Patent Publication Number: US-2016245430-A1

Title: Extensible flexible hose

Description:
FIELD OF THE INVENTION 
     The present invention is relates to a flexible hoses, and more particularly relates to a flexible hose, preferably an irrigation hose or a garden hose for transporting water, which is extensible, or adapted to automatically elongate upon passage of a fluid and automatically retract when pressure from the fluid stops. 
     DEFINITIONS 
     As used herein, the expression “textile reinforcement layer” or derivative thereof relates to 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 to leave free portions thereof, generally square-, rectangular- or rhomboid- shaped. 
     As used herein, the expression “textile yarn” or derivative thereof relates to 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, the expression “spiral textile layer” or “spiraling” or derivative thereof relates to a layer consisting of a single yarn wound as a spiral on the supporting layer with a predetermined pitch or groups of yarns wound as a spiral on the supporting layer non overlapping to each other. 
     As used herein, the expression “textile braided layer” or “braiding” or derivative thereof relates to a layer consisting of at least two yarns or groups of yarns wound as a spiral on the supporting layer with opposite inclinations and overlapping but not connected to each other. Therefore, a braiding consists of two or more overlapping spirals. 
     As used herein, the expression “textile knitted layer” or “knitting” or thereof relates to 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 knit, also known as “tricot”-type chain knit. 
     As used herein, the expression “textile woven layer” or “weaving” or derivative thereof relates to 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, the expression “textile knotted layer” or “knotting” or derivative thereof relates to 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, the expression “compatible materials” or derivative thereof materials relates to 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, the expression “matrix” of a polymer or derivative thereof relates to a polymeric material capable of providing the molecular structure of the finished product. 
     As used herein, the expression “providing” or derivative thereof relates to 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, the expression “film” or derivative thereof relates to a layer of polymeric material whose thickness is less than 0.5 mm. 
     BACKGROUND OF THE INVENTION 
     Extensible flexible hoses for transporting liquids, such as irrigation water, are known, which automatically elongate upon the passage of a fluid inside the hose and automatically retract when the pressure of the fluid stops. 
     The working pressure of the transported fluid, such as a liquid, causes an elongation over its original length and a more or less apparent increase in the original diameter, so that the flexible hose is susceptible to transport the liquid at a greater distance with respect to its length when not in use. 
     In known manner, the automatic elongation is due to a restriction inside the hose or connected therewith, for example internal to a connector or to a diffuser or an irrigation lance. 
     The restriction creates a pressure drop such that the pressure upstream of the restriction acts inside the tube, thus elongating and enlarging it. 
     For example, an irrigation hose is known from US2003/0098084 that has an inner layer, an outer layer and a coil integrated therebetween. Under pressure from the transported liquid the spiral automatically extends, allowing the tube to elongate. Once the pressure of the liquid stops, the spiral automatically retracts, allowing the tube to resume its original length. 
     Apparently, this hose is difficult to manufacture, due to the presence of the coil. Furthermore, it is cumbersome and impractical to use. For example, it is difficult if not impossible to roll up the hose on a hose reel. 
     Another drawback of such a hose is that the burst pressure is relatively low. In fact, the resistance to the burst is exclusively imparted by the inner and outer polymeric layers. 
     Another extensible irrigation hose is known from EP2520840 that consists of an inner elastic tube and a rigid outer fabric. Under pressure from the transported liquid the inner tube elongates and enlarges its diameter up to a maximum length and a maximum diameter determined by the outer fabric. When the liquid pressure stops, the inner tube retracts, and the outer fabric lies in an undulated manner on the inner tube. 
     An apparent drawback of this hose is that it is difficult and expensive to manufacture. In fact, for each hose it is necessary to separately produce the inner tube and the outer fabric, then insert the first through the latter and then connect the tube and the fabric to each other through end fittings. 
     These operations are very difficult to perform in a continuous manner, and practically impossible to carry out in line, that is, by means of a single automatic production line. In fact, in order to manufacture such a hose, the use of human operators is needed. 
     Moreover, the presence of the fabric renders the hose bulky and unwieldy to use and store. For example, this tube is very difficult to store on a classic hose reel since the fabric occupies a relatively high space, much greater than the actual volume of the inner tube. 
     Further, the burst pressure is extremely low, because in practice it is only determined by the inner tube. 
