such as external wave, impact and internal weight of users in the boat), and yet be flexible to allow erection and folding down. 
         [0012]    Previous attempts at creating flexible hinges are resulted in cumbersome, heavy or unreliable hinges. 
         [0013]    Continuous extruded hinges with resilient spines have been proposed in at least earlier patent application. However, such continuous extruded hinges tend to be heavy, relatively costly to manufacture and install and not aesthetically pleasing, as well as not providing a required rigidity or sufficiently improving rigidity to the hull. 
         [0014]    With these problems in mind, it has been found desirable to develop a hinge for a collapsible boat hull that provides a requisite degree of flexibility, longevity or rigidity to the hull. 
         [0015]    It has also been found desirable to develop a hinge for a collapsible boat hull that contributes to functional configuration or geometry of the hull. 
         [0016]    The present invention attempts to overcome at least in part some of the aforementioned disadvantages. 
       SUMMARY OF THE INVENTION 
       [0017]    With the aforementioned in view, an aspect of the present invention provides a collapsible boat hull including two bottom panels and two opposed side panels, the bottom panels connected to each other by a first continuous flexible hinge along adjoining longitudinal edges of the bottom panels, and each bottom panel connected to an adjacent side panel by a respective second continuous flexible hinge. 
         [0018]    In accordance a further aspect of the present invention there is provided a collapsible boat hull comprising: a pair of bottom panels, each bottom panel having a first continuous hinge along an inner edge thereof and a second continuous hinge along an outer edge thereof; and a pair of side panels, each side panel being connected to an adjacent bottom panel along a respective second continuous hinge. 
         [0019]    Another aspect of the present invention provides a collapsible boat hull including a pair of bottom panels joined by a flexible first continuous hinge, the flexible hinge permitting the pair of panels to be moved between a collapsed configuration and an erected configuration of the hull and wherein the flexible hinge facilitates or accommodates curving of at least a portion of the panels when the panels are moved to the erected configuration. 
         [0020]    Thus, the bottom panels can be moved from a flat folded orientation to a curved erected orientation of the hull, with the flexible hinge(s) retaining its/their integrity. 
         [0021]    A second continuous hinge may be provided along a respective outer edge of each said bottom panel. A pair of side panels may be provided, each connected to an adjacent said bottom panel along a respective said second continuous hinge, each said second continuous hinge being flexible and facilitating curving of at least a portion of the side panels with the bottom panels when the hull is in the erected configuration. 
         [0022]    The bottom and/or side panels may be formed of or incorporate a composite material, such as a polymer or resin impregnated foam board. Alternatively, the or each panel may include or be formed of core material (such as a honeycomb material), preferably having an outer polymeric coating/jacket with preferably a polymeric honeycomb (such as a foam) core. Preferably the honeycomb core is of polypropylene, and the coating/jacket may be a solid or skin of polyester or PVC or the like. Further alternatives for the panel core include aramid polymer(s), para-aramid polymer(s), Nomex®, paper impregnated with phenolic resin, or aluminium, or expanded PVC foam. 
         [0023]    The flexible first continuous hinge is desirably continuous along the length of the boat hull and forms a keel hinge at the bottom of the boat. 
         [0024]    The first continuous hinge may form a keel hinge at the bottom of the boat. The second hinges may form respective chine hinges at the transition between the side panels and respective bottom panel. 
         [0025]    The first and second continuous hinges may have resilient flexibility along respective longitudinal and, transverse planes thereof, thereby facilitating the bottom and side panels to be moved between a folded configuration and an erected configuration. 
         [0026]    The or each aforementioned continuous hinge may also be or include a flexible hinge. Thus, the first continuous hinge may be or include a flexible first continuous hinge and the second continuous hinge may be or include a flexible second continuous hinge. Therefore, each of the first and second continuous hinges may be or include a respective flexible hinge. 
         [0027]    The or each flexible hinge advantageously enables the boat hull to move from a substantially flat configuration to form a conventional boat hull shape when erected. The flexible hinge facilitates bending of the pair of panels into the shape of a hull as the panels are moved to the erected configuration. 
         [0028]    Advantageously, this allows the boat hull to move from a substantially flat configuration when folded to form a conventional hull shape when erected. 
