WO1991017914A1

WO1991017914A1 - Folding dinghy

Info

Publication number: WO1991017914A1
Application number: PCT/AU1991/000207
Authority: WO
Inventors: Charles Caulder Bree; Michael John Grant
Original assignee: Charles Caulder Bree; Michael John Grant
Priority date: 1990-05-16
Filing date: 1991-05-15
Publication date: 1991-11-28
Also published as: AU7889991A

Abstract

A folding dinghy comprises at least two flexible panels (12, 14) which have curved edges along which the panels are hinged together by a flexible connecting element (26) having one or more longitudinally extending cavities (42) in which an enlarged distal portion of one of the panels is held captive. The connecting element and the distal portion have curved interfaces and the connecting element bears resiliently on the distal portion at the interfaces. A resiliently compressible sealing strip (90) may be interposed between the connecting element and the distal portion.

Description

Title

FOLDING DINGHY

HELP OF THE INVENTION

This invention relates to folding dinghies.

DESCRIPTION OF PRIOR ART

One example of a folding dinghy known to the applicant comprises side panels each of which has a curved lower edge which is joined to the similarly curved outer edge of a bottom panel by means of a water proof strip of flexible sheet material so that the strip can act as a hinge about which the side panel can pivot in relation to the bottom panel. By this arrangement the side panel can pivot between a folded position in which it lies parallel to the bottom panel and an erected position in which it arises from the bottom panel. In the folded position the side panels and the bottom panel are flat but in the raised position both the side panels and the bottom panel are curved, this due to the curvature of the lower edge of each side panel and the outer edges of the floor panel. The transom of this dinghy is constituted by a sheet of flexible material of the same kind as is used to make up the hinges.

The applicant has found that a dinghy constructed substantially as described above has insufficient rigidity in at least two aspects. First the flexible strips by which the side panels are joined to the bottom panel and the manner in which the strips are affixed causes a substantial amount of 'play' between the side panels and the bottom panel. Not only is there thus constant flexure therebetween when the dinghy is under way but also the degree of flexure increases when there is greater water pressure on the dinghy as when it is driven through the water by an outboard motor or when it lies deeper in the water when heavily laden. This leads to a perception that the dinghy is not seaworthy and is unacceptable from a marketing point of view as well as from the point of view of long term safety. Because of the need for the strips to function as hinges it does not appear possible to eliminate this flexure in a dinghy constructed as described above.

In the second place the transom itself is problematical. Of course where the transom

SUBSTITUTE SHEET π consists solely of the sheet of flexible material it would be wholly unsuitable for mounting an outboard motor. However, even where a rigid board is mounted at the aft end of the dinghy against the flexible sheet constituting the transom, in the dinghy constructed as described the applicant has found that the board is still prone to excessive vibration due to the lack of rigidity in the dinghy as a whole.

Other folding dinghies of which the applicant is aware have no means for mounting an outboard motor thereon and tend to be insufficiently rigid for that purpose for reasons similar to those outlined above. On the other hand those folding dinghies which are able to mount an outboard motor are not able to be folded very compactly and the components of which they are constructed, especially the side panels and bottom panel thereof, are heavy and rigid so that this kind of dinghy is inconveniently heavy and bulky.

Included in this category are the dinghies disclosed in British patent #16661, French patent #1320846 and US patents #4556009, 2577970 and 4282616.

In an effort to overcome these problems the applicant has conceived a folding dinghy comprising side panels hinged to a one-piece bottom panel by means of a light rope which laces the components together at their curved edges. The joints are sealed by a rubber strip glued to the edges. This dinghy is the subject of the applicant's New Zealand patent #220669. Various other important features contribute to the rigidity of this dinghy including (a) the interconnected edges of the bottom and side panels are tightly curved at the ends so that at their extremities they are disposed at a steep angle to the horizontal; (b) a bracket is clamped on the aft end of the dinghy. This bracket is curved to follow the contour of the bottom panel and is also provided with a horizontal lower plate which serves not only as a planing skeg but also substantially to stiffen the bracket.

