EP2438658A1

EP2438658A1 - An interface device for a bundle of electrical connector conductors

Info

Publication number: EP2438658A1
Application number: EP10723000A
Authority: EP
Inventors: Bruno Dupont
Original assignee: Tyco Electronics France SAS
Current assignee: Tyco Electronics France SAS
Priority date: 2009-06-05
Filing date: 2010-05-17
Publication date: 2012-04-11
Also published as: FR2946467A1; WO2010139550A1; FR2946467B1

Abstract

An interface device for a conductor bundle for an electrical connector, including a body from which protrudes a bundle retention portion (12), said portion extending longitudinally in the direction of the conductor bundle and transversely perpendicular to said bundle, the portion having a transverse section along its entire length with two concave grooves (13 A, 13B) either side of a central convex strip (14), and the retention portion having a through hole (15) for a tightening strip (20) to transversely tighten the bundle against said portion.

Description

AN INTERFACE DEVICE FOR A BUNDLE OF ELECTRICAL CONNECTOR

CONDUCTORS

The present invention generally relates to electrical connectors. Electrical connectors are generally designed to act as an intermediary to connect an electrical device to a bundle of electrical connectors.

More specifically, the present invention relates to an interface device for a bundle of electrical connector conductors.

In the field of electrical connectors, one of the most commonly encountered problems is retaining the conductor bundle on the connector in order to prevent its detachment from the connector due to mechanical stress and, more generally, the transmission of mechanical forces from the bundle to the electrical terminals inside the connector via the electrical conductors connected thereto.

Therefore, this problem is particularly manifest behind the connectors, at the interface between the conductor bundle and the connector.

In practice, the same connector, which is manufactured in bulk quantities, is used for various applications requiring various cable bundles, both in terms of the number of conductors and their diameters relative to each other.

The cable retention devices on the connector therefore must be able to adapt to a widely variable number of conductors and diameters relative to each other.

To this end, a certain number of interface devices are known from the prior art for conductor bundles for retaining cable bundles on a connector, using a bundle retention portion having the overall shape of a profiled duct and a tightening strip to transversely tighten the bundle against said portion.

The profiled ducts, known in the prior art, generally present a transverse "U" or "V" concave profile to join the conductors against one another and a ribbed transverse profile to increase the detachment resistance of the bundle along its longitudinal direction.

These types of devices are notably known in documents US 4080035 and US 5700156.

These retention devices with a concave profile are not satisfactory since the tightening force is poorly distributed on the conductors. Furthermore, these devices are poorly suited for bundles with few conductors and/or small diameters.

Devices are also known from the prior art, which have a plastic hinge cover which folds over the support portion of the bundle and locks by a catching means on the end opposite the hinge. This type of device is particularly known from document US 4035051. The retention proposed by this type of device is unsatisfactory when the applications have to use a wide range of conductor diameters, as these devices are designed to suit low numbers and small diameters of conductors.

More specifically, when a small quantity of cables is used, the quality of cable retention by these devices is unsatisfactory.

As a result of these observations, the general purpose of the present invention is to overcome these disadvantages.

More specifically, the present invention proposes the provision of a reliable device, which is easy to use and to manufacture in bulk quantities and which provides effective retention of the bundle for a wide range of diameters and quantity of conductors in the bundle. To this end, the invention proposes an interface device for a conductor bundle for an electrical connector, including a body from which protrudes a bundle retention portion, said portion extending longitudinally in the direction of the conductor bundle and transversely perpendicular to said bundle, the portion having a transverse section along its entire length with two concave grooves either side of a central convex strip, and in that the retention portion has a through hole for a tightening strip to transversely tighten the bundle against said portion.

In this way, the invention advantageously allows, in a simple and effective manner, reliable tightening of a wide range of numbers and diameters of conductors. In effect, when using a single conductor, said conductor will locate itself in one of the concave grooves, provided either side of the strip, when the strip is tightened.

When using a larger number of connectors, they will spread between the two grooves on the convex portion during tightening of the strip, thus guaranteeing uniform distribution of the tightening force.

According to an advantageous feature of the invention, the bundle retention portion has a transverse hollow which extends transversely from the external end of a groove to the external end of the opposite groove, the profile of the transverse section essentially remaining the same in the hollow as along the entire length of the retention portion, the hollow being positioned longitudinally in line with the location of the tightening strip and having a width longitudinally at least equal to that of the strip through hole.

Advantageously, these provisions allow the detachment resistance of the bundle from the interface device to be increased by combining tightening and a hollow perpendicular to the longitudinal direction of the bundle.

