Pipe coupling, sealing gasket for said coupling, and installation comprising said coupling

Abstract

The invention relates to a coupling for pipes, comprising a male part and a female part, wherein the male part can be partially inserted, by its free end, into the female part; said coupling also having a gasket for sealing the join between the parts, said gasket remaining in contact with the female part and the male part during use and being housed in a cavity in one of the aforementioned parts, characterised in that said gasket has, on the outside, two protrusions, each of said protrusions being in contact with a surface of a respective part by means of an interference fit, the protrusions being arranged in such a way that the contact of the protrusions with said surfaces closes the passage of fluid from the inside of the coupling to the outside.

Description

[0001] PIPE COUPLING, SEALING JOINT FOR SAID COUPLING AND INSTALLATION COMPRISING SAID COUPLING

[0002] DESCRIPTION

[0003] The present invention relates to a piping system, and in particular to couplings especially suitable for mobile or demountable piping systems. More specifically, the present invention relates to quick-connect pipe coupling systems. These types of couplings or joints are particularly used in non-permanent water systems. Such systems are used, for example, for agricultural and industrial applications, and in particular for irrigation.

[0004] Current mobile pipeline systems for transporting liquids are essentially of two types, hydraulic and mechanical, with different models and shapes, but with the same operating principles.

[0005] In hydraulic systems, watertightness is achieved from the moment the fluid inside the conduit has a certain pressure (usually greater than 1.5 kg / cm²). 2Thanks to this hydraulic pressure within the pipe, the outer lip of the seal located on the female part presses against the wall of the female part. This same pressure also presses the inner lip against the male part, thus achieving a seal based on this specific pressure. Figure 1 shows an example of a common hydraulic system with the pipes in the disassembled position. The sealing gasket is a double-lip type, with a smooth head from which two lips extend, one outer and one inner. The outer lip fits against the inner surface of the female part, while the inner lip is in contact with the male part of the coupling. The inner lip is angled relative to the outer lip. When the pressure increases, it pushes the inner lip against the male part, ensuring a seal.

[0006] In mechanical systems, sealing is achieved through the mechanical pressure exerted on an O-ring located in the female part, compressing it against the male part via a mechanical clamping system. In mechanical systems, the sealing of liquids does not depend on the liquid pressure, but rather on the compressive force previously applied to the O-ring. Figure 2 shows an example of a mechanical system according to the prior art.

[0007] One drawback of current systems is that users are forced to choose between two types of systems when making a purchase decision. However, especially in mobile installations and depending on the application, users might be interested in having pipes that drain automatically once the pump stops. Furthermore, it is often desirable for this drainage to be gradual to avoid flooding the field. This way, when the system is dismantled and moved, the pipes will already be completely empty. However, other applications require that the system not be drained when the pumps stop, thus preventing fluid loss. An example of this is when the distributed fluids are pollutants, as their spillage could cause environmental problems.Hydraulic systems are easier to assemble and disassemble, and more economical compared to mechanical systems, which are more complex to assemble and disassemble and therefore more expensive. However, the mechanical components of each system (pipes, fittings) differ, so currently, users are required to purchase two complete systems if they want self-draining installations below a certain pressure, or watertight installations at any pressure.

[0008] The present invention aims to disclose a type of coupling or joint that avoids the aforementioned drawbacks, allowing users to easily create an installation that can function in either self-draining or watertight mode. More specifically, the present invention is based on the use of a specific gasket in couplings that can replace the double-lip gaskets currently used in hydraulic systems, ensuring that these systems are always watertight. This solution offers the advantage of allowing a hydraulic installation to operate in either self-draining or watertight mode, as desired, requiring only a simple change of sealing gaskets to switch between modes.

[0009] More specifically, the present invention discloses a pipe coupling comprising a male part and a female part, the male part being partially insertable, at its free end, into the female part. The coupling also includes a gasket for sealing the joint between the parts, preferably a double-lip gasket, which, in use, remains in contact with the female and male parts. This gasket is housed in a cavity of one of the parts. Characteristically, this gasket has two external protrusions, each of which is in contact, by dimensional interference fit, with a surface of a respective part. Advantageously, the protrusions are arranged such that their contact with the surfaces prevents fluid from flowing from the inside of the coupling to the outside.