This dinghy is sufficiently rigid to enable an outboard motor of up to 6 hp to be mounted thereon. However, the operation of lacing the side panels to the bottom panel is time consuming and the dinghy is on this account rather expensive. SUMMARY OF THE INVENTION

According to the invention there is provided a folding dinghy comprising first and second flexible panels having substantially similarly curved edges along which the panels are pivotably connected together by a flexible elongate connecting element so that the second panel can pivot between a folded position and an erected position, the connecting element comprising a longitudinally extending cavity in which the curved edge of the second panel is held pivotably captive.

Further according to the invention there is provided a folding dinghy comprising first and second flexible panels having substantially similarly curved edges along which the panels are pivotably connected together by a flexible elongate connecting element so that the second panel can pivot between a folded position and an erected position, the connecting element comprising a first longitudinally extending cavity in which the curved edge of the first panel is held captive and a second longitudinally extending cavity in which the curved edge of the second panel is held pivotably captive.

In one form of the invention the cavities have longitudinally extending openings through which the curved edges project, the curved edges having distal portions which are located in the cavities and have enlargements which are wider than the openings so that they cannot pass therethrough.

According to one aspect of the invention the cavities and the distal portions are substantially similarly shaped and are disposed symmetrically on either side of the longitudinal centre of the connecting element.

According to another aspect of the invention each cavity comprises a longitudinally extending seat in which the distal portion of the panel located therein remains pivotably seated as the panel pivots between the folded position and the raised position.

In one form of the invention the enlargement of said distal portion comprises a flange having an outer edge which comprises a first longitudinally extending segment of said distal portion and which is seated in said seat.

In one aspect said distal portion comprises a second longitudinally extending segment which is located adjacent said flange and which bears on a longitudinally extending segment of said cavity located opposite said seat.

In another aspect the connecting element comprises a longitudinally extending wall having a face opposite said seat and comprising said segment of the cavity.

Advantageously, according to the invention, a portion of said cavity is defined by two longitudinally extending walls of the connecting element which have inner faces which meet at a junction constituting said seat.

Said seat and said segment of the cavity preferably comprise concave surfaces. Moreover, said first and second longitudinally extending segments of the distal portion preferably comprise convex surfaces.

It is an advantage of the invention that the connecting element bears resiliently on said distal portion at said seat and at said segment of the cavity.

Advantageously a resilient sealing member is inserted in at least one of the cavities and is sealingly compressed by said distal portion of the panel located in that cavity as the panel is moved to the erected position.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further discussed with reference to the accompanying drawings in which

Figure 1 is a plan view of a folding dinghy in the folded condition;

Figure 2 is a plan view of the folding dinghy in the erected condition;

Figure 3 is a cross sectional view on arrow A - A in Figure 2;

Figure 4 is a cross sectional view on arrow B - B in Figure 2;

Figure 5 is a cross sectional view drawn to scale of a connecting element used on the dinghy shown in Figures 1 to 4;

Figure 6 is a view, similar to Figure 5, showing the edges of a side panel and a bottom panel of the dinghy joined together in the folded position;

Figure 7 is a view similar to Figure 6 with the panels pivoted to an erected position;

Figure 8 is a view similar to Figure 7 showing a modified connecting element;

Figure 9 is a cross sectional detail showing the manner of mounting a buoyancy tube and a seat on the dinghy; and

Figure 10 is another cross sectional detail showing the manner of mounting a valve in a tube wall.

DESCRIPTION OF THE EXAMPLES SHOWN IN THE DRAWINGS

In Figures 1 to 4 of the drawings a folding dinghy 10 has a bottom panel 12 and two side panels 14, 16. The bottom panel has outer edges which are smoothly and similarly curved. The bottom panel thus has a shape which is symmetrical about either side of its fore-and-aft centre line. It tapers from a location of maximum width just aft of the transverse centre line thereof towards its front end 18 and also towards its aft end 20. The side panel 14 has a lower edge which is curved, its profile being substantially identical to the profile of the left hand outer edge of the bottom panel. Thus, when the side panel 14 is laid flat on the bottom panel, its lower edge exactly overlies the left hand outer edge of the bottom panel. Similarly the side panel 16 has a curved lower edge which exactly overlies the right hand outer edge. The forward end of each side panel 14, 16 tapers to a point as indicated at 22. Similarly the aft end of each side panel tapers to a point as indicated at 24. The forward end of the bottom panel is more tapered than the aft end as will be explained.