         [0029]    The flexible hinge may include a flexible sheet or web forming a hinge line between adjacent connected panels. The flexible sheet or web may include a shear resistant material. Preferably the sheet or web is or includes polyester (woven or continuous sheet), or an advanced composite fibre material, such as Kevlar or glass fibre, or polyester coated glass fibre, or a polymeric material coating or impregnating a flexible sheet material, such as polyester or kevlar. Alternatively, the flexible hinge may include a polyester fabric coated with a polymer, such as PVC, rubber, neoprene, rubber and neoprene combinations (e.g. Hypalon®). Thus, the material at the core of the hinge is protected by the coating or impregnation. 
         [0030]    The flexible hinge may include a support material extending along the hinge adjacent the hinge line. Thus, the flexible sheet or web may form the hinge line whilst the support material runs along the longitudinal extent of the hinge and closely adjacent the hinge line. The support material of the hinge may be provided by one or more rods of resilient or flexible material, which may be flat in section or round. 
         [0031]    Preferably the support material includes or is a glass fibre or polymeric material, such as polyethylene, PVC or polypropylene, or a rubber or silicone based material. 
         [0032]    To accommodate shape of the boat hull in the erected configuration, where the bottom panels are substantially flat towards a stern of the boat and curved towards a bow of the boat hull, the flexible hinge advantageously changes shape or flexes along the length of the hull as the panels are moved between the collapsed and erected configurations. That is, the flexible hinge adopts different configuration or geometry at different locations along the length of the hull. Thus, the flexible hinge adopts a first configuration towards the stern and a second configuration towards the bow when the panels are in the erected configuration. 
         [0033]    Advantageously, the flexible hinge flexes substantially along the hinge line as the panels are moved from collapsed to erected configuration to create a shape or configuration that contributes to functional configuration or geometry of the hull. 
         [0034]    The hinge between the adjacent bottom panels may form an internal ridge along the interior of the bottom of the hull when the boat hull is erected. Thus, with the hull erected, the bottom panels may angle downward from the side panels and meet at the keel hinge. The support material may then project upwards towards the interior of the boat hull and the sheet or web material forms the hinge line extending along the hinge. This ‘W’ form hinge arrangement provides additional strength and rigidity to the boat hull compared with a flat hinge arrangement. 
         [0035]    At the bow, when the hull is erected, the support material may adopt a configuration where the sheet or web material projects substantially downwardly from the interior of the boat hull and the sheet or web material again forms the hinge line extending along the hinge. That is, the support material and hence the hinge forms an external ridge along this portion of the exterior of the bottom of the hull. 
         [0036]    Along the bow, the hinge preferably thus forms a ‘V’ arrangement which advantageously allows the bow to cut into the water and into waves when the boat is not planing. 
         [0037]    Towards an outermost end of the bow, with the hull erected, the support material may adopt a configuration where the sheet or web material is substantially flat across and between the pair of panels and across the hinge line. In adopting this flat arrangement, the support material is under traction, which is an advantageous state for this portion of the boat where there is highest tension stress. 
         [0038]    Advantageously, the flexing of the hinge as the panels are positioned into the erected configuration and the subsequent configuration that the hinge adopts at different locations on the hull, minimises stress applied to the sheet or web material. 
         [0039]    The hinge may include one or more strengtheners running along the hinge. Preferably each hinge includes a said strengthener either side of the hinge line. 
         [0040]    The strengthener may be in the form of or include or have applied a rib running along the continuous hinge. The rib may be provided along the hinge on the interior side of the hull, or along the hinge on the exterior of the hull, or both on the interior and exterior. 
         [0041]    Each rib may be provided as a triangular section elongate member, which may form part of a moulding of the protective material. Each rib may be a rod of flexible material, which may preferably be flat or round in cross section. The or each rib may be formed of a resilient and/or strong material providing additional strength and stability to the hinge. 
         [0042]    The support material may entrap the sheet or web of material forming the hinge line and linking the adjacent panels. 
         [0043]    The strengthener provides flexion along the length of the protective material. As the strengthener has to flex along the length of the hinge to accommodate the change of geometry with the panel flexing to get in the shape of the hull, the support puts the sheet or web material in tension (in between the flange) on most of the length of the hinge. 
         [0044]    The rib may be provided as a ridge (such as triangular section). The rib may be applied as a, for example, triangular section elongate strip 20 mm wide 10 mm high, 90 degrees at the top (rounded), 45 degrees at the base on each side, about 15 mm away from the hinge line on each side. The chine hinge may have smaller ribs (such as 3 mm thick). 
         [0045]    A further aspect of the present invention provides a collapsible boat hull hinge, the hinge including a flexible sheet or web material for connection to adjacent panels of the collapsible boat. 
