Patent Publication Number: US-6662743-B1

Title: Foldable boats

Description:
FIELD OF THE INVENTION 
     This invention relates to boats. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention there is provided a boat wherein two sections of its length are hinged together to enable a first of the sections to be folded over the second section for reducing overall length, and the second section is supported longitudinally on an elongate spine that is selectively extendable lengthwise to afford longitudinal support for the first section when unfolded from the second section for use of the boat on water. 
     The foldability of the boat to reduce overall length is of especial advantage for towing and storage purposes on land, and the use of the extendable spine for longitudinal support of the first section when unfolded, as well as of the second section, gives a longitudinal strength to the boat unifying the two sections, without the need to rely for such strength on interconnection between them. Moreover the spine, which may be telescopically-extendable, provides a means for attachment and handling of the boat for towing and maneuvering the boat whether folded on land or unfolded on land or water. 
     The two sections may be bow and stern sections, and may be of substantially the same length as one another to provide the maximum saving of overall length. More especially in this case, the bow section may fold over the stern section, and the spine when extended may provide support for the bow section along substantially the full length of the unfolded bow section. Furthermore, the stern section may be mounted on a chassis that includes the extendable spine, and the chassis may have wheels, for example a pair of laterally-spaced wheels, for transporting the boat on land. The wheels may be retractable. 
     According to another aspect of the present invention there is provided a boat having wheels that are deployed for transporting the boat on land, the wheels being selectively retractable from the deployed condition into one or more recesses of the hull of the boat, for use of the boat on water. 
     When retracted, the wheels preferably lie within the compass of the hull such that they do not project from, or do not project to any substantial extent from, the generally streamline contour defined by the hull. In this regard, more particularly, the wheels may be selectively retractable into respective compartments that open through the bottom of the hull of the boat, and the openings through the hull to the compartments may be closed by respective doors in response to retraction of the wheels. 
     The boat with selectively-retractable wheels may have, as referred to above, bow and stern sections that are hinged together to enable the bow section to be folded over the stern section, and an extendable spine for supporting the two sections. In these circumstances, the wheels may be mounted on a chassis that includes the extendable spine, and an interlock may be provided to preclude the retraction of the wheels until the spine is extended. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A foldable boat with retractable wheels, according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a side elevation of the boat according to the present invention, folded in half and with its wheels deployed ready for towing; 
     FIGS. 2 and 3 are, respectively, a side elevation and a perspective view from the front, of the folded boat of FIG. 1 in a preparatory state for unfolding; 
     FIG. 4 is a side elevation of the boat of FIG. 1 when unfolded and in use afloat with its wheels retracted from their deployed condition; 
     FIG. 5 is a perspective view from above of the boat of FIG. 1, unfolded; 
     FIG. 6 is a plan view of a chassis of the boat of FIG. 1; 
     FIGS. 7 to  9  show details of the hinging of the boat during successive stages of unfolding, the section of FIG. 7 being taken on the line VII—VII of FIG. 3; 
     FIGS. 10 and 11 are perspective views illustrative of features of the chassis of the boat; and 
     FIGS. 12 to  14  are illustrative of successive stages during retraction of the wheels of the boat from their deployed condition. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 to  5 , the hull of the boat is divided into respective water-tight bow and stern sections  1  and  2  of substantially equal length, by respective bulkheads  3  and  4 . The bulkheads  3  and  4  are hinged together allowing the bow section  1  to be folded over the s: tern section  2  as shown in FIGS. 1 to  3 , to reduce the length of the boat for towing and storage. The hinging is effected through a panel  5  which, as illustrated in FIG. 3, closes a gap between the bulkheads  3  and  4  in the folded boat and which in the boat unfolded as illustrated in FIG. 5, provides a central seat. Referring now also to FIG. 6, a pair of tired wheels  6  are mounted laterally spaced from one another on an A-frame chassis  7  to which the stern section  2  is bolted. The chassis  7  includes a central, telescopic spine  8  of the boat that extends within a longitudinal central-well or-channel  9  (FIG. 3) in the underside of the stern section  2  to project forwardly from the bulkhead  4 . The projecting end of the spine  8  is terminated, in the folded condition of the boat, by a tubular towbar  10  that has a conventional coupling-head  11  for engaging the tow-ball (not shown) of a towing vehicle. 
