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Title:
CONNECTION DEVICE FOR PIPES
Document Type and Number:
WIPO Patent Application WO/2019/150404
Kind Code:
A1
Abstract:
Connection device (10) to connect a first pipe (11) to another pipe, comprising at least an external body (12) provided with an annular cavity (15), a first internal element (13) and a second internal element (14) assembled coaxially in the annular cavity (15), wherein the first internal element (13) is configured to allow to verify the correct coupling of the first pipe (11) to the second pipe (13).

Inventors:
VISENTIN, Eros (Via Romagna 26, PORCIA, 33080, IT)
Application Number:
IT2019/050015
Publication Date:
August 08, 2019
Filing Date:
January 23, 2019
Export Citation:
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Assignee:
EMMETI S.P.A. (Via Brigata Osoppo, 166, FONTANAFREDDA, 33074, IT)
International Classes:
F16L19/065; F16L33/22
Foreign References:
ITUB20155015A12017-04-29
US20060163872A12006-07-27
US6523862B12003-02-25
FR1423894A1966-01-07
EP1388701A12004-02-11
Attorney, Agent or Firm:
PETRAZ, Davide Luigi et al. (GLP SRL, Viale Europa Unita 171, UDINE, 33100, IT)
Download PDF:
Claims:
CLAIMS

1. Connection device to connect a first pipe (11) to another pipe, said device comprising:

- at least a hollow external body (12) configured for the stable and releasable connection of said first pipe (11) and said other pipe,

- a first internal adaptor element (13) configured to adapt the connection of said first pipe (11) to said other pipe, said first internal element (13) being able to be assembled coaxially to said first pipe (11) in said external body (12),

wherein said first internal element (13) is provided with a first coupling portion (19) which can be inserted in said first pipe (11) and with a second portion (20) surrounding at least part of said first portion (19) defining a compartment (25) that, during use, is affected by the coupling of said first pipe (11) with said first internal element (13), characterized in that said second portion (20) has a flared shape, it is in a single body integral and solid with said first internal element (13) together with said first portion (19) and is provided with at least one inspection aperture (30) configured to render visible from the outside at least one portion of said compartment (25) in order to verify, during use, a correct coupling position of said first pipe (11) with said first internal element (13).

2. Device as in claim 1, characterized in that it comprises a reference ring (26) able to be axially fitted on said first portion (19), and a housing seating (28) to define an axial end-of-travel position of said reference ring (26), made in said compartment (25), wherein, in said correct coupling position, said reference ring (26) is disposed on one side in abutment against said housing seating (28) and on the other side is in direct contact with the head end of said first pipe (11) fitted axially on said first portion (19).

3. Device as in claim 2, characterized in that said reference ring (26), in said correct coupling position, is concealed from view by at least one part of said second portion (20) provided between said inspection aperture (30) and said housing seating (28).

4. Device as in claim 2, characterized in that said reference ring (26), in said correct coupling position, is visible from said inspection aperture (30).

5. Device as in any claim hereinbefore, characterized in that said inspection aperture (30) has an open profile defining a hollow in said second portion (20).

6. Device as in any of the claims from 2 to 5, characterized in that said first portion (19) has an inclined segment (27) with a taper that develops in the opposite direction to an axial coupling direction of said first portion (19) with said first pipe (11), said inclined segment (27) having a maximum diameter in proximity to said housing seating (28), and in that said reference ring (26) has a smaller diameter with respect to said maximum diameter of said inclined segment (27) in order to cooperate with the latter by interference so that, during use, it tends to determine a progressive axial sliding of said reference ring (26) toward said first pipe (11).

7. Device as in any of the claims from 2 to 6, characterized in that at least part of the external surface of said reference ring (26) is colored.

8. Device as in any claim hereinbefore, characterized in that said device also comprises a second internal clamping element (14) able to be fitted axially on said first pipe (11) and to be assembled coaxially to said first internal element (13) in said external body (12).

9. Device as in claim 8, characterized in that said second internal element (14) is defined by an elastic ring disposed, during use, outside said first pipe (11).

10. Device as in claim 9, characterized in that said elastic ring has an air gap (40) inclined with respect to the longitudinal extension of the elastic ring that interrupts the continuity of the material.

11. Device as in any claim hereinbefore, characterized in that the axial extension of said external body (12) astride said first internal element (13) is coordinated with the position of said at least one inspection aperture (30) so as to leave free a passage gap (39), able to sight said at least one inspection aperture (30), so as to enable visibility from the outside of said at least one portion of said compartment (25).

