TECHNICAL FIELD

The present invention relates to conduits for conveying a gas, in particular con duits for conveying a gas for an air conditioning assembly.

PRIOR ART

Conduits for conveying gases are known, e.g. for conveying air in an air con ditioning assembly, which are composed of a ribbon comprising: a first tape made of polymeric material and a second tape made of polymeric material, between which a tape, or layer, of insulating material is interposed. Such rib bon is wound in a helical fashion so as to form a tubular body wherein the adjacent portions of ribbon, or the edges of the adjacent coils realized by the winding of the ribbon, are solidly constrained to each other through gluing with adhesive products.

A problem of such solution is that, because of gluing with adhesive products, the conduit has an internal wall that is conformed like a plurality of lateral surfaces of truncated cones substantially identical and placed in series. In other words, the inner wall is shaped like a sequence of substantially identical converging conduits, wherein the passage portion between the smaller section of one conduit and the larger section of the subsequent one creates a step. Because of this conformation the conduit is adapted to convey an air flow in one direction only, that in which the various sections of the conduit are crossed moving from the larger section to the smaller section. A use of the tube in that way realized in the opposite direction would imply excessive load losses. Another known problem of the solution is that the adhesives tend to crystallize, limiting the flexibility of the conduit.

An object of the present invention is to solve said problems of the prior art, with a simple, rational and low-cost solution.

Such object is accomplished by the characteristics of the invention given in the independent claim. The dependent claims outline preferred and/or particularly advantageous aspects of the invention. DISCLOSURE OF THE INVENTION

The invention, particularly, makes available a method for producing a semi rigid conduit for conveying a gas, comprising the steps of:

- arranging a mandrel, a first tape made of thermoplastic material, a sec ond tape made of thermoplastic material and a third tape made of insu lating material,

- forming a continuous three-layer ribbon by superposing the second tape with the first tape and interposing the third tape between the two,

- winding the ribbon in a helical fashion onto the mandrel partially super posing the adjacent portions of the ribbon itself so as to realize a tubular body wherein the first tape faces towards the inside of the tubular body itself,

- heating the ribbon so as to heat seal the superposed portions of the ribbon.

Thanks to such solution, the resulting conduit does not have the steps that conduits of the prior art have and can be used to convey a flow in both travel ling directions of the conduit. Furthermore, the solution allows conduits to be obtained having greater elasticity with respect to known devices and that can therefore be compressed and stored in smaller volumes.

Another aspect of the invention envisages that in the step of heating the ribbon, the ribbon is heated through a flow of hot air.

Thanks to such a solution, the tapes are heat-sealed within the context of a particularly simple and cheap solution.

A further aspect of the invention envisages that the method may comprise the step of arranging a wire made of elastic material and inserting such wire be tween the first tape and the second tape during the step of forming a ribbon. Thanks to such solution the semi-rigid conduit maintains high elasticity and at the same time is structurally reinforced so as to be stronger and more durable. An aspect that contributes to preventing the presence of steps inside the con duit is that the step of heating the ribbon envisages placing a portion of the first tape of a coil of the ribbon in contact with a portion of the first tape of an adja cent coil of the ribbon and heating such portions. Furthermore, the invention makes available a method for producing a semi rigid and flame-resistant conduit for conveying a gas, comprising the steps of:

- arranging a mandrel, a first tape made of thermoplastic material, a sec ond tape made of thermoplastic material, a third tape made of insulating material and a fourth tape made of aluminium

- forming a continuous four-layer ribbon by superposing with the fourth tape, in this order, the first tape, the third tape and the second tape,

- winding the ribbon in a helical fashion onto the mandrel partially super posing the adjacent portions of the ribbon itself so as to realize a tubular body wherein the fourth tape faces towards the inside of the tubular body itself,

- heating the ribbon so as to heat seal the superposed portions of the ribbon.

The invention also makes available a semi-rigid conduit for conveying a gas comprising: a ribbon provided with a first tape made of thermoplastic material, a second tape made of thermoplastic material and a third tape made of insu lating material, wherein the ribbon is wound in a helical fashion with respect to a longitudinal axis of the conduit and has adjacent portions of the coils of the helix superposed with each other so as to define a tubular body provided with a tubular inner wall and a tubular outer wall, said conduit being characterized in that the tubular inner wall is continuous along the entire longitudinal exten sion of the conduit.

In this way the conduit allows a flow of gas to be guided in both available di rections. In other words it is not important during the installation step to check the orientation of the conduit, which simplifies and speeds up the installation operations.

A further aspect of the invention envisages the portions of first tape and second tape of a coil being heat sealed to the first tape of the adjacent coil.