     In addition, in case of breakage of the inner tube, such a hose is impossible to repair, and must be replaced with a new one. 
     For the same reason, it is not possible to customize the length of the tube, for example to obtain two hoses from a single longer hose. 
     Another known drawback of this known hose is that it must necessarily include the end fittings, since the outer fabric and the inner tube are elements independent of one another. Therefore, in case of breakage or simple damage to the original fittings the hose must be replaced with a new one. 
     This further limits the user&#39;s freedom in customizing the hose, since the original fittings cannot be replaced. 
     Further, the outer fabric tends to become dirty, making the use of such a hose very cumbersome and difficult. In fact, the textile fabric when dragged on a wet ground tends to collect mud and/or dirt and to get heavy. Moreover, after hardening the sludge adheres firmly to the fabric, thus increasing difficulty of use and storage of this known hose. 
     Other documents describing to the state of the art before the present invention are: U.S. Pat. No. 3,028,290, EP2778491, U.S. Pat. No. 4,009,734, WO2011/161576, WO00/77433, WO97/37829, GB740458, GB 1481227, US2003/0062114, WO2015/177664, US2014/0130930, US2013/0087205, FR2784447 and WO2013/105853. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to overcome at least partially the above drawbacks, by providing an extensible flexible hose of remarkable efficiency and relative low cost. 
     Another object of the invention is to provide an extensible flexible hose which can be manufactured in a simple and fast manner. 
     Another object of the invention is to provide an extensible flexible hose which can be manufactured automatically in line. 
     Another object of the invention is to provide an extensible flexible hose which is wieldy to use. 
     Another object of the invention is to provide an extensible flexible hose from which is simple to remove any residual dirt and/or mud due to dragging on wet soils. 
     Another object of the invention is to provide an extensible flexible hose which has a relatively high burst pressure. 
     Another object of the invention is to provide an extensible flexible hose that has minimum bulk. 
     Another object of the invention is to provide an extensible flexible hose which is simple and practical to store. 
     Another object of the invention is to provide an extensible flexible hose that can be repaired in case of breakage. 
     Another object of the invention is to provide an extensible flexible hose that can be customized in length. 
     These and other objects are achieved by a flexible hose for transporting liquids, particularly an irrigation hose or garden hose for the transport of water as described hereinafter. 
     Advantageous embodiments of the invention are also described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the invention will be apparent upon reading the detailed description of a preferred, non-exclusive embodiment of an extensible flexible hose and a production line for the manufacture thereof, which are described as non limiting examples with the support of the enclosed drawings, in which: 
         FIGS. 1 to 3  are schematic views of a hose according to the invention during use; 
         FIG. 4  is a schematic side view of an inner tube at rest; 
         FIG. 5  is a schematic side view of the inner tube 1 of  FIG. 4  under pressure; 
         FIG. 6  is a schematic side view of a manufacturing line according to the invention; 
         FIG. 7  is a radial sectional view of the inner tube 1 of  FIG. 4 ; 
         FIGS. 8 and 9  show two examples of a woven textile reinforcement layer; 
         FIG. 10  shows an example of a knotted textile reinforcement layer; 
         FIGS. 11A and 11B  show a hose according to the invention, respectively at rest and under pressure; 
         FIGS. 12A and 12B  show a hose according to the invention, respectively at rest and under pressure; 
         FIGS. 13A and 13B  show a hose according to the invention, respectively at rest and under pressure; 
         FIGS. 14A and 14B  show a hose according to the invention, respectively at rest and under pressure; 
         FIGS. 15A and 15B  show an inner tube  1  according to the invention, respectively at rest and under pressure; 
         FIGS. 16A and 16B  show an inner tube  1  according to the invention, respectively at rest and under pressure; 
         FIGS. 17A and 17B  show a hose according to the invention, respectively at rest and under pressure; 
         FIGS. 18A and 18B  show an inner tube according to the invention, respectively at rest and under pressure; 
         FIGS. 19A and 19B  show an inner tube according to the invention, respectively at rest and under pressure; 
         FIGS. 20A and 20B  show a hose according to the invention, respectively at rest and under pressure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     With reference to the above figures, an extensible hose  200  is advantageously used for the transport of liquids. In particular, the extensible hose  200  may be an irrigation hose or garden hose for the transport of water. 
     The extensible hose  200  may include an outer sheath  70  and an inner tube  1 . 
     The inner tube  1  may include an inner polymer layer  10  and an outer polymer layer  20 . 
     Internally to the inner layer  10 , a detaching film  11  may be provided susceptible to come in contact with the liquid to be transported, the function of which will be explained later. 