         [0046]    Preferably the sheet or web is of a polyester or other polymeric material, or carbon fibre (e.g. Kevlar) or glass fibre material, or material with reinforcing properties equivalent to glass fibre or Kevlar, held between supporting material along either side of the hinge line, and preferably on one or both sides of the hinge (i.e. external or internal, of the hull). The supporting material may include PVC or other polymer that allows flexibility in the hinge for function but provides support and structural integrity to the hinge. 
         [0047]    The sheet or web may therefore provide a reinforcing function for the hinge, which can help with flexural strength and resist frictional or impact damage. 
         [0048]    An alternative sheet or web may be provided by fibre reinforced plastic resin and/or polyester coated fabric. The fabric core may be a woven Kevlar. The polyester coated fabric may also be used as a membrane at the stern of the boat e.g. for waterproofing adjacent a face of the transom. 
         [0049]    Advantageously, the hinge flexes or changes shape substantially along the length of the hull as the boat is erected to form the conventional hull shape. 
         [0050]    The flexible sheet or web may be bonded into the support materials, and the support materials may be bonded to the respective panels either side of the hinge line. 
         [0051]    The support material may include or be fibreglass or polypropylene or other polymeric material, such as a PVC. The hinge may be formed with the flexible material bonded into the support materials for later bonding between the edges of the panels of the hull. The support material may be friction bonded to the hinges and/or panels. Such friction bonding has been founded suitable for certain applications, such as rescue boat configurations of the present invention. 
         [0052]    At least one of the said panels (bottom and/or side panel(s)) of the hull may include or be formed of a core of material (preferably having a honeycomb structure) coated or impregnated with a polymer. The (honeycomb) core may be or include PVC or polypropylene material. The polymer coating or impregnation material may be or include a resin, such as epoxy, or polymer such as polyester. 
         [0053]    A further aspect of the present invention provides a flexible hinge for a collapsible boat hull having at least two panels to be hinged by the flexible hinge for erecting and collapsing the boat hull, the flexible hinge including a flexible material forming a hinge line along the flexible hinge, and support material either side of the hinge line, the support material providing structural support. The flexible hinge may include a flexible protective material extending over or through the flexible material of the hinge line. 
         [0054]    The support material of the flexible hinge is preferably made with or includes fibres orientated along the hinge and/or having the stiffening ribs aligned along the hinge such that the hinge predominantly flexes along the line of the hinge and has restricted flexure across the hinge (and so avoids the typical undulation/bulging experienced in isotropic material without stiffening/corrugation). 
         [0055]    The flexible hinge may include at least one strengthener orientated extending along a length of the flexible hinge. At least one said strengthener may be positioned adjacent the hinge line, preferably external of the hull. The flexible hinge may have fibres integral to the hinge orientated along the hinge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0056]    One or more embodiments of the present invention will hereinafter be described with reference to the accompanying figure, in which: 
           [0057]      FIG. 1  shows a boat hull erected but with the transom and bow members to be installed, according to an embodiment of the present invention. 
           [0058]      FIG. 2  shows a boat hull erected with the transom and bow members being installed, according to an embodiment of the present invention. 
           [0059]      FIG. 3  shows a cross section through a collapsible boat hull showing hinges according to a hinge arrangement according to an embodiment of the present invention. Chine hinge marked ‘A’ is shown in more detail in  FIG. 4 , and central (keel) hinge marked ‘B’ is shown in  FIG. 5 . 
           [0060]      FIGS. 4 and 5  shows detail of various hinges according to an embodiment of the present invention. 
           [0061]      FIG. 6  shows the boat hull folded to a transport/storage configuration and incorporating the hinge according to an embodiment of the present invention. 
           [0062]      FIGS. 7 and 8  show alternative embodiments of a hinge of the present invention incorporating support ribs. 
           [0063]      FIG. 9  shows a side view of a collapsible boat hull in an erected configuration, illustrating portions of flexible hull which exhibit varying shape when the hull is erected according to an embodiment of the present invention; 
           [0064]      FIG. 10  shows cross sections through a collapsible boat hull showing flexible hinge at ‘A’, ‘B’ and ‘C.’ of  FIG. 9 ; and 
           [0065]      FIG. 11  shows an underside of the collapsible boat hull in the erected configuration and illustrating location of ‘B’ and ‘C’ of  FIG. 9 . 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
       [0066]      FIGS. 1 and 2  show an erected collapsible boat hull  10 . The hull has two bottom panels  12 ,  14  connected along their inside edges by a central flexible hinge  16 . Two side panels  18 ,  20  are connected to respective outside edges of the bottom panels by chine hinges  22 ,  24 . 
