GB2320468A - Inflatable boat - Google Patents

Abstract

An Inflatable boat comprises two substantially parallel inflatable chambers 3 made of a flexible material each having a rear end 6' of substantially conical shape with a reinforcing conical end cap 7 made of a semi-rigid material, characterized in that the tip of the rear end 6' of each chamber 3 is frustoconical and open towards the rear, and the edge of the conical cap 7 and the edge of the opening 8 are secured together in a leaktight manner. Preferably an internal ring 10 is provided.

Description

Inflatable boat The present invention relates to improvements made to inflatable boats comprising buoyancy means comprising two inflatable chambers made of a flexible material, more or less parallel to one another and bordering along two sides a central hull to which they are attached, the said chambers each having a rear end of approximately conical shape with a reinforcing approximately conical end cap made of a semi-rigid material.

In Figure 1 of the appended drawing, the buoyancy means 2 of the inflatable boat 1, depicted diagrammatically viewed in three-quarters perspective from behind and above, comprise two inflatable chambers 3 which may meet at the front 4; the two chambers 3 bordering along two sides a central hull 5 to which they are secured. The rear end 6 of each chamber 3 is of conical shape, and its rear tip is protected by an attached cap 7.

As best seen in Figure 2 which, on an enlarged scale, shows a sectional view through the end 6 of the chamber, in this widespread known arrangement, the conical end 6 of the chamber 3 is made of a flexible gastight and watertight material, generally a coated fabric, as is the rest of the chamber. The conical shape of this end is obtained by appropriate cutting of strips of leaktight flexible material which are then joined together and secured to one another in leaktight fashion to obtain the desired conical shape. Because of this special shaping at its end, the chamber of flexible material then constitutes a self-contained closed pocket from the inflation and sealing point of view.

From this point of view, the protective cap, which is made of a thick semi-rigid material, is simply attached over the tip of the conical end 6 to which it is secured. Its role is purely mechanical, and has no inflation purpose.

The drawback exhibited by this known structure lies in the difficulty of manufacturing the conical tip which, so that the sealing needed for durable inflation of the chamber and precision in the conical shape of this tip to be obtainable at the same time, requires a great deal of accuracy in the cutting and joining-together of the constituent strips of flexible material. This results in a relatively lengthy assembly process and finally in a relatively high cost of manufacture of this part of the boat.

What is more, it may be pointed out that the cap, made by moulding of a synthetic semi-rigid material, intrinsically has qualities of being leaktight to fluids, which qualities are not exploited because this sealing function remains the preserve of the conical tip made of flexible material.

The object of the invention is therefore essentially to overcome the drawbacks exhibited by the aforementioned arrangement of the prior art and to provide an improved arrangement which, while retaining the required leaktightness and mechanical strength qualities, appreciably simplifies the conditions of manufacture of this part of the boat and appreciably reduces its cost.

With these goals in mind, an inflatable boat like the one mentioned in the preamble is essentially characterized, being arranged in accordance with the invention, in that: - the tip of the rear end of each chamber is frusto conical and open towards the rear, - and the edge of the conical cap made of semi-rigid material externally caps and closely matches the edge of the rear opening of the end of the chamber, - the edge of the cap and the edge of the opening being secured to one another in such a way that the conical cap is secured in a leaktight way to the chamber at the frustoconical end.

To make assembly easier and to give the assembly good strength and good leaktightness, it is desirable that an internal ring made of a semi-rigid material should internally surround and closely match the edge of the opening of the end of the chamber to which it is secured at the same time as the cap, the edge of the opening being trapped in a leaktight way between the ring and the edge of the cap; advantageously, the internal ring is of more or less frustoconical shape with a cone angle more or less identical to those of the end of the chamber and of the cap.

As a preference, the ring and the cap are made of the same semi-rigid material, it being possible for these two components to be manufactured by moulding under highly advantageous economic conditions and for them to be mass-produced in great numbers.