According to advantageous features of the invention, essentially combined: said strip through hole at least partially overlaps said hollow of the retention portion; the surface of the retention portion on the surface having two concave grooves either side of a central convex strip presents means of retaining the tip of the tightening strip so that the end opposite the head of the strip may tighten the cable bundle and then traverse the hole in the retention portion provided to this end, in order to engage in the tip of the tightening strip; the body of the device presents means for mounting to an electrical connector; the tightening strip is integral with the retention portion of the bundle; - the strip is made in a single piece using bi-material moulding, the strip being produced from a material having different mechanical characteristics to the material used to produce the body of the device.

According to the latter two features, the device according to the invention may be manufactured in a particularly cost-effective manner.

According to a further feature, the invention relates to the use of the aforementioned device, including the following steps:

- inserting the tip of a tightening strip into retention means on the device provided to this end;

- inserting a bundle of at least one conductor on the bundle retention portion of the device;

- closing the strip by passing the end opposite the tip into the strip through hole, and then into the tip of the strip; - tightening the strip around the at least one conductor and the retention portion.

According to a further feature, the invention relates to a manufacturing process for the aforementioned device, including the following steps: - preparing an injection mould of plastic material having the form of a device according to the invention having at least two material injection points, one of which is located at a free end of the tightening strip;

- injecting a plastic material via each of the mould injection points; - opening the resulting device mould once the plastic material has hardened.

According to advantageous features, the material injected via the injection point located at a free end of the tightening strip differs from the material injected via the other injection point and said material injected via the free end of the tightening strip has higher elasticity limit characteristics than the material injected via the other injection point.

The description of the invention will be better understood by the detailed description of an embodiment, provided hereafter for illustration and non-limiting purposes only, with reference to the appended drawings, wherein:

Figure IA is an overall perspective view of a device according to the invention connected to a connector;

Figure IB is a detailed view of a device according to figure IA;

Figure 1C is a detailed view of the opposite surface of a device according to figure IB;

Figure 2 is a transverse cut-out view of a device according to the invention in an operating configuration;

Figure 3 is a transverse cut-out view of a device according to the invention in another operating configuration;

Figure 4 is a longitudinal cut-out view of a device according to the invention;

Figure 5A is an exploded perspective view of a device according to the invention and a tightening strip;

Figure 5B is a perspective view of a device according to figure 5A in an assembled position with a tightening strip;

Figure 6 is a perspective view of another embodiment of a device according to the invention. As can be seen more specifically in figure IA, an interface device 10 according to the invention is shown in a perspective view wherein it is connected to an electrical connector 1. The interface device 10 for a conductor bundle has a body 11 from which protrudes a bundle retention portion 12 having the overall shape of a duct.

The body of the device has means for mounting to an electrical connector, in practice this involves two catching portions 2, 3 either side of the connector, each designed to co-operate with a corresponding portion of an electrical connector.

As can be seen more specifically in the detailed view in figure IB, the interface device 10 has a transverse section with two concave grooves 13A and 13B on the retention portion 12, disposed either side of a central convex strip 14.

The retention portion 12 further comprises a through hole 15 for a tightening strip 20 for transversely inserting the bundle against the retention portion 12.

The surface of the retention portion 12 opposite the surface having the two concave grooves 13A and 13B and the central convex strip 14 has means 16 for retaining the tip 21 of the tightening strip 20. These retention means 16 are constituted by a reinforcement forming an abutment surface 16A for the tip of the tightening strip 21, said reinforcement being drilled with an opening 16B for the passage of the tightening portion 22 of the tightening strip. The abutment surface 16A is disposed so that the tip of the strip 21 is located opposite the hole 15 when it is in abutment with said surface 16 A.

In this way, as can be seen more specifically in figures 2 and 3, when the strip is tightened around a bundle 30 of conductors 31, the tightening portion 32 tightens the conductors 31 before passing through the hole 15 to engage in the tip of the strip 21 , thus generating a tightening force which is uniformly distributed on the conductors 31. As can be seen more specifically in figure 2, when a small number of conductors, in this case two conductors, is inserted into the interface device, they naturally locate in the grooves 13A and 13B under the tightening effect of the strip 20. The tightening force is uniformly distributed on the two conductors.

When more conductors are used, as can be seen in figure 3, they spread from the groove 13A to the groove 13B, in a uniform manner, on the convex strip 14. The presence of this strip 14 allows a uniform distribution of the tightening force of the strip 20 on the conductors 31.

According to an advantageous feature, the interface device according to the invention has a transverse hollow 17 which extends transversely from the external end of the groove 13A to the external end of the opposite groove 13B. The profile of the transverse section essentially remains the same in the hollow 17 as over the entire length of the retention portion 12, that is, two concave grooves 13A and 13B surrounding a central convex strip 14. The hollow 17 is positioned longitudinally in line with the location of the tightening strip 20. In the longitudinal direction, the width is at least equal to that of the strip, preferably at least equal to three times the width of the strip. The hollow further comprises connection fillets 18 at its ends having a radius selected to prevent damage to the conductor isolation.

