ROUND CONNECTOR WITH SEALING EYELET AND RETAINING RING

Description

TECHNICAL FIELD

[0001] The present invention relates to a circular electrical connector with a sealing grommet. More particularly, the invention relates to a circular electrical connector with a sealing grommet that provides a reliably watertight and secure connection. The invention also relates to a connection with such a connector and a rear fitting. PREVIOUS STATE OF THE ART

[0002] GB 721 872 A discloses a circular electrical connector according to the preamble of claim 1.

[0003] In the aerospace industry, the manufacture of electrical harnesses often uses circular electrical connectors. These connectors allow wires to be connected to each other neatly and quickly. A preferred type of circular connector is one that conforms to the ASD-STAN standard, for example EN 3646 or EN 2997.

[0004] These connectors comprise a female part with a socket. Typically, the socket is substantially cylindrical, extending along a central axis, and has an axial end with cavities extending inward along the axis. Each cavity leads to an electrical contact and is designed to receive electrical components, such as a wire or a pin connected to a wire, or the pins of a connector connected to wires, etc. The socket is housed within a casing that extends around the socket. The casing, particularly the circumferential wall surrounding the socket, is provided with a means of attachment, such as a thread on the circumferential wall.

[0005] The connector also includes a sealing grommet, which is an elastomer layer attached to the axial end, positioned over the socket cavities to ensure the connector is sealed. The grommet is also circular and approximately the same diameter as the socket, comprising a front face, often extending beyond the housing, and a circumferential wall. Its front face has holes passing through the grommet and leading to a respective cavity. The connector may experience condensation when installed in an aircraft, and the grommet, with electrical components or shutters when the electrical components are not in use, inserted through the grommet, prevents water or fluid from entering the connector cavities.

[0006] Electrical components are generally fitted with a back fitting, which includes a substantially tapered sleeve surrounding the electrical components with a corresponding attachment means, such as a threaded clamping nut rotatably mounted on the sleeve, for attaching to the connector. A preferred type of back fitting is one conforming to AS85049. Once the electrical components or shutters are inserted into the connector, the sleeve, which is frequently chamfered at its leading edge to facilitate passage around the grommet and to slightly compress the grommet in the radial direction, is advanced around the grommet toward the housing.

[0007] Next, the locking nut is screwed onto the threads of the connector housing. Once the connection is made, the fitting's sleeve is fully engaged (butted against it in this case, but can be nested) with the connector housing. In this position, the chamfer seals the plugs and electrical components within the cavities to improve the seal of the cable gland. This connector and fitting are of known types, shown in the diagrams. Figures 1A to 1C .

[0008] However, due to the insertion of electrical components or shutters through the grommet, it sometimes undergoes diameter expansion, resulting in the connector not guaranteeing a proper fit. More specifically, the chamfer of the sleeve catches on the grommet because of its enlarged diameter, sometimes exacerbated by its material, and by the fact that the grommet is positioned further forward than the housing, preventing complete axial engagement between the connector sleeve and the connector housing. The operator may feel that the connection is correctly installed, as tightening the locking nut to the specified torque may reach the required value.

[0009] This results in significant stress on the grommet, which can deform and, with the incomplete engagement described above, cannot fulfill its sealing function. Furthermore, the housing, as well as the fitting, is sometimes made of conductive material designed to provide a path for electricity (accidental or grounded), and the incomplete engagement affects this electrical path. In some cases, the rear fitting doesn't even fit around the grommet due to expansion. Consequently, a proper connection is not achieved in terms of sealing, tightness, and electrical conductivity.

[0010] Currently, there is no reliable solution for securely and securely attaching a rear fitting to a circular connector with a sealing grommet. Consequently, there remains a need for a circular connector with a grommet that can be securely and securely attached to a fitting. DESCRIPTION OF THE INVENTION

[0011] The present invention thus proposes a circular electrical connector according to claim 1.

[0012] Preferably, the rush is circular in shape.

[0013] Ideally, the rush should be of uniform thickness.

[0014] Preferably, the rush is made of composite material.

[0015] Alternatively, the ring is made of stainless steel.

[0016] According to the invention, the surface of the outer wall of the rod is less rough than the circumferential wall of the grommet.

[0017] Preferably, the most forward part of the rod is at the same level as the front face of the cable gland.