[0010] In particular, the present invention is based on the development and use of a seal that allows hydraulic systems to operate in a consistently leak-proof mode. Using the same pipes and connectors of a hydraulic system, the seal of the present invention enables leak-proof operation at low pressures. If the user wishes to use the system in self-draining mode for another application, they only need to change the hydraulic seals, replacing the coupling seal of the present invention with a standard double-lip seal. Likewise, the present invention allows for the easy creation of systems that are self-draining only at selected points, while remaining leak-proof at other points.

[0011] More specifically, the present invention discloses a new type of protruding seal that allows, simply by changing the double-lip rubber seal installed in both new and used hydraulic lines, for a watertight seal to be achieved. At any time, by replacing the protruding seal with a double-lip seal, a hydraulic seal can be restored. This change can be made to existing lines.

[0012] In known lip seals used in pipe couplings, a seal is achieved at a certain pressure. However, in the coupling of the present invention, a seal is achieved without pressure, thanks to the interference between the protrusions on the seal itself and the coupling elements. One protrusion is compressed, preventing the flow of fluid from the inside of the pipe through the wall of the female part, while the other protrusion prevents the flow of fluid from the inside of the pipe through the male part.

[0013] Additionally, the outer lip of the gasket compresses against the female part from the moment of its installation and regardless of the pressure, as does the inner lip, which does the same on the male part, thus achieving a total seal thanks to the interferences existing between the gasket, the female part and the male part.

[0014] Preferably, the sealing gasket is located in a cavity of the female part. Also preferably, this cavity may have a generally cylindrical shape.

[0015] Also preferably, the sealing gasket is a double-lip gasket. More preferably, the gasket comprises a head and two lips oblique to each other.

[0016] Preferably, the gasket is positioned to seal a clearance space between the aforementioned male and female parts.

[0017] In particularly advantageous embodiments, one of the protrusions is placed in contact with an outer surface of the male part, and, more advantageously, another of the protrusions is placed in contact with a wall of the cavity.

[0018] Preferably, one of the protrusions is located on a lip in contact with the male part. More preferably, another of the protrusions is located on the head of the joint.

[0019] As already indicated, the present invention also discloses a novel sealing gasket particularly suitable for existing types of couplings. In particular, the present invention discloses a sealing gasket comprising a cylindrical crown-shaped head, an outer lip, preferably cylindrical, and an inner lip oblique to the outer lip, featuring cylindrical protrusions, one located on the inner lip and the other on the outer surface of the head. Preferably, the protrusions are rounded. Also preferably, the gasket has no external protrusions other than those indicated.

[0020] The present invention also comprises the use of a double-lip seal with two external protrusions to ensure pressure-free sealing in a coupling according to the present invention.

[0021] The present invention also discloses the installation comprising at least one coupling according to the present invention. In certain applications, all couplings in the installation may be couplings according to the present invention. Preferably, the installation may be a mobile installation. Also preferably, the installation is an irrigation installation.

[0022] According to another aspect, the present invention also discloses installations comprising a plurality, plurality being understood as one or more of a coupling, said couplings characterized in that they contain a double-lip sealing gasket with external protrusions located accordingly as follows: the first protrusion located on the circular crown head of the sealing gasket, thus making contact with the female part and preventing the passage of fluids to the outside, and the second protrusion located on the inner lip of the sealing gasket, making contact with the male part and preventing the passage of fluid to the outside, ensuring the sealing of the coupling.

[0023] Additionally, the present invention also discloses the installation of a plurality, plurality being understood as one or more of a coupling, said couplings characterized in that they contain a hydraulic seal or a double-lip sealing gasket with external protrusions located accordingly as follows: the first protrusion located on the circular crown head of the sealing gasket, thus making contact with the female part and preventing the passage of fluids to the outside, and the second protrusion located on the inner lip of the sealing gasket, making contact with the male part and preventing the passage of fluid to the outside, ensuring the sealing of the coupling, thus allowing them to be watertight at specific points and self-draining at other points.This presents a perfect synergy between a coupling with a hydraulic seal and a coupling with a sealing seal, since by allowing self-draining at certain points and being watertight at other certain points, it allows the user to choose according to their convenience, thus saving time and costs.