Thanks to such solution, a conduit is made available provided with a continu ous inner wall and therefore free from discontinuities that would cause load losses while conveying the gas and that would impose having to use the con duit for conveying a flow of fluid in one direction only. Furthermore, the conduit would be extremely flexible and could be compressed and stored in smaller volumes with respect to devices of the prior art.

The invention also makes available a method for producing a semi-rigid con duit for conveying a gas, comprising the steps of:

- arranging a mandrel, a first tape made of thermoplastic material, a sec ond tape made of thermoplastic material and a wire made of elastic ma terial,

- forming a continuous three-layer ribbon by superposing the second tape with the first tape and interposing the flexible wire between them,

- winding the ribbon in a helical fashion onto the mandrel partially super posing the adjacent portions of the ribbon itself so as to realize a tubular body wherein the first tape faces towards the inside of the tubular body itself,

- heating the ribbon so as to heat seal the superposed portions of the ribbon

The invention also makes available an air conditioning assembly comprising a conditioning unit, configured to vary at least one physical characteristic of the air and a semi-rigid conduit, realized with the above method, connected in fluid communication with said conditioning unit.

Thanks to such solution, a conditioning assembly is made available provided with at least one semi-rigid conduit as described above and therefore with the above-described advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will become clear from reading the following description provided as a non-limiting example, with the help of the figures illustrated in the attached tables.

Figure 1 is a view from above of a semi-rigid conduit according to the invention. Figure 2 is a sectional view according to the sectional plane ll-ll of the semi rigid conduit of Figure 1 .

Figure 3 is a sectional view according to the sectional plane Ill-Ill of the semi rigid conduit of Figure 1 .

Figure 4 is a sectional view according to the sectional plane IV-IV of a semi- rigid conduit according to a different embodiment.

Figure 5 is a sectional view according to the sectional plane V-V of the same embodiment of Figure 4.

DETAILED DESCRIPTION

With particular reference to such figures, number 1 indicates as a whole a con duit, being semi-rigid, for conveying a gas (or a mixture of gases).

The conduit 1 has a tubular shape, i.e. it has a tubular inner wall 5 that delimits a channel C for conveying a gas and a tubular outer wall 10.

In particular, the conduit is defined by the helical winding about a longitudinal axis L of the conduit 1 itself of a ribbon 15, of multi-layer type, along an ad vancement direction A parallel to the longitudinal axis L.

The ribbon 15 is firstly composed of a first tape 20, for example smooth, made of thermoplastic material.

Preferably, the first tape 20 is made of polyolefin based polymeric material. The thickness of the first tape 20 is lower with respect to the width of the first tape itself.

It is specified that in this document width means the size of the tape in the transverse direction to a longitudinal axis of the tape itself.

For example, the ratio between the thickness and the width is comprised be tween 1 :50 and 1 :200, preferably it is 1 :100.

The ribbon 15 then has a second tape 25, for example smooth, made of ther moplastic material.

For example, the second tape 25 is made of polyolefin-based polymeric mate rial.

The thickness of the second tape 25 is lower with respect to the width of the second tape 25 itself.

For example, the ratio between the thickness and the width is comprised be tween 1 :50 and 1 :200, preferably it is 1 :100.

The second tape 25 has the same width with respect to the width of the first tape 20, e.g. the second tape 25 has the same dimensions with respect to the first tape 20.

The second tape 25 is adapted to be superposed in contact with the first tape 20.

The ribbon 15 can then comprise a third tape 30 interposed between the first tape 20 and the second tape 25.

The third tape 30 is made of porous material, e.g. thermally and acoustically insulated.

For example, the third tape 30 is made of expanded polyethylene.

The thickness of the third tape 30 is lower with respect to the width of the third tape itself 30.

For example, the ratio between the thickness and the width is comprised be tween 1 :10 and 1 :50, preferably it is 1 :25.

The third tape has the same width as the width of the first tape 20 and of the second tape 25 and a higher thickness with respect to said tapes, e.g. between 10 to 500 times higher.

The first tape 20, the second tape 25 and the third tape 30 are joined together and fixed to form the ribbon 15, of multi-layer type.

For example, the first tape 20, the second tape 25 and the third tape 30 are heat sealed to each other, e.g. by means of a forced flow of hot air.

The ribbon 15 also has a wire 35 of elastically deformable material interposed between the first tape 20 and the second tape 25 i.e. inserted at the third tape 30.

The wire 35 is made of metal, e.g. harmonic steel, and can have a diameter comprised between 0.5 mm and 3 mm, preferably 1 .2 mm.

It is not excluded that in other embodiments, the wire 35 may be made of an other rigid and elastically deformable material.