[0018] Preferably, the bead is adapted to prevent the expansion of the diameter of the cable gland.

[0019] The present invention also proposes a connection comprising a connector such as that defined above, and a rear fitting, the rear fitting comprising electrical elements, a sleeve surrounding the electrical elements, and an attachment means, in which the electrical elements are inserted into the cavities of the socket, and the rear fitting and the connector are attached together by their attachment means.

[0020] Preferably, the rear fitting includes a right angle at its most forward part. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following are described, by way of non-limiting examples, embodiments of the invention, with reference to the attached drawings, in which: there Figure 1A illustrates a connector of a known type; the figure 1B illustrates a partial cross-sectional view of a connection including the connector of the Figure 1A and a rear fitting of a known type; the figure 1Cillustrates a partial cross-sectional view of part of the connection of the figure 1B ; there figure 2A illustrates a connector according to a preferred embodiment; the figure 2B illustrates a partial cross-sectional view of a connection including the connector of the figure 2A and a rear fitting of a known type; and the figure 2C illustrates a connection similar to that of the figure 2B , with a modified rear fitting.

[0022] In all these figures, identical references may designate identical or similar elements. Furthermore, the different parts represented in the figures are not necessarily shown to a uniform scale, in order to make the figures more legible. DETAILED DESCRIPTION OF SPECIFIC METHODS OF IMPLEMENTATION

[0023] There Figure 1A illustrates a circular electrical connector 20 with a known type of sealing grommet 25 (without electrical components or shutters inserted in its cavities). figure 1BFigure illustrates a connection 70 comprising a connector 20 of a known type and a rear fitting 40 of a known type. Electrical elements 42 of the fitting 40, which are individual wires 42 here, are inserted into the connector 20, and unused cavities 23 allow for the insertion of shutters 32. Of course, the fitting 40 may include wires 42 connected to a multi-pin connector instead of individual wires 42. The figure 1C illustrates a partial cross-sectional view of part of connection 70 of the figure 1B illustrating the case where the sleeve 43 of the fitting is caught on the cable gland 25 due to the expansion of the cable gland 25. As already described previously, this connector 20 is not always able to guarantee a tight and secure connection.

[0024] There figure 2A illustrates a connector 20 according to a preferred embodiment. It is substantially the same as the connector 20 of the Figures 1A to 1C, with the exception of a 35mm wire retaining ring.

[0025] The ring 35 is intended to limit the expansion of the cable gland 25. It is placed around the cable gland 25 on the socket 21 of the connector 20. More specifically, it is placed around the circumferential wall 27 of the cable gland 25.

[0026] It is circular in shape, corresponding approximately to the shape of the grommet 25, which is also circular. The diameter of the inner wall 36 is the same as that of the circumferential wall 27 of the grommet 25. Of course, this diameter may be slightly smaller than that of the circumferential wall 27 of the grommet 25, for example, to allow for a more secure connection between the rod 35 and the grommet 25 (if the grommet 25 is made of a sufficiently flexible material). Similarly, the inner diameter of the inner wall 36 of the rod 35 may be slightly larger than that of the grommet 25.

[0027] The 35 ring is rather thin so as not to take up much space in the radial direction. When the 35 ring is installed, it is designed such that the diameter of the cable gland 25 and the 35 ring together, with or without the electrical components 42 and the shutters 32, is less than that of the cable gland 25 alone with the electrical components 42 and / or the shutters 32 inserted. The thickness of the 35 ring may vary along its circumference, but a uniform thickness is generally preferred. Here, its outer wall 37 is located in the middle of the outer diameter of the cable gland (without electrical elements 42 or shutters 32) and the inner diameter of the most forward part, typically the chamfer 44 of the sleeve 43, of the fitting 40 intended to be attached to the connector 20. The play facilitates the passage of the sleeve 43 around the socket 21 during the initial engagement phase.Of course, depending on the need, the craftsman can choose a thickness of the 35 reed which is different depending on the structural integrity and the preferred play.