     The inner tube  1  may further include a first inner knitted textile layer  30  with a tricot-type chain knits and a second braided textile layer  40 , mutually overlapping. The pitch of the spirals of the second braiding textile layer  40  may be relatively short, for example 1 mm to 3 mm. 
     The inner tube  1  may further include one intermediate polymeric layer  15  interposed between the textile reinforcement layers  30  and  40  for the separation thereof. 
     It is to be understood that although the following description relates to an inner tube  1  with the above structure, the inner tube may include three or more layers. 
     For example, a single textile reinforcement layer may be provided, or one or more additional polymeric layers internal or external to the above layers. 
     It is also to be understood that although the following description relates to an inner tube  1  with the above structure, the technical features herein described are applicable to an inner tube which includes at least three layers. 
     It is further to be understood that although reference is made here to a garden hose for the transport of water, the hose  200  can have any application and can transport any liquid or other fluid. 
     In a preferred but not exclusive embodiment, inner layer  10 , intermediate layer  15  and outer layer  20  may be made of a styrene-based thermoplastic elastomer (TPE-S) having a matrix based on polypropylene (PP), for example the Nilflex® SH (Taro Plast SpA), having a Shore A hardness measured according to ASTM D2240 (3″) of 40. Such a material has a tensile strength measured according to ASTM D412/C of about 6.5 MPa and an elongation at break measured according to ASTM D412/C of approximately 880%. 
     Indicatively, the inner layer  10  may have a thickness of 1.5 mm to 2.5 mm, preferably 1.6 mm-2 mm. On the other hand, the film  11  may have a thickness of 0.05 mm to 0.4 mm, preferably 0.1 mm-0.3 mm. 
     Preferably, the detaching film  11  also may be made of the same above described material, to which a small percentage of lubricant-release additive agent may be added. 
     For example, a material that may be added for about 1% by weight total is CRODAMIDE® (CRODA Polymer Additives), a migrant agent who has the purpose of decreasing friction and blocking the material on itself. 
     In a preferred but not exclusive embodiment, the textile reinforcement layers  30  and  40  may be made of polyester (PET)-based yarns, for example Brilen GLE® (Brilen Tech SA) having a linear density of 550 dtex. Such yarns have an ultimate tensile strength, measured according to BISFA (Chap 7), of 42.7+/−4.2 N, an elongation at break measured according to BISFA (Chap 7) of 12.5+/−2.5% and toughness measured according BISFA (Chap 7) of 75.5+/−7 cN/tex. 
     The first textile reinforcement layer  30  may be placed on the outer surface  12  of the inner layer  10  so as to leave thereon a plurality of open areas  13 , which are directly facing the corresponding portions of the inner surface  16  of the intermediate layer  15 . 
     On the other hand, the second textile reinforcement layer  40  may be placed on the outer surface  12 ′ of the intermediate layer  15  so as to leave thereon a plurality of open areas  13 ′, which are directly facing the corresponding portions of the inner surface  21  of the outer layer  20 . 
     Suitably, the inner layer  10 , intermediate layer  15  and outer layer  20  may be reciprocally bonded in correspondence with the respective uncovered areas  13 ,  13 ′. 
     The bond between the inner layer  10 , intermediate layer  15  and outer layer  20  may be assured by the use of materials compatible with each other or by a layer of adhesive material interposed between them. 
     To effect such a coupling, the inner layer  10 , intermediate layer  15  and outer layer  20  form a unitary tubular member  50 , inside of which the reinforcing textile layers  30  and  40  may be integrated or embedded. 
     The possible choice of the same material for all the polymeric layers of the inner tube makes the mechanical behavior of the unitary tubular member  50  homogeneous, and ensures maximum compatibility between the materials. 
     As particularly shown in  FIGS. 1-3 , at the ends  51 ,  52  of the hose  200  appropriate mutual union elements may be provided. 
     For example, respective couplers  60 ,  61  may be provided. 
     In a preferred but not exclusive embodiment, the coupler  60  may be e.g. a female coupler, and may be adapted to connect the hose  200  to a point of use, for example a hose bibb R. On the other hand, the coupler  61  may be a male coupler, and may be adapted to connect the hose  200  to one or more sprinkler accessories D, for example a lance or a sprinkler. 
     In another embodiment, the end  52  of the hose  200  may be fixedly coupled to the sprinkler accessory D, for example a lance or a sprinkler. In this case, the hose  200  does not include the coupler  61 , and cannot be coupled to more sprinkler accessories. At the other end  51  the coupler  60  may be provided for connecting the hose  200  to a point of use, for example a tap R. 
     Due to the above features, the inner tube  1  may be susceptible to automatically expand under the working pressure imparted by the water that flows within it, thus increasing its original length and diameter. 
     To achieve this, at least one restriction inside the hose or connected therewith may be provided as known in the art. 