The ribbon 15 is therefore substantially conformed like a multi-layer tape, e.g. having a substantially quadrangular cross section, which has a first longitudinal edge 40 and a second longitudinal edge 45 opposing the first edge 40.

In particular, the ribbon 15 thus conformed has a width equal to that of the first tape 20, of the second tape 25 and of the third tape 30, and thickness equal to the sum of the thicknesses of the first tape 20, of the second tape 25 and of the third tape 30.

The ribbon 15 is wound to form the conduit 1 , i.e. the conduit 1 is defined by a series of coils S of the ribbon 15 wound in a helical, consecutive and flanked fashion along the advancement direction A and realized so that two consecu tive coils S are at least partially superposed.

The coils S are identical to each other, i.e. they are realized so that each wind ing coil S of the ribbon 15 defines an equal portion of conduit 1 .

The coils S are superposed so that a portion of first longitudinal edge 40 of the ribbon 15 related to a coil S is superposed with a portion of second longitudinal edge 45 of the ribbon 15 related to the adjacent coil S.

In particular, a portion of first tape 20 of a coil S is superposed with a preceding portion of second tape 25 of a coil S, with respect to the advancement direction A. For example, a portion of first tape of said coil S is superposed with a portion of first tape 20 of a subsequent coil S, with respect to the advancement direc tion A.

The portion of first tape 20 related to a coil S is joined and fixed to the portion of first tape 20 and of second tape 25 of a preceding coil S with which it is in contact.

In other words, a portion of first tape 20, corresponding to the second edge 45, of a coil S is superposed and fixed to a portion of second tape 25, correspond ing to the first edge 40, of a preceding coil S.

Furthermore, a portion of first tape 20, corresponding to the second edge 45, of a coil S is superposed and fixed to a portion of first tape 20, corresponding to the first edge 40, of a preceding coil S, e.g. said portions are fixed together to a portion of second tape 25, corresponding to the first edge 40, of the pre ceding coil S.

In particular, the superposed portions are fixed at the contact point of the first edge 40 of a coil S with a subsequent coil S.

Said superposed and fixed portions are heat sealed to each other.

The tubular inner wall 5 of the conduit is defined by the first tape 20 and is continuous along the entire longitudinal extension of the conduit.

Specifically, in any cross section containing the longitudinal axis L of a longi tudinal half of the conduit 1 , the first tape 20 defines a single continuous line at least along two consecutive coils S, preferably along the whole conduit 1 . Furthermore, in any cross section of the conduit, the first tape 20 has the profile of a single continuous line closed in a loop.

At the same time, the wire 35 made of rigid and elastically deformable material also defines a structural reinforcement helicoid inside the conduit 1 , and in particular is wound at the portions of superposed coils S.

Each coil S is therefore flexible thanks to the structural properties of the mate rials of the first tape 20, of the second tape 25 and of the third tape 30 and at the same time structurally sustained by the wire 35 made of elastically deform able rigid material.

In particular, the superposed portions of the coils S are also elastically flexible. In one embodiment of the conduit, being semi-rigid, illustrated in Figures 4 and 5, the ribbon 15’ comprises, as well as the first tape 20, second tape 25 and third tape 30, a fourth tape 50 made of aluminium, which is superposed in contact with a face of the first tape 20 opposite the second tape 25.

The fourth tape 50 is heat sealed to the first tape 25.

The fourth tape 50 has the same width and thickness as the first tape 20.

The ribbon 15’ is therefore conformed like a multi-layer tape, e.g. having a quadrangular transverse shape, formed by the superposition of the fourth tape 50 with the first tape 20, the third tape 30 and the second tape 25.

The ribbon 15’ can comprise a wire 35 made of elastically deformable material for stiffening the conduit.

In this embodiment, the conduit 1 is defined by a series of coils S of the ribbon 15’ wound in a helical, consecutive and flanked fashion along the advance ment direction A.

Furthermore, the coils S are superposed so that a portion of fourth tape 50 of a coil S is superposed in contact with a portion of second tape 25 of a preced ing coil S, with respect to the advancement direction A.

In other words, a portion of first tape 20, corresponding to the second edge 45, of a coil S is superposed and fixed to a portion of second tape 25, correspond ing to the first edge 40, of a preceding coil S. For example a portion of fourth tape 50 of said coil is superposed with a portion of fourth tape 50 of a subse quent coil S, with respect to the advancement direction A. The superposed portions are heat sealed at the contact point of the first edge 40 of a coil S with a subsequent coil S.

The invention further makes available a method for producing the conduit 1 , being semi-rigid, as illustrated in Figures 1 , 2 and 3.

The method envisages arranging a winding mandrel, the first tape 20, the sec ond tape 25 and the third tape 30 and realizing the ribbon 15 by superposing the third tape 30 with the first tape 20 and the second tape 25 with the third tape 30.

