Technical field of the Invention

The present invention generally relates to connectors for pneumatic systems such as compressed air braking systems of transport vehicles like trucks and buses, and in particular to a connector assembly of the type comprising a female element and a male element that are removably connected to one another.

Background

Known connector assemblies for pneumatic systems comprise a male element, often called nipple, which is hollow, has a generally tubular shape and is configured to be tightly fitted in a pipe or conduit, as well as a hollow female element configured to receive in an axial direction an end of the male element opposite to the end to which the pipe or conduit is connected in order to create a tight coupling therewith. Axial locking between the two components of the connector assembly is mechanical, typically in the form of a snap fit for example made by way of an elastic ring associated with one between the male element and the female element. Pneumatic seal is ensured by annular shaped gaskets, such as O-rings, that are fitted on the male or female element.

The male and female elements of connector assemblies according to the prior art are traditionally made of metal, typically brass, and manufactured by machining. Nevertheless connector assemblies including injection molded plastic elements are more and more popular, because injection molding allows to remarkably reduce the manufacturing costs.

Injection molding processes also allow to manufacture components having a more complex shape than the corresponding metallic ones without resorting to machining operations. This allows, for example, to make female elements including means for mechanically locking the male element in the axial direction.

An example of a connector assembly comprising a female element made of plastic material and comprising integrated means for mechanically locking the male element in the axial direction is described in EP 1714068 Bl . More particularly, the locking means integrated in the female element are longitudinal flaps, whose free ends protrude in the space intended to receive the male element. The locking flaps also have engagement means that can be maneuvered by a tool, such as a traditional Seeger ring gripper, so as to urge the flaps away from one another in order to remove the male element. The engagement means may be holes or recesses.

While the male element of a connector assembly has a generally tubular or cylindrical shape suitable to be fitted into a corresponding cylindrical seat formed in a female element, the shape of the female element depends on the number and type of coupling for which the connector assembly is configured. Female elements having an elbow, T, Y shape and the like are in fact known and widely employed.

The manufacturing of female elements of different types by injection molding of plastic materials therefore requires different mold types depending on the shape of these elements, which results in high manufacturing costs.

For the same reason, the manufacturing of connectors assemblies of the type above is affected by a low standardization level.

Summary of the Invention

The technical problem underlying and solved by the present invention is therefore to provide a connector assembly that allows to overcome the drawbacks mentioned above with reference to the prior art.

This problem is resolved by a device according to claim 1.

Preferred features of the present invention are specified in the dependent claims.

An idea of solution underlying the invention is to connect the male element and the female element not directly, but through an annular shaped axial locking element configured to engage on the one side a seat formed at one end of the female element and to receive the male element on the opposite side.

Thanks to this combination of features, it is possible to simplify the structure of the female element thus creating a seat having a standard geometry that can be easily manufactured by injection molding thanks to the reduced number of undercut elements. The female element can thus be used with a whole range of connector assemblies.

The axial locking element is advantageously provided with means configured to allow assembly on the female element as well as on the male element, which contributes to the structural simplification of the connector assembly.

The connector assembly may also advantageously comprise a rotation locking element configured to prevent rotation of the male element relative to the female element. This makes the connector assembly more robust and stable as a whole, and allows to ensure better pneumatic seal conditions e.g. in case it is subjected to vibrations and accidental contacts with adjacent objects.

The use of a rotation locking element is particularly important in pneumatic circuits supplying brake valves for motor vehicles, wherein the relative rotations between the components are undesired because they result in a misalignment between the axes of the connector assemblies and the axes of the conduits.

The rotation locking element has an annular shape and includes a plurality of radial projections or teeth formed along its inner periphery and configured to engage respective indentations formed in an axial direction on a portion of the male element.

According to an embodiment of the invention, the rotation locking element may advantageously be configured to be retractable in the axial locking element thus not affecting the overall size of the connector assembly.

Further advantages, features and operation modes of the present invention will become apparent from the following detailed description of some embodiments thereof presented as non-limiting examples.

Brief description of the drawings

Reference will be made to the figures of the attached drawings, in which:

Figure 1 is an exploded perspective view showing a connector assembly according to the present invention;

Figures 2 and 3 are a perspective view and a front view, respectively, of an axial locking element of the male element of the connector assembly according to the invention;

Figures 4 and 5 are longitudinal section views showing subsequent assembly steps of the male element into the female element of the connector assembly according to the invention;

Figures 6 to 8 are a perspective view, a side view, and a top plan view, respectively, of a rotation locking element of the male element of the connector assembly according to the invention;

Figure 9 is a perspective view schematically showing the position of the rotation locking element on the male element of the connector assembly according to the invention.

Detailed description of preferred embodiments

Referring initially to figures 1 to 5, a connector assembly according to the invention is generally indicated by reference numeral 100.