12. Method to connect a first pipe (11) to another pipe by means of a connection device (10) as claimed in any of the claims from 1 to 11, wherein said method provides to verify a correct coupling position of said first pipe (11) to said first internal element (13) by visually observing from the outside at least one portion of said compartment (25) through at least one inspection aperture (30) provided in said second portion (20) of said first internal element (13).

13. Method as in claim 12, characterized in that said method provides to visually observe through said inspection aperture (30) whether a reference ring (26) fitted axially on said first portion (19) is visible, said correct coupling position being defined when said reference ring (26) is disposed on one side in abutment against said housing seating (28) and on the other side is in direct contact with the head end of said first pipe (11) fitted axially on said first portion (19).

14. Adaptor element configured to adapt the connection of a first pipe (11) to another pipe, said adaptor element being able to be assembled coaxially to said first pipe (11) in an external body (12) of a connection device (10) as claimed in any of the claims from 1 to 11, wherein said adaptor element is provided with a first coupling portion (19) which can be inserted in said first pipe (11) and with a second portion (20) surrounding at least part of said first portion (19) defining a compartment (25) that, during use, is affected by said first pipe (11), characterized in that said second portion (20) has a flared shape, it is in a single body integral and solid with said adaptor element together with said first portion (19) and is provided with at least one inspection aperture (30) configured to render visible from the outside at least one portion of said compartment (25) in order to verify, during use, a correct coupling position of said first pipe (11) to said adaptor element.

Description:
“CONNECTION DEVICE FOR PIPES”

* * * * *

FIELD OF THE INVENTION

Embodiments of the present invention concern a connection device to connect two tubular elements to each other, in which a pressurized fluid flows during use.

The connection device allows to connect two tubular elements, for example each made of metal or non-metal material, guaranteeing both a high mechanical stability and also a high hydraulic seal.

In particular, the connection device is suitable to allow the user to visually verify the correct connection between the two tubular elements and the connection device itself, so as to prevent the risk of insufficient hydraulic seals, or non-stable connections during the passage of the pressurized fluid.

Embodiments of the present invention also concern the connection method to connect two tubular elements to each other by means of said device, as well as the adapter element used to visually verify the correct connection of the two tubular elements.

BACKGROUND OF THE INVENTION

Numerous connectors are known, for the sealed connection of two tubular elements, such as for example a fixed metal pipe of a hydraulic apparatus and a removable rubber pipe.

It is necessary that these connectors must guarantee a perfect seal even in the presence of fluids at high pressures and ensure a stability over time against the detachment of the connected parts.

Connectors also exist which normally comprise an external element, or nut, to which the second pipe is screwed, a first element, of the deformable elastic ring type, disposed coaxial inside the nut and possibly open along one side to grip the first pipe, and a second element disposed coaxial with the elastic ring, to guide the correct positioning of the first pipe.

The screwing of the second pipe on the nut causes an axial movement of the second element inside the first pipe, with consequent narrowing of the elastic ring so as to clamp the latter axially with the first pipe.

To verify the correctness of the reciprocal coupling before making the connection definitive, solutions are known in which, on the external surface of the nut, one or more inspection through apertures are provided.

Through these apertures, during the coupling step, the user can visually verify if the first pipe has been positioned correctly with respect to the elements of the connector.

However, this solution has the disadvantage that during the screwing of the second pipe, due to the axial movement of the second element and to the narrowing of the elastic ring, the first pipe is progressively covered.

This means that the user is not able to verify the correct positioning of the first pipe in a final step of the connection, with the risk that the connector will not be sufficiently tightened and that there will be fluid leaks.

Other known solutions provide connectors in which the first pipe to be connected is inserted previously in a seating made between the elastic ring and the second element, and in which the nut is screwed to the second element, or to another additional coaxial element.

When the nut is screwed to the second pipe, the elastic ring is tightened by deformation against the end of the first pipe, and is clamped.

The connectors described heretofore are the blind type and therefore have the disadvantage that they do not allow to verify, before making the connection definitive, whether the second tubular element has been correctly inserted.

In fact, if the end of the second tubular element is not inserted up to the end- of-travel, there is a risk that the gripping surface of the first internal element is not sufficient to guarantee the stability and seal over time of the connection.

