INFLATABLE ENCLOSURE AND METHOD FOR PRODUCING AN INFLATABLE ENCLOSURE

Description

The present invention relates to the field of inflatable enclosures, more particularly of the type having an inflatable structure covered with a flexible cover, for example covering enclosures such as shelters, hangars, industrial or test enclosures, tents or any other object having an inflatable structure to which a flexible cover is attached in order to delimit an interior volume.

Inflatable enclosures having a structure made from constant-air inflatable tubular beams are known in this field. However, these structures require special arrangements in order to permanently blow an airflow that keeps the structure inflated. Inflatable enclosures having a structure made from airtight inflatable tubular beams, wherein the beam is provided with an inflation valve that keeps the inflated tube closed, are also known. These structures are generally self-supporting; once inflated, they maintain their shape and support the covers, doors and other elements of the enclosure.

In all cases, the inflatable structure must support a cover that has the role of protecting the volume of the enclosure from the weather, heat, dust, electromagnetic radiation, or of isolating it from the outside.

Self-supporting inflatable enclosures are known from documents FR3069001 or FR3092126. These enclosures have a structure having beams and spacers that support a cover separating the internal part of the enclosure from the outside. Such enclosures are very light; they are generally made from flexible materials and their manufacturing requires particular attention with regard to the spread in terms of shape and dimensions of their geometry due in particular to manufacturing tolerances. More particularly, if the geometric shape is non-compliant, the structure cannot fulfil its supporting function correctly. Furthermore, if folds form in the region at which the cover and an element of the structure are joined, these folds may form regions in which rainwater becomes stored, which may result, above a certain limit, in the structure collapsing. Furthermore, these folds degrade the quality of the visual impression of the entire enclosure.

It is thus necessary to rework the assembly of the elements of the inflatable enclosure (formed by sewing, adhesive bonding, welding). Such reworking (or alteration) of the assembly results in a decrease in the manufacturing productivity of the enclosure and an increase in the manufacturing cost.

The invention aims to overcome the drawbacks of the above-mentioned documents and to provide an original solution for producing a higher-quality inflatable enclosure that allows liquids to flow over its external surfaces without accumulating in pockets or folds and has an improved appearance, all for a lower production cost.

This aim is achieved by the invention, which proposes an inflatable enclosure having an inflatable structure comprising at least one inflatable beam and a cover supported by said structure, wherein the cover comprises a longitudinal dimension for fastening to a corresponding longitudinal dimension of said beam, characterized in that an elastic strip, which runs along said longitudinal dimensions, is interposed between said cover and said beam.

In other words, the invention proposes connecting the cover and the inflatable structure along their opposing longitudinal dimensions by interposing an elastic strip between them so as to exert tension in a transverse direction between the cover and the beam once they have been connected or assembled. An elastic strip is understood to mean a flat elastic band having a much smaller width than its length, said length corresponding substantially to the longitudinal dimensions of the beam and of the cover. An elastic strip preferably has elastic properties in the transverse direction of the strip and even more preferably in the transverse direction and in the longitudinal direction of the strip.

Thus, it has been found during laboratory tests that such an elastic strip made it possible, once the cover and the beam had been assembled, to continuously exert elastic tension between the assembled parts, it being possible for said tension to vary temporarily in order to absorb excessive spread in terms of manufacturing tolerances. This is all the more effective when the cover and the inflatable structure are textile materials that are sewn together, because the manufacturing spread, which is very large in this case, is completely absorbed by the deformation of the elastic strip connecting them.

This therefore eliminates the need for alterations when the structure and the cover are sewn, welded or adhesively bonded together, which increases productivity, improves the appearance of the assembly and achieves a smooth appearance of the covers that are fastened to various inflatable structures.

Said elastic strip may be tensioned in a transverse direction once it has been assembled with the beam or with the cover. The elastic strip of the invention is introduced between the cover and the beam of the inflatable structure such that its longitudinal direction follows those of the beam and of the cover. Tensioning the elastic strip in its transverse direction ensures better absorption of dimensional variations that may occur during the assembly of the cover and the beam.

Said beam may comprise a flexible casing enclosing an inflatable tube and said casing may be connected to a flexible flap at a first end thereof. The casing and the flap may be made from a woven material, thereby making it easier to sew them together.

Said elastic strip may be assembled with said flap in a region that is close to a second end of the flap and opposite said first end for fastening to the casing.

The cover and the beam may have removable assembly means.

Said cover and said flap may be connected by a zip fastener.

The elastic strip may be fastened in line with a fold of said flap. This makes it possible to give the fabric of the flap latitude.

Said elastic strip may be a woven elastic strip.

Said inflatable structure may comprise two parallel arch-shaped beams supporting said cover and each beam may be fastened to the cover by interposing an elastic strip therebetween. Such a curved structure is able to span a space while at the same time being able to support a significant weight.

The aim of the invention is also achieved by a method for assembling an inflatable enclosure having an inflatable structure comprising at least one inflatable beam and a cover supported by said structure, wherein the cover comprises a longitudinal dimension for fastening to a corresponding longitudinal dimension of said beam, characterized in that an elastic strip, which runs along said longitudinal dimensions, is interposed between said cover and said beam.

The elastic strip may be sewn together with one of the ends of the cover or of the beam so as to be able to tension the strip in the transverse direction thereof.

The elastic strip may be sewn together with the end of a flap integral with said beam, thereby forming a fold above the elastic strip.

