Electrical connector element for conductors with crimped contacts

An electrical connector element (1) includes a connector body (2) wherein contact housings (20) are formed, electrical contacts (4) crimped to respective electrical cables (8) and able to be housed in the contact housings (20) of the connector body (2) and locking elements (5) designed to be fixed in the connector body (2) after insertion of the contacts (4). The locking elements (5) include stops (55), which protrude into the contact housings (20) so as to prevent the contacts (4) from coming out of their housings.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention refers to an electrical connector element for conductors with crimped contacts.

2. Description of the Related Art

As is known, electrical connectors are generally composed of a pair of connector elements. Each connector element comprises an insulated body (commonly known as connector body) wherein are mounted the respective contacts (male and female) which are connected to electrical cables with one of the various connection technologies available, such as screw, spring, insulation piercing and crimping.

In crimping connection technology, the top portion of the contact is crimped, by means of an appropriate crimping tool, to the end of the wires of the electrical cable, so as to form an optimal electrical contact. Crimping is the preferred connection technology in professional and military applications, where the connection must stand up to strong mechanical stresses (impacts and vibrations) and to aggressive atmospheres. Once the contact has been crimped with the electrical cable, it is inserted into its housing in the connector body.

Therefore, for connectors with crimped contacts, a factor of particular importance is retention of the contacts in the connector body during coupling with the other electrical connector element and in the event of stresses (tractions and/or rotations) on the cables, which are transmitted to the contacts.

In the connector elements of the prior art, locking of crimped contacts takes place by means of a spring (generally of steel or of plastic) disposed inside the connector body. Said spring is elastically deformed during insertion of the contact and then it returns to its original shape, retaining the contact in its housing. Said contact locking system presents some drawbacks:

Variation in the elasticity of the spring is related to the tolerances of the materials and of the manufacturing processes.

In order to be able to remove the contacts from the connector body a particular extractor tool is necessary which, once inserted in the housing of the contact, compresses the spring by a sufficient amount to allow extraction of the contact.

To be able to retain the contacts firmly in their housings, springs whose strength and stiffness increases as the dimensions of the spring increase are necessary. Thus, in the case of large-sized contacts, it is necessary to oversize the spring and to apply greater stresses thereto for release (extraction) of the contacts. As a result insulating connector bodies with a greater mechanical strength must be made, to avoid breakage thereof during operation of the extractor tool.

SUMMARY OF THE INVENTION

The object of the present invention is to eliminate the drawbacks of the prior art, providing an electrical connector element for conductors with crimped contacts, which ensures an efficient, effective and safe locking system for the contacts.

Another object of the present invention is to provide such an electrical connector element for conductors with crimped contacts that is cheap, easy to make and easy to assemble.

These objects are achieved in accordance with the invention to provide an electrical connector element (1) that includes a connector body (2) wherein contact housings (20) are formed, electrical contacts (4) crimped to respective electrical cables (8) and adapted to be accommodated in said contact housings (20) of the connector body (2), and locking means (5) adapted to be fixed to said connector body (2) after insertion of the contacts (4), said locking means (5) comprising stops (55) which protrude into said contact housings (20) so as to prevent said contacts (4) from coming out of their seats.

Advantageous embodiments of the invention are apparent from the dependent claims. The electrical connector element according to the invention comprises a connector body wherein are formed contact housings adapted to house electrical contacts crimped to respective electrical cables. The main characteristic of the invention is represented by the fact that said connector element comprises locking means adapted to be fixed in said connector body, after insertion of the contacts. The locking means comprise stops, which protrude into the contact housings so as to prevent the contacts from coming out of their seats.

Said locking means allow the use of the contact-locking springs, and thus all the drawbacks related to said springs, to be eliminated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The connector element according to the invention, denoted as a whole with reference numeral1, is described with the aid of the Figures. As shown inFIG. 1, the connector element1comprises:

an insulating connector body2,

two electrical contacts4destined to be housed in the connector body2,

a locking element5adapted to lock the electrical contacts4inside the connector body2and

two locking keys7adapted to lock the locking element5inside the connector body2.