     In a preferred but not exclusively embodiment, the at least one restriction may be defined by a flow restrictor as known in the art located inside the coupler  61 . 
     On the other hand, the inner tube  1  may internally include one or more restrictions, such as thickened portions or the like. 
     The at least one restriction may also be provided in the sprinkler accessory D, for example a lance or a sprinkler. 
     The at least one restriction may create a pressure drop such that the pressure upstream of it acts internally to the inner tube  1 , thus axially elongating inner tube  1  along the axis X and radially enlarging it perpendicularly to the same axis X. 
     In practice, after the hose  200  is connected to a point of use, for example to a hose bibb R, upon the opening of the hose bibb the water that passes through the inner tube  1  promotes its axial elongation and radial enlargement, as shown in  FIGS. 2 and 3 . 
     In other words, the water flow promotes the passage of the inner tube  1  from an original length and diameter ( FIG. 1 ), that the same inner tube  1  has when no water passes through it, to a working length and the diameter ( FIG. 3 ). 
     The transition from the original diameter and length to the working diameter and length occurs gradually, passing through an intermediate stage, shown in  FIG. 2 , in which the hose starts to enlarge and elongate under the thrust of the water pressure. 
     By contrast, upon the closing of the hose bibb R the hose  200  automatically retracts, thus returning to its original length and diameter. 
     In order to achieve the above, the unitary tubular member  50  and the textile layers  30 ,  40  can cooperate with each other. 
     More precisely, the unitary tubular member  50  may have such an elasticity that it lengthens automatically under the working pressure imparted by the water and retracts automatically after the working pressure stops. 
     Moreover, due to its elasticity, under the working pressure the unitary tubular member  50  may radially enlarge to increase its original diameter and then automatically retract after the working pressure stops. 
     On the other hand, the elongation and the enlargement of the unitary tubular member  50  promotes the passage of the textile reinforcement layers  30 ,  40  from a rest configuration, shown in  FIG. 4 , which they have when no water flows through the inner tube to a working configuration, shown in  FIG. 5 , which they have under the working pressure. 
     Conversely, after the working pressure stops the automatic retraction of the unitary tubular member  50  returns the textile reinforcement layers  30 ,  40  to their rest configuration. 
     Under the working pressure, in addition to increasing the length and diameter of the inner tube, a thinning of the entire thickness thereof further occurs. With the above described configuration and materials, the wall thickness under pressure decreases by about half. 
     The first textile reinforcement layer  30  may be configured to intercept the unitary tubular member  50  upon its elongation to determine the maximum length. 
     Similarly, the second textile layer  40  may be configured to intercept the unitary tubular member  50  upon its enlargement or radial expansion in order to determine the maximum diameter. 
     To do this, the yarn of the textile reinforcement layers  30 ,  40  and the materials of the unitary tubular member  50  may be suitably selected, for example as described above. 
     The second textile reinforcement layer  40  may be placed externally with respect to the first textile reinforcement layer  30 . 
     In fact, because of its configuration the first textile reinforcement layer  30  tends to restrain the axial elongation but to yield in the radial direction. By contrast, the second textile reinforcement layer  40  tends to restrain the radial enlargement but to yield in the axial direction. The cooperation of the two textile reinforcement layers  30 ,  40  enables restraining the expansion of the inner tube in both axial and radial directions, thus determining the maximum length and diameter. 
     In alternative to the knitted configuration, the first textile reinforcement layer  30  may be woven or knotted.  FIGS. 8 and 9  show two examples of a textile reinforcement woven layer, different from each other for orientation, number and configuration of the yarns.  FIG. 10  shows an example of a textile reinforcement knotted layer. 
     On the other hand, the second textile reinforcement layer  40  may consist of one or more spirals, in other words of one single spiral or a braiding. 
     Suitably, the unitary tubular member  50  and the textile reinforcement layers  30 ,  40  may cooperate with each other so that under a working pressure of 2 bar the inner tube  1  is susceptible to increase its length at least 1.5 times with respect to the its original length, preferably at least 2 times with respect to its original length, and more preferably of at least 2.5 times with respect to its original length. 
     For example, with an inner tube having the structure described above and manufactured from the above materials, with an inner diameter at rest of 9 mm, outer diameter at rest of 14 mm and weight of 80 g/mt, the elongations at different internal working pressures are provided in Table 1 below. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Working pressure (bar) 
                 Length under pressure: original length 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 2 
                 2 
               
