The present invention relates to a plug for an electrical connector, in articular for the electrical connection between a towing vehicle and a trailer.

More precisely, the invention relates to a plug according to the preamble of the main claim, that is to say of the type including a contact-carrier body fixed to a tubular casing by means of a bayonet-type attachment.

Plugs of this type known up to now have the disadvantage that dismantling the plug-carrier body from the casing is a rather complicated operation.

The present invention seeks to achieve the objective of providing improvements to a plug of the above-specified type, which will make the operation of dismantling the contact-carrier body simpler and faster.

A further object of the present invention is that of making a plug of the above-specified type simpler and more economical .

According to the invention this object is achieved by a plug having the characteristics forming the subject of the claims .

Further characteristics and advantages of the present invention will become apparent during the course of the following detailed description, given purely by way of non-limitative example, with reference to the attached drawings, in which:

Figure 1 is a perspective view of a plug according to the invention;

Figure 2 is an exploded perspective view of the plug of Figure 1;

Figures 3 to 6 are front elevation views seen from the direction of the arrow III of Figure 1, illustrating the assembly sequence of the plug according to the invention; and

Figure 7 is a section on an enlarged scale taken on the section line VII-VTI of Figure 6.

With reference to the drawings, the reference numeral 10 indicates a plug for an electrical connector, comprising a casing 12, a contact-carrier body 14 and a protective cap 16.

The casing 12 has a tubular portion 18 fixed to a flange 20 provided with fixing holes 22. A tubular portion 18 has a cylindrical internal surface 24 from which a plurality of sectors 26 project radially inwardly. The sectors 26 are circumferentially spaced from one another in such a way as to define a series of passage zones 28 (see in particular Figure 3) . The sectors 26 have flat front and rear faces respectively facing the front aperture 30 and the