FIELD OF THE INVENTION

The present invention is generally applicable to the technical field of flexible hoses, and particularly relates to a flexible hose, preferably an irrigation hose or garden hose for transporting water, which is enlargeable, i. e. susceptible to automatically enlarge upon the passage of the fluid inside it and to automatically retract when the pressure of the liquid stops.

Definitions

As used herein, with the expression “textile reinforcement layer” or derivative thereof is meant a layer consisting of at least one textile yarn arranged on a layer that supports it. The “textile reinforcement layer” is disposed on the supporting layer so as to leave free portions thereof, generally square-, rectangular- or rhomboid-shaped.

As used herein, with the expression “textile yarn” or derivative thereof includes an elongated thread-like member of any shape and made of any material, provided that the magnitude of the length is significantly prevailing over the other. For example, the textile yarn may be a polymer yarn, which may have a unitary structure or may in turn consist of the union of several elementary threads, or a textile band having rectangular section.

As used herein, with the expression “textile knitted layer” or “knitting” or derivative thereof is meant a layer consisting of at least two yarns or groups of yarns laying on the supporting layer and connected to each other to form a plurality of chain-like stitches or knit.

As used herein, with the expression “textile woven layer” or “weaving” or derivative thereof is meant a layer consisting of at least two yarns or groups of yarns laying on a supporting layer with opposite inclinations and connected to one another alternately to form a weave. In a weaving a yarn is interlaced with another yarn once above and then below the latter. Depending on the inclination, the weaving is also known as fabric.

As used herein, with the expression “textile knotted layer” or “knotting” or derivative thereof is meant a layer consisting of at least two yarns or groups of yarns laying on the supporting layer with opposite inclinations and interconnected to each other by means of one or more knots. In a knotting a yarn cannot slide with respect to another due to the constraint imposed by the knots.

As used herein, with the expression “compatible materials” or derivative thereof materials are meant having chemical and/or physical compatibility to each other, that is materials which once coupled give rise to a junction adapted to support the transfer of tensile or shear stresses through the contact surface. Therefore, identical materials or in any case materials having the matrix with the same base have the maximum compatibility.

As used herein, with the expression “matrix” of a polymer or derivative thereof is meant a polymeric material capable of providing the molecular structure of the finished product.

As used herein, with the expression “providing” or derivative thereof is meant the preparation of an element of interest to a process step of interest, thus including any preventive treatment act for the optimum exploiting of the same step of interest, from the simple withdrawal and possible storage to pre-heat and/or chemical and/or physical treatments and the like.

As used herein, with the expression “film” or derivative thereof is meant a layer of polymeric material whose thickness is less than 0.5 mm.

STATE OF THE ART

Hoses are known, especially fire hoses, which includes an outer jacket and an inner flexible tube.

The outer jacket is generally made of synthetic textile fibers and has a predetermined inner diameter, whereas the inner tube is made of rubber and is designed to enlarges upon working pressure imparted by the water flowing therethrough up to an outer diameter coinciding with the inner diameter of the jacket.

As a result, the latter defines the inner diameter of the whole hose when in use. On the other hand, when not in use, i.e. when no water flows through the hose, the inner tube collapse and became flat, so that the whole hose has a relatively low bulkiness so that it can be stored on a reel.

This kind of hose is difficult and cumbersome to manufacture, since the jacket and the inner tube have to be manufactured separately and subsequently assembled.

Moreover, this kind of hoses are to be used by specialized operators, and is heavy, bulky and difficult to handle.

SUMMARY OF THE INVENTION

Object of the present invention is to overcome at least partially the above drawbacks, by providing an enlargeable flexible hose of remarkable efficiency and relative cheapness.

Another object of the invention is to provide an enlargeable flexible hose which can be manufactured in a simple and fast manner.

Another object of the invention is to provide an enlargeable flexible hose which can be manufactured automatically in line.

Another object of the invention is to provide an enlargeable flexible hose which is wieldy to use.