               
                   
                 3 
                 2.2 
               
               
                   
                 4 
                 2.4 
               
               
                   
                 5 
                 2.4 
               
               
                   
                 6 
                 2.5 
               
               
                   
                   
               
            
           
         
       
     
     For such an inner tube, the radial expansion with respect to the diameter at rest at the working pressure of 3 bars is 0.8 mm, whereas at the working pressure of 5 bar is 1 mm. 
     It is understood that these data may change depending on the materials and/or the features of the inner tube, such as the inner or outer diameter or the weight/mt thereof. 
     Advantageously, the radial enlargement of the inner diameter of the inner tube of the present invention under a working pressure of 5 bar may be less than 20% with respect to the value of the inner diameter at rest, and preferably less than 15% with respect to the value of the inner diameter at rest. 
     In a preferred but not exclusive embodiment, the outer layer  20  may be a protective film, of which the weight per meter may be 3% to 10% of the total weight of the unitary tubular member  50 , for example 5% of the total weight of the unitary tubular member  50 . 
     Preferably, the film  20  may be made in accordance with the teachings of international application PCT/IB2014/067091, to which one may refer for consultation. 
     Indicatively, the film  20  may have a thickness of 0.05 mm to 0.4 mm, preferably 0.1 mm-0.3 mm. 
     This film  20  has the purpose of protecting the underlying layers, in particular the textile layers, and to give appearance to the inner tube. It is also important for resistance to external agents and the sliding of the inner tube on the ground. In fact, it minimizes fouling of the inner tube as a result of the use on muddy grounds or in a garden. 
     Similarly, the intermediate layer  15  may also be a film having the same features of the outer film  20 . 
     The inner tube  1  can be manufactured by means of a line  100 , which works continuously. 
     The line  100  can be fed by the inner layer  10 , which can for example be extruded through a first extruder  110  at the inlet  101  of the line  100 . 
     In a known manner, the extruder  110  may co-extrude the inner layer  10  and the detaching film  11 , which may then pass through a first pair of faced rotating rollers  120  configured to press the inner tube. 
     Subsequently, the inner layer  10  and the detaching film  11  may pass through a first station  130  for making the textile reinforcement layer  30 , to obtain a first semi-finished product  25 . 
     The station  130  may include a knitting machine  131 , of a known type, to make the first textile knitted layer with knits of the tricot type  30 , for example of the plain stitch type. 
     Subsequently, the first semi-finished product  25  may pass through a second pair of faced rotating rollers  121  configured to press the inner tube. 
     The rollers  121  may rotate faster than the roller  120 , and the ratio between the speed of the first upstream roller  120  and the speed of the second downstream rollers  121  may be of 1:2 to 1:5, and more preferably of 1:3 to 1:5. 
     In this way, the two pairs of rollers  120 ,  121  continuously elongate the inner layer  10  with the inner film  11 , so that the textile reinforcement layer  30  is made on the elongated inner layer  10 . 
     Subsequently, the semi-finished product  25  may pass through a second extruder  135 , which extrudes a film constituting the above intermediate layer  15 . Advantageously, in accordance with the teachings of international application PCT/IB2014/067091, the extrusion head  136  of the extrusion station  135  may be placed under vacuum by a vacuum pump  137 , for example at a pressure of 250-400 mmHg. 
     The second semi-finished product  25 ′ at the outlet of the second extruder  135  passes through a third pair of faced rotating rollers  122  configured to press the inner tube. The rollers  122  may rotate at substantially the same speed of the rollers  121 , or slightly higher. 
     In this way, the film  15  is extruded on the textile reinforcement layer  30  in the elongated working configuration. 
     Subsequently, the second semi-finished product  25 ′ at the outlet of the rollers  122  passes through a fourth pair of faced rotating rollers  123  configured to press the inner tube. The rollers  123  rotate more slowly than the roller  122 . 
     The ratio between the speed of the fourth upstream rollers  123  and that of the third downstream rollers  122  may be of 2:1 to 5:1, and preferably of 3:1 to 5:1. 
