WO2008007396A1

WO2008007396A1 - Connection for pipes

Info

Publication number: WO2008007396A1
Application number: PCT/IT2006/000526
Authority: WO
Inventors: Fausto Ungari
Original assignee: Fra.Bo S.P.A.
Priority date: 2006-07-11
Filing date: 2006-07-11
Publication date: 2008-01-17

Abstract

A connection device (1) for joining a tubular portion of a first component in fluid connection with a second component in a fluid conveyance system comprises a main body (3) which defines a passage space (33) inside, and a substantially tubular connection portion t (5) in fluid communication with such passage space (33) . The connection portion (5) defines a seat (7) for receiving such tubular portion (2) and is radially pressable for engaging this tubular portion (2) by interference . The seat (7) comprises at least one projection (9) which radially juts inward and which is arranged and shaped such to at least partially penetrate into an outer layer (8) of the tubular portion (2) following the radial pressing of the connection portion (5) .

Description

DESCRIPTION "CONNECTION FOR PIPES"

[0001] Object of the present invention is a connection for connecting components in fluid conveyance systems, in particular a connection for connecting pipes, for example in drinking water distribution facilities or in heating facilities .

[0002] With particular reference to the water transportation facilities, substantially two types of pipes currently find wide use . The first pipe type is the so-called multilayer pipe, which consists of several alternating and concentric tubular layers of polyethylene and aluminium. The second pipe type has only a first inner layer of copper, inside of which the fluid flows, and a second cover layer in polyethylene.

[0003] In complex facilities, i.e. those composed of a multiplicity of elements, there is the need to mutually connect by means of connections the pipes which make up such facility, or one or more of these pipes with additional elements of the facility, such as for example pumps, valves, heat exchangers or tanks. [0004] Since the multilayer or polyethylene-copper pipes foresee an outer layer of polyethylene, their connection to other elements of the facility creates considerable difficulties. The polyethylene, in fact, is much more pliable than a metal, and moreover tends to be greatly deformed at high temperatures as well as lose adherence at the low temperatures. It is therefore not possible to use connection solutions similar to those which are used for purely metal pipes, for example copper pipes, whose outer layer is more rigid and less deformable at high temperatures .

[0005] In the known press connections for pipes with outer layer in polyethylene, a tubular pressure portion is foreseen which receives the end of the pipe to be connected and locks it by means of interference following a pressing of the pressure portion around the end of the pipe . [0006] Due to the mentioned characteristics of the outer polyethylene layer, the interference coupling between the pipe and the pressure portion is not sufficiently reliable. To overcome such problem, it has been proposed to provide an opposing tubular element which is inserted in the end of the pipe before the pressing of the pressure portion, so to tighten the end of the pipe between such opposing element and the pressure portion. [0007] Such known devices do not, however, lack drawbacks. [0008] A first drawback is represented by the reduction of the diameter of the passage opening of the pipe due to the insertion of the opposing element. Such diameter reduction of the conduit causes turbulence in the flow and consequently head losses, to the detriment of the overall efficiency of the entire facility. [0009] A further drawback of the connections according to the prior art consist of the fact that the opposing element, being hit by the fluid flow, can also be subject to a high static and⁴above all dynamic pressure, and therefore risks escaping from the inside of the pipe. [0010] Finally, the opposing element creates recesses inside the conduit, an invitation for impurities and bacteria, unacceptable for example in the food and hospital sectors . [0011] Object of the present invention is therefore that of making available a connection device which has characteristics such to overcome the drawbacks mentioned with reference to the prior art.

[0012] In particular, object of the present invention is that of making available a connection device which makes it possible to safely connect components of a conveyance system of fluids, in particular liquids, without intervening on the inner passage of the components themselves, for example pipes or valves. [0013] A further object of the invention is that of proposing a connection device which minimises the turbulences and overall head losses in the fluid conveyance system.

[0014] These and other objects are achieved by means of a connection device for joining a tubular portion of a first component in fluid connection with a second component in a fluid conveyance system, wherein such connection device comprises:

- a main body which defines a passage space inside;

- a substantially tubular connection portion in fluid connection with said passage space, wherein the connection portion defines a seat for receiving the tubular portion and is radially pressable so to engage said tubular portion by interference, and wherein this seat comprises at least one projection which radially juts inward and which is arranged and shaped so to at least partially penetrate into an outer layer of the tubular portion, following such radial pressing of the connection portion.