Document IT102015000066788 describes a tightening joint for pipes with predetermined torque. The joint described here comprises a body configured for connection to an external system and provided with a tubular portion intended to be inserted inside the pipe to be tightened. On the opposite side with respect to the tubular portion, the body comprises an attachment portion disposed to be connected to the external system. The joint also comprises a cylindrical bush connected to the body through a first threaded connection; the cylindrical bush is screwed to the body with a preset tightening torque. Consequently, the cylindrical bush is a separate element with respect to the body on which the tubular portion and the attachment portion are present. The joint also comprises a tightening element, such as a ring nut, which surrounds the pipe and which is connected through a second threaded connection to the cylindrical bush. The first threaded connection and the second threaded connection comprise respective screws of the threads, oriented opposite to each other, consequently a screwing of the ring nut on the cylindrical bush triggers an unscrewing of the bush from the body when the preset tightening torque is reached; the triggering of the unscrewing acts as an indicator that the pipe has been correctly tightened. When the cylindrical bush begins to unscrew from the body, it means that the tightening torque with which the ring nut is screwed onto the cylindrical bush has reached the value of the preset tightening torque with which the cylindrical bush had been previously screwed to the body; at this moment the ring nut has been screwed onto the cylindrical bush at least with a tightening torque equal to the preset one, suitable to guarantee a correct tightening of the pipe over time. When the operator sees that the cylindrical bush is starting to unscrew from the body, it is possible to interrupt the tightening of the ring nut since the pipe has been tightened correctly. A safety device is associated with the body and is disposed to prevent the cylindrical bush from unscrewing from the body beyond a certain predetermined threshold. Moreover, the joint comprises visual indicator means disposed to signal to an operator that the pipe has been correctly clamped to the body and the cylindrical bush comprises one or more inspection lights configured as through windows so that an operator can release the end of the pipe through them when the latter rests on the body, in particular on the annular gasket that surrounds the tubular portion. The inspection gaps, therefore, are made on a component, that is, the cylindrical bush, which is a separate element and mobile with respect to the body on which the tubular portion and the attachment portion are present, in particular it can be screwed and unscrewed with respect to the body. This aspect, in the known joint, ensures the correct functioning of the system which indicates to the operator that the ring nut has been screwed onto the cylindrical bush at least with a tightening torque equal to the preset one, suitable to guarantee a correct tightening of the pipe over time.

Document US-B-6,523,862 also describes a connector for pipes having a connector body with a tubular portion for insertion into a pipe and on which a separate crimping ring is connected, to compress the end of the pipe on the connector end. There is therefore a need to perfect the state of the art and make a connection device available which overcomes at least one of the disadvantages of the state of the art.

In particular, one purpose of the present invention is to provide a connection device for pipes that allows the user to visually verify the correct positioning of the first pipe in the initial insertion step, and the successful correct final connection of the two pipes.

Another purpose of the invention is to provide a connection device for pipes that allows a user to check in advance the correct and complete positioning of the components of the connection device itself, before making the connection with a second pipe definitive, in order to guarantee that both the connections of the pipes with the connection device are safe and stable over time.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, the present invention concerns a connection device to connect a first pipe to another pipe.

The connection device comprises at least a hollow external body for the stable and releasable connection of the first pipe and the other pipe, and a first internal element, also called adaptor element, configured to adapt the connection of the first pipe to the other pipe, and able to be assembled coaxially to the first pipe in the external body.

The first internal element is provided with a first coupling portion which can be inserted in the first pipe and with a second flared portion surrounding at least part of the latter defining a compartment that, during use, is affected by the coupling of the first pipe with the first internal element.

According to one aspect of the invention, the second portion is in a single body integral and solid with the first internal element together with the first portion and comprises at least one inspection aperture configured to render visible from the outside at least one portion of the compartment in order to verify, during use, a correct coupling position of the first pipe with the first internal element.

This solution allows to visually verify the correct positioning of the first pipe in the initial insertion step, checking in advance the correct and complete positioning of the connection device, before making the connection with a second pipe definitive.

According to possible embodiments, the connection device can comprise a reference ring able to be axially fitted on the first portion, and a housing seating to define an axial end-of-travel position of the reference ring, made in the compartment.

In the latter case, in the correct coupling position, the reference ring is disposed on one side in abutment against the housing seating and on the other side is in direct contact with the head end of the first pipe fitted axially on the first portion.

The presence of the reference ring allows to easily identify if the connection is correctly made.

