WO2011039623A2

WO2011039623A2 - Connector for tubing, containing a plastic insert

Info

Publication number: WO2011039623A2
Application number: PCT/IB2010/002490
Authority: WO
Inventors: Eduardo Santos BURGOA MÁRQUEZ
Original assignee: Grupo Rotoplas, S.A. De C.V.
Priority date: 2009-10-01
Filing date: 2010-09-30
Publication date: 2011-04-07
Also published as: UY32907A; PE20120890Z; MX337447B; GT201200018U; BR212012007531U2; PE20131155Z; ECSP12011797A; AR078484A1; WO2011039623A3; PE20131154Z; CR20120165A; MX2009010612A

Abstract

The invention relates to a connector for tubing, consisting of a body and a screw insert, the material forming the insert being a plastic material with high mechanical resistance and the material forming the body being a thermoplastic resin. The insert is partially or completely housed in the body of the connector, tightly coupled thereto by means of an anchoring system consisting of at least one circular or polygonal ridge formed on the outer face of the insert, the ridge(s) peripherally surrounding the cylindrical wall of the insert. The separation between the ridges creates at least one groove into which the thermoplastic material forming the body of the connector penetrates, enabling the long-term tightness of the connection. The structure of the connection can include a reinforcement ring which provides the connector with a resistance higher than that provided solely by the insert material.

Description

PIPE CONNECTOR CONTAINING A PLASTIC INSERT

FIELD OF THE INVENTION

The illustrated embodiments of the present invention generally relate to pipe connectors and, more particularly, to plastic connectors of the type having a threaded plastic insert.

BACKGROUND OF THE INVENTION

Plastic pipes for transporting fluids are increasingly used, because they are easier to handle than metal pipes, they are resistant to corrosion, have light weight, are easy to mold and have a low cost. To connect the components of the pipe it is common to use connectors, preferably made of a material compatible with the plastic of the pipe. The most commonly used plastic materials for this purpose are thermoplastic polymers, such as polypropylene or other polyolefins, capable of making highly reliable connections through a thermofusion bonding process.

The connections that are joined by thermofusion generally require the integration of the thermoplastic material with a threaded metal insert, since the metal component has high resistance to the torque action when connected with threaded fittings, and can withstand working pressures and temperatures high. However, the selection of the metal and its coating where appropriate, the high weight and difficulty of molding the metal inserts, constitute important disadvantages that can be overcome by replacing the metal insert with a plastic insert. The latter must obviously have properties of resistance to the action of the torque when connecting with other threaded fittings, it must be compatible with the external plastic material It forms the body of the connector and be resistant to the chemical agents it might be conducting. Similarly, the coupling between the insert and the body of the connector must be highly reliable to avoid liquid leaks when working in high temperature and pressure conditions. There are currently several proposals for connectors with plastic insert. For example, U.S. Patent No. 7,469,935 describes a pipe connection formed by two layers of different materials. The inner layer is in contact with the liquid that is transported, and is made of a plastic material that withstands high temperatures. Although the connector integrates two types of plastic with different properties, it does not include threaded means in the insert for coupling to threaded pipe, nor reliable means of coupling between the insert and the connector body.