[0024] For better understanding, attached hereto, by way of explanatory but not limiting example, are drawings of an embodiment of the object of the present invention and two representative drawings of the prior art.

[0025] Figure 1 shows a longitudinal section of a prior art hydraulic coupling, in which the pipes are shown uncoupled.

[0026] Figure 2 shows a longitudinal section of a mechanical coupling according to the prior art.

[0027] Figure 3 shows a sectioned detail view of a hydraulic joint used in the coupling according to the present invention.

[0028] Figure 4 shows a cross-sectional longitudinal view of a coupling according to the present invention.

[0029] Figure 1 shows an example of a known type of hydraulic system with the pipes in their disassembled position. The coupling consists of a female part 1, a male part 2, and a hydraulic seal 3'. Both the male part 2 and the female part 1 have receiving areas for a corresponding pipe. As shown in the figure, the male part 2 is partially inserted inside the female part 1. The hydraulic seal 3' is a double-lip seal with a smooth head from which two lips extend: an outer and an inner lip. The outer lip fits against the inner surface of the female part 1, while the inner lip is in contact with the male part 2 of the coupling. The inner lip is angled with respect to the outer lip.In this system, a seal is achieved when the fluid inside the pipe reaches a certain pressure, causing the outer lip of the gasket located on the female part 1 to press against the female part 1, and simultaneously, the inner lip to press against the male part 2. When the pressure increases, it pushes the inner lip against the male part 2, ensuring a seal. However, when the pressure is insufficient, the system will leak.

[0030] Figure 2 shows an example of a prior art mechanical system. The components are shown unassembled. The system comprises a female part 1, a male part 2, and a sealing gasket 3. The sealing gasket 3, in this case, is an O-ring that is pressed into place by a clamping mechanism 4. The force generated by the clamping mechanism 4 creates the dimensional interference fit that ensures a tight seal. In this system, the seal is independent of the fluid pressure inside the installation.

[0031] Figure 3 shows, in section, an example of a sealing gasket 3 according to the present invention. The example shows a double-lip sealing gasket 3 comprising a circular crown-shaped head 33 from which an outer lip 34 and an inner lip 35 extend. The outer lip 34, in the example shown, has a cylindrical outer surface for a better fit with an inner surface of the female part (not shown in the figure). The inner lip 35 is oblique with respect to the outer lip 34, presenting, in the area of ​​connection with the head 33, a diameter larger than its diameter at its free end. A cavity 36 is formed between the two lips, from which the fluid flowing through the installation can push the upper lip against the female part and the lower lip against the male part (parts not shown in the figure).Characteristically for the invention, the joint 3 has a protrusion 32 in the area of ​​smaller diameter of the head and another protrusion 31 on the radial surface of the head 33. In the example shown, the section shown in the figure is developed circumferentially, making it suitable for couplings of cylindrical pipes.

[0032] Figure 4 shows an example of an embodiment of a coupling according to the present invention.

[0033] The coupling consists of a female part 1, a male part 2, and a sealing gasket 3. Both the male part 2 and the female part 1 have areas for receiving a corresponding tube. In the example shown, the receiving areas comprise recesses located on the inner face of both parts. The tubes (not shown in the figure) are placed in these recesses. As can be seen in Figure 4, the male part 2 is partially inserted inside the female part 1.

[0034] The coupling also has a sealing gasket 3, as shown in Figure 3. The sealing gasket 3 closes a clearance between the male 2 and female 1 parts, with the gasket 3 housed in a cavity located in the female part 1. In this example, due to the shape of the coupling, the lips of the double-lip gasket face the side of the pipe connected to the female part (pipe not shown in the figure). In the recess shown, the cavity is generally cylindrical.

[0035] The coupling cavity in the example comprises three walls that are oblique to each other. One of these walls, in the example shown, is a perimeter wall and approximately parallel to the outer surface, while the other two face each other at opposite ends of said perimeter surface. In the example shown, the perimeter surface is a cylindrical surface. It could also be, for example, a prismatic surface.