As can be seen more particularly in figure 4, according to this particularly advantageous feature of the invention, the hollow 17 contributes to the detachment resistance of the bundle from the interface device, when the bundle is mechanically stressed along its length. In effect, the presence of the hollow 17 combined with the tightening force of the strip 20, provides the bundle, locally, with two consecutive curves forming a chicane, and contributes to improving the detachment resistance along the longitudinal direction of the bundle.

An interface device as described previously is shown in figures 5A and 5B in an exploded perspective view and an assembled perspective view, respectively. The interface device 10 according to this embodiment is moulded from a reinforced plastic material having highly resistant mechanical properties. The strip is moulded in non-reinforced plastic, having particularly advantageous mechanical elasticity properties. In particular, the modulus of elasticity is higher for the material forming the tightening strip than it is for the material forming the body of the interface device 10. During manufacture, the collar is inserted into the passage 16B provided on the retention portion 12 for this purpose. Once this operation is complete, the position is as shown in figures 1C and 5B. The production bundle may be subsequently inserted in the interface device and the strip can be closed on itself and tightened around the conductor bundle. This position is more specifically shown in figures 2, 3 and 4.

According to an alternative embodiment of the invention shown in figure 6, the body of the interface device 10 and the strip 20 are produced in one piece by a plastic mould. Advantageously, this involves a bi-material mould, the two materials being injected via the different injection points in the mould used to manufacture the device. In practice, an injection point is provided at the free end of the strip 20 and a second injection point is provided at the opposite end of the body 10. The two injection points are respectively supplied, during manufacture of the device, with the two plastic materials described previously in order to provide the body 10 and the tightening strip 20 with the same mechanical characteristics as in the previously described embodiment. This second embodiment is particularly advantageous in terms of manufacturing costs, insofar as the step for assembling the body 10 with the strip 20 can be omitted.

Numerous other variants are possible according to circumstances and it should be noted in this respect that the invention is not limited to the examples described and shown.

Claims

1. An interface device 10 for a conductor bundle for an electrical connector 1, including a body 11 from which protrudes a bundle retention portion 12, characterised in that said portion extends longitudinally in the direction of the conductor bundle 30 and transversely perpendicular to said bundle, the portion having a transverse section along its entire length with two concave grooves 13 A, 13B either side of a central convex strip 14, and in that the retention portion has a through hole 15 for a tightening strip 20 to transversely tighten the bundle 30 against said portion.

2. The device according to claim 1, characterised in that the bundle retention portion has a transverse hollow 17 which extends transversely from the external end of a groove 13A to the external end of the opposite groove 13B, the profile of the transverse section essentially remaining the same in the hollow as along the entire length of the retention portion, the hollow being positioned longitudinally in line with the location of the tightening strip 20 and having a width longitudinally at least equal to that of the strip through hole 15.

3. The device according to claim 2, characterised in that said strip through hole 15 at least partially overlaps said hollow 17 of the retention portion.

4. The device according to any one of the previous claims, characterised in that the body of the device has means 2, 3 for mounting to an electrical connector.

5. The device according to any one of the previous claims, characterised in that the surface of the retention portion on the surface having two concave grooves either side of a central convex strip has means of retaining 16 a tip 21 of a tightening strip so that the end opposite the head of the strip may tighten the cable bundle and then traverse the hole in the retention portion provided to this end, in order to engage in the tip of the tightening strip.

6. The device according to any one of claims 1 to 4, characterised in that the tightening strip 20 is integral with the retention portion 12 of the bundle.

7. The device according to claim 6, characterised in that the strip 20 becomes one-piece using bi-material moulding, the strip being produced from a material having different mechanical characteristics to the material used to produce the body of the device 10.

8. The use of a device according to any one of claims 1 to 4, characterised in that it includes the following steps:

- inserting the tip 21 of a tightening strip 20 into the retention means on the device provided to this end;

- inserting a bundle 30 of at least one conductor on the bundle retention portion of the device;

- closing the strip 20 by passing the end opposite the tip into the strip through hole 15, and then into the tip of the strip; - tightening the strip around at least one conductor and the retention portion 12.

9. A process for manufacturing a device according to claim 6 or 7, characterised in that it includes the following steps:

- preparing an injection mould of plastic material having the form of a device 10 according to claim 6 or 7 and having at least two material injection points, one of which is located at a free end of the tightening strip 20;

- injecting a plastic material into each of the mould injection points;

- opening the resulting device mould once the plastic material has hardened.

10. The process according to claim 9, characterised in that the material injected via the injection point located at a free end of the tightening strip 20 differs from the material injected via the other injection point and in that said material injected via the free end of the tightening strip has higher elasticity limit characteristics than the material injected via the other injection point.

PAGE INTENTIONALLY LEFT BLANK