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The present invention essentially concerns a watertight device, installed in welding ends for hoses, and more exactly in welding ends for flexible hoses, said device including one or more radial grooves, achieved on the outer surface of the part that is inserted in hoses, called spigot; the grooves are housings where respective O- rings are installed.

From the state of the art some previous solutions are known, in order to achieve the watertight property of flexible hoses, with reference to industrial applications where high pressure liquids should be moved on site.

A first solution, called wet system, includes a two-components resin, usually an epoxide resin, that in a first step is mixed, and then it is spilled in big quantity in the inner part between welding end and outer pressure ring. This resin using an activator takes approximately 6-8 hours in order to harden, so to achieve a unique body including hose, welding end and outer ring.

The main advantage of this system is to achieve a good level of watertight property, but it involves some serious drawbacks:

- the resin represents a dangerous chemical product to be handled by assigned operators;

- the resin, during the step of pushing on pressure, spills over machines and over the floor, with a consequent damage and dirty of the surrounding space;

- the resin, after the hardening process, becomes strong like a stone, and in case of leaking hose, there would be no possible recovery and the hose would be no longer usable;

- the resin, requiring approximately 6-8 hours in order to harden, would lead to long processing times, before to be tested and then delivered to the client.

A second solution, called dry system, includes a lip gasket, placed in the welding end, between the hose and the outer pressure ring. This system has the advantage to be fast and comfortable, but often it results to be not perfectly effective, because during the tests sometimes the welding end connected to the hose is not watertight, and there is leakage of liquids.

Therefore, the main objective of the present invention is to disclose a device achieving welding ends for hoses, and more exactly welding ends for flexible hoses, characterized by a high level of watertight property.

Another objective is that the insertion procedure of the welding ends inside the hoses results to be particularly fast, easy and safe for the assigned operators.

Another further objective is that the watertight device can be adapted, by using proper materials according to different applications of hoses, and therefore can achieve the watertight property, even in cases of being in touch with particularly aggressive chemical products.

Therefore, it is specific subject of the present invention a welding end for hoses, comprising a watertight device, said device being composed of:

a basic structure comprising one or more grooves, placed on the radial outline of the part of welding end, called spigot, that is inserted in a hose;

- one or more O-rings, made of an elastic material, that is natural or synthetic, which are respectively inserted and housed in said one or more grooves, maintaining therefore a prominent upper side in respect to the radial outline of said spigot, so that when the above said spigot is inserted in said hose, said one or more O-rings can change, under pressure, the outline of their prominent upper side and can grip homogeneously to the inner wall of the same hose, therefore no cracks and/or gaps are left behind, by which a liquid could pass through, leading to a watertight property of the whole welding end that is placed in connection to said hose.

The present invention will now be described for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to figures of the enclosed drawings, wherein:

figure 1 is a front perspective view of a welding end, according to the present invention, having two O-rings;

figure 2 is a front perspective view of the same welding end of figure 1 , where two radial grooves are visible, in said grooves the respective O-rings are inserted; figure 3 is a top view of the same welding end of figure 1 ;

figure 4 is a front view of the same welding end of figure 1 ;

figure 5 is a lateral view of the same welding end of figure 1 ;

figure 6 is a front perspective view of the same welding end of figure 1 , in a first step of insertion and connection to a composite hose having a double metallic spiral, inside and outside;

figure 7 is a front perspective view of the same welding end of figure 1 , in a second step of completed insertion and connection to a composite hose having a double metallic spiral, inside and outside;

figure 8 is a front perspective view of a welding end, according to an embodiment with outer pressure ring, in a first step of insertion and connection to a composite hose having a double metallic spiral, inside and outside;

figure 9 is a front perspective view of a welding end, according to an embodiment with outer pressure ring, like in figure 8, in a second step of completed insertion and connection to a composite hose having a double metallic spiral, inside and outside; figure 10 is a lateral view of the same welding end of figure 8, in a first step of insertion and connection to a composite hose having a double metallic spiral, inside and outside;

figure 1 1 is a lateral view of the same welding end of figure 9, in a second step of completed insertion and connection to a composite hose having a double metallic spiral, inside and outside.

It is here underlined that only few of the many conceivable embodiments of the present invention are described, which are just some specific non-limiting examples, having the possibility to describe many other embodiments based on the disclosed technical solutions of the present invention.