US patent application 2003/0184085 refers to an adapter for connecting two pipe segments. The adapter includes: a) an insert made of a rigid material, such as bronze or other metallic material, or even a rigid plastic material; and b) a receiving body made of a soft plastic material, such as CPVC. The insert has a female internal thread to receive a thread from a pipe. Advantageously, the connector has coupling means between the insert and the receiving body, consisting of a plurality of projections formed on the external part of the insert, which, when coupled with the receiving body, are housed in a series of grooves formed in the receiving body. To help the insert remain in a fixed position during engagement with other threaded fittings, it is proposed that the projections of the insert have a polygonal shape, for example, hexagonal. A disadvantage of the connector described in the application US 2003/0184085 is that the securing between the insert and the receiving body is done mechanically, by means of a complex system of projections and grooves annular, which hinders both its manufacture and its installation. It also has an aesthetic disadvantage, since the insert is not completely embedded in the receiving body, but. that a part of the insert is unprotected and would be visible on the connection. Obviously, the insert will be exposed to environmental conditions that may shorten its useful life. In particular, one of the embodiments of this patent application describes an insert that is completely embedded in the receiving body. However, in this mode, the internal threading to receive the pipe is actually in the insert and in the same connector. Consequently, the pipe thread would necessarily have to be coupled to two pieces, sacrificing the tightness of the connection. Moreover, it is known that the material of the receiving body is not sufficiently resistant to the action of the torque, so that the threading will be susceptible to be swept, at least in the threaded portion that corresponds to the receiving body. Patent 7,234,906 protects an insert with internal thread, the insert is designed to be housed in a wrapping material. The insert has male type strings on the outer surface, to engage the wrapping material. It also includes protrusions that secure the insert inside the wrapping material and prevent the relative rotation of the insert when it receives another threaded fitting. In this case, the insert only imparts a thread resistant to the wrapping material, but said wrapping material is not a hot melt body.

US Patent No. 5,879,115 describes a method for attaching a plastic insert to a plastic base having a recess formed in said base. The insert has projections in a circular arrangement, separated from each other, said projections are adjusted under pressure within the plastic base. When the two plastics merge, the plastic of the projections flows into the spaces, and the plastic of the base flows into the spaces. This causes the assurance of the two components preventing the relative rotation of one with respect to the other. However, this assurance would not be sufficient to resist torque when the insert is coupled with other threaded fittings, in fact, the patent does not mention or suggest the existence of a threaded insert. None of the documents describe a connector in which the joining means between the insert and the body are strong enough to resist torque and also an effective anchoring system between the two pieces to prevent slippage. There is, therefore, the need for a pipe connector that overcomes all the inconveniences of the connectors developed in the past.

SUMMARY OF THE INVENTION

In accordance with the present invention, a pipe connector device is presented, suitable for use under extreme conditions of temperature and pressure. The connector is constituted by a body of the connector and an insert, where the body constitutes a housing for the insert. The body is formed of a thermoplastic material, while the insert is made of a material with high mechanical resistance and also capable of withstanding high temperatures, so that the combination of the two types of plastics give this connector properties superior to that would be achieved using each plastic separately. The connector is formed by overinjection of the thermoplastic material on the insert, which allows to achieve a tightness of the connection in the long term. In addition, the two components that form the connector are secured to each other by an extremely effective anchoring system, formed by a plurality of ridges on the outer wall of the insert, which are coupled with a corresponding plurality of grooves on the inner wall of the connector body . A modality of male connector is presented, and a second modality of female connector, the latter includes within its structure a reinforcement ring that gives the connector a resistance to the torque greater than that offered by the insert material alone, without the need of using a large amount of material in the insert, which saves manufacturing costs.

OBJECTIVES:

1. Provide a pipe connector made of a lightweight, low-cost, corrosion-resistant material that is resistant to high temperatures and pressures.

2. Provide a pipe connector in a plastic material, which is resistant to the action of torque when threading with other threaded fittings.

3. Provide a connector made of thermoplastic material for. be able to join with tubing of the same material by thermofusion and thus achieve an extremely reliable coupling between the pieces.

4. Provide a pipe connector consisting of two components, one internal and one external, where both components are connected by an extremely effective anchoring system to prevent the internal component from being swept or slipped with respect to the external component.

5. Provide a pipe connector with a plastic insert, resistant to leaks when transporting fluids at high pressures and temperatures. BRIEF DESCRIPTION OF THE DRAWINGS OR FIGURES

The above aspects and many of the advantages concomitant with this invention will be better understood when the following detailed description is consulted and considered in conjunction with the accompanying drawings, in which:

Figure 1 is a perspective view of the male type connector of the present invention.

Figure 2 shows a perspective view of the female type connector of the present invention. Figure 3 shows a longitudinal section of the male type connector of the present invention.

Figure 4 shows a side perspective view of the male connector insert.