     In this way, the semi-finished product  25 ′ returns in a rest configuration, in which the layers  10 ,  11  and  15  have the original length and the textile reinforcement knitted layer  30  is in the rest configuration. 
     The semi-finished product  25 ′ in the rest configuration may be fed to a second station  140  for making thereon the textile reinforcement layer  40 . 
     The station  140  may include a pair of spiraling machines  141 ,  142 , to make a corresponding pair of spirals one in a clockwise direction and the other one in the opposite direction. The set of the two spirals constitutes the textile reinforcement layer  40 . 
     The third semi-finished product  25 ″ at the outlet of the station  140  may then be fed to a third extruder  150 , which may make the film  20 . Similarly to what has been described for the second extruder  135 , in accordance with the teachings of international application PCT/IB2014/067091, the extrusion head  151  may be placed under vacuum by a vacuum pump  152 , for example at a pressure of 250-400 mmHg. 
     Upon extrusion, the inner layer  10 , the intermediate film  15  and the outer film  20  adhere to each other at the uncovered areas  13 ,  13 ′ to form the unitary tubular member  50 . In this way, the textile reinforcement layers  30 ,  40  remain embedded therein. 
     Because the intermediate film  15  and the outer film  20  are made in accordance with the teachings of international application PCT/IB2014/067091, the same intermediate film  15  and the outer film  20  have a uniform thickness and adhere strongly to the underlying layer, as shown in  FIG. 7 . 
     This minimizes material waste and gives an optimum aesthetic finish to the inner tube  1 . 
     The inner tube  1  thus produced may then pass through a fifth pair of faced rotating rollers  124  configured to press the inner tube. 
     Advantageously, the rollers  124  may rotate at substantially the same speed of the rollers  123 , or slightly higher. 
     In this way, the second textile layer  40  and the film  20  are made on the semi-finished products  25 ′ and  25 ″ in the rest configuration. 
     The detaching film  11  enables the detachment of the inner wall of the inner tube  1  after pressing immediately upon passage through the rollers  120 ,  121 ,  122 ,  123  and  124 . 
     In a preferred but not exclusive embodiment, the second textile layer  40  and the film  20  can also be made on the semi-finished product  25 ′ in the elongated configuration. To do this, the rollers downstream the station  140  and the extruder  150  rotate faster than the ones upstream thereof, preferably in the above ratios. 
     In this case, the inner diameter of the elongated semi-finished product  25 ′ may preferably be brought to the inner diameter of the inner tube at rest by blowing air at adequate pressure. 
     To do this, suitable means may be provided for blowing air, of a known type, at the outlet  102  of the line  100 . 
     The rollers  120 ,  121 ,  122 ,  123  and  124  may be mutually configured so that the air blown at the outlet  102  goes back up through the inner tube in correspondence of the rollers  121 . 
     It is understood that in the line  100  in place of the rollers  120 ,  121 ,  122 ,  123  and  124  any rotary conveying device may be employed without departing from the scope of the appended claims. 
     The outer sheath  70  may have any configuration, and may be made of any material. The outer sheath  70  and the inner tube  1  may be connected to each other in correspondence of the couplers  60 ,  61 . Apart the latter points, the outer sheath  70  and the inner tube  1  may be unconnected along the entire length of the hose or may be connected to each other at other points along the length of the hose. 
     For example, outer sheath  70  may be a fabric made of polyester or polyamide, or may be made of a polymer, for example a thermoplastic polymer, an elastomer or a thermoplastic elastomer. In another embodiment, the outer sheath  70  may be made of yarns to form a net, a braid of a knitting. 
     In general, the outer sheath  70  may be continuous or may be provided with one or more passing-through apertures. 
     The outer sheath  70  may be rigid or elastic. In any case, the outer sheath  70  matches the elongation of the inner tube  1 . 
     Therefore, in case of a rigid outer sheath  70 , the length thereof must be sufficient to match the elongation of the inner tube  1 . On the other side, in case of elastic outer sheath  70  the elasticity thereof must be sufficient to impart to the same outer sheath  70  an elongation that matches the elongation of the inner tube  1 . 
     The outer sheath  70  may includes only rigid yarns, only elastic yarns or a mixture thereof, in any relative amount. 