Each electrical contact4is made of a conductive metal material, is substantially cylindrical in shape and has at one end a top collar40which defines a housing41adapted to accommodate the wires of an electrical conductor cable8(FIG. 2).

Beneath the collar40of the contact4there is defined a cylindrical crimping portion42, which is crimped with a suitable crimping tool, so as to lock the wires of the conducting cable8inside the seat41of the contact.

Beneath the crimping portion42there extends an intermediate collar43with a larger diameter beneath which a cylindrical portion44with a smaller diameter extends, which defines the contact proper. In this manner an annular abutment surface45is defined between the intermediate collar43and the proper contact portion44.

In the Figures a female contact4has been illustrated by way of example. Thus, the cylindrical portion44is hollow on the inside and open at its end to be able to receive therein a male contact. For this purpose longitudinal slots46are formed in the cylindrical portion44which allow elastic yielding of the cylindrical portion44, when it receives the male contact therein.

For greater clarity, a connector element1with contacts4without an electrical cable8will be illustrated in the Figures; however, it is obvious that the contacts4must be crimped to the cable8before being assembled in the connector element1. Furthermore, even if a connector element with female contacts4has been illustrated in the Figures, it is obvious that the invention also extends to connector elements with male contacts.

The connector body2comprises a body22taking the form of a parallelepiped block substantially square in cross section. The bottom part of the connector body is smaller in size and is the coupling portion, which is of such a shape as to be able to couple, in a per se known manner, with a complementary coupling portion of another connector element.

As shown better inFIG. 3, two substantially cylindrical housings20are formed in the connector body2, destined to accommodate the contacts4.

In the Figures, by way of example the axes of the housings20lie on a plane passing through a diagonal of the body22of the connector body and the housings20are separated from each other by a partition21lying on the plane passing through the other diagonal of the body22. However, the housings20can differ in number and can be disposed differently.

Each seat20is made like a through channel consisting of a first hole23with a larger diameter, a second hole24with a smaller diameter than the first one and a third hole25with a smaller diameter than the second one. In this manner a first annular abutment surface26is defined between the first hole23and the second hole24and a second annular abutment surface27is defined between the second hole24and the third hole25.

A widening32, which extends for about 180° in order to give rise to a semicircular abutment surface, is formed in the top part of the first-hole23.

The contacts4are disposed in the respective housings20of the connector body, so that the annular abutment surface45of the intermediate collar43of each contact4abuts against the first abutment surface26of the respective seat20, preventing axial movement downward (with reference to the Figures) of the contact4. In this situation, the bottom end of the cylindrical portion44of the contact proper is tightly close to the second abutment surface27of the housing20.

As shown also inFIG. 4, inside the body22are formed two further seats28disposed near the two corners of the body on one side and on the other with respect to the contact housings20. The seats28are substantially triangular shaped in cross section, are upwardly open and end in a bottom abutment wall29.

Two rectangular slots30(only one visible inFIGS. 1 and 4) which communicate with the respective seats28are formed in the side wall of the body22. Beneath each slot30a tapered entry guide31formed in the outer side surface of the body22is defined.

Each slot30of the body of the connector body is designed to be engaged by a substantially L-shaped locking key7(FIG. 1). The locking key7comprises a tapered surface70destined to cooperate with the tapered surface31of the wall of the body22of the connector body. Furthermore the key7has a protruding tooth71, which engages in the slot30of the wall of the body of the connector body. Outwardly protruding ribs72are provided on the side walls of the key7to allow an engagement with a certain interference in the slot30.

In order to keep the contacts4locked in the housings20of the connector body, a locking element5in the form of a bridge consisting of two supporting legs50connected to a top joining element51is used. The locking element5can be made in a single piece by injection moulding of plastic materials.

Each leg50is substantially triangular in cross section and of such a size as to be able to be inserted in the respective seats28formed in the body of the connector body2. For this purpose, the corners of the seats28are chamfered and each leg50also has a chamfered edge52. In this manner, when the legs50of the locking element are inserted in their seats28in the connector body, the edges52of the legs slide in a guided manner on the corners of the seats28of the connector body.

As shown also inFIG. 5, each leg has two longitudinal seats53(only one visible inFIG. 1) ending in a bottom abutment surface54.