Figure 5 shows a longitudinal section of the female type connector of the present invention.

Figure 6 shows a perspective view of the female connector insert.

Figures 7 and 8 represent partial cuts of the female connector that allow alternative reinforcement modalities to be observed in the female insert. Figure 9 represents a rear perspective view of an alternative mode of the anchoring system in the female insert.

Figure 10 shows a rear perspective view of another alternative embodiment of the anchoring system in the female insert. DETAILED DESCRIPTION OF THE PREFERRED MODES

Figures 1 and 2 show, respectively, a perspective view of the male type connector (1) and the female type connector (2). Both connectors consist of a body (3) of the connector and a threaded insert (4). The insert (4) and the body (3) are formed of different plastic materials. The material that forms the insert (4) is a plastic with high mechanical resistance and capable of withstanding for a long time high temperatures, approximately 95 ° C. The plastic that forms the body (3) is a thermoplastic resin that allows the union by thermal means to a pipe made of a compatible material.

The plastic that forms the body of the connector is selected, without being limited to, the following materials: PE, PP, PPR or other polyolefins; PVC, CPVC and engineering plastics, or any other thermoplastic resin or thermofix.

The plastic that forms the insert is selected, without being limited to, the following materials: Noryl (mixture of polyphenylene oxide (PPO) and polystyrene (PS), owned by SABIC), polyphenylene oxides, polysulfones, acetals, polycarbonates or any other engineering plastic, Noryl being the material used in the preferred mode.

First, the male type connector (1) will be described based on Figures 3 and 4, which show, respectively, a longitudinal section of the connector and a side perspective view of the insert. It can be seen that this connector has a male insert (4) with a front portion (5), which protrudes from the body (3), said front portion has an external thread for coupling to connections and / or accessories with internal thread. The male insert (4) also has a rear portion (6), which will be embedded in the body (3) of the connector, in close connection with it. The anchoring system between the body (3) and the rear portion (6) of the male insert (4) will be explained below:

The insert (4) has one or more ridges (7) formed in the rear portion (6), specifically on the outer face of the insert, said ridges (7) preferably circumferentially surrounding the cylindrical wall of the insert (4). The separation between the ridges (7) results in a plurality of circular grooves or grooves (9). The pattern of ridges and grooves mentioned above results in a highly effective anchoring system at high temperatures and pressures. Additionally, the base (10) of the insert, located at the rear end of said piece, may include one or more ridges (11) and grooves (12) oriented perpendicularly in relation to the ridges (7) of the cylindrical wall of the insert ( 4). These ridges (11) and grooves (12) constitute a rear anchoring system that reinforces the coupling between the pieces. Additionally, each of the ridges (7) can have a plurality of grooves (13) formed, preferably, on the entire periphery of the ridge (s) (7), said grooves (13) are oriented in the longitudinal axis Stretch marks (13) allow better resistance to torque action, preventing the insert from sliding with respect to the connector body when connecting with threaded fittings.

The body (3) of the male connector houses only the rear portion of the insert, and is made of a plastic material, so that when overinjected onto the insert, the plastic material of the body flows into the grooves (9) and (12) of the insert, and towards the stretch marks (13) of the insert, achieving a tight coupling. Next, the female type connector based on Figures 5 and 6 will be described. In the case of the female type connector, the insert (4) is completely housed in the body (3) of the connector. The insert (4) has an internal thread (14) and on the external face it has a pattern of ridges (7) and grooves (9) similar to that described for the insert (4) of the male connector mode. The ridges (7) are located in the outer wall of the insert, and each ridge (7) can include a plurality of grooves (13) on the periphery of the ridge (s). One or more ridges (11) and one or more grooves (12) may also be present at the base (10) of the insert.

In the preferred embodiment, the female insert (4) has a free portion of ridges (15), adjacent to the front end of the piece, and of smaller thickness to the rest of the insert, said portion constitutes a recess for a reinforcement ring (16 ). The ring (16) surrounds the front portion of the insert, without protruding from the body (3) of the connector, as shown in Figure 5. Preferably, the outer face of the ring (16) has at least one crest formed, and grooves adjacent to the ridge (s), to achieve an effective anchor between the ring (16) and the body (3) of the connector.