[0015] Such objects are moreover reached by means of an adapter insert adapted to be inserted in an outer portion of a radially pressable connection portion of a connection device so to join a tubular portion of a first component in fluid connection with a second component in a fluid conveyance system, wherein such adapter insert is substantially tubular, defines a seat for receiving the tubular portion and is radially pressable so to engage said tubular portion by- interference, and wherein said seat comprises at least one projection which radially juts inward and which is arranged and shaped so to at least partially penetrate into an outer layer of the tubular portion following such radial pressing.

[0016] To better understand the invention and appreciate its advantages, several of¹ its exemplifying and not limiting embodiments will be described below, making reference to the attached figures, wherein:

[0017] Figure 1 is a side, sectional view of an assembled connection device according to a first embodiment of the invention;

[0018] Figure 2 is a side, sectional view of an assembled connection device according to a further embodiment of the invention;

[0019] Figure 3 is a perspective, sectional view of an assembled connection device according to a further embodiment of the invention; [0020] Figure 4 is a perspective, sectional, exploded view of the connection device of figure 3;

[0021] Figure 5 is a perspective view of a detail of the connection device of figure 3 ; [0022] Figure 6 is a side, sectional view of a further detail of the connection device of figure 3; [0023] Figure 7 is a perspective, sectional view of the detail of figure 6;

[0024] Figure 8 is a side, sectional view of the detail of the connection device of figure 6 according to a further embodiment of the invention;

[0025] Figure 9 is a perspective, sectional view of the detail of figure 8.

[0026] With reference to the figures, a connection device is indicated in its entirety with the reference number 1. Such connection device 1 is adapted to connect at least one tubular portion 2 of a component of a fluid conveyance system with an additional component of such system. Such components to be connected (not shown in the figures) can be pipes, for example, eventually of different sizes, or pumps, valves, heat exchangers, tanks or the like.

[0027] The connection device 1 comprises a main body 3 which defines a passage opening 33 at its interior. Such main body 3 is adapted, depending on its conformation, to deviate and/or divide the flow of fluid between the components of the conveyance system interconnected by means of the connection device 1. For example, the main body 3 can be rectilinear, U-shaped, T-shaped or elbow- shaped. [0028] The connection device 1 moreover comprises at least one connection portion 5, substantially tubular and in fluid communication with the passage space 33 of the main body 3. Such connection portion 5 comprises a radially inner surface 6 which defines a seat 7 adapted to receive the tubular portion 2 of the component to be connected.

[0029] The seat 7 is radially pressable, so to be able to engage by interference the tubular portion 2 received in it. [0030] Moreover, the seat 7 comprises at least one projection 9 which radially juts inward and which is shaped so that when the tubular portion 2 is inserted in the seat 7, by applying a radial pressing action the projecting element 9 at least partially radially penetrates into an outer layer 8 of the tubular portion 2 , tightly constraining it with the respect to the connection portion 5.

[0031] In accordance with one embodiment, the seat 7 of the connection portion 5 comprises two projections 9, preferably arranged in proximity to the two opposite ends, so to ensure a substantially symmetrical hold on the tubular portion 2 within the seat 7.

[0032] Advantageously, such projections 9 are annular, so to engage the outer layer 8 of the tubular portion 2 along an entire perimeter. [0033] With further advantage, the projections 9 have in section a V-pointed form, tilted in the insertion direction of the tubular portion 2 inside the seat 7. The pointed vertex of the V ensures that the projections 9 can easily penetrate into the outer layer 8 of the tubular portion 2, usually, as said, in polyethylene. The tilting of the V, moreover, ensures a favoured sliding direction of the tubular portion 2, which can be easily inserted in the seat 7 in assembly phase, but which is not free to slide in the opposite direction once the pressing has occurred.