The top joining element51of the locking element5is substantially X-shaped in plan view and has two semi-cylindrical stops55(only one visible inFIG. 1). As shown inFIG. 5, the two semi-cylindrical stops55are disposed like two Cs with the concave parts facing outwards and the convex parts spaced apart from each other by a space56sufficient to allow the passage of the intermediate partition21, which separates the two contact housings.

Each semi-cylindrical stop55of the locking device is of such a size as to be able to be housed in the widening32of each contact housing20. Then, after the contacts4have been inserted in their housings20in the connector body, the locking element5also is inserted in the connector body2, as shown inFIG. 6. That is, the legs50of the locking element5are inserted into the corner seats28of the connector body, until the base of the legs50abuts against the abutment surface29(FIG. 4) of the seats28of the connector body.

In this situation the semi-cylindrical stops55of the locking element are housed in the widenings32of the contact housings20, the bottom ends of the semi-cylindrical stops55of the locking element abut against the top end of the collar40of the contacts and the partition21between the two housings20of the contacts is disposed between the two stops55.

At this point, in order to lock the locking element5inside the connector body2, as shown inFIG. 7, the keys7are inserted in the respective slots30of the side wall of the connector body. In this operation the tapered surface70of the key7abuts against the tapered surface31of the wall of the body22of the connector body beneath the slot30and the ribs72of the key7ensure insertion with a certain forcing of the protruding part71of the key in the slot30of the connector body.

Furthermore it should be noted that the particular shape of the key7and in particular the tapered surface70thereof which cooperates with the tapered surface31of the wall of the body22of the connector body allow easy removal of the key, possibly with the aid of the tip of a screwdriver which levers beneath the end of the key.

As shown inFIG. 9, the retaining tooth71of each key7enters the longitudinal seat53of the respective leg50of the locking element and abuts on the abutment surface54of the base of the respective leg50, thus preventing axial extraction of the locking element5.

As a result, each contact4is locked in its seat20and any axial movement thereof is prevented. In fact, the top end of the top collar40of the contact will abut against the bottom end of the semi-cylindrical stops55of the locking element5and the abutment surface45of the intermediate collar43of each contact4will abut against the abutment surface26of the intermediate hole24of the contact housing20.

Returning toFIG. 1, four protrusions35(two protrusions35in each wall) are formed in two opposite side walls of the body22of the connector body. The two protrusions35of one wall are spaced apart from each other and aligned. One protrusion35is situated above the respective slot30of the key7. Furthermore grooves36are formed in the edges of the body22of the connector body. In each wall of the connector body wherein there are protrusions35, a slot37is provided disposed beneath the protrusions35in a median position.

Such a configuration of the side walls of the connector body2serves to apply on the connector body2a frame9, like that illustrated inFIG. 10. The frame9is formed by four rectangular metal plates, which surround the middle part of the connector body2. The frame9serves as a seat for the earth contacts91and also contains, besides the connector body2, other connector bodies (in the case illustrated, the connector bodies92and93).

In this manner the top edge of the frame9abuts against the protrusions35of the connector body2and the bottom edge of the frame9is locked by means of two keys90(only one visible inFIG. 10). Each key90has three teeth, which engage in a snap coupling relationship in the two slots26in the edges of the body of the connector body and in the intermediate slot37in the wall of the body of the connector body.

It should be noted that the walls of the frame9compress the keys7which lock the locking element5, thus preventing any possibility of disengagement of said keys7, even in the case of particularly violent vibrations or impacts.

It must moreover be considered that the stops55of the locking element5have been configured in a semi-cylindrical shape to be able to rest on a large surface of the upper edge of the contact4. This solution ensures greater safety with respect to springs of the prior art, which have a small surface that locks the contact. Therefore the connector element1ensures that the contact4is retained even in the presence of strong traction on the electrical cable.

Even if a connector element with two poles disposed diagonally has been illustrated in the Figures, it is obvious that the present invention also extends to multipolar connector elements in which a plurality of poles disposed side by side in two rows is provided.

Numerous changes and modifications of detail within the reach of a person skilled in the art can be made to the present embodiment of the invention without thereby departing from the scope of the invention as set forth in the appended claims.