According to possible embodiments, the reference ring in the correct coupling position, is concealed from view by at least one part of the second portion provided between the inspection aperture and the housing seating.

According to other possible embodiments, the reference ring in the correct coupling position, is visible from the inspection aperture.

According to possible embodiments, the inspection aperture can have an open profile defining a hollow in the second portion of the first internal element.

This embodiment allows to increase the visual field and allow the user to easily verify the correct coupling position.

In accordance with possible embodiments, the first portion has an inclined segment with a taper that develops in the opposite direction to an axial coupling direction of the first portion with the first pipe.

The inclined segment has a maximum diameter in proximity to the housing seating.

According to possible embodiments, the reference ring has a smaller diameter with respect to the maximum diameter of the inclined segment in order to cooperate with the latter by interference so that, during use, it tends to determine a progressive axial sliding of the reference ring toward the first pipe.

This solution makes it possible to identify connections that have been made almost correctly, which are often identified as correct.

Every time the reference ring is not located in the housing seating, it slides progressively along the inclined segment, making it visible through the inspection aperture, signaling to an operator that the connection is not correct.

In accordance with possible embodiments, the reference ring is located, during use, in contact with the edge of the head end of the first pipe to make an efficient hydraulic seal between the first pipe and the part that exits from the first pipe of the first portion.

This solution allows the ring to be used also with a gasket in order to obtain the hydraulic seal of the first pipe with respect to the connection device.

According to possible embodiments, at least part of the external surface of the reference ring can be colored.

This solution allows to make the reference ring particularly evident with respect to the other parts of the connection device.

In accordance with possible embodiments of the present invention, the connection device comprises a second internal clamping element able to be fitted axially on the first pipe and to be assembled coaxially to the first internal element in the external body.

According to possible embodiments, the second internal element, during use, has at least one portion located between the external body and the first pipe and at least another portion located between the first internal element and the first pipe.

According to possible embodiments, the second internal element has at least two protruding portions which, during use, are engaged in corresponding anchoring seatings respectively of the first internal element and of the external body.

These solutions allow to obtain a secure coupling between the components of the connection device which radially tighten the first pipe and are constrained to each other in the position which guarantees the correct connection of the first pipe to the connection device. Moreover, this allows an operator to easily separate the components of the connection device from each other, so as to be able to carry out maintenance or replacement of components.

According to possible embodiments, the second internal element can be defined by an elastic ring, or elastic ring having an air gap that interrupts the continuity of the material, disposed during use external to the first pipe.

According to possible embodiments, the elastic ring has an air gap inclined with respect to the longitudinal extension of the elastic ring itself which interrupts the continuity of the material.

This solution is advantageous compared with an air gap made along the longitudinal extension since it allows to clamp the first pipe during use, improving the distribution of the radial gripping forces on the first pipe. This allows to not deform the first pipe near the air gap in an anomalous way.

In accordance with possible embodiments, the axial extension of the external body astride the first internal element is coordinated with the position of the at least one inspection aperture so as to leave free a passage gap, able to sight the at least one inspection aperture, so as to enable visibility from the outside of the at least one portion of the compartment.

In accordance with possible embodiments, the present invention also concerns a method to connect a first pipe to another pipe by means of a connection device.

According to one aspect of the present invention, the connection method provides to verify a correct coupling position of the first pipe to the first internal element by visually observing from the outside at least one portion of the compartment through at least one inspection aperture provided in the second portion of the first internal element.

According to possible embodiments, the method provides to visually observe through the inspection aperture whether a reference ring fitted axially on the first portion is visible, said correct coupling position being defined when the reference ring is disposed on one side in abutment against the housing seating and on the other side is in direct contact with the head end of the first pipe fitted axially on the first portion.

In accordance with possible embodiments, the present invention also concerns an adaptor element configured to adapt the connection of a first pipe to another pipe.

According to possible embodiments, the adaptor element is able to be assembled coaxially to the first pipe in an external body of a connection device. The adaptor element is provided with a first coupling portion which can be inserted in the first pipe and with a second flared portion surrounding at least part of the first portion defining a compartment that, during use, is affected by the first pipe.

In accordance with one aspect of the present invention, the second portion has a flared shape, it is in a single body integral and solid with the adaptor element together with the first portion and is provided with at least one inspection aperture configured to render visible from the outside at least one portion of the compartment in order to verify, during use, a correct coupling position of the first pipe to the adaptor element thereof.

