EP0037313B1 - Devices permitting the sealing of electrical connectors - Google Patents

Abstract

An improved sealing system for use with cooperating electrical connectors for placing two cables of the type wherein each of the cables has an insulator sheath in contact. A contact is inserted into a lodging in each of the connectors with a resulting space between the outer diameter of the insulator sheath and the inner diameter of the electrical connector. The sealing system includes: (a) an electrical contact having a contact element and a tail portion, the tail portion being adapted to be crimped onto one of the cables; and (b) a flexible sealing sleeve molded onto the tail portion of the electrical contact, the sealing sleeve being adapted to seal the space.

Description

The present invention relates to improvements to the devices enabling the electrical connectors to be sealed.

An electrical connector is generally constituted in its simplest form by two parts made of an insulating material and each containing a metallic member, or contact, connected to the end of an electrical conductor. By engaging the two parties in one another, the contacts are made to cooperate.

For many applications, it is important that the contacts are isolated from the atmosphere, especially if the latter is vitiated or particularly humid.

If the problem of sealing is fairly easy to solve at the right of the connection of the insulating parts, it is more delicate at the right of the cable entries whose diameter is much greater than that of the insulated cables.

In the current state of the art, the annular orifice formed between the entry orifice of the insulating part and the external surface of the cable is closed by a sleeve made of a very soft synthetic rubber made integral with the tail of the contact. by crimping.

This sleeve is engaged on the cable and positioned on the latter prior to the connection of said cable to the tail of the contact which has, for this purpose, two additional crimp tabs similar to those used to fix the end of the cable to said contact.

This process is not satisfactory for the following reasons: the sleeve must have a stepped portion to allow crimping, which complicates its manufacture; the crimping of the sleeve is only possible if the latter is rigorously positioned relative to the stripped end of the cable, hence an additional operation prior to crimping; crimping complicates the production of crimping machines; the fixing of the sleeve is very random due to its extreme flexibility and the crimping must be carried out with great precision. Indeed, if the crimping is too strong there is a risk of crushing of the shoulder part of the sleeve causing the cutting thereof, but, if the crimping is too weak, the sleeve is not maintained and an untimely action on the cable causes the sleeve to escape from its housing.

GB-A-1 283 093 also discloses a contact having a sleeve molded onto it in line with the crimping lugs. This solution is not advantageous since the production of the sleeve cannot be carried out before the cable is put in place.

The present invention relates to a device for ensuring the tightness of electrical connectors comprising an electrical contact housed in an insulating body and crimping lugs for the connection of an electrical cable, said insulating body having a housing for receiving a sleeve. , made of a natural or synthetic rubber, making it possible to seal between said housing and said cable, characterized in that the sleeve is overmolded on the end of the contact tail, extending beyond the tabs of crimping, before fixing the contact on the electric cable.

• La figure 1 est une vue en coupe d'un des contacts d'un connecteur usuel modifié en vue de recevoir le manchon de l'invention;
• La figure 2 est la vue de dessus de la figure 1 ;
• La figure 3 est une vue, analogue à la figure 1, montrant un contact de l'invention;
• La figure 4 est une vue en coupe effectuée selon la ligne IV-IV de la figure 3;
• La figure 5 est une vue analogue à la figure 3, montrant le contact fixé à l'extrémité d'un câble;
• La figure 6 est une vue en coupe, à plus petite échelle, montrant l'utilisation de contacts de l'invention dans un connecteur électrique usuel.

The invention will be better understood from the description which follows made with reference to the attached drawing by way of indicative example only, in which:

• Figure 1 is a sectional view of one of the contacts of a conventional connector modified to receive the sleeve of the invention;
• Figure 2 is the top view of Figure 1;
• Figure 3 is a view, similar to Figure 1, showing a contact of the invention;
• Figure 4 is a sectional view taken along the line IV-IV of Figure 3;
• Figure 5 is a view similar to Figure 3 showing the contact attached to the end of a cable;
• Figure 6 is a sectional view, on a smaller scale, showing the use of contacts of the invention in a conventional electrical connector.

Referring to the drawing, it can be seen that the electrical contact comprises two usual parts 1 and 2, that 1 constituting the contact member proper while that 2 forms a tail to which the electrical cable C is connected.

For this purpose and in the usual way, the tail 2 has two pairs of lugs 3a and 3b, the lugs 3a being crimped on the stripped end of the cable C while those 3b are crimped on the insulation of said cable.

According to the invention, a sleeve 4 made of a very flexible natural or synthetic rubber is molded onto the end of the tail 2, extending beyond the legs 3b.

To this end and according to one embodiment, the end of the tail has an extension 5 suitably cut and arched which after overmolding the sleeve is embedded in the latter and cooperates in its maintenance.

This method eliminates all the drawbacks mentioned in connection with the known sealing devices mentioned above.

The external diameter of the sleeve is greater than that of the internal housing L of the connector to receive it and that of its central opening 6 is slightly greater than that of the cable C.

In this way, the cable freely crosses the sleeve which, thus, does not interfere with the positioning of the cable prior to its attachment to the contact. When the sleeve enters the housing L of the connector, the material constituting it then compresses around the cable, ensuring sealing.

To favor the deformation of the sleeve, the outer periphery and the inner periphery of the latter have grooves 7.

Claims (4)

1. Devices permitting sealing of electrical connectors, comprising an electrical contact (1) housed in an insulating body and crimping lugs (3a, 3b) for connection of an electric cable (C), said insulating body having a housing (L) receiving a sleeve (4), made from a natural or synthetic rubber, permitting sealing between said housing and said cable, characterized in that the sleeve (4) is molded over the end of the tailpiece (2) of the contact, extending beyond the crimping lugs, previous to fixing the contact on the electric cable.

2. Devices permitting the sealing of electrical connectors, according to claim 1, characterized in that means are provided on the tailpiece of the contact for ensuring retention of the molded sleeve.

3. Devices permitting sealing of electrical connectors, according to any one of claims 1 and 2, characterized in that the external diameter of the sleeve is greater than that of the housing receiving it whereas the internal diameter (b) is slightly greater than that of the cable intended to pass therethrough.

4. Devices permitting the sealing of electrical connectors, according to any one of claims 1 to 3, characterized in that the outer periphery and the internal periphery of the sleeve have grooves (7).

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