     In another embodiment, the outer sheath  70  may configured to elongate in the axial direction and to not enlarge in the radial direction. To this end, the outer sheath  70  may preferably include rigid yarns in the radial direction and elastic yarns in the axial direction. 
     The outer sheath  70  may have any diameter, for example an inner diameter matching the outer diameter of the inner tube  1  or a diameter greater than the outer diameter of the inner tube. In the latter case a rigid outer sheath  70  determines the diameter of the entire hose. 
       FIGS. 11A to 20B  show a number of embodiments of the hose  1  or the inner tube  200 . In any embodiment all the materials of the outer sheath  70  and of the inner tube  1  may be the same as described above. In any of these embodiments the one or more textile reinforcement layers may have any configuration, as described above. For example, it may be a braid, a spiral or a knitting. 
       FIGS. 11A and 11B  show an embodiment of the hose  200  having an outer sheath  70  and an inner tube  1  which consists of three layers, an inner layer  10 , an intermediate textile reinforcement layer  30  and an outer layer  20 . 
       FIGS. 12A and 12B  show an embodiment of the hose  200  having an outer sheath  70  and an inner tube  1  which consists of two layers, an inner layer  10  and an outer textile reinforcement layer  30 . 
       FIGS. 13A and 13B  show an embodiment of the hose  200  having an outer sheath  70  and an inner tube  1  which consists of four layers, an inner layer  10 , a first textile reinforcement layer  30 , an outer layer  20  and a further textile reinforcement layer  40 ′. 
       FIGS. 14A and 14B  show an embodiment of the hose  200  having an outer sheath  70  and an inner tube  1  which consists of five layers, an inner layer  10 , a first textile reinforcement layer  30 , an intermediate layer  15 , a second textile reinforcement layer  40  and an outer layer  20 . The inner tube  1  may be configured as described above, e.g. as shown in  FIGS. 3 and 4 , or in any other configuration. For example, the first textile reinforcement layer  30  and the second textile reinforcement layer  40  may be two knittings or two braidings. 
       FIGS. 15A and 15B  show an embodiment of the inner tube  1  consisting of seven layers, an inner layer  10 , a first textile reinforcement layer  30 , an intermediate layer  15 , a second textile reinforcement layer  40 , a further intermediate layer  15 ′, a further textile reinforcement layer  41  and an outer layer  20 . 
       FIGS. 17A and 17B  show an embodiment of the hose  200  having an outer sheath  70  and an inner tube  1  configured as shown in  FIGS. 15A and 15B , as described above. It is understood that the inner tube  1  may be used as such, e.g. without the outer sheath  70 , as depicted in  FIGS. 15A and 15B . 
       FIGS. 16A and 16B  show an embodiment of the inner tube  1  consisting of six layers, an inner layer  10 , a first textile reinforcement layer  30 , an intermediate layer  15 , a second textile reinforcement layer  40 , a further intermediate layer  15 ′ and an outer layer  20 . 
       FIGS. 18A and 18B  show an embodiment of the hose  200  having an outer sheath  70  and an inner tube  1  configured as shown in  FIGS. 16A and 16B , as described above. It is understood that the inner tube  1  may be used as such, e.g. without the outer sheath  70 , as depicted in  FIGS. 16A and 16B . 
       FIGS. 19A and 19B  show an embodiment of the inner tube  1  consisting of six layers, an inner layer  10 , a first textile reinforcement layer  30 , an intermediate layer  15 , a second textile reinforcement layer  40 , a further textile reinforcement layer  41  and an outer layer  20 . 
       FIGS. 20A and 20B  show an embodiment of the hose  200  having an outer sheath  70  and an inner tube  1  configured as shown in  FIGS. 19A and 19B , as described above. It is understood that the inner tube  1  may be used as such, e.g. without the outer sheath  70 , as depicted in  FIGS. 19A and 19B . 
     From the above description, it is apparent that the invention fulfils the intended objects. 
     The invention is susceptible of numerous modifications and variations, all falling within the inventive concept expressed in the attached claims. All the details may be replaced with other technically equivalent elements, and the materials may be different according to requirements, without departing from the scope of the invention. 
     Although the invention has been described with particular reference to the attached figures, the reference numbers in the description and in the claims are used to improve the intelligence of the invention and are not to be interpreted as limitations of the claimed scope.