A feature of the dinghy 10 shown in Figures 1 to 4 is that the maximum width of each side panel is only slightly less than the maximum width of the bottom panel 12. A one- piece bottom panel, which is very desirable for rigidity, is used. The dinghy is nevertheless still compact in the erected condition.

The side and bottom panels are joined together along the curved edges already described by connecting elements 26, 28. The side panels 14, 16 can pivot to an erected position shown in Figures 2 to 4. Because of the fact that the interconnected edges are curved the action of pivoting the side panels to the erected position causes the forward and aft ends of the side panels to be drawn inwardly and of the bottom panel to be drawn upwardly. The degree to which the ends are so drawn depends naturally on the curvature of the edges. This curvature is such that the extremity of the bottom panel at the aft end is substantially vertical when the dinghy is erected as shown in Figure 3. This adds considerably to the rigidity of the dinghy and the buoyancy thereof at the aft end. It is also useful for mounting an outboard motor.

The connecting elements are mutually identical so only the element 26 will be described. The cross sectional shape thereof is shown in large scale in Figures 5 to 7. The element 26 is a moulding or extrusion of plastics material such as polypropylene or ASA which is tough and has a good memory. It comprises a base portion 30 from opposite longitudinal edges of which arise spaced side walls 32, 32'. The wall 32 has an upper edge in which a lip 34 is formed. The lip projects towards the opposite wall 32' and constitutes a longitudinally extending hook formation. At the junction of the lip and the wall 32 the inner face 36 of the wall is concavely curved at 36a in the shape of a segment of a cylinder with its longitudinal axis located at 38.

An upwardly projecting internal wall 40 is moulded into the base portion 30. Two longitudinally extending cavities 42, 42' are thus formed in the element 26. The wall 40 has a left hand face which merges smoothly with the curved upper face 46 of the base portion 30. The curvature of the face 46 will be described in greater detail below.

The cavity 42 has a mouth 48 located between the lip 34 and the upper edge of the wall 40.

The element 26 is symmetrical about what in Figure 5 is a vertical central plane. The wall 32' thus has a lip 34' and an inner face 36' which, at the junction with the lip comprises a cylindrical segment 36a' having an axis 38'. The curved upper face 46' of the base merges smoothly with the right hand face of the wall 40.

The connecting element 26 co-acts with a distal portion 50 of the curved edge of the side panel 14 and also with a distal portion 52 of a curved edge of the bottom panel 12.

These portions 50, 52 are of substantially similar cross sectional shape although one is right handed and the other is left handed. Only the portion 50 will be described in detail. It is held captive in the cavity 42 by virtue of being larger than the mouth of the cavity. It is provided with a lip 56 which constitutes a longitudinally extending hook formation defining a recess 58 in which the lip 34 is engaged. At the extremity of the lip 56 its outer face is convexly curved complementally to the curvature of the concave segment 36a. It thus has an axis of curvature coincident with the axis 38. Furthermore the distal portion 50 has a convex cylindrical face 60 with an axis of curvature which is also coincident with the axis 38. The radius of curvature of the face 60 is however greater than that of the lip 56. The face 60 merges smoothly with the flat inner face 62 of the side panel 14.

The distal portion is an interference fit in the cavity 42 so that when it is inserted in the cavity the lip 34 must be sprung upwardly and the wall 32 must be sprung outwardly. The lip 56 is thus held seated in the concave segment 36a by virtue of the contact between the curved faces 60, 46 as the side panel pivots between the folded and erected positions. The interengaging hook formations ensure that the side panel 14 cannot be disengaged from the connecting element. Moreover the contact between the distal portion and the connecting element forms a surprisingly good seal against leakage of water through the joint.