These and other aspects, characteristics and advantages of the present disclosure will be better understood with reference to the following description, drawings and attached claims. The drawings, which are integrated and form part of the present description, show some forms of embodiment of the present invention, and together with the description, are intended to describe the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

- figs. 1 and 2 are two sections of a connection device installed on a pipe according to a possible embodiment of the present invention, in which fig. 1 shows the pipe in a not correctly connected position and fig. 2 shows the pipe in a correctly connected position;

- fig. 3 is an exploded view of a connection device with a pipe according to a possible embodiment of the present invention;

- figs. 3a and 3b show possible variant embodiments of a first and a second internal element of a connection device according to possible embodiments of the present invention;

- figs. 4-6 show a connection device in three steps of an assembly sequence. To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can conveniently be incorporated into other embodiments without further clarifications.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

We will now refer in detail to the various embodiments of the present invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one embodiment can be adopted on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.

With reference to figs. 1-6, which show non-restrictive examples of the invention, we will now describe embodiments of a connection device 10 able to connect a first pipe 11 with a second pipe, not shown in the drawings.

For example, the first pipe 11 can be made of rubber, plastic, or other material, and the second pipe can comprise a threaded metal pipe such as, for example, the end portion of a tap.

According to possible embodiments, the connection device 10 comprises an external body 12, also known as a nut, hollow and configured for the stable and releasable connection of the pipes, and a first internal element 13, also called adapter element, configured to adapt the connection between the pipes.

The first internal element 13 is able to be assembled coaxially with the first pipe 11 in the external body 12.

According to possible embodiments, the connection device 10 can also comprise a second internal clamping element 14, also called an elastic ring, able to be fitted axially on the first pipe 11 and to be assembled coaxially with the first internal element in the external body 12.

The external body 12, the first internal element 13 and the second internal element 14, during use, are substantially coaxial to each other along a common coupling axis X.

According to possible embodiments, the external body 12 and the two internal elements 13 and 14 can be previously assembled in a single block and can be reciprocally mobile with a certain play, before the first pipe 11 and the second pipe are connected to the connection device 10.

According to possible embodiments, the external body 12 can be internally equipped with an annular cavity 15 in which the first internal element 13 and the second internal element 14 are at least partly positioned.

According to possible embodiments, the first internal element 13 is located, at least partly, between the external body 12 and the second internal element 14.

According to possible embodiments, not shown, the external body 12 can be provided with a thread to be able to connect the latter to the second pipe, or to the first internal element 13 in a prior assembly step of the connection device 10.

According to possible variants, the external body 12 can comprise an external portion 16 shaped like a hexagon, so as to be able to easily handle the latter with a standardized tool.

According to possible embodiments, the external body 12 can comprise two or more apertures 17 made on angularly distanced parts on its external surface 18.

According to possible embodiments, the apertures 17 can extend axially with respect to the external body 12, that is, in the direction of the coupling axis X between the first pipe 11 and the second pipe.

The apertures 17 can be used to engage an extractor tool with the external body 12 to easily disconnect the latter from the second pipe.

According to possible embodiments, the first internal element 13 can comprise a first portion 19 which extends longitudinally in its axial direction and a second flared or tapered portion 20 connected to the first portion 19, and surrounding at least part of the external surface 21 thereof. The second portion 20 is in a single body, integral and solid with the first internal element 13 together with the first portion 19. Consequently, the second portion 20 is static with respect to the first portion 19 of the first internal element 13.

The first portion 19 is of an essentially tubular shape, defining an axial hole 19b for the passage of fluids and is substantially concentric with respect to the second portion 20, disposed inside it. The second portion 20 therefore forms a flared or tapered collar structure which surrounds the first tubular portion 19.

The first internal element 13 is therefore advantageously a monoblock body, in which the first portion 19 and the second portion 20 are in a single body with the first internal element 13, integral and solid parts of the latter.

The first internal element 13 also comprises an end base 13a, tubular in shape, defining an aperture 13b fluidically in communication with the axial hole 19b, for the passage of fluids. On the end base 13a there is a circumferential seating 13c to house a fluid seal element 13d, for example an annular gasket. The end base 13a also forms part of the monoblock structure of the first internal element 13 to which the first portion 19 and the second portion 20 belong. The first portion 19 and the second portion 20 substantially protrude from the end base 13a of the first internal element 13.