Alternatively, instead of the reinforcement ring (16) being in the front part of the insert, it is embedded in the same insert (see figure 7). As another alternative, the reinforcement ring (16) is embedded in the connector body (see figure 8). The advantage of having the ring completely covered is that a greater contact surface between the two plastic materials is obtained, improving the tightness in the connector.

The reinforcement ring (16) gives the insert an even greater resistance to the torque than would be achieved using only the plastic material. Obviously, the resistance to the torque is also a function of the thickness of the material that forms the connector, but when the reinforcement ring exists, superior resistance is achieved without the need to increase the amount of material either The insert or in the body. The result is a saving of plastic material and therefore a lower cost of the product.

The reinforcement ring (16) can be. Made of a material such as stainless steel, brass with nickel plating, bronze, carbon steel, aluminum, duralumin, or any other corrosion-resistant metal material, which is compatible with both plastics.

The body (3) of the female connector is made of a plastic material, so that when overinjected into the insert, the plastic material of the body flows to the grooves (9) and (12) of the insert, and to the stretch marks (13) of the insert, achieving a tight coupling.

In both types of connector, the pattern of grooves and ridges described above, offers an additional advantage: the resulting structure is highly resistant to leaks, since water or any fluid that is transported through the pipeline, before leaving through the union between the insert and the body, would have to follow a long trajectory given by the set of ridges and furrows.

To reinforce the anchoring system, both the male insert and the female insert may include at the rear end one or more protuberances (17), such as those seen in Figures 9 and 10. In the embodiment of Figure 9, The insert includes eight protuberances (17) spaced apart in an equidistant manner around the circumference of the insert base. In the embodiment of Figure 10, the insert includes four protuberances (17) separated from each other at approximately ninety degrees around the circumference of the base of the insert.

The modalities described above for the anchoring system of circular ridges and grooves can be replaced with other types of anchorage. For example, the ridges of the plastic insert may have a polygonal shape, for octagonal, hexagonal, pentagonal, square example, among others. The fact of having different faces prevents the insert from rotating with respect to the body and "sticks" when threading the piece with other accessories, even without the presence of stretch marks. The resulting connector of the present invention is capable of withstanding working temperatures from 5 ° C to 95 ° C, and working pressures up to 20 kg / cm ² , which makes it suitable for use in piping systems for the conduction of liquid or gaseous fluids in residential, commercial and industrial facilities. While the preferred embodiments of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. For example, the male type connector may also include a reinforcing ring surrounding the insert, or embedded in the insert or in the same body of the connector, similar to the female type connector. Moreover, the ring may have ridges formed on the inner face, or on both sides. The present invention is applicable to a wide range of connectors, for example, male, female, male-female, female-female, male-male, 90 ° elbow, 45 ° elbow, "T" connection, connection "Y" and straight connector.

Claims

CLAIMS:

1. A pipe connector consisting of a connector body and a threaded male insert, where the insert and the body are formed of different plastic materials, characterized in that the material that forms the insert is a plastic with high mechanical resistance and the material that forms the body is a thermoplastic resin, the insert has a front portion with an external thread, and a rear portion that is housed in the body of the connector, in close coupling with it through an anchoring system consisting of one or more circular or polygonal ridges formed on the outer face of the posterior portion of the insert, the crest (s) circumferentially surround the cylindrical wall of the insert and the separation between the ridges results in one or more grooves or circular grooves of insertion.

2. The pipe connector according to claim 1, wherein the ridge (s) surrounding the cylindrical wall of the body has a plurality of grooves oriented in the longitudinal axis.

3. The pipe connector according to claim 2, wherein the grooves are formed on the entire periphery of the ridges of the cylindrical wall of the insert.