         [0067]      FIG. 1  shows the hull  10  without a removable transom or bow member installed.  FIG. 2  shows the bow member  26  installed and the transom member  28  in partially installed. 
         [0068]      FIG. 3  shows a vertical cross section across the beam of the boat hull. The structure of the central hinge and chine hinges is shown in more detail identified as sections labelled A and B, which are shown in close up in  FIGS. 4 and 5 . 
         [0069]    Each hinge includes a flexible hinge line material  30 , such as a web or sheet of resilient material e.g. a Kevlar or glass fibre material. 
         [0070]    As shown with reference to  FIG. 4 , the chine hinge  17 ,  19  is provided between the side panel  18 ,  20  and a bottom panel  12 ,  14 . Each panel terminates at a respective bevelled edge  32 ,  34 . 
         [0071]    The flexible sheet or web material  30  forms the hinge line, which is supported on either side by a support material  36 ,  38 . The support material preferably covers and protects the flexible hinge material apart from at the hinge line, or is sufficiently thin at the hinge line as to not prevent flexure of the hinge material during opening and closing of the hull. The support material connects the flexible hinge material to the respective side panels. 
         [0072]    The support material advantageously protects from impact the hinge material by providing the two opposed extensions (flanges′) of support material substantially cover the hinge material and only leave a small amount of the hinge material exposed or have a thin covering of support material or other material as a protection without functionally impairing the operation of the hinge. 
         [0073]    It will be appreciated that the bevelled panel edges help to create a smooth, flush hinge-line when the boat hull is fully erected, as shown in  FIG. 4 . 
         [0074]      FIG. 5  shows detail of the central (keel line) hinge. The support material forms a ridge  40  projecting into the interior of the boat hull i.e. the hinge is generally ‘W’ shaped in cross section. This adds strength in relation to carrying weight in the boat and reduces stress and external (water side) exposure on the flexible hinge material compared with a flat hinge. Construction of the hinge is generally the same as the chine hinges, with the bottom panels edges  42 ,  44  bevelled. The resultant external channel  46  formed by the exterior ‘valley’ of the ridge helps stability of the boat at speed. 
         [0075]    Preferably the hinge is bonded to the respective panels. For example, by fibreglass bonding to composite panels. Alternatively, the support material may support the flexible hinge material and the support material is bonded to the panel(s), such as by a marine grade adhesive. 
         [0076]      FIG. 6  shows the boat hull  10  in collapsed configuration ready for transport or storage. The side panels  18 ,  20  are folded in between the bottom panels  12 ,  14 . The central (keel line) hinge  16  at one edge of the collapsed hull and the two chine hinges are at the opposite end. As shown, the side panels include gunwale edges  48 ,  50 . 
         [0077]      FIGS. 7 and 8  show strengtheners in the form of additional ribs  52 ,  54  integrated with the protective material of each hinge. The ribs are shown on the external (water) side of the hull, but may be provided on the interior side of the hull, or on both interior and exterior sides. 
         [0078]    The ribs may be rods or other elongate members. The ribs are shown in the figures as triangular sections, but it will be understood that other cross sectional shapes are envisaged to fall within the scope of the present invention. For example, curved or half round, half hexagonal, trapezium etc. The ribs provide strength to the hinge whilst allowing flexure in the longitudinal direction of the hinge. 
         [0079]      FIGS. 9 and 11  show an erected collapsible boat hull  110 . The hull has two bottom panels  112 ,  114  connected along their inside edges by a central flexible hinge  116 . Two side panels  118   a ,  118   b  are connected to respective outside edges of the bottom panels by suitable hinges such as chine hinges. 
         [0080]      FIG. 10  shows a series of vertical cross sections across the beam of the boat hull  110  and demonstrates structure of the central hinge  116  at various locations along the length of the hull  110  when the panels  112 ,  114  are in an erected configuration, forming a typical boat hull arrangement. 
         [0081]      FIG. 10  shows central hinge structure at locations marked ‘A’, ‘B’ and ‘C’ on  FIGS. 9 and 11 , corresponding to: a section adjacent an outer end of the bow; a section at the bow; and a section towards the stern of the boat hull  110  respectively. 