[0034] Still more advantageously, the seat 7 comprises an annular groove 12 adapted to receive an inner seal 13. In accordance with one embodiment, such annular groove 12 has in section a substantially semicircular form and can receive a seal 13 of 0-ring type with substantially circular section. In accordance with a further embodiment, such annular groove 12 has a substantially symmetrical, elongated form, wherein two curved ends are connected with each other by a substantially rectilinear segment (figures 8 and 9) . In the so formed groove 12, a seal 13 can be advantageously received of 0-ring type with substantially °° section (i.e. shaped like the °° symbol) . Preferably, the two portions of such °° section have different diameters, such that when the 0-ring is inserted in the annular groove 12, which has in section a substantially symmetrical shape, the greater diameter portion projects radially inward for a greater amount with respect to the smaller diameter portion. Preferably, the °° O-ring is positioned in the annular groove 12 such that its smaller diameter portion is turned towards an outer end 31 of the connection portion 5, at which the tubular portion 2 is inserted in the seat 7. [0035] Advantageously, between* the two projections 9 and the annular groove 12 for the seal 13, the seat 7 comprises two second inner grooves 14, preferable having in section a substantially triangular or upside-down V form. Such second grooves 14 have the function of receiving the material of the outer layer 8 of the tubular portion 2, which is moved during the pressing when the projections 9 penetrate into it, and ensure in this manner a form coupling between the tubular portion 2 and the connection portion 5. [0036] At an inner end 30, opposed to the outer end 31, the seat 7 of the connection portion 5 advantageously comprises a stroke-end stop 15 for the tubular portion 2, such that, during the assembly operation, the latter is inserted inside the seat 7 until it is in abutment against such stroke-end stop 15, in a position adapted for the pressing action (figure 3) . Preferably, such stroke-end stop 15 is an annular shoulder of substantially rectangular section which radially juts inward. This annular shoulder advantageously has a passage diameter which is- greater or substantially equal to that of the tubular portion 2 to be connected, such that the fluid which flows inside the latter is not disturbed. [0037] Advantageously, between the annular shoulder 15 and the projection 9 closest to the inner end 31 in the seat 7, a third annular groove 27 is formed, adapted to receive further material of the outer layer 8 of the tubular portion 2 moved when such projection 9 penetrates into it . [0038] The connection portion 5 comprises an external tubular portion 17 having an outer surface 34 which is intended to be engaged by a pressing tool (not shown in the figures) and an adapter portion 16 which defines the seat 7. [0039] In accordance with one embodiment, the outer portion 17 and the adapter portion 16 are realised in a single piece (figure 1) .

[0040] In accordance with a further embodiment, the outer portion 17 and the adapter portion 16 are separate from each other, so that the adapter portion 16 forms an adapter insert which can be inserted in the outer portion 17 to adapt the connection device 1 to a specific type of tubular portion 2 to be connected (see for example figures 2-5) . [0041] A radially inner surface 18 of the outer portion 17 advantageously forms an adapter seat 19 adapted to receive the adapter portion 16 at its interior (figure 5) . [0042] With further advantage, such adapter seat 19 comprises an annular groove 20 adapted to receive a seal 21 at its interior, preferably an O-ring. Such seal 21, arranged between the outer portion 17 and the adapter portion 16, realises an elastic connection between these portions 16, 17 in order to prevent an accidental loss of the adapter portion 16 from the adapter seat 19.

[0043] In accordance with one embodiment (figure 2) , an outer edge 22 of the outer portion 17 is radially folded inward, so to form a constraint which prevents the extraction of the adapter portion 16 from the adapter seat 19 of the outer portion 17 in the direction of the outer end 31. Still more advantageously, such folded outer edge 22 forms an additional projection 23 having a substantially V profile, so to penetrate into the outer layer 8 of the tubular portion 2, thus collaborating with the projections 9 of the adapter portion 16 in their holding of the tubular portion 2.

[0044] In accordance with a further embodiment (figures 3- 5) , such outer edge 22 is not folded. At its outer end 31, the adapter portion 16 advantageously comprises an annular protuberance 24 which radially juts outward, so to form a stroke-end stop * for the insertion of the adapter portion 16 within the adapter seat 19 of the outer portion 17 (figures 6-9) . Such annular protuberance 24 is adapted to be in abutment against a front surface 25 of the outer edge 22 of the outer portion 17 when the adapter portion 16 reaches the correct mounting position within the adapter seat 19. [0045] In order to be able to be completely inserted in the adapter seat 19 of the outer portion 17, without hitting a converging portion 28, the adapter portion 16 at its inner end 30 can comprise a bevel 29. [0046] Advantageously, a radially outer surface 35 of the adapter portion 16 forms anti-extraction means adapted to lock the adapter portion 16 to the outer portion 17. [0047] In accordance with one embodiment, such anti- extraction means comprise a radially outer annular groove 26, preferably situated in proximity to the inner end 30. The annular groove 26 has the advantageous role of receiving part of the material of the outer portion 17 which is moved during the pressing, thus making possible a form coupling between the adapter portion 16 and the outer portion 17.

[0048] Advantageously, the adapter insert 16 comprises one or more notches 32, preferably axially oriented, which are arranged inwardly with respect to the annular groove 12 for the seal 13 and which open towards the inner end 30 of the adapter portion 16 (figures 8 and 9) . In this manner, the adapter portion 16 is locally more pliable and therefore the pressing operation to constrain the tubular portion 2 in the seat 7 is facilitated. Preferably, there are four notches 32, arranged spaced by a 90° angle from each other.