Another object of the invention is to provide an enlargeable flexible hose which has a relatively high burst pressure.

Another object of the invention is to provide an enlargeable flexible hose that has minimum bulkiness.

Another object of the invention is to provide an enlargeable flexible hose which is simple and practical to be stored.

Another object of the invention is to provide an enlargeable flexible hose that can be repaired in case of breakage.

Another object of the invention is to provide an enlargeable flexible hose that can be customized in length.

This and other objects are achieved by a flexible hose for transporting liquids, particularly an enlargeable irrigation hose or garden hose for the transport of water and by a hose assembly which includes such hose, according to which is herein described, shown and/or claimed.

The hose has a non-corrugated, non-coiled tubular structure, typical of the irrigation hoses or garden hoses. The polymeric layers may be tubular shaped.

An example of a corrugated hose is known from document U.S. Pat. No. 3,028,290, whereas an example of a coiled hose is known from document U.S. Pat. No. 4,009,734.

The flexible hose may comprise at least one inner layer of a first polymeric elastic material, at least an outer layer of a second polymeric elastic material and at least one textile reinforcement layer interposed therebetween.

The at least one inner layer and at least one outer layer may be joined together to form a unitary tubular member that integrates, that is embed, the at least one textile layer.

To do this, the at least one outer layer and the at least one inner layer may be reciprocally joined in correspondence of the areas of the outer surface of the at least one inner layer not covered by the at least one textile reinforcement layer. In other words, the at least one outer layer and the at least one inner layer may be reciprocally joined except at the regions occupied by the textile yarns of the at least one textile layer.

Suitably, the unitary tubular member may have an elasticity such as to automatically enlarge and possibly elongate under the pressure imparted by the working fluid that flows therethrough to increase its original diameter and possibly its original length and such as to retract automatically once the working pressure stops to return to the original diameter possibly to the original length.

The enlargement is apparent and appreciable at sight, whereas the elongation is less apparent and eventually not appreciable at sight. In other word, the elongation may occur or not, and in case of elongation is remarkably less apparent with respect to the enlargement.

To do this, the first and the second polymeric elastic material forming the unitary tubular member are to be suitably chosen.

The first and the second polymeric materials may be elastomers or thermoplastic elastomers (TPE).

Suitable TPEs may be TPE-S, such as PP/SEBS or PP/EPDM, or TPE-O, such as Ethylene-Octene copolymer.

Suitable elastomers may be natural rubber or latex.

Suitably, the unitary tubular member may have a Shore A hardness measured according to ASTM D2240 (3″) of 30 ShA to 50 ShA.

The textile yarns of the at least one textile layer may be polyester, nylon 6,6, polyvinyl alcohol, para-aramid fibers, meta-aramid fibers, Rayon®.

Advantageously, the textile yarns of the at least one textile layer may have an elongation at break measured according to BISFA (Chap 7) less than 30%, and preferably less than 25%.

Advantageously, the textile yarns of the at least one textile layer may have a toughness as measured according to BISFA (Chap 7) of at least 50 cN/tex.

In a per se known manner, the automatic enlargement and possibly elongation is promoted by one or more restrictions or flow restrictors inserted in the hose or connected therewith, as taught by the documents EP2520840 and/or EP2778491, which are referred to for proper consultation. Suitably, one of the ends of the hose may be connected to means for supplying the liquid to be transported, for example a faucet.

As known, a textile reinforcement layer in a flexible hose if stressed tends to elongate axially and/or to enlarge radially, depending on the type.

Suitably, the unitary tubular member and the at least one textile reinforcement layer may cooperate each other so that under a working pressure of 2 bar the hose enlarges its outer diameter of at least 1.3 times with respect to its original outer diameter, preferably of at least 1.4 times with respect to its original diameter, more preferably at least 1.45 times with respect to its original diameter and still more preferably at least 1.5 times with respect to its original diameter.