Thanks to the provisions in accordance with the invention, the elimination pure and simple of the conical tip of the chamber made of flexible material allows the cutting and joining-together of the strips of material to be simplified considerably. what is more, thanks to the leaktight connection produced between the conical cap and the open end of the chamber, it is the cap that now ends the cone formed by the tapering end of the chamber, and there is no longer any needless and expensive superposition of two materials which have the same leaktight qualities.

The invention will be better understood from reading the detailed description which follows of a number of preferred embodiments given merely by way of non-limiting examples. In this description, reference is made to the appended drawing in which Figures 3 and 4 depict, in section, one basic embodiment, and a preferred embodiment, respectively, of an arrangement of a conical end of a buoyancy chamber in accordance with the invention.

Referring first of all to Figure 3, this depicts, in the same way as in Figure 2, an end 6' of an inflatable chamber 3 (the same numerical references being kept to denote identical parts or members). According to the invention, the tip of the end 6' of the chamber 3 is open; in other words, this end is no longer conical, but frustoconical with an axial terminal opening 8.

The conical cap 7, which may be of the same type and produced from the same semi-rigid material as the one depicted in Figure 2, has its peripheral edge slightly covering the edge of the opening 8, on the outside, or in other words overlaps the end region 6' bordering the opening 8. The cap 7 and the end 6' are therefore secured to one another in their annular region 9 of overlap, in a fluidtight way, by any appropriate method known to a person skilled in the art (welding, bonding, etc.).

In this arrangement, it is the cap 7 which closes the internal volume of the chamber 3 and which, in this end region, fulfils the fluidtightness function, at the same time as the mechanical protection function, which it retains.

Figure 4 illustrates, also in section, a preferred embodiment in which an internal ring 10 is inserted inside the open end 6' that it matches closely in the aforementioned region 9 of overlap. This ring 10 is secured to the open end 6' in the same way (welding, bonding etc.) as the conical cap 7. To ensure perfect mutual contact between the various surfaces and ensure that the assembly maintains a purely conical shape, the ring 10 is preferably of frustoconical shape with the same cone angle as the open end 6' and as the cap 7.

Thanks to this arrangement, the material bordering the opening 8 is trapped between the internal ring 10 and the edge of the cap 7, which makes the assembly operation easier and mechanically strengthens the assembly. In general, despite the addition of an extra part consisting of the ring 10 (which can be made from the same material as the cap 7 and, itself also, be produced by moulding in great numbers) the manufacture of a conical end piece thus formed for the chamber 3 proves appreciably less expensive and less time-cons-ing than before.

As goes without saying and as is already evident from the foregoing, the invention is not in any way limited to that one of its applications and embodiments which have been more specifically envisaged; on the contrary, it encompasses all alternative forms thereof.

Claims (4)

1. Inflatable boat comprising buoyancy means (2) comprising two inflatable chambers (3) made of a flexible material, more or less parallel to one another and bordering along two sides a central hull (5) to which they are attached, the said chambers (3) each having a rear end (6') of approximately conical shape with a reinforcing approximately conical end cap (7) made of a semi-rigid material, characterized in that: - the tip of the rear end (6') of each chamber (3) is frustoconical and open (8) towards the rear, - and the edge of the conical cap (7) made of semi rigid material externally caps and closely matches the edge of the rear opening (8) of the end (6') of the chamber (3), - the edge of the cap (7) and the edge of the opening (8) being secured to one another in such a way that the conical cap (7) is secured in a leaktight way to the chamber at the frustoconical end (6').

2. Inflatable boat according to Claim 1, characterized in that an internal ring made of a semi-rigid material internally surrounds and closely matches the edge of the opening (8) of the end (6') of the chamber (3) to which it is secured at the same time as the cap (7), the edge of the opening (8) being trapped in a leaktight way between the ring (10) and the edge of the cap (7).

3, Inflatable boat according to Claim 2, characterized in that the internal ring (10) is of more or less frustoconical shape with a cone angle more or less identical to those of the end (6) of the chamber (3) and of the cap (7).

4. Inflatable boat according to Claim 2 or 3, characterized in that the ring (10) and the cap (7) are made of the same semi-rigid material.