In a modification to the above construction, the radius of curvature of the curved face 46 decreases progressively as the distance from the flat face 44 along the face 46 increases. This has the effect that the wall 32 is sprung further outwardly as the side panel is moved from the folded to the erected position. This in turn exerts a progressively greater compressive force on the distal portion along its lines of contact therewith. The seal along these lines is thereby improved.

The distal portion of the bottom panel 12 is held captive in the cavity 42' in exactly the same way. It is not considered necessary to describe the side and bottom panels in greater detail. Insofar as details of their construction are not described herein they are substantially conventional. They are however usefully made of polyethylene or similar suitable plastics material by a rotation moulding process. When made of polyethylene they have a wall thickness of about 5 mm. They emerge from the mould in a substantially finished condition. However it may be necessary to finish-machine the recesses 58, 58', after moulding. This is a quick operation and could be done by means of a hand held tool. When made by this process the side panels and bottom panel are sufficiently flexible to undergo considerable flexure within their elastic limits and at the same time have sufficient strength for the service required of them.

The side panels and bottom panel may also be made of a glass reinforced plastics material. In this case they could be cut from sheet material. The distal portions could be extrusion moulded which are glued or otherwise fixed to the edges.

It is important that the connecting elements minimise flexure therebetween as already explained. The joint tends to prevent the edges of the side panels and bottom panel moving away from one another in any direction. Inward flexure of the side panel or upward flexure of the bottom panel at the joint under static or dynamic pressure from the water in which the dinghy is floating or moving is thus prevented or at least reduced.

The connecting element is sufficiently flexible to take up the curvature of the joints between the side panels and the bottom panel when the dinghy is erected. This is an important consideration in the assembly of the dinghy. In this operation the side panels are laid over the bottom panel, all of them being flat and substantially in the position illustrated in Figure 1. The edges which will be joined together are then in register. One end of the connecting element 26 is then offered up to the ends of a pair of the mating edges and the connecting element is pushed in the longitudinal direction, feeding over the meeting edges and taking up the curvature thereof in the process. The second connecting element 28 is next mounted in the same manner.

Alternatively the dinghy may be assembled by mounting the panels in a jig in which they are positioned next to each other upside down in the erected position. The connecting elements are then pushed over the meeting edges of the panels. In a modified construction of the connecting element 26 there is no internal wall 40; this is replaced by a cusp rising from the centre of the base portion 30. The curved faces 46, 46' of the element 64 meet at the apex of the cusp. The side and bottom panels are substantially similar to those of the dinghy 10. When the distal portions of the panels are in place, their curved faces 60, 60' are in contact with each other. Moreover these faces remain in rolling contact as the side panel pivots between the folded and the erected positions. They form a seal along the line of contact.

In the example shown the side panels pivot through about an arc of about 120° between the folded and erected positions. In some dinghies, for example in those with a two piece bottom or in canoes comprising only two side panels which meet at a V, a smaller pivotal arc may be sufficient. In this case the joint shown in Figure 8 may be suitable. Here a connecting element 80 having a single cavity 82 may be provided. The element 80 is rigidly connected to (or integrally moulded with) a curved edge of one panel 84. The cavity is in principle substantially similar to one of the cavities of the element 26. The second panel 86 has a curved edge with a distal portion 88 which is, again in principle, substantially similar to that of the side panels 14, 16. It is not considered necessary to describe the components of this joint in further detail. The joint will allow relative pivotal movement of the panels through about 90° about the axis 89.

In the above examples, the distal portions of the panels have convex surfaces along which they are in contact with concave surfaces of the connecting elements. This is not necessarily essential. In each case the distal portion may comprise one or more longitudinally extending ribs which makes line contact with the concave surface of the connecting element. Alternatively the concave surface of a connecting element may be replaced by one or more similar ribs which makes line contact with a convex surface of a distal portion.