     When the boat is to be used, it is unfolded from the condition illustrated in FIGS. 1 to  3 , after first extending the spine  8 , and releasing from the rear a tailboard (not shown) that not only gives conformity to road-traffic regulations but also secures the bow and stern together. The telescopic spine  8 , which is formed by an outer tube  12  and an elongate, inner bar  13 , has a retracted condition as illustrated in FIGS. 1 and 6, in which the bar  13  projects slightly from the tube  12  just forwardly of the bulkhead  4 , and is extended by drawing the bar  13  forwardly out from within the tube  12  as illustrated in FIGS. 2 and 3. A bolt  14  that is held in a hole (not shown) through the forward end of the tube  12  is used to secure the spine  8  in both the retracted and extended conditions, the bolt  14  extending through an aligned hole  15  (revealed in FIG. 2) of the bar  13  for the retracted condition, and through a corresponding hole (not shown) for the extended condition. A further bolt  16  is used to secure the tubular towbar  10  to the forward end of the bar  13 . 
     As illustrated in FIG. 1, a jockey-wheel  17  is stowed during towing close upon the bulkhead  4 , being clamped to both the spine  8  and the tubular towbar  10  and bridging the divide between them. In this regard, the jockey-wheel  17  augments the function of the bolts  14  and  16  in securing the spine  8  to the towbar  10 , and is removed and relocated on the towbar  10  as illustrated in FIG. 2, as a preliminary to extension of the spine  8 . The jockey-wheel  17  may in itself couple the spine  8  to the towbar  10  with sufficient strength for towing, to enable the removable bolts  14  and  16  to be replaced by spring-actuated pins for engaging the bar  13  in the retracted and extended conditions. Alternatively, where adequate strength for towing is achieved with the bolts  14  and  16  or otherwise, the jockey-wheel  17  may be attached to the towbar  10  permanently. 
     Having extended the spine  8  with the jockey-wheel  17  located on the towbar  10 , the folded-over bow section  1  is lifted up from the stern section  2 , and turned on the hinging of the panel  5  to bring it down towards alignment with the stern section  2 . As illustrated in FIG. 7, the panel  5  is hinged by means of two pivots  18  and  19  at either end, the pair of pivots  18  hinging it to the bow section  1  and the pair of pivots  19  hinging it to the stern section  2 . Accordingly, as the bow section  1  is lifted up and turned over, the panel  5  turns on both pairs of pivots  18  and  19  as illustrated in FIG. 8, until the bow section  1  is brought through 180 degrees, into alignment with the stern section  2  as illustrated in FIG.  9 . The panel  5  has now turned through 90 degrees to form a transverse seat (FIG. 5) with the bulkheads  3  and  4  abutting one another back to back beneath. 
     A central-channel  20  (FIG. 3) corresponding to the channel  9 , runs longitudinally of the underside of the bow section  1 , so as to enable the section  1  to be brought down over the extended spine  8  into alignment with the stern section  2 . The bow section  1  is now secured to the spine  8  using two bolts  21  that screw into holes  22  (FIG. 3) in the bar  13 . The bow and stern sections  1  and  2  are in this way clamped together as one through the spine  8  with the bulkheads  3  and  4  pressed hard upon one another without the need for interconnection between them. Moreover, a projecting lip  23  of the bulkhead  3  is squeezed into a recess  24  of the bulkhead  4  to provide an effective seal between them. 
     The unfolded boat can be maneuvered on its wheels  6  very easily and can be pulled or pushed to, and into, the water, using the towbar  10  whether still coupled to the vehicle or held manually. The towbar  10  with the attached jockey-wheel  17 , is then, or earlier, removed by withdrawing the pin  16 , leaving the bow of the boat clear. Even with the towbar  10  removed, the boat can be maneuvered easily on the wheels  6  using hand-holds  25  (FIG. 5) in the bow section  1 . 
     Once the boat is afloat, the wheels  6 , are retracted through the bottom of the boat into the stern section  2 . More particularly, the wheels  6  even when fully deployed, extend partially into respective open-bottom compartments  26  (FIG. 6) of the hull of the boat that are large enough to accommodate the wheels  6  fully retracted. The wheels  6  are carried by radial arms  27  which are interconnected by a shaft  28  that extends transversely of the spine  8 , and are retracted into the compartments  26  by upward angular movement of the arms  27  relative to the chassis  7 . 
     In this regard, and referring to FIGS. 1,  2  and  4 , each arm  27  is pivoted to the chassis  7  and its angular disposition relative to a bracket  29  of the chassis  7  is determined by links  30  and  31  that are pivoted to one another and to the arm  27  and bracket  29  respectively. A spring  32  is active on the links  30  and  31  to provide them with a strong over-center action by which in one condition (illustrated in FIGS. 1 and 2) the arm  27  extends downwardly for deployment of its wheel  6 , and in the other of which (illustrated in FIG. 4) the arm  27  extends upwardly for full retraction. Operation of the over-center mechanism is effected manually by means of an extendable lever-arm  33  that is coupled to the link  31  within one of the compartments  26  and is accessible from within the boat through a cover  34  (FIG. 5) to that compartment  26 . Pulling the arm  33  to pivot rearwardly brings about retraction of both wheels  6  together, whereas pulling in the opposite direction deploys them. 