The flared shape of the second portion 20, in particular, is substantially a convergent-divergent shape with respect to the coupling axis X and is mainly formed by a flared or tapered layer which extends circumferentially around the first portion 19. In particular, the convergent-divergent flared shape of the second portion 20 is formed by a first inclined truncated-cone segment 20a which all in all defines the flared or tapered shape of the second portion 20 and which develops from the end base 13a of the first internal element 13, in particular from a more internal position, axially downstream of the circumferential seating 13c with respect to the aperture 13b, and by a second substantially cylindrical element 20b which extends from the first inclined truncated-cone segment 20a, and on which, at the end, an annular tooth 20c is provided, protruding toward the inside, which defines an anchoring seating 35, the function of which is explained in more detail below.

According to possible embodiments, during use, the first portion 19 of the first internal element 13 is located in the first pipe 11.

According to possible embodiments, ridges 22 can be made on the external surface of the first portion 19, able to cooperate by mechanical interference with the internal surface of the first pipe 11.

In the hollows 23 defined by at least some of the ridges 22, sealing rings 24 can be disposed, for example gaskets of the O-ring type.

According to possible embodiments, a compartment 25 is defined between the first portion 19 and the second portion 20.

According to possible embodiments, a reference ring 26 can be located in the compartment 25.

According to possible embodiments, in the compartment 25 at least one housing seating 28 can be defined for the reference ring 26.

According to possible embodiments, the housing seating 28 is located in the connection segment between the first portion 19 and the second portion 20.

According to possible embodiments, the reference ring 26 can be substantially configured as the sealing ring 24 in order to guarantee, during use, an efficient hydraulic seal between the first pipe 11 and the part that protrudes from the latter of the first portion 19.

The reference ring 26 can be made of an elastic material, such as rubber for example, so that it can be elastically deformed.

According to possible embodiments, at least part of the external surface of the reference ring 26 can be advantageously colored so that the latter can be easily identified.

For example, the reference ring 26 can be red, while the other sealing rings 24 can be black.

According to possible embodiments, the first portion 19 has an inclined segment 27, near the housing seating 28, having its maximum diameter, so as to cause a reduction in the diameter of the first portion 19 to move away from the housing seating 28.

According to possible embodiments, the reference ring 26 has a diameter slightly less than the maximum diameter of the inclined segment 27.

During insertion of the first portion 19 into the first pipe 11, the inclined segment 27 determines the progressive sliding of the reference ring 26, by virtue of the diameter of the latter which is less than the maximum diameter of the inclined segment 27, toward the edge 29 of the end of the first pipe 11. The inclined segment 27 defines, during use, at least a first configuration in which the reference ring 26 is in contact with the edge 29 of the end of the first pipe 11 outside the housing seating 28, and a second configuration in which the ring reference 26 is in contact with the edge 29 of the end of the first pipe 11 in the housing seating 28.

When the reference ring 26 is positioned inside the housing seating 28 and is in contact with the edge 29 of the end of the first pipe 11, that is, when the second configuration is made, the first pipe 11 is correctly connected to the first internal element 13.

According to one aspect of the present invention, the second portion 20 can comprise at least one inspection aperture 30 able to make visible at least part of the first portion 19 from the outside so as to allow to check, during use, the correct coupling position of the first pipe 11 to the first internal element 13, by visually observing the possible presence of the reference ring 26. In particular, said at least one inspection aperture 30 can be made in the first inclined truncated-cone segment 20a of the second portion 20. The second segment 20b of the second portion 20 can be continuous and not have interruptions or apertures.

Advantageously, since the second portion 20 is in a single body together with the first portion 19 in the first internal element 13, the second portion 20 and the first portion 19 are static one with respect to the other and therefore the visual verification from the outside of the at least part of the first portion 19 through the at least one inspection aperture 30 is reliable and safe since there are no undesired and unpredictable relative movements between the first portion 19 and the second portion 20.

The inspection aperture 30 can be positioned and sized in such a way as to observe only the zone where the housing seating 28 is present so as to visually observe whether the reference ring 26 is in the latter.

According to possible embodiments, the inspection aperture 30 can be positioned and sized so as to observe the zone of the compartment 25, where there is no housing seating 28, so as to visually observe when the reference ring 26 is not in the latter.

According to possible embodiments, the inspection aperture 30 can have an open profile defining a hollow in the second portion 20 of the first internal element 12.

According to possible embodiments, the inspection aperture 30 can have a closed profile which defines a window in the body of the second portion 20.