It will usually be necessary to improve the sealing of the joint, by providing one or more sealing strips between adjacent surfaces of the distal portions and the connecting element. A sealing strip 90 which is moulded to conform to the cross sectional shape of the surfaces is shown in cross section in Figure 6. The strip 90 is an extrusion of a suitable high quality synthetic rubber such as neoprene or Santoprene™. The extrusion comprises a hollow lower portion 92 which conforms to the shape of, and is inserted in, the recess 58'; and a wedge shaped upper portion 94. The portion 94 comprises flat surfaces which bear on the upper face of the lip 34' and the lower flat face of the bottom panel 12. The portions 92 and 94 are joined by a ligament, leaving a recess 96 therebetween in which the lip 34' is received.

The portion 92 is hollow since it is subject to relatively severe distortion by the lip 34'. The sealing strip functions not only as a water seal but also to stop sand and grit from getting into the joint.

In an alternative construction the hollow lower portion 92 is replaced by a solid portion which does not fill the recess 58'.

Of course, a sealing strip will also usually be inserted in the recess 58.

Alternatively, sealing strips may be inserted in other positions, for example between the curved faces 60, 60' and the faces 46, 46' in the Figure 5 construction; or the curved faces 60, 60' where they are in rolling contact with each other. The alternative sealing strip could be round or flat. A flat strip could if necessary be glued to the faces with which it is in contact.

The connecting elements act as efficient rubbing strips. If one side of a connecting element becomes worn, as for example by rubbing against a dock, it can be removed, turned around end to end and replaced.

The dinghy may incorporate other improvements. A rotation moulded outboard motor mounting bracket 100 may demountably fixed to the aft end of the dinghy after it has been erected. The rotation moulding enables the bracket 100 to be an enclosed hollow body which adds buoyancy to the aft end of the dinghy. The front wall 102 of the bracket 100 can be made to conform closely to the profile of the upwardly curved portion of the dinghy bottom. This contributes to the rigidity and moreover distributes the thrust of the outboard motor over a large area tending to reduce flexure of the bottom panel. The bracket can be provided with a horizontal lower wall 104 which functions as a planing skeg.

The bracket 100 may be fixed to the dinghy by means of bolts which are embedded in the bottom panel 12 when it is moulded.

To further stiffen the aft end of the dinghy, lugs may be moulded in the bracket 100 which overlie the rear ends 24 of the side panels and are bolted thereto.

A flange 108 may be moulded into the bottom panel. This flange may be used for attachment of a rope for mooring or towing the dinghy.

Sockets 110 for rowlocks may be moulded into the side panels of the dinghy in the rotation moulding operation.

The dinghy may be provided with one or more prefabricated inflatable tubes 112 mounted around the gunwhale to act as buoyancy aids. These tubes may be rotation moulded from material such as EVA (ethylvinylacetate) or cut from PVC to conform to the shape of the dinghy. Commercially available valves for connection to an air supply line are mounted in holes cut or moulded in the tube walls.

The bag is provided with a number of flanges 114 which are received in recesses 116 moulded into the side panels in the rotation moulding operation. (The tubes have been omitted from Figure 1 in order to show the recesses 116). The flanges are fixed in the recesses by pins 118 which pass through the walls 120 of the recesses.

The tubes serve to substantially reduce flexure of the dinghy.

The dinghy may be provided with seats 124 made up also from inflatable bags of a material such as EVA or PVC. The advantage of such seats is that when inflated and located in place they apply a force against the side and bottom panels. By themselves the seats are capable of holding the dinghy in the erect condition. They can be rotation moulded or cut to conform to the shape of the dinghy so that they bear on it in preselected places.

The seats may be held in place in the dinghy by the provision of end flaps 126 (see Figure 9) which are attached to the walls 120 by the pins 118.

A considerable advantage of using suitably shaped inflatable seats is that they can remain attached to the dinghy when they are deflated and the dinghy is folded. The dinghy can then be erected simply by reinflating the seats, particularly the seat located amidships. This process is made even easier if the dinghy is provided with a cylinder of compressed air which is connected to the valves for inflating the seats. The cylinder may also of course be connected to the buoyancy tubes 112.