         [0082]    The hinge  116  includes a flexible hinge line material  120 , such as a web or sheet of or including a flexible yet resilient material e.g. a Kevlar or glass fibre material. The hinge  116  also includes a support material extending along the hinge adjacent the hinge line. The flexible hinge line material  120  forms the hinge line  121  whilst the support material  130  runs along the longitudinal extent of the hinge and closely adjacent the hinge line  121 . In a preferred embodiment, the support material  130  is or includes a glass fibre material or polymeric material. In the embodiment shown in  FIGS. 9 to 11 , the flexible sheet or web is integrated or embedded with the support material  130 . 
         [0083]    Sub- FIGS. 10A to 10C  shows detail of the central (keel line) hinge when the collapsible boat is in an erected configuration and the support material  130  is therefore flexed. 
         [0084]    Referring to sub- FIG. 10A , the support material when flexed ( 130   b ) forms a generally flat formation at the end of the bow, spanning between the pair of bottom panels  112 ,  114 . In this configuration, the support material  130  is under traction. This is an area of the hinge  116  that is under high tension stress relative to other areas of the hinge and so a flat configuration is ideal for structural purposes. Significant departure from the flat configuration at this region of the hinge  116  could create a sharp fold line and potentially damage the web or sheet of the hinge line material  120 . 
         [0085]    It is therefore desirable for the support material  130  to form a substantially flat configuration at any region of the hinge  116  where there is traction when the panels  112 ,  114  are in the erected configuration. In the embodiment shown in  FIGS. 9 to 11 , this will generally be adjacent beginning and end of curved portions of the boat hull  110 . Referring to sub- FIG. 10A , the position of support material  130  in a substantially un-flexed position is depicted with dotted lines and referenced as  130   a.    
         [0086]    Sub- FIG. 10B  shows detail of the central hinge adjacent the bow area of the hull. The support material  130   b  when flexed, as a result of the panels  112 ,  114  being moved to the erected configuration, forms a ridge  122  projecting away from an interior of the boat hull, That is, the hinge is generally ‘V’ shaped, providing an ideal shape to cut into and deflect water before the boat commences planing, or to minimise resistance to movement of the boat when the boat encounters waves. The angle of the ‘V’ can vary along the length of the hull. The ‘V’ shape is formed by application of compression to the support material as the panels  112 ,  114  are moved into the erected hull formation. The dotted lines in Sub- FIG. 10B  represent the support material  130   a  when in a substantially un-flexed state. 
         [0087]    At and towards the stern of the boat, as shown in Sub- FIG. 10C , the support material  130  forms a ridge  140  when flexed, projecting into the interior of the boat hull i.e. the hinge is generally ‘W’ shaped in cross section. This adds strength in relation to carrying weight in the boat and reduces stress and external (water side) exposure on the flexible hinge material compared with a flat hinge. Each of the bottom panels has bevelled edges and the flexible sheet or web material forms the hinge line therebetween. The resultant external channel  46  formed by the exterior ‘valley’ of the ridge along the portion of the keel hinge towards the stern helps stability of the boat at speed. 
         [0088]    In each variation of geometry or configuration of the hinge  116  along the hull, the stress as applied to the flexible hinge line material  120  when the panels  112 ,  114  are arranged in the erected configuration is advantageously minimised. 
         [0089]    Preferably the hinge  116  is bonded to the respective panels  112 ,  114 . For example, by fibreglass bonding to composite panels. Alternatively, the support material  130  can support the flexible hinge material  120  and the support material  30  is bonded to the panel(s), such as by a marine grade adhesive. 
         [0090]    It is desirable that the support material  130  is bonded to the respective panels  112 ,  114  such that it is arranged at an angle of between 10° and 45° when the panels  112 ,  114  are in the collapsed or folded configuration. This arrangement facilitates flexion along the line of the keel hinge whereby the angle of the support material  130  relative to the panels  112 ,  114  flexes and adopts configurations as described above as the panels  112 ,  114  are moved into the erected configuration. 
         [0091]    Whilst the hinge is flexible, it also has rigidity which assists in creating a smooth transition between change of geometry of the hinge  116  along the length of the hull. That is, there is a smooth transition from the W or inverted ‘V’ shape at the stern, to the ‘V’ shape at the bow and the substantially flat geometry towards the end of the bow. 
         [0092]    The flexing of the hinge  116  as the panels  112 ,  114  are moved to the erected configuration therefore advantageously and usefully creates a configuration or geometry that contributes to the functional configuration of the hull  110 .