According to possible embodiments, the axial extension of the external body 12 astride the first internal element 13 is coordinated with the position of the inspection aperture 30 so as to leave free a passage gap 39, able to sight the latter, so as to enable visibility from the outside of at least a portion of the compartment 25.

According to possible embodiments, the passage gap 39 can be axially symmetrical, for example it can have a shape with a toroidal development.

The inspection aperture 30 can be positioned so as to be able to visually observe the first pipe 11, when the reference ring 26 is located in the housing seating 28, that is, the second configuration, and the reference ring 26 and/or part of the first portion 19, when the reference ring 26 is not located in the housing seating 28, that is, the first configuration.

If only the first pipe 11 is visible through the inspection aperture 30, then the connection of the latter to the first internal element 13 is correctly made.

According to possible embodiments, by positioning the inspection aperture 30 in correspondence with the housing seating 28 it is possible to verify the correct connection when the reference ring 26 is in the latter.

By using a reference ring 26 that is at least partly colored on its external surface, it is possible to easily identify it through the inspection aperture 30.

According to possible embodiments, the second internal element 14 is defined by an elastic ring, or an elastic ring having an air gap which interrupts the continuity of the material, disposed, during use, outside the first pipe 11.

According to possible embodiments, the second internal element 14 has at least a portion located between the external body 12 and the first pipe 11 and at least another portion located between the first internal element 13 and the first pipe 11.

According to possible embodiments, shown in fig. 3a, the second internal element 14 can be defined by an open ring, the ends of which are closed at the moment of connection, in order to clamp the first pipe 11.

According to possible embodiments, the second internal element 14 can be provided with an air gap 40 inclined with respect to the longitudinal extension of the second internal element 14 itself, which interrupts the continuity of the material.

The second internal element 14 also comprises an internal surface 31, which can be provided with a plurality of crimping teeth 32 which, during use, incise and axially retain the first pipe 11.

In accordance with possible embodiments, the second internal element 14 is conformed so as to have two protruding portions 33 and 34 which, during use, are engaged in corresponding anchoring seatings 35 and 36 respectively of the first internal element 13 and of the external body 12, so as to obtain a stable association of the three components of the connection device 10.

According to possible embodiments, the second portion 20 of the first internal element 13 has a curved terminal portion 37, defined by the annular tooth 20c, which defines the anchoring seating 35.

The association of the protruding portion 33 with the anchoring seating 35 constrains the reciprocal movement of the second internal element 14 and the first internal element 13.

According to possible embodiments, the external body 12 can comprise an internal portion 38 which defines the anchoring seating 36.

The internal portion 38 can be conical so as to cooperate, during use, with a mating protruding portion 34 of the second internal element 14.

The association of the protruding portion 34 with the anchoring seating 36 constrains the reciprocal movement of the external body 12 and the first internal element 13.

With reference to the sequence shown in figs. 4, 5 and 6, the connection between the first pipe 11 and the connection device 10 can take place according to the sequence described below.

The first portion 19 of the first internal element 13 is inserted into the first pipe 11 which is in turn inserted into the second internal element 14.

During this step, the reference ring 26 is located in contact with the edge 29 of the end of the first pipe 11.

The second internal element 14 is connected to the first internal element 13 by associating the protruding portion 33 with the anchoring seating 35. The assembly formed by the first pipe 11 and the first and second internal element 13 and 14 is inserted into the external body 12, associating the latter with the second internal element 14 by coupling the protruding portion 34 with the anchoring seating 36.

The first pipe 11 is thrust, causing the latter to advance with respect to the first internal element 13, with consequent advance of the reference ring 26 until the latter is positioned in the housing seating 28.

During this operation, the operator can monitor from the outside the progressive and correct connection of the first internal element 13 to the first pipe 11, visually following the axial advance of the reference ring 26 through the inspection aperture 30.

Once the tightening of the connection device 10 and the final clamping of the two pipes have been completed, only the first pipe 11 will be visible from the inspection aperture 30.

In this way, if the user visually verifies that the reference ring 26 is visible, outside the housing seating 28, it means that the tightening of the connection device 10 is not complete and that the clamping of the pipes is not definitive, and the user is thus able to complete or correct this tightening.

It is clear that modifications and/or additions of parts can be made to the connection device 10 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of connection devices 10, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

In the following claims, the sole purpose of the references in brackets is to facilitate reading: they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.