4. The pipe connector according to claim 1, wherein the base of the insert includes a rear anchoring system consisting of one or more circular ridges and circular grooves oriented perpendicularly in relation to the crests of the cylindrical wall of the insert.

5. The pipe connector according to claim 4, wherein the circular ridge (s) of the insert base have one or more protuberances formed.

6. A pipe connection consisting of a body of the connector and a female type insert with internal thread, where the insert and the body are formed of different plastic materials, characterized in that the material that forms the insert is a plastic with high mechanical resistance and the material that forms the body is a thermoplastic resin, the insert is completely housed in the body of the connection, in close coupling with it through an anchoring system consisting of one or more circular or polygonal ridges formed on the external face of the posterior portion of the insert, the ridge (s) circumferentially surround the cylindrical wall of the insert and the separation between the ridges results in one or more circular insertion slots.

7. The pipe fitting according to claim 6, wherein the ridge (s) surrounding the cylindrical wall of the body has a plurality of grooves oriented in the longitudinal axis.

8. The pipe fitting according to claim 7, wherein the grooves are formed on the entire periphery of the ridges of the cylindrical wall of the insert.

9. The pipe fitting according to claim 6, wherein the base of the insert includes a rear anchoring system consisting of one or more circular ridges and circular grooves oriented perpendicularly in relation to the crests of the cylindrical wall of the insert.

10. The pipe fitting according to claim 9, wherein the circular ridge (s) of the base of the insert have one or more protuberances formed.

11. The pipe connection according to claim 1, wherein the connection also has a concentric reinforcement ring at the same connection and which It is found around the insert, or embedded in the insert or in the body of the connector.

12. The pipe connector according to claim 6, wherein the connector also has a concentric reinforcement ring to the same connector, in the front part thereof.

13. The pipe connector according to claim 12, wherein the reinforcement ring is coupled to the female insert in a recess located on the outer face of the insert, adjacent to the front end of the piece, and of smaller thickness to the rest of the insert, so that the ring surrounds the front portion of the insert, without protruding from the body of the connector.

14. The pipe connector according to claim 12, wherein the reinforcement ring is embedded in the same insert.

15. The pipe connector according to claim 12, wherein the reinforcement ring is embedded in the connector body.

16. The pipe connector according to claim 11 or 12, wherein the ring has at least one circular ridge, and grooves adjacent to the crest (s) of the ring,

17. The pipe connector according to claim 16, wherein the circular ridge (s) of the ring are located on the outer face thereof.

18. The pipe connector according to claim 11 or 12, wherein the reinforcement ring is made of a corrosion-resistant metal material.

19. The pipe connector according to any one of claims 1 and 6, wherein the thermoplastic resin forming the connector body is selected from the following materials: PE, PP, PPR or other polyolefins; PVC, CPVC and engineering plastics, or any other thermoplastic resin or thermofix.

20. The pipe connector according to any of claims 1 and 6, wherein the plastic forming the insert is selected from the following materials: Noryl, polyphenylene oxides, polysulfones, acetals, polycarbonates or any other engineering plastic.

21. The pipe connector according to claim 18, wherein the metal material of the ring is selected from stainless steel, brass with nickel plating, bronze, carbon steel, aluminum and duralumin.

22. The pipe connector according to any of claims 5 and

10, wherein the insert includes four protrusions separated from each other at approximately ninety degrees around the circumference of the insert base.

23. The pipe connector according to any of claims 5 and 10, wherein the insert includes eight protrusions separated from each other equidistant around the circumference of the insert base.

24. The pipe connector according to any of claims 1 and 6, wherein the ridges on the outer face of the insert have an octagonal, hexagonal, pentagonal or square shape.

25. The pipe connector according to claim 1, wherein the connector is part of a connection device selected from the following types: male-female, male-male, 90 ° elbow, 45 ° elbow, connection " T ", connection" Y "and straight connector.

26. The pipe connector according to claim 6, wherein the connector is part of a connection device selected from the following types: female-female, male-female, 90 ° elbow, 45 ° elbow, "T" connection, "Y" connection and straight connector.