[0049] The adapter portion 16 is preferably realised by means of moulding or casting in brass, in plastic material, aluminium or aluminium alloy.

[0050] From the above provided description, the man skilled in the art can appreciate how the connection device according to the invention resolves the problems connected with connection devices according to the prior art .

[0051] In particular, the man skilled in the art can appreciate how the connection device according to the invention, not requiring the presence of an opposing element to be inserted in the passage opening for the fluid of the pipe or the tubular portion of the component to be connected, permits maintaining the fluid flow substantially undisturbed, even near the connection itself, avoiding abrupt section variations, shutter effects and therefore undesired turbulences and head losses .

[0052] The man skilled in the art can also appreciate how the connection device according to the invention reduces the risk of escaping of the tubular portion inserted in the device itself, since the axial forces acting on the latter are nearly nonexistent.

[0053] The man skilled in the art can finally appreciate how the adapter insert according to the invention can be easily coupled with main connection bodies of the most varied forms and functions. For example, with the adapter, it will be possible to adapt for use with multilayer pipes or polyethylene-copper pipes even connections per se conceived^"* for being fixed directly on copper pipes. [0054] In order to satisfy specific and contingent needs with regard to the above described embodiments of the connection device, the man skilled in the art can make numerous adaptations, modifications and substitutions of elements with other functionally equivalent elements, without however departing from the scope of the following claims.

Claims

1. Connection device (1) for_χ joining a tubular portion (2) of a first component in fluid connection with a second component in a fluid conveyance system, said connection device (1) comprising:

- a main body (3) defining a passage space (33) inside;

- a connection portion (5) , substantially tubular and in fluid communication with said passage space (33) , wherein the connection portion (5) defines a seat (7) for receiving said tubular portion (2) and can be radially pressed in order to engage said tubular portion (2) by interference, characterised in that said seat (7) comprises at least one projection (9) which radially juts inward and which is arranged and shaped such to at least partially penetrate into an outer layer (8) of the tubular portion

(2) following said radial pressing of the connection portion (5) .

2. Connection device (1) according to claim 1, wherein said seat (7) of the connection portion (5) comprises two projections (9) situated in proximity to opposite ends of said seat (7) .

3. Connection device (l) according to claim 1 or 2, wherein said projections (9) of said seat (7) are annular and have a V form in section which is tilted in the insertion direction of the tubular portion (2) .

4. Connection device (1) according to any one of the preceding claims, wherein said seat (7) of said connection portion (5) comprises an annular groove (12) adapted to receive a seal (13) .

5. Connection device (1) according to claim 4, wherein said annular groove (12) of said seat (7) has a substantially semicircular form and receives an O-ring of substantially circular section.

6. Connection device (1) according to claim 4, wherein said annular groove (12) of said seat (7) receives an CD- ring with substantially °°-shaped section, the two portions of which have different diameters, said O-ring being arranged in said annular groove (12) of the seat (7) such that its smaller diameter portion is turned towards an outer end (31) of the connection portion (5) .

7. Connection device (1) according to any one of the preceding claims, wherein said seat (7) of said connection portion (5) comprises two second, substantially triangular grooves (14) arranged on both sides of the annular groove (12) , respectively between one of the two projections (9) and said annular groove (12) . i

8. Connection device (1) according to any one of the preceding claims, wherein at an inner end (30) opposite to the outer end (31) the seat (7) of said connection portion (5) comprises an annular shoulder (15) which defines a stroke-end stop for said tubular portion (2) .

9. Connection device (1) according to the preceding claim, wherein said annular shoulder (15) has a passage diameter which is greater than or substantially equal to that of said tubular portion (2) to be connected.

10. Connection device (1) according to claim 8 or 9, wherein a third annular groove (27) is formed in said seat (7) between said annular shoulder (15) and the projection (9) closest to sa^d inner end (31) .

11. Connection device (1) according to any one of the preceding claims, wherein said connection portion (5) comprises an outer tubular portion (17) with an outer surface (34) intended to be engaged by a pressing tool and an adapter portion (16) separate from the outer portion (17) , said adapter portion (16) defining said seat (7) and being inserted in the outer portion (17) in order to adapt the connection device (1) for a specific type of pipe to be connected.

12. Connection device (l) according to claim 11, wherein said adapter portion (16) comprises, at its outer end (31) , an annular protuberance (24) which radially juts outward and forms a stroke-end stop for the insertion of the adapter portion (16) in the outer portion (17) .