[0028] The retaining ring 35 limits the expansion of the diameter of the cable gland 25 when the electrical components 42 or the shutters 32 are plugged into the connector 20. It is configured such that the diameter of its outer wall 37 does not change, or increases very little, when the electrical components 42 are plugged into the connector 20. If it is of the type where the diameter of the outer wall 37 does not change, the expansion of the cable gland 25 is prevented (completely limited). Therefore, the retaining ring prevents the cable gland 25 from exceeding a certain diameter. Thanks to this fact, when the attachment means 46 of the fitting 40, i.e. the clamping nut 46 with the thread 49, are attached to the clamping means 29 of the connector 20, i.e. the thread 29 on the circumferential wall 30 of the housing 28, the cable gland 25 no longer prevents the passage of the sleeve 43 and the complete engagement of the fitting 40 and the connector 20.

[0029] As a result, a 100% watertight and secure connection is obtained, as shown in the image. figure 2B Although the 35 ring of the type where the diameter of the external wall 37 does not change is preferred, the type where the diameter can increase a little may also be suitable. The important point is that once electrical components 42 or shutters 32 are inserted, the cable gland 25 with the connecting rod 35 does not interfere with the subsequent connection to the fitting 40. The connecting rod 35 can be of a height that is less than or greater than the thickness of the cable gland layer 25. According to the invention, the connecting rod 35 is of a height that is at least equal to the thickness of the cable gland 25, and is arranged on the cable gland 25 so that it does not protrude from the front face 26 of the cable gland 25 when it is installed on the connector 20. Here, the most forward part of the connecting rod 35 is at the same level as the front face 26 of the cable gland 25 in the direction of the axis of the socket 21.

[0030] The surface of the outer wall 37 of the rod 35 can be smooth or rough. A smooth surface can facilitate the advancement of the sleeve 43 around the rod 35, while a rough surface can facilitate manual handling during installation. Similarly, the surface of the inner wall 36 of the rod 35 can be smooth or rough. A smooth surface can facilitate the installation of the rod 35 around the grommet 25, while a rough surface can help to hold the rod 35 around the grommet 25 once installed. According to the invention, the surface of the outer wall 37 of the rod 35 is less rough than that of the grommet 25.

[0031] The retaining ring 35 is made of a material resistant to expansion, which can be caused by physical force or even temperature, allowing it to limit or prevent the expansion of the cable gland 25. Materials with high structural strength and temperature resistance are preferred. Materials such as composites, for example, carbon fiber reinforced plastic, or metals, for example, stainless steel, may be suitable. Preferably, the ring 35 is made of a single piece.

[0032] The mounting of the ring 35 is essentially the same for all connectors 20. The ring 35 is axially aligned with the socket 21 of the connector 20 and extended beyond the edge of the grommet 25. It is then lowered along the circumferential wall 27 of the grommet 25. If the connector 20 has a shoulder 31 at the bottom of the grommet 25, for example, between the grommet 25 and the housing 28, or between the socket 21 and the housing 28, the ring 35 can be lowered to this shoulder 31, so that it rests on the shoulder 31 while remaining around and in contact with the grommet 25. To facilitate mounting on the grommet 25, a chamfer may be provided on the ring 35.

[0033] The 35mm ring can be mounted on the socket 21 of the connector 20 during manufacturing or just before the connector 20 is installed in a harness. Furthermore, the 35mm ring can also be retrofitted to connectors 20 installed in pre-existing connections 70.

[0034] Of course, certain characteristics of the retaining ring 35 can be modified by a person skilled in the art depending on the type of connector, the application, the temperature, the required tightening torque, etc. In one variation, the retaining ring 35 can be slightly elliptical in shape, for example, to fit a cable gland 25 of a slightly elliptical connector. Note that the sealing cable gland 25 is shown with holes 24 opening onto the cavities 23 of the socket 21. These can be self-sealing holes, for example, without the electrical components. Alternatively, it can be of the type where the holes are formed when the electrical components are first inserted.

[0035] The attachment method may also differ; for example, instead of the clamping nut 46 with thread 49, the fitting 40 may have threads on the sleeve, while instead of the thread 29 on the circumferential wall 30 of the housing, the connector 20 may have a clamping nut with a thread. Furthermore, instead of the thread 29 or 49, the attachment method between the connector and the rear fitting may include a bayonet fitting.

