TECHNICAL FIELD

The present invention relates to a pontoon for use in a lake, pool or corresponding water area, and comprising a carrier element for realising buoyancy and an upwardly facing support surface for carrying a load.

The present invention also relates to a carrier element for a pontoon.

BACKGROUND ART Pontoons are known in a huge number of different fields of use, such as for bathing landing stages, mooring boats, fishing and other activities where the wish is for ready access to water of a certain depth. Typically, the pontoons are moored in lakes, seas, pools and similar waterways. They may be disposed beside beaches, piers or fixed landing stages, but may also be placed freely by being anchored with the aid of an anchor or other weight which causes the pontoon to remain in the desired position in the water. The advantages inherent in pontoons are numerous: they are easy to move, are independent of the structure of the bottom, are substantially insensitive to differences in the water level, since they always float on the surface, and they can always be moved and rebuilt for realising a different pontoon structure.

Unfortunately, there are also disadvantages. Even if the pontoons always float, the construction as a whole is heavy and unwieldy when being transported on land. They also show a tendency to be bulky, since they must include large elements of low density in order to obtain maximum buoyancy. In general, such elements are disposed on the underside of the pontoon, which implies that the pontoon is not only of considerable length, but also considerable depth. To sum up, it may be said that the transport and storage of pontoons require considerable space.

A further disadvantage is that the assembly of pontoons is quite a complicated procedure.

They are often built at factories, which contributes to the large space requirements on transport, since such pontoons are generally transported in the finished state.

PROBLEM STRUCTURE It is thus one object of the present invention to realise a pontoon which requires little space on transport and storage in relation to its final size, at the same time as maximum payload is obtained. Assembly should be so simple that it can be put into effect wholly or partly close to the site of final use.

SOLUTION The object forming the basis of the present invention will be attained if the pontoon intimated by way of introduction is characterised in that the carrier element and the support surface are of one piece manufacture with one another.

Concerning the carrier element, the object of the present invention will be attained if this is characterised in that it has a shell and foamed material disposed therein.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS The present invention will now be described in greater detail hereinbelow with reference to the accompanying Drawings. In the accompanying Drawings: Fig. 1 is a perspective view of a pontoon according to the present invention; Fig. 2 is a top plan view of a carrier element included in the pontoon of Fig. 1 ; Fig. 3 is a straight side elevation of the carrier element of Fig. 2; Fig. 4 is a sectional view of a frame included in the pontoon according to the present invention; and Fig. 5 is a perspective view of a corner element included in the frame.

DESCRIPTION OF PREFERRED EMBODIMENT

Fig. 1 shows a pontoon 1 according to the present invention. The pontoon is constructed from a number of buoyant bodies or carrier elements 2 which are united by at least two longitudinal profile bodies, but preferably by a circumferential, complete frame 3.

The carrier elements 2 possess the buoyancy which entails that the pontoon 1 floats on the surface of the water and is capable of carrying a load, for example people on the pontoon. The carrier elements 2 are mutually identical and are replaceable. In the illustrated embodiment, they are five in number, but this number is optional depending on the desired length of the pontoon 1. The carrier elements 2 are intended to serve an upwardly facing support surface 9 at the same time as they realise the requisite buoyancy of the pontoon 1.

Regardless of how the carrier elements 2 are joined together, by means of a complete frame 3 or opposing longitudinal profile bodies in the longitudinal direction of the pontoon, it is important that the frame or the profile bodies are flexurally rigid in the vertical direction when the pontoon is in use, so that the entire pontoon moves in the water as a rigid unit.

At their short sides, the carrier elements 2 are provided with engagement members for cooperation with the surrounding frame 3 or the longitudinal profile bodies. However, the engagement members are not visible in Fig. 1, but are concealed by the frame 3 since they are accommodated in it.

The frame 3 includes a profile which, in the preferred embodiment, is extruded and is manufactured, for example, from aluminium or plastic. The frame 3 has two longitudinal sides 4 and two short sides 5 which are built up from the same profile. The longitudinal sides 4 and the short sides 5 are united in the corners by specific corner elements 6 which, in the preferred embodiment, are manufactured from plastic. However, other production materials such as aluminium are conceivable. The frame 3 is interconnected to the carrier elements 2 preferably in that the carrier elements 2 display specific projections which are accommodated in corresponding recesses on the inside of the frame 3. With the aid of the frame 3, a torsionally rigid arrangement is realised of the individual carrier elements 2. The frame 3 further serves for securing anchorage members 7 in which the pontoon 1 may there be secured to some other structure or other objects such as, for example, small craft which may be moored to the pontoon 1.

Fig. 2 shows an individual carrier element 2 straight from above. In this Figure, the engagement members 8 which cooperate with the inside of the frame 3 are visible. The engagement members 8 are in the form of projections which extend over a substantial part of the short sides of the carrier elements 2. The engagement members 8 may naturally be given a different extent, but should be quite elongate in order to reduce the risk of twisting of the carrier element 2 in relation to the frame 3 and thereby causing instability in the pontoon 1.

Thus, an increased length of the engagement members 8 results in increased rigidity in the pontoon 1 as a whole.

The carrier element 2 further has a support surface 9 which is intended to directly support a load, for example a person walking on the pontoon 1. Thus, no specific coating is required on the carrier elements, but these per se and with the aid of the frame 3 possess the requisite rigidity to permit direct access to the pontoon. The support surface 9 is further advantageously provided with some form of friction-increasing surface structural pattern for reducing the risk of slipping. Such patterns may have very different appearances, and for the sake of simplicity they are not shown in Fig. 2.

The carrier element 2 has an outer shell which is of one piece manufacture, preferably by blow moulding or rotation casting. As a result, the carrier element will be substantially without joints, with the exception of an aperture for the introduction of a filler material.