[0036] The inner lip 35 of gasket 3 contacts an outer surface of the male part 2, while the outer lip 34 of gasket 3 contacts the inner perimeter surface of the female part 1. More specifically, the outer lip 34 contacts a cylindrical surface of the cavity in the female part 1 where the gasket is located. Additionally, in the example shown, the free end of the outer lip 34 contacts another surface of the cavity in the female part 1. Gasket 3 has two protrusions, both of which contact one of the coupling parts. The protrusion 32 of the inner lip 35 contacts the aforementioned outer surface of the male part 2, while the other protrusion 31 of the gasket contacts one of the walls of the cavity in which gasket 3 is located.The dimensions of the male part 2, the female part 1, and the gasket 3 are chosen so that the protrusions 31 and 32 make contact with the respective surfaces of the male part 2 and the female part 1 without requiring a fluid to push the gasket lips apart. This ensures a watertight seal even at atmospheric pressure. To facilitate placement and contact, the gasket protrusions have a generally semicircular cross-section. More specifically, the protrusions in this example have a rounded shape.

[0037] In the example shown, the protrusion 31 is located on the outer surface of the gasket head 33, such that it makes contact with a cavity surface that is oblique to the aforementioned outer surface of the coupling. This location is advantageous because it makes it relatively easy to ensure the dimensional fit of the gasket within the cavity, especially if the free end of the outer lip 34 is in contact with the cavity wall opposite the wall that contacts the head 33. Furthermore, this dimensional fit is achieved without hindering the installation of the coupling. Moreover, with this embodiment, the outer lip 34 makes contact with its respective surface along a large area. Finally, the pressure of a fluid inside the pipes will exert additional pressure on the protrusion 31 against the surface, further ensuring a tight seal.

[0038] Although the invention has been described with respect to a preferred embodiment, this should not be considered limiting to the invention, which will be defined by the broader interpretation of the following claims.

Claims

CLAIMS 1. A pipe coupling comprising a male part and a female part, the male part being able to be partially inserted, at its free end, into the female part; said coupling also having a gasket for sealing the joint between parts, said gasket, in use, being in contact with the female part and the male part, said gasket being housed in a cavity of one of the said parts, characterized in that said gasket has, externally, two protrusions, each of said protrusions being in contact, by dimensional interference, with a surface of a respective part, the protrusions being arranged in such a way that the contact of the protrusions with the said surfaces closes the passage of fluid from the inside of the coupling to the outside.

2. Coupling, according to any of the preceding claims, characterized in that the sealing gasket is located in a cavity in the female part.

3. Coupling, according to the previous claim, characterized in that said cavity has a generally cylindrical shape.

4. Coupling, according to any of the preceding claims, characterized in that the sealing gasket is a double lip gasket.

5. Coupling, according to any of the preceding claims, characterized in that the sealing gasket comprises a head and two oblique lips.

6. Coupling, according to any of the preceding claims, characterized in that the gasket is positioned to seal a clearance space between the aforementioned male and female parts.

7. Coupling, according to the preceding claim, characterized in that one of the protrusions is located on a lip in contact with the male part.

8. Coupling, according to the previous claim, characterized in that another of the protrusions is located on the head of the joint.

9. Coupling, according to the preceding claim, characterized in that one of the protrusions is located in contact with an outer surface of the male part, and another of the protrusions is located in contact with a wall of the cavity.

10. Sealing gasket for coupling, according to any of the preceding claims, characterized in that it comprises a cylindrical crown-shaped head, an outer lip and an inner lip oblique to the outer lip, having two cylindrical protrusions, one located on the inner lip and the other on the outer surface of the head.

11. Gasket, according to the previous claim, characterized in that the protrusions have a rounded section.

12. Gasket, according to claim 10 or 11, characterized in that it does not have any external protrusions other than those indicated.

13. Use of a gasket with two external protrusions to ensure pressure-free sealing in a coupling, according to any of claims 1 to 9.

14. Use, according to the preceding claim, characterized in that the seal is a double lip seal.

15. Use, according to the preceding claim, characterized in that the gasket is a gasket according to any of claims 10 to 12.

16. Installation characterized in that it comprises a coupling, according to any of claims 1 to 9.

17. Installation, according to the preceding claim, characterized in that all couplings of the installation are couplings according to any of claims 1 to 9.

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