[0036] Instead of a rear fitting 40 with a chamfer 44, a modified rear fitting 50 with a right angle 45 at the forwardmost part of the sleeve 43 can also be used. Inserting the electrical components 42 and the plugs 32 when the ring 35 is installed compresses the cable gland 25 and improves its seal. Consequently, the chamfer 44 no longer needs to be designed to compress the cable gland 25. figure 2Cillustrates a connection 110 with such a fitting 50, the right angle 45 not touching the ring 35, its internal diameter being wider than the external diameter of the ring 35.

[0037] Until now, modifying the chamfer 44 has been the primary approach taken by connector manufacturers. However, this solution does not resolve the problem for every plug configuration because the expansion of the cable gland diameter 25 is not always the same and depends, for example, on the proportions of the electrical components 42 and the shutters 32, their dimensions, etc. Consequently, the quality of the connection is not consistent.

[0038] The solution proposed by the invention is advantageous. With the ring 35 installed around the cable gland 25, the expansion of the cable gland 25 is limited or prevented, and therefore the clearance between the fitting 40, 50 and the ring 35 remains essentially the same. Consequently, the fitting 40, 50 always manages to fully engage with the connector 20 and fasten together. Furthermore, the fact that the external diameter of the ring 35, i.e., the diameter of the outer wall 37, remains essentially the same when the electrical components 42 or the shutters 32 are inserted, implies that the fitting 40, 50 always comes into contact with the ring 35 at the same point, or not at all. This precision ensures consistency in terms of the reliability of the connection 100, 110 and the quality of the seal.

[0039] Of course, the fact that the connector 20 is adapted to receive the electrical components 42 in the cavities 23 does not preclude it from receiving other components, for example, shutters 32, which is also within the scope of the invention. Likewise, the fact that the ring 35 is adapted to limit or prevent the expansion of the diameter of the cable gland 25 when the electrical components 42 are inserted through the cable gland 25 does not preclude it from limiting or preventing the expansion of the diameter of the cable gland 25 when other components are inserted, for example, shutters 32.

Claims

1. A circular electrical connector (20) comprising a socket (21) extending along an axis and provided at an axial end with cavities (23), and a sealing grommet (25) provided on the axial end defining a front face (26) through which electrical elements (42) can be inserted into the cavities (23) and a circumferential wall (27), the connector (20) additionally comprising a housing (28) in which the socket (21) is housed, the housing (28) extending in the direction of the axis of the socket (21) and surrounding it, the housing (28) comprising an attachment means (29) for attachment with a backshell (40, 50), the connector (20) comprising a retaining ring (35) around the circumferential wall (27) of the grommet (25), the ring (35) being adapted to limit the expansion of the diameter of the grommet (25) when the electrical elements (42) are inserted through the grommet (25), wherein the surface of the outer wall (37) of the ring (35) is not as rough as the circumferential wall (27) of the grommet (25), characterized in that the ring (35) is of a height which is at least equal to the thickness of the grommet (25), and provided on the grommet (25) such that it does not exceed the front face (26) of the grommet (25) when it is installed on the connector (20), and in that the connector is adapted so that once the electrical elements (42) are inserted, the grommet (25) with the ring (35) do not hinder the subsequent connection with the backshell (40).

2. The connector according to claim 1, characterised in that the ring (35) is of circular shape.

3. The connector according to claims 1 or 2, characterised in that the ring (35) is of uniform thickness.

4. The connector according to any preceding claim, characterised in that the ring (35) is made from composite material.

5. The connector according to any of claims 1 to 3, characterised in that the ring (35) is made from stainless steel.

6. The connector according to any preceding claim, characterised in that the foremost portion of the ring (35) is at the same level as the front face (26) of the grommet (25).

7. The connector according to any preceding claim, characterised in that the ring (35) is adapted to prevent the expansion of the diameter of the grommet (25).

8. A connexion (100, 110) comprising a connector (20) according to any preceding claim and a backshell (40, 50), the backshell (40, 50) comprising electrical elements (42), a sleeve (43) surrounding the electrical elements (42), and an attachment means (46, 49), wherein the electrical elements (42) are inserted into the cavities (23) of the socket (21), and the backshell (40, 50) and the connector (20) are attached together by their attachment means (29, 49).

9. The connexion (110) according to claim 9, characterised in that the backshell (50) comprises a right angle (45) at the foremost portion of the sleeve (43).