Inside the carrier element 2, there is disposed a filler material of low density in the form of a continuous foamed element. A few examples of filler material are expanded polystyrene or polyurethane foam.

On the expansion of the filler material so that the foamed element is formed, this will have a surface layer, a so-called casting skin, which imparts to the foamed element superior mechanical strength and in particular torsional rigidity. The foamed element interiorly in the outer skin supports this from inside so that it will display superior mechanical strength and may also resist spot loadings from the outside without buckling inwards. The superior strength of the carrier element 2 contributes to a great extent to the pontoon 1 being capable of being built up without any specific carrying surface needing to be provided on top of the carrier elements, even though the function of the frame 3 is also important for ensuring

torsional rigidity between the carrier elements 2. A feature common to those materials that are employed as filler materials is that they have low density and preferably closed cells.

In practical trials, each respective carrier element 2 has proved to be able to carry loads of about 120 kg. These levels naturally depend on the production material in and size of the carrier elements 2.

Fig. 3 shows the carrier element 2 straight from the side, i. e. in the direction of the arrow A in Fig. 2. In this view, the cross sectional profile of the projections 8 is apparent. In such instance, it will be seen that the profile is undercut for realising a reliable anchorage with the frame 3. The thickness of the carrier elements 2, i. e. their extent in the vertical direction, is of the same order of magnitude as the height of the frame 3.

The profile included in the frame 3 is shown in cross section in Fig. 4. As was mentioned previously, the profile is particularly well suited for extrusion, for example in plastic or aluminium.

The frame 3 has an undercut groove 10 for accommodating the elongate projections 8 of the carrier elements 2. Preferably, the projections 8 are intended to be slid into the undercut groove 10, but depending on material properties in both the carrier elements 2 and the frame- 3, a snap action locking may also come into consideration. The dimensioning of the undercut in the groove 10 and the projections 8 is also decisive as to whether a snap action locking is possible.

In the upper region of the frame 3, there is provided a longitudinal upper groove 11. The groove 11 serves for receiving and accommodating screws so that extra equipment may be provided anywhere whatever along the length of the frame 3. Such extra equipment may be devices for mooring boats, simple taffrails and handrails and means for interconnection with other pontoons 1 provided with frames. The screw groove or pocket 11 further displays a laterally disposed space 14 which functions as a drawing groove for a strip disposed therein.

Such a strip may be provided either for decorative purposes or also for interconnection with a substantially parallel groove on another pontoon 1 which is positioned adjacent the first pontoon.

At the lower end of the frame 3, there is provided a lower longitudinal groove 12 which, like the groove 11, functions as a screw pocket for disposing equipment on the frame. Such possible equipment is advantageously secured in position with the aid of screws which engage in both the upper screw pocket 11 and the lower screw pocket 12.

Along the outside of the frame 3, there is provided a longitudinal groove 13. This serves as a countersink for parts such as the anchorage means 7 which are disposed on the outside of the frame 3. Consequently, the risk is reduced that people sustain injuries on projecting parts such as screw heads, fittings or the like.

Fig. 5 is a close up view of a corner element 6 included in the frame 3, this element being disposed between the longitudinal sides 4 and the short sides 5 in the frame 3. In the mounted position, the corner element 6 has an outwardly facing corner portion 15 which forms a unitary transition between a longitudinal side 4 and a short side 5 in the frame 3. The matching with the outside of the frame results in smooth transitions between the corner element 6 and the profiles included in the frame 3, whereby the risk of injury on projecting corners or edges is eliminated.

The corner element 6 further displays two more powerful arms 16 which are disposed, like the projections 8 of the carrier elements 2, to project inwards in the undercut longitudinal groove 10 of the frame 3. In order that the arms 16 remain in position in the groove 10, they are secured with the aid of anchorage means such as screws or rivets in the holes 18.

The corner element 6 is further provided with two shorter, narrower projections 17 which are screwed in position in the straight section 19 of the frame 3 which is disposed below the elongate undercut groove 10. The shorter projections 17 are also provided with holes 18 for anchorage members such as screws or rivets.

DESCRIPTION OF ALTERNATIVE EMBODIMENTS It is possible to vary the frame 3 included in the pontoon 1. In the preferred embodiment, there was shown a frame 3 with quite a detailed cross section. It is naturally possible to simplify the frame 3 considerably even if some of the advantage attained by the provision of the screw pockets 11 and 12 is lost. The simplification that is most readily to hand is that the

frame 3 in its entirety consists of a C-profile which substantially corresponds to the elongate projections 8 of the carrier elements 2. In particular if the simpler, just-described embodiment of the frame 3 is selected. It is possible to modify both manner of manufacture and choice of materials. For a simpler frame 3, forming by means of roll forming of sheet material is a conceivable alternative.

In one particularly simple and economical variation of the subject matter of the present invention, the projections 8 on the carrier elements 2 may be dispensed with. Instead, there are provided material accumulations along the short sides of the carrier elements 2 so that the material thickness will be sufficient to permit screwing the carrier elements 2 to the frame 3 or the longitudinal profile bodies.

Another method of modifying the pontoon 1 according to the present invention is to provide, between the carrier elements 2 included in the pontoon 1, specific joint profiles in order to overbridge the joints between them. Such joint profiles give a smoother surface and also contribute to increased rigidity in the pontoon 1, in particular in the event of a moving cargo, such as when a person moves along the pontoon 1. Advantageously, the joint profiles are secured in or inside the longitudinal sides 4 of the frame 3.

Finally, it is naturally possible to provide, on the pontoon 1, an additional upwardly facing carrying surface. Such a provision preferably serves a decorative purpose, since a separate carrying surface is not necessary for the stability and rigidity of the pontoon 1.

The present invention may be modified further without departing from the scope of the appended Claims.