GB2229147A - Collapsible water craft - Google Patents

Abstract

A collapsible water craft having an inflatable upper hull portion 1, a lower portion provided by a dependent flexible apron 5, and a removable shaped bull element 10 formed from two or more longitudinally extending inter engageable portions 11, 12, 13 adapted to be held together, said element being located between the upper hull portion and the flexible apron. The assembled hull element is inserted into the hull by sliding towards the bow above the transom 8 and below a thwart 9 and tensioned by means acting between the transom and element or by pneumatically operated means acting between the bow and element. A centreboard opening with a sock 25 may be provided. <IMAGE>

Description

COLLAPSIBLE WATER CRAFT This invention relates to a collapsible water craft.

Such craft are often used as a tender to larger craft and a well known type is that usually referred to as an "inflatable". Thus this type of craft is made from a rubberised fabric and contains air tight chambers which can be inflated. The inflatable type of construction is also sometimes applied to dinghies which can be used for sailing or fishing or other waterborne pursuits. Such craft traditionally had a flat bottom made from,one or more layers of flexible material surrounded by the buoyancy chambers which acted as gunwales. There is usually a fixed transom made, for example, from wood or 2 plastics material and some kind of thwart is usually provided. Such flat bottomed craft, although extremely popular, can provide difficult to steer and are, of necessity, not rigid.In an attempt to overcome this it is known to provide a rigid lower hull section to which an inflatable upper hull section is securely attached. This provides a much more rigid type of craft and the solid lower section reduces the possibility of damage to the lower hull, it also tends to provide a hull of better cross-section which can be more easily driven and is more controllable.

A difficulty with the second type of construction is that when the craft is collapsed the rigid lower hull section retains its original shape and the upper portion of the hull merely collapses on to it. The advantage of the completely non rigid type of lower hull is that the whole craft can be collapsed and bundled up, perhaps being placed in a large bag, so that it can be stowed, for example, below decks in a larger craft. Although the lower rigid hull type of craft is often preferable it cannot be stowed in this manner, and it usually has to be fastened down above decks.

It s also rather bulky even when stored ashore.

The present invention is intended to overcome some of the disadvantages of the lower rigid hull type craft and to allow it to be stowed in a more convenient manner.

According to the present invention a collapsible water craft has an inflatable upper hull portion, a lower hull portion provided by a flexible apron, and a removable shaped lower hull element formed from two or more longitudinally extending interengagable portions adapted to be held together, said element being located between the upper hull portion and the flexible apron.

Thus, with the construction set forth above the lower hull element can be removed, the upper inflatable portion collapsed and folded up and the element itself dismounted into its separate portions which can thus be easily stowed away.

In a preferred arrangement the element is in three or more portions to provide rigid members which can be conveniently stowed as required.

In a convenient construction the lower hull element is inserted into place from the stern.

The upper hull portion may be formed by two or more parallel buoyancy chambers which provide gunwales.

Means are preferably provided for holding the interengagable portions together and may include means for tensioning the envelope about the lower hull element. Such tensioning means can be pneumatically operated.

If desired the apron can be provided with a sock to extend into a centreboard opening provided in one of the said interengagable portions.

The upper hull portion and apron can be made from any suitable material, for example a rubber or neoprene impregnated fabric and the lower hull element can be made from a synthetic plastics material which can be moulded or made up from glass reinforced plastics material, and may be hollow filled with a rigid foam material for example expanded polyurethane.

The invention can be performed in various ways but one embodiment will now be described by way of example and with reference to the accompanying drawings in which : Figure 1 is a cross-sectional side elevation of a craft according to the invention on the line I-I of Figure 3; Figure 2 is a cross-sectional end view on the line II-II in Figure 1 without the lower hull element in place; Figure 3 is a plan view of the hull shown in Figures 1 and 2; Figure 4 is a cross-sectional side view of a lower element taken on the line VI-VI of Figure 6; Figure 5 is a cross-sectional end view taken on the line V-V of Figure 6 Figure 6 is a plan view of the element shown in Figures 4 and 5; Figure 7 is a side view showing the hull and the lower element ready for insertion therein; Figure 8 is a cross-section through the hull with the lower element in place;; Figure 9 is a plan view with the lower element in place; Figure tO shows the means for rigidly interconnecting the various portions of the lower hull element; Figure 11 is a part cross-sectional side view of the assembled hull showing the construction of a centreboard casing.