As shown in Figure 10, indentations 130 in which the valves (shown in outline only at 132) are located may be formed in the walls 134 of the tubes or seats. Substantial tension is applied to a tube wall when the tube is inflated and there is a tendency for the the tube wall to be pulled away from the valve at the joint under this tension. The provision of the indentations substantially reduces this tendency.

Vertical direction-stabilising skegs 128 can be fixed the rear end of the dinghy by any suitable means.

One or more wheels (not shown) for trundling the dinghy may be mounted near the aft end. Sockets or other fixtures for detachably mounting the wheels may be moulded into the bottom panel.

It is not intended that the scope of a patent granted in pursuance of the application of which this specification forms a part should exclude modifications and/or improvements to the embodiments described and/or illustrated which are within the spirit and scope of the invention as defined in the claims or be limited by details of such embodiments further than is necessary to distinguish the invention from the prior art.

Claims

CLAIMS:

1. A folding dinghy CHARACTERISED IN THAT it comprises first and second flexible panels [12, 14, 16, 84, 86] having substantially similarly curved edges along which the panels are pivotably connected together by a flexible elongate connecting element [26, 80] so that the second panel can pivot between a folded position and an erected position, the connecting element comprising a longitudinally extending cavity [42, 42', 82] in which the curved edge of the second panel is held pivotably captive.

2.

A folding dinghy CHARACTERISED IN THAT it comprises first and second flexible panels [12, 14, 16] having substantially similarly curved edges along which the panels are pivotably connected together by a flexible elongate connecting element [26] so that the second panel can pivot between a folded position and an erected position, the connecting element comprising a first longitudinally extending cavity [42] in which the curved edge of the first panel is held captive and a second longitudinally extending cavity [42'] in which the curved edge of the second panel is held pivotably captive.

3.

A folding dinghy according to claim 2, CHARACTERISED IN THAT the cavities have longitudinally extending openings [48, 48'] through which the curved edges project, the curved edges having distal portions [50, 52] which are located in the cavities and have enlargements which are wider than the openings so that they cannot pass therethrough.

4.

A folding dinghy according to claim 3, CHARACTERISED IN THAT the cavities and the distal portions are substantially similarly shaped and are disposed symmetrically on either side of the longitudinal centre of the connecting element.

5.

A folding dinghy according to claim 4, CHARACTERISED IN THAT each cavity comprises a longitudinally extending seat [36a, 36a'] in which the distal portion of the panel located therein remains pivotably seated as the panel pivots between the folded position and the raised position and in that the enlargement of said distal portion comprises a flange [56] having an outer edge which comprises a first longitudinally extending segment of said distal portion and which is seated in said seat.

6.

A folding dinghy according to claim 5, CHARACTERISED IN THAT said distal portion comprises a second longitudinally extending segment [60, 60'] which is located adjacent said flange and which bears on a longitudinally extending segment [46, 46'] of said cavity located opposite said seat and in that the connecting element comprises a longitudinally extending wall [40] having a face opposite said seat and comprising said segment of the cavity.

7.

A folding dinghy according to any one of claims 4 to 6, CHARACTERISED IN THAT a portion of said cavity is defined by two longitudinally extending walls [32, 34] of the connecting element which have inner faces which meet at a junction constituting said seat.

8. A folding dinghy according to any one of claims 5 to 7, CHARACTERISED IN THAT said seat and said segment of the cavity comprise concave surfaces and in that said first and second longitudinally extending segments of the distal portion comprise convex surfaces.

9.

A folding dinghy according to any one of claims 5 to 8, CHARACTERISED IN THAT the connecting element bears resiliently on said distal portion at said seat and at said segment of the cavity.

10.

A folding dinghy according to any one of claims 2 to 9, CHARACTERISED IN THAT a resilient sealing member [90] is inserted in at least one of the cavities and is sealingly compressed by said distal portion of the panel located in that cavity as the panel is moved to the erected position.