For example, the method may envisage arranging the wire 35 made of elastic material between the first tape 20 and the second tape 25, i.e. at the third tape 30.

The step of forming the ribbon 15 envisages heat sealing the three tapes 20, 25, 30 together.

Once the ribbon 15 has been formed, the method envisages the step of wind ing the ribbon 15 onto the mandrel in a helical fashion.

The step of winding the ribbon 15 onto the mandrel in a helical fashion envis ages forming a tubular body, so that the first tape 20 defines the inner wall 5 which delimits the conveying channel.

Furthermore, the step of winding the ribbon 15 in a helical fashion envisages forming a plurality of consecutive coils S of ribbon 15, so that each subsequent coil S is at least partially superposed with the preceding coil S, e.g. along at least one whole 360° angle with respect to the longitudinal axis L.

The method also envisages heating the ribbon 15 during the winding, e.g. through a flow of hot air forced towards the mandrel, so as to heat seal the superposed portions of the coils S.

In other words, so as to heat seal the portion of first tape 20 of the coil S with the portion of second tape 25 of the preceding coil S and the portion of first tape 20 of the subsequent coil S with the portion of first tape 20 of the preced ing coil S.

An embodiment of the invention illustrated in figures 1 , 4 and 5 is made avail able by another method of realizing a conduit, being semi-rigid, for conveying a gas. The method envisages arranging a winding mandrel, the first tape 20, the sec ond tape 25, the third tape 30 and the fourth tape 50 and realizing the ribbon 15’ by superposing with the fourth tape 50, in this order, the first tape 20, the third tape 30 and the second tape 25.

For example, the method may envisage arranging the wire 35 made of elastic material between the first tape 20 and the second tape 25, i.e. at the third tape 30, e.g. inside the third tape 30.

The step of forming the ribbon 15’ envisages heat sealing the four tapes 20, 25, 30 and 50 together.

Once the ribbon 15’ has been formed, the method envisages the step of wind ing the ribbon 15’ onto the mandrel in a helical fashion.

The step of winding the ribbon 15’ onto the mandrel in a helical fashion envis ages forming a tubular body, so that the fourth tape 50 defines the inner wall 5 which delimits the conveying channel C.

Furthermore, the step of winding the ribbon 15’ in a helical fashion envisages forming a plurality of consecutive coils S of ribbon 15’, so that each coil S is at least partially superposed with the preceding coil S, e.g. along at least one whole 360° angle with respect to the longitudinal axis L.

The method also envisages heating the ribbon 15’ during the winding, e.g. through a flow of hot air forced towards the mandrel, so as to heat seal the superposed portions of the coils S.

In other words, the portion of fourth tape 50 of a coil S is heat sealed with the portion of second tape 25 of the preceding coil S.

A further embodiment of the invention makes available another method of re alizing a conduit, being semi-rigid, for conveying a gas (or a mixture of gases), in particular not provided with an intermediate insulating layer.

The method firstly envisages arranging a mandrel adapted to support the con duit 1 during the realization thereof.

The method then envisages arranging the first tape 20 and the second tape 25.

In particular, in such a way that the second tape 25 is superposed in a plan arrangement with the first tape. Subsequently, the method envisages arranging the wire 35 made of elastic material between the first tape 20 and the second tape 25.

The method then envisages fixing the first 20 and the second 25 tape to each other to form with the wire 35 made of elastic material a ribbon, comprising three layers and continuous, e.g. through heat sealing by means of a hot air flow forced towards the mandrel.

The method also envisages winding the ribbon onto the mandrel in a helical fashion so as to form a tubular body, in such a way that the first tape 20 faces towards the inside of the tubular body itself.

In particular the method envisages forming consecutive coils of ribbon, so that each subsequent coil is at least partially superposed with the preceding coil, i.e. so that a portion of first tape 20 of a subsequent coil is at least superposed with a portion of second tape 25 of the preceding coil S and that then said portion of first tape 20 descends again to the level of the portion of first tape 20 of the preceding coil S itself.

The method also envisages heating the ribbon during winding, e.g. through the flow of hot air forced towards the mandrel, so as to heat seal the superposed portions of the coils S, i.e. the portion of first tape 20 of the subsequent coil S with the portion of second tape 20 of the preceding coil S and the portion of first tape 20 of the subsequent coil S with the portion of first tape 20 of the preceding coil S.

The invention thus conceived can undergo numerous modifications and vari ants all of which are covered by the inventive concept.

Moreover, all of the details can be replaced by other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and sizes, can be whatever according to the requirements without for this reason depart ing from the scope of protection of the following claims.