The connector assembly 100 comprises a male element 110 and a female element 120 configured to be tightly connected to each other in an axial or assembly direction schematically indicated by an arrow F.

The male element 110 is hollow and has a generally cylindrical shape, a first portion 111 of which, for example a threaded portion, a knurled portion or the like, is configured to be tightly fitted in a pipe or conduit (not shown) suitable to transport a fluid such as compressed air. A second portion 112 of the male element 110, having a generally cylindrical shape, is configured to be tightly connected to the female element 120. To this aim a plurality of circumferential grooves are formed in the second portion 112 of the male element 110. These grooves are configured to house sealing elements such as O-ring gaskets. In the illustrated embodiment two O-ring gaskets 113, 114 are e.g. shown.

The male element 110 further comprises a central portion 115 arranged between the first portion 111 and the second portion 1 12. The central portion 115 has, for example, an hexagonal shape suitable to be maneuvered with a fork wrench so as to allow screwing of the element male element 110 in a suitable threaded seat, such as a valve, but it will be appreciated that this is not an essential feature of the invention and that the central portion 115 might have a different shape, for example a cylindrical, smooth or knurled, shape.

The female element 120 comprises a hollow body 121 a first portion 122 of which has a generally cylindrical shape and is configured to receive the second portion 112 of the male element 110. A pneumatic seal can be obtained in a known manner at an internal portion of the hollow body 121, for example having a frusto-conical shape, whose walls come in contact with the sealing elements 113, 114 mounted on the second end 112 of the male element 110.

In the illustrated embodiment, the body 121 of the female element 120 has the shape of an elbow wherein a second portion 123, having a generally cylindrical shape, is arranged at right angles relative to the first portion 122, but it will be appreciated that such a feature does not limit the invention and that the female element might have other shapes well-known in the field, such as a T shape, a Y shape and the like.

According to the invention, the connector assembly 100 further comprises an axial locking element 130 configured to allow axial connection between the male element 110 and the female element 120.

The connection between the male element 110 and the female element 120 is therefore not direct, but achieved through a third member arranged between them.

The axial locking element 130 comprises an annular base 131 whose diameter allows the second portion 112 of the male element 110 to pass there through with a play. The locking element 130 also comprises at least one pair of flaps 132, 133 which generally extend in the direction of an axis A of the annular base 131 and are inclined radially towards said axis, for example, at an angle of 5°. The flaps 132, 133 thus converge towards the axis A of the locking element 130.

The flaps 132, 133 respectively include raised portions 132a, 133a protruding radially outwards and defining gripping teeth suitable to allow a snap connection with the first portion 122 of the female element 120. Correspondingly, at least one pair of radial protrusions 122a are formed on the first portion 122 of the female element 120 which form undercut portions in the assembly direction F.

As shown in figure 1, the first portion 122 of the female element 120 has openings formed in its cylindrical mantle, through which the radial protrusions 122a are visible. These openings are used during the injection molding process to insert movable elements of a mold that allow to form these undercut portions.

In an operational configuration of the connector assembly 100, the locking element 130 is axially fitted in the first portion 122 of the female element 120 in the assembly direction F by placing the annular base 131 against a free end of the first portion 122. When in contact with the radial protrusions 122a, the raised portions 132a, 133a cause the flaps 132, 133 to be bent towards the axis A of the locking element 130. Once the flaps 132, 133 are moved beyond the radial protrusions 122a, they snap radially outwards, thus causing the raised portions 132a, 133a to engage the radial protrusions 122a and preventing the locking member 130 from being disengaged from the female element 120.

In order to prevent rotation of the locking member 130 relative to the portion 122 of the female element 120 in which it is fitted, shoulders 122b are provided at the ends of the radial protrusions 122a in the circumferential direction. The radial protrusions 122a and the related shoulders 122b are therefore configured as seats suitable to receive the flaps 132, 133 of the locking member 130 with a slight circumferential clearance.

With particular reference to figures 4 and 5, the flaps 132, 133 of the locking element 130 do not only serve as anchoring means of the female element 120, but also as axial holding means of the male element 110.

The male element 110 is assembled in two steps. In a first step the male element is fitted and axially locked in a first position between the flaps 132, 133 of the locking element 130, while not compressing the flaps 113, 114 in their seats formed in the body 121 of the female element 120. In a second step, the male element 110 is further made to advance and locked between the flaps 132, 133 at a second position wherein the gaskets 113, 114 are compressed in the seat formed in the body 121 of the female element 120 in order to provide a pneumatic seal.

The male element 110 comprises at least one step-shaped discontinuity, i.e. a saw tooth discontinuity, formed in the axial direction F, which allows snap locking thereof in a known manner.