13. Connection device (1) according to claim 11 or 12, wherein an outer surface (35) of said adapter portion (16) forms anti-extraction means adapted to lock the adapter portion (16) to the outer portion (17) .

14. Connection device (1) according to claim 13, wherein said anti-extraction means comprise an annular groove (26) adapted to receive a material part of the outer portion (17) which is moved during the pressing.

15. Connection device (1) according to any one of the claims 11-14, wherein said adapter portion (16) comprises one or more longitudinal notches (32) arranged inward with respect to the annular groove (12) for the seal (13) , said notches (32) opening towards the inner end (30) of the adapter portion (16), so to increase the radial pliability of the latter.

16. Connection device (1) according to any one of the claims 11-15, wherein said, adapter portion (16) is realised in brass, or in plastic material, aluminium, or aluminium alloy.

17. Connection device (1) according to any one of the claims 11-16, wherein a seal (21) is arranged between said outer portion (17) and said adapter portion (16) , received in an annular groove (20) .

18. Connection device (1) according to any one of the claims 11-17, wherein an outer edge (22) of the outer portion (17) of the connection portion (5) is radially folded inward so to prevent the extraction of the adapter portion (16) .

19. Adapter insert (16) adapted to be inserted in an outer portion (17) of a radially pressable connection portion (5) of a connection device (1) for joining a tubular portion (2) of a first component in fluid connection with a second component in a fluid conveyance system, said adapter insert being substantially tubular and defining a seat (7) for receiving said tubular portion (2) and being radially pressable in order to engage said tubular portion (2) by interference, characterised in that said seat (7) comprises at least one projection (9) which radially juts inward and which is arranged and shaped such to at least partially penetrate into an outer layer (8) of the tubular portion

(2) following said radial pressing.

20. Adapter insert (16) according to claim 19, wherein said seat (7) comprises two projections (9) situated in proximity to two of its opposite ends.

21. Adapter insert (16) according to claim 19 or 20, wherein said projections (9) are annular and have a V form in section which is tilted in the insertion direction of the tubular portion (2) .

22. Adapter insert (16) according to any one of the claims 19-21, wherein said seat (7) comprises an annular groove (12) adapted to receive a seal (13) .

23. Adapter insert (16) according to claim 22, wherein said annular groove (12) has a substantially semicircular form and receives an O-ring of substantially circular section.

24. Adapter insert (16) accqrding to claim 22, wherein said annular groove (12) receives an O-ring with substantially °°-shape section, the two portions of which have different diameters, said O-ring being arranged in said annular groove (12) such that its smaller diameter portion is turned towards an outer end (31) of the adapter insert (16) .

25. Adapter insert (16) according to any one of the claims 19-24, wherein said seat (7) comprises two further substantially triangular second grooves (14) between said two projections (9) and said annular groove (12) for the seal (13) .

26. Adapter insert (16) according to any one of the claims 19-25, wherein at an inner end (30) opposite to the outer end (31) the seat (7) comprises an annular shoulder (15) which defines a stroke-end stop for said tubular portion (2) .

27. Adapter insert (16) according to the preceding claim, wherein said annular shoulder (15) has a passage diameter which is greater than or substantially equal to that of said tubular portion (2) to be connected.

28. Adapter insert (16) according to claim 26 or 27, wherein a third annular groove (27) is formed in said seat (7) between said annular shoulder (15) and the projection (9) closest to said inner end (31) .

29. Adapter insert (16) according to any one of the claims 19-28, comprising, at its outer end (31) , an annular protuberance (24) which radially juts outward and forms a stroke-end stop for the insertion of said connection device (1) in the outer portion (17) .

30. Adapter insert (16) according to any one of the claims 19-29, wherein an outer surface (35) forms anti- extraction means adapted to lock the adapter insert (16) to said outer portion (17) of the connection device (1) .

31. Adapter insert (16) according to claim 30, wherein said anti-extraction means comprise an annular groove

(26) adapted to receive a material part of the outer portion (17) of the connection device (1) which is moved during the pressing.

32. Adapter insert (16) according to any one of the claims 19-31, comprising one or more longitudinal notches (32) arranged inward with respect to the annular groove (12) for the seal (13) , said notches (32) opening towards the inner end (30) so to increase the radial pliability of the adapter insert (16) .

33. Adapter insert (16) according to any one of the claims 19-32, realised in brass, or in plastic material, aluminium, or aluminium alloy.