Figure 12 is a cross-sectional end view of the centreboard casing shown in Figure 11.

Figure 13 is a cross sectional side elevation of an alternative construction.

Figure 14 is an enlarged view of the construction shown in Figure 13.

Figure 15 is a cross sectional side elevation of another alternative construction; and Figure 16 is an enlarged view of the bow and stern details of the construction's shown in Figure 15.

As shown in Figures 1-12 of the drawings a collapsible water craft according to the present invention comprises an upper hull potion 1 which is inflatable by means of parallel buoyancy chambers 2 and 3 which are in turn carried in an outer casing so that a third buoyancy chamber 4 is provided between them. The lower hull portion is provided by a flexible apron 5 which is shown hanging loose in Figure 2 The end of the hull is closed by a wooden transom 8 and a thwart 9 is also provided, both of which are permanently bonded to the inflatable buoyancy chambers, and in the case of the transom also to the stern end of the apron 5.

The hull comprising the upper portion and the flexible apron is made from a flexible rubber or neoprene material, such material being well known in itself for inflatable craft.

As shown in Figures 4, 5 and 6 a shaped lower element 10 is provided which is made up from a bow portion 11, a centre portion 12 and a stern portion 13. The various portions are shaped to provide, what is in effect, a lower hull. A centreboard opening 14 is provided and will be described in more detail hereafter. In order to assemble the craft ready for use the three portions 11, 12 and 13 of the lower element are assembled together (in a manner to be described) and the lower hull element thus formed is inserted into the hull by sliding it towards the bow above the transom 8 and below the thwart 9, with the buoyancy chambers 2, 3 and 4 deflated as shown in Figure 7. The general overall shape of the craft with the element in place is shown in Figures 8 and 9.After the element has been placed in position the chambers 2, 3 and 4 can be inflated to provide a buoyant craft which has a rigid lower hull.

The manner of connecting the three portions of the lower element together is shown in Figure 10. The bow portion has a pair of blind sockets 15, the centre portion 12 has a pair of longitudinally extending cylindrical passages 16 and the stern portion 13 also has a pair of longitudinally extending passages 17. As shown in Figure 10 the passages and sockets are lined with suitable tubing indicated by reference numeral 18. A cylindrical stop 19 is arranged at an appropriate distance from the open end of each passage or socket. To provide interconnection each joint between the portions has a tubular location spigot 20 and a similar spigot 21 is provided in the two passages adjacent the transom 8, the spigots being arranged to extend into openings 22 in the transom.

In order to hold the lower element in place and tension the outer skin provided by the apron 5 the portions 11, 12 and 13 are placed in compression by providing a pair of captive nuts 23 on the transom 8 and a pair of cavity bolts 24 which are threaded into the nuts. As will be seen from Figure 10 the bolts 24 are rotated inwards to bear against the ends of the spigots 21 to compress the portions 11, 1 < and 13 together and tension the apron 5.

In order to collapse the craft, it is merely necessary to deflate the inflatable chambers 2, 3 and 4, undo the bolts 24 on the transom, remove the lower hull element 10, and slide the various hull portions off the spigots. The buoyancy chambers 2, 3, 4 can now be completely exhausted and the fabric of the hull bundled up. The various portions of the lower element can be stacked or stowed as required.

If it is desired to sail the craft then a centreboard can be provided by the provision of a slot 14 in the centre portion 12. The apron is provided with an upwardly projecting sock 25 which is pushed upwardly into the centreboard opening 14, as is most clearly shown in Figures 11 and 12 A centreboard trunk 26 made from any suitable material is now pushed upwardly through the slot until a lower flange 27 is engaged. A pair of battens 28 are provided which fit on each side of the upper end of the trunk 26 and are held in place by suitable pins 29 or by means of suitable wedges (not shown) acting beneath battens 28 which bias the trunk 26 upwards to compress the lower portion of the sack 25 around the opening 14. A centreboard 30 is shown in position in Figure 12.It will be appreciated that although, in the construction described above a single hull craft is shown, the invention can be applied to multi-hull craft if desirable. Thus, the multihulled craft might comprise two separate hulls of similar construction to that shown above or it might be a craft which has what is, in effect, a single upper portion but from the lower portion of which project two separate lower hulls. In which case two separate aprons to receive lower hull elements can be provided.