On the other hand, the unitary tubular member and said at least one textile reinforcement layer may cooperate each other so that under a working pressure of 5 bar the elongation in length of said unitary tubular member is less than 20% with respect to the original length when in the unitary tubular member does not flow the liquid, and preferably less than 15% with respect to the original length when in the unitary tubular member does not flow the liquid.

Advantageously, the at least one textile reinforcement layer of the enlargeable hose of the present invention may be susceptible to move between a rest configuration that has at rest, i.e. when the liquid does not flow through the unitary tubular member, and a working configuration that has when the unitary tubular member is actuated by the working pressure of the liquid flowing therethrough.

In the working configuration the at least one textile reinforcement layer expands radially and possibly extends axially to accompany the enlargement and possibly the elongation of the unitary tubular member.

Depending on whether the yarns of the textile reinforcement layer are elastic or rigid and on the type of the textile reinforcement layer, such enlargement and possible elongation is more or less apparent.

However, the yarns of the textile reinforcement layer may preferably be rigid, so as to effectively act on the unitary tubular member upon the enlargement thereof.

Preferably, the at least one textile reinforcement layer and the unitary tubular member may be mutually configured so that the former intercepts the latter upon its enlargement and possible elongation in order to determine the maximum diameter and possibly the maximum length.

In other words, for a given inner hose pressure the maximum radial enlargement and possibly the maximum axial elongation of the at least one textile reinforcement layer is lower than the maximum radial enlargement and possibly the maximum axial elongation of the unitary tubular member, so that the maximum radial enlargement and possibly the maximum axial elongation of the at least one textile reinforcement layer determines the maximum radial enlargement and possibly the maximum axial elongation of the whole hose.

Suitably, the automatic retraction of the unitary tubular member allows the at least one textile reinforcement layer to return to the rest configuration once the pressure inside the hose stops.

This automatic retraction of the unitary tubular member can only be accomplished by its elasticity, without any other help. In particular, the hose of the invention may be free of coil springs or similar automatic retraction means.

Thanks to one or more of the above features, it is possible to obtain a flexible enlargeable hose wieldy and practical to use.

The flexible hose according to the present invention allows to combine all the advantages of an enlargeable hose with those of a “classic” flexible hose, without all the drawbacks of the enlargeable hoses of the prior art.

In fact, the flexible hose according to the present invention has a relatively high burst pressure, absolutely comparable to that of the “classical” flexible hoses.

In fact, the at least one textile reinforcement layer ensures high burst pressure, and therefore greater durability of the hose.

Moreover, thanks to the fact that the at least one outer layer is of polymeric material, the flexible hose is simple and quick to clean from any residual dirt and/or mud due to dragging on wet soils.

Further, the overall bulkiness of the flexible hose according to the present invention is minimal. This allows for example to store it in a very small space. It is moreover easily storable on a classic hose reel.

In addition, the flexible hose according to the present invention in case of breakage or damage can be restored as a “classic” hose. It is also possible to replace the original fittings, if any, using the classic fittings for flexible hoses on the market, for example in case to rupture of one thereof.

It is however understood that in the hose of the present invention fittings or any element for connecting the ends are not needed to connect each other the various layers. In fact, in the hose of the present invention all the elements are integrated, and in particular the at least one textile reinforcement layer is integrated trough the unitary tubular member.

It is further possible to cut the hose of the present invention to any size while maintaining the features of the whole structure. This makes further possible the customized per meter commercialization thereof.

Preferably, the reinforcing textile layer of the enlargeable hose according to the present invention may be a textile knotted layer or a textile knitted layer. Preferably, the stitches of the latter may be a of the tricot-type, radial-type or diamond-type, or may be interlocked or interweaved.

The at least one first textile layer and the unitary tubular member may be mutually configured so that the former intercepts the latter upon its enlargement in order to determine the maximum diameter.

Advantageous embodiments of the invention are described in the dependent claims.