Said elastic strip may be sewn using a sewing machine with fixed spacing.

The method of the invention may comprise a step of assembling the cover and the end of said flap by means of a zip fastener.

The invention will be better understood by virtue of the remainder of the description, which refers to the following figures:

FIG. 1 is a schematic perspective view of the inflatable structure of an inflatable enclosure of the invention;

FIGS. 2a, 2b and 2c are top, front and side views of an inflatable enclosure of the invention;

FIG. 3 is a view in cross section along the plane A-A in FIG. 2b illustrating an embodiment of the assembly of the enclosure according to the prior art;

FIG. 4 is a view in cross section along the plane A-A in FIG. 2b illustrating an embodiment of the assembly of the enclosure according to the invention.

In the various figures, identical or similar elements bear the same reference signs. Their description is therefore not systematically repeated.

FIG. 1 shows a perspective view of the inflatable structure 2 of the enclosure 1 according to an exemplary embodiment of the invention. The inflatable structure 2 is made up of two peripheral beams or arches 10, 12, one intermediate arch 14, and three crossmembers 11, 13 and 15 connecting the arches together at different levels starting from their top. The peripheral arches 10, 12 and the intermediate arch 14 are each made up of a plurality of pieces of fabric sewn together (the seams are visible in the form of transverse lines in the figures) to form the casing of a fabric arch into which an inflatable tube provided with an inflation valve is introduced. Similarly, the crossmembers 11, 13 and 15 are each obtained by sewing pieces of fabric to form the casing with a cylindrical side into which an inflatable tube provided with an inflation valve is introduced. The various inflatable tubes are then advantageously placed in communication (for example by means of airtight external connecting hoses) in order to make it easier to inflate the entire structure using a single inflation valve. An inflatable tube is a closed cylindrical tube, for example made from polyurethane, the dimensions of which are substantially those of the casing into which it is inserted.

The casing of the elements of the inflatable structure 2 is made from a synthetic Dacron-type fabric. The casing of each element is closed and produced by sewing a plurality of pieces of fabric together, and in which an opening allowing an inflatable tube to be inserted therein has been formed.

The inflatable structure 2 is connected to a cover 3, preferably by means of a removable fastener. More specifically, a fabric flap 17 is sewn to the casing of the beam 10 and one part of a zip fastener 30 is sewn to the end of the flap 17, the other part of the zip fastener being sewn to the end of the cover 3. The end of the flap 17 opposite the end for assembly with the cover 3 has a second zip fastener 32 for fastening to a module of the enclosure or to another cover.

According to the invention, the inflatable beam 10 or 12 of the inflatable enclosure 1 comprises a longitudinal dimension for fastening to a corresponding longitudinal dimension of the cover 3 and an elastic strip 20 is interposed or introduced therebetween, said strip running along said longitudinal dimensions of the beam 10 or 12 and of the cover 3. Such an elastic strip is able to continuously exert elastic tension between the assembled parts. This prevents folds from forming on the cover, in which folds rainwater could accumulate.

As may be seen more clearly in FIG. 4, the elastic strip 20 is fastened, at its ends 22 and 24, in line with a fold 19 formed in the flap 17. The elastic strip 20 is preferably fastened to the intrados of the flap 17. The intrados is understood to mean the face facing towards the interior of the enclosure of the flap or of the fabrics of the various components of the enclosure, as opposed to the extrados, which is the external face of the components of the enclosure. Thus, by fastening the elastic strip to the intrados, the external appearance of the enclosure is preserved, and the internal space of the enclosure is protected by the materials covering the enclosure.

The elastic strip may be sewn to the flap 17 using a twin-needle sewing machine with fixed spacing. The elastic strip 20 is tensioned by the fold thus formed, which also makes it possible to give the fabric of the flap 17 latitude. Preferably, the elastic strip 20 is tensioned in the direction of its width when its edges 22, 24 are sewn below the fold 19.

The cover 3 is made, for example, from spinnaker fabric.

The elastic strip 20 is a flat woven elastic strip having weft threads and warp threads made from an elastic material, for example from elastane or nylon. The Young's modulus of the elastic strip may range from 20 to 300 MPa, depending on the nature of the materials chosen. Furthermore, the Young's modulus of the fabrics used for the covers is in the range of 550 to 600 MPa. Thus, the elastic strip is at least half as rigid than the fabric of the cover and the fabric that connects the elastic strip to the inflatable beam, preferably between half as rigid and thirty times less rigid than the latter.

By way of example, for an enclosure having dimensions of 7100 mm ×5000 mm ×1200 mm, the elastic strip has a width of 50 mm.

In a variant, the cover 3 is attached to the inflatable structure by means of velcro-type strips or hook-and loop strips, one part of the strips being sewn to the end of the flap 17 integral with the beam 10 of the inflatable structure 2 and another to the cover 3 of the enclosure 1.

Other variants and embodiments of the invention may be envisaged within the scope of the invention as claimed. Thus, in a variant, the longitudinal end of the cover and the longitudinal end of the flap are each assembled directly to the elastic strip. It is also possible to use the solution of the invention with any other non-arch shaped inflatable beam, for example a right-prism-shaped or a right-cylinder-shaped beam.

Furthermore, it is possible to envisage sewing or welding the elastic strip to the cover by forming a fold above the elastic strip in order to give the material of the cover latitude.