Figure 1 shows a welding end 100 for hoses, comprising a watertight device. This welding end 100 has a basic structure, typically with a cylindrical shape, with a front end 108, properly tapered and threaded in order to be screwed in a flexible hose, and a rear end 103 also properly tapered and threaded in order to be connected to another structure, in example a rigid structure, or to another hose.

Usually, the flexible hose where the front end 108 of the welding end 100 is inserted is a composite hose, reinforced with a double metallic spiral, inside and outside, like in example a Compotec® hose.

Figure 2 shows how the smooth part 105 of the welding end, that is inserted in the hose, comprises two grooves 102a, 102b, on the radial outline.

These grooves 102a, 102b, are housings where two respective O-rings 101 a, 101 b are inserted and, as shown in figure 1 , the O-rings 101 a, 101 b maintain a prominent upper side in respect to the radial outline of spigot 105.

Figures 3, 4 and 5, show the exact geometrical shape of the welding end 100, according to respective top, front and lateral views. The insertion of spigot 105 in the hose 120 is provided, as illustrated in figures 6 and 7, by pushing the welding end 100 along the longitudinal arrow, and rotating the same welding end 100 along the transversal arrow.

According to the above insertion, the two O-rings 101 a, 101 b, change under pressure the outline of their prominent upper side so that they grip homogeneously to the inner wall of the same hose 120, therefore no cracks and/or gaps are left behind, by which a liquid could pass through, leading to a watertight property of the whole welding end 100 that is placed in connection to the hose 120.

An alternative embodiment of the present invention, as illustrated in figures 8 and 9, further comprises an outer pressure ring 1 10, surrounding the outer part of said spigot 105, and defining an inner space between ring 1 10 and spigot 105, where the end 123 of a hose 120 is inserted, said end 123 having been previously made free, by a cut, of an ending part of inner 122 and outer spiral 121 .

Again, the insertion of spigot 105 in the hose 120 is provided by pushing the welding end 100 along the longitudinal arrow, and rotating the same welding end 100 along the transversal arrow.

The above insertion is illustrated more in detail in figures 10 and 1 1 , where it is represented the initial and final position of the welding end 100 and the hose 120. When the operation is completed, the ring 1 10 surrounds the outer part of said hose 120, and then it is submitted to a process of radial compression along the inner direction, so that the components are definitely assembled in a stable a watertight position.

Therefore, the part between welding end 100 and hose 120 results to be watertight: inside, the O-rings 101 a, 101 b, gripping homogeneously to the inner wall of the same hose 120 do not leave any space or crack where a liquid could pass through; outside, the ring 1 10 bonding homogeneously to the outer wall of the same hose 120, and keeping the outer spiral 121 under pressure, does not leave any space or crack where a liquid could pass through.

An alternative embodiment of the present invention comprises, instead of said O-rings 101 a, 101 b, a unique O-ring, having a rectangular cross-section with a larger bottom part, inserted in a unique radial groove, again placed on the radial outline of the part of welding end 100, called spigot 105.

The working principle is similar to the one described previously, that is: when the above said spigot 105 is inserted in said hose 120, said O-ring with rectangular cross- section changes, under pressure, the outline of its prominent upper side. In such a way it grips homogeneously to the inner wall of the same hose 120, therefore no cracks and/or gaps are left behind, by which a liquid could pass through, leading to a watertight property of the whole welding end 100 that is placed in connection to said hose 120.

Another further embodiment of the present invention includes, in addition to the components previously described, a lip gasket placed between said pressure ring 1 10 and the outer surface of hose 120, so that a synergic effect is produced with the above said elements, and the watertight property of the welding end 100 is even more effective.

Therefore, the above examples show that the present invention achieves all the proposed objectives. In particular, it discloses a device achieving welding ends for hoses, and more exactly welding ends for flexible hoses, characterized by a high level of watertight property.

In addition, according to the invention, the insertion procedure of the welding ends inside the hoses results to be particularly fast, easy and safe for the assigned operators.

Furthermore, the watertight device can be adapted, by using proper materials in respect to different applications of hoses, and therefore can achieve the watertight property, even in cases of being in touch with particularly aggressive chemical products.

The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is clear that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope, as defined in the enclosed claims.