More particularly and referring to the illustrated embodiment, the male element 110 comprises a first frusto-conical portion 116 and a second frusto-conical portion 117 that are arranged axially one after the other starting from the free end of the second portion 112 and moving towards the central portion 115. By referring to an axial direction of the male element 110, the frusto-conical portions 116, 117 define two steplike diameter discontinuities suitable to lock the male element as will be described in more detail below. The sealing elements, in particular the O-ring gaskets 113, 114, are housed in respective seats formed in the first frusto-conical portion 116 arranged at the free end of the second portion 112.

By fitting the male element 110 into the female element 120 in the axial or assembly direction F, once the locking element 130 has been mounted on the latter the first frusto-conical portion 116 meets the flaps 132, 133 and is snap-fitted therein while abutting their free ends and thus defining a first engagement position of the male element 110 in the female element 120. This position is shown in figure 4.

In this position, the male element 110 and the female element 120 are restrained to each other axially, but no pneumatic seal is achieved because, as shown in figure 4, there is a small radial gap between the sealing elements 113, 114 and the cavity of the female element 120. In this position, it is thus possible to rotate the male element 110 relative to the female element 120, for example in order to adjust the position of a conduit connected to the male element 110 relative to other surrounding bodies.

By making the male element to further advance in the assembly direction F, the second frusto-conical portion 117 meets the flaps 132, 133 and is snap-fitted beyond them thus defining a second engagement position of the male element 110 in the female element 120. This position is shown in figure 5, where it can appreciated that a pneumatic seal is achieved because the sealing elements 113, 114 are compressed and radially seal the cavity of the female element 120.

This configuration of the connector assembly 100, already known per se in the field, is extremely advantageous because it allows to safely check the assembly condition and, more generally, the condition of a pneumatic line comprising several tubes and connector assemblies. In fact, when, during assembling of a pneumatic line the male and female elements of a connector assembly are connected axially but not tightly restrained to each other, a technician can easily detect controlled losses that occur at the first engagement position by pressurizing the line, while avoiding the risk that some components are disengaged from each other and/or are moved in an uncontrollable and dangerous manner due to air pressure.

In order to allow the male element 110 to be disassembled from the female element 120, the flaps 132, 133 of the locking member 130 further comprise respective maneuvering portions 132b, 133b that are configured to allow engagement of a tool such as a gripper for Seeger rings. In the illustrated embodiment, the maneuvering portions are, for example, U-shaped through openings, but it will be appreciated that, in a totally equivalent manner, they might be through holes or low reliefs.

By pulling the flaps 132, 133 away from one another, it is possible to create an axial passage having a size suitable to allow the second portion 112 to be disengaged, more particularly to allow its frusto-conical portions 116, 117 to exit the cavity of the female element 120.

Now referring now to figures 6 to 9, according to a further aspect of the invention, the connector assembly 100 may further comprise a rotation locking element configured to prevent the male element 110 from rotating relative to the female element 120. The rotation locking element is indicated by reference number 140.

The rotation locking element 140 comprises an annular base 141 along whose inner periphery a plurality of radial projections 142 are formed, for example wedge shaped projections.

Correspondingly, the male element 110 comprises a plurality of indentations 118 whose shape matches the shape of the radial projections 142 of the rotation locking element 140. The indentations 118 extend in an axial direction and are arranged circumferentially in the second portion 112 of the male element 110, for example close to the central portion 115.

Figure 9 schematically shows an engagement condition between the rotation locking element 140 and the male element 110. As it may be seen, in a working condition of the connector assembly 100 the rotation locking element 140 substantially abuts the central portion 115.

Still with reference to figure 3, according to an embodiment of the invention the axial locking element 130 further comprises an annular seat 134 formed in its annular base 131 on the side opposite to the side on which the flaps 132, 133 are formed. The annular seat 134 is configured to define a shape coupling with the outer periphery of the rotation locking member 140 which e.g. has a plurality of radial protrusions suitable to engage corresponding recesses formed in the seat 134.

The seat 134 is preferably configured to fully accommodate the annular base 141 of the rotation locking member 140, which offers the advantage of minimizing the size of the connector assembly 100 in an axial direction.

Still with reference to figure 4, in the first engagement position, the male element 110 is axially spaced from the rotation locking member 140 and can freely rotate relative thereto.

In the second engagement position, shown in figure 5, the male element 110 is fully inserted in the axial locking element 130, thus also engaging the rotation locking element 140.

According to an embodiment of the invention, the male element is made of brass, for example according to European standards EN 12164 or EN 12165, while the female element 120, the axial locking member 130, the rotation locking element 140 are made of a plastic material such as polyamide 6.6 reinforced with glass fibers or polyamide 6.10 reinforced with glass fibers.

The present invention has herein been disclosed with reference to preferred embodiments thereof. It will be appreciated that further embodiments relating to the same inventive idea may exist, as defined by the scope of protection of the claims set out below.