Standardised parts can be used for craft of different sizes, thus the same bow and stern portions of, for example, one metre long, can be used with a centre portion of different lengths or with a number of centre portions. By varying the centre portions boats of different lengths can be produced, only the outer envelope needing to be of different lengths.

A boat with an overall length of 2.5 metres can comprise standard bow and stern portions with no centre portion, no centreboard, and which can be used for rowing or for power.

A boat with an overall length of 3.5 metres can comprise standard bow and stern portions with 0.5 metre centre sections which can be used for rowing, power or sail.

A boat with an overall length of 3.5 metres, as above, with a 1 metre centre portion, as shown in the accompanying drawings.

Larger lengths can have extra centre portions.

An alternative construction is shown in Figures 13 and 14 in which similar referenced numerals are used to indicate similar parts to the earlier described construction. In this alternative however, the buoyancy chambers 2, 3 and 4 of the earlier construction are replaced by a single buoyancy chamber 40 which extends around the upper part of the hull. In order to retain the lower element 10 in place an inflatable end pad 41 is provided which acts between the stern portion 13 and the transom 8. The pad 41 is provided with openings 42 to allow the passage of tubular locational spigots 43 which extend through openings 44 in the transom 8 and into a pair of spaced apart sockets indicated by reference numeral 45. A cylindrical stop 46 is arranged at the appropriate distance from the open end of each socket 45.If desired a locking plate, as indicated by broken lines 47 can be provided to hold the spigot 43 in place.

With this construction inflation of the pad 41 acts to hold the lower element 10 in place and to tension the apron to prevent rippling. It will be appreciated that the inflatable pad pushes the element 10 towards the bow.

Figures 15 and 16 illustrate another alternative construction in which similar reference numerals are again used for similar parts as in the other figures. With this arrangement a single buoyancy chamber 40 is again provided but the lower element 10 is pushed towards the transom 8 to hold it in place. The transom is provided with a rigid batten 50 which extends athwartships and an inflatable pad 51 arranged at the bow. In order to assemble this construction the lower element 10 is pushed into place by deflecting the transom downwardly. With the element located the transom is allowed to rise so that the batten 50 overlaps the stern end of the stern portion 13. The bow pad 51 is now inflated thus forcing the element 10 hard against the inner wall of the transom 8. If desired the pad 51 can be arranged to be inflated independently or it can be connected to the buoyancy chamber 1.

Although not shown the constructions illustrating Figures 13, 14, 15 and 16 can be provided with a thwart and centreboard trunk.

With the constructions shown in Figures 13. 14 15 and 16 clips 52 can be provided if desired to hold the lower element portions together.

Claims (14)

1. A collapsible water craft having an inflatable upper hull portion, a lower hull portion provided by a flexible apron, and a removable shaped hull element formed from two or more longitudinally extending inter engageable portions adapted to be held together, said element being located between the upper hull portion and the flexible apron.

2. A collapsible water craft as claimed in claim 1 in which the lower hull element is in three or more interengageable portions.

3. A collapsible water craft as claimed in claim 1 or claim 2 in which the lower hull element is inserted into place from the stern.

4. A collapsible water craft as claimed in anyone of claims 1-3 in which the upper hull portion is formed by two or more parallel buoyancy chambers which provide gunwales.

5. A collapsible water craft as claimed in anyone of the preceding claims including means for holding the interengageable portions together.

6. A collapsible water craft as claimed in anyone of the preceding claims including means for tensioning the envelope about the lower hull element.

7. As claimed in claim 6 in which said tensioning means acts to force the lower hull element towards the bow.

8. As claimed in claim 7 in which said tensioning means act between the stern and of the lower element and a 7 transom.

9. As claimed in claim 7 in which said tensioning means act between the bow end of the lower hull element and a bow portion of said envelope.

10. As claimed in claim 7, 8 and 9 in which said tensioning means are pneumatically operated.

11. As claimed in anyone of the preceding claims in which the envelope is provided with a sock to extend into a centreboard opening provided in the lower hull element.

12. As claimed in anyone of the preceding claims in which the upper hull portion and envelope are made from rubber or neoprene impregnated fibre.

13. As claimed in anyone of the preceding claims in which the interengageable portions are made from a synthetic plastics material.

14. A collapsible water craft substantially as described herein with reference to and as shown in Figures 1-12, Figures 13 and 14, and Figures 15 and 16 of the accompanying drawings.