     An interlock is active between the spine  8  and the shaft  28  to preclude retraction of the wheels  6  from the deployed condition until the spine  8  has been extended. The action of the interlock is illustrated in FIGS. 10 and 11 and will now be described. 
     Referring to FIG. 10, the bar  13  of the spine  8  projects rearwardly from the tube  12  while the spine  13  is retracted, and in this condition extends through a gap  35  in the shaft  28 . This blocks positively any upward angular displacement of the shaft  28 , and therefore of the arms  27  carrying the wheels  6 , from the deployed condition. It is only when the bar  13  has been pulled forwardly through the tube  12  to extend the spine  8  and vacate the gap  35  as illustrated in FIG. 11, that the shaft  28  and with it the arms  27 , can turn upwardly to retract the wheels  6  into the compartments  26 . 
     Retraction of the wheels  6  is accompanied by closing of the bottom-openings of the compartments  26  by doors  36  to give the hull of the boat a substantially uninterrupted streamline configuration. The doors  36  are hinged to respective arms  37  (FIG. 6) that project rearwardly from,the chassis  7  alongside the wheels  6 , and as illustrated more especially in FIGS. 12 to  14 , each is urged by springs  38  to swing downwardly to close onto the adjacent wheel  6 . While the wheel  6  is deployed, however, and as illustrated in FIG. 12, a small runner-wheel  39  abuts an angled extension-flap  40  of the door  36  to restrain it from turning from a swung-back, fully-open condition. The runner-wheel  39  is coupled via an arm  41  to the shaft  28  so that it is not until the shaft  28  has turned sufficiently as illustrated in FIG. 13 during retraction of the wheel  6 , that the runner-wheel  39  clears the flap  40 . Once the runner-wheel  39  has cleared the flap  40 , the door  36  is free to turn under the action of the springs  38 . The wheel  6  is at this time wholly within its compartment  26  so that the door  36  continues to turn until it closes the bottom-opening of the compartment  26  beneath the wheel  6 , to the condition illustrated in FIG.  14 . The springs  38  hold the door  36  firmly closed. 
     The boat may be powered by sail or outboard motor. For sail, the fore-most bolt  21  holding the bow section  1  to the spine  8  may be replaced by a screw-cup fixing for the support of a mast such as indicated by broken line  42  in FIG. 5 A slot  43 , slightly off-center in order to avoid the spine  8 , is provided for a centerboard or daggerboard. 
     When the boat is to be brought onto land, the wheels  6  are deployed from the retracted condition while the boat is still afloat in water deep enough to give significant clearance of the water-bottom. The wheels  6  are deployed by opening the cover  34  and pulling the extended lever-arm  33  forwardly. This acts through the link  31  to operate the over-center mechanism formed with the link  30  to turn the arms  27  carrying the wheels  6 , downwardly. As each wheel  6  moves downwardly within its compartment  26 , it pushes down on a ramp  44  of the door  36  beneath it (FIG.  14 ), to open and progressively turn the door  36  back. The turning back of the door  36  accompanies continued turning of the shaft  28  and, with it, downward movement of the wheel  6 , to bring the runner-wheel  39  onto the flap  40  again. Further downward movement of the wheel  6  to complete deployment restores the condition illustrated in FIG. 12 in which the door  36  is held in the swung-back, fully-open condition. 
     Once the wheels  6  have been deployed, the boat can be readily propelled under sail, motor or otherwise, until the wheels  6  ground. The boat can then be drawn or pushed from the water on the wheels  6  using, for example, the hand-holds  25  or the re-attached towbar  10 . Having established the boat supported by the wheels  6 , it can be folded again ready for towing, and to this end, it is simply necessary to release the bolts  21  and lift the bow section  1  up to hinge back over the stern section  2 . As this is done, the panel  5  turns on its pivots  18  and  19  to close the space between the bulkheads  3  and  4  in the folded boat. The spine  8  can now be retracted by pushing the bar  13  rearwardly into the tube  12  and securing it with the bolt  14 . The pushing back of the bar  13  re-establishes the interlock in which the bar  13  extends through the gap  35  in the shaft  28  to block retraction of the wheels  6 . 
     For towing, the towbar  10  is re-attached to the bar  13  using the bolt  16  (if this has not already been done), the jockey-wheel  17  is stowed close upon the bulkhead  4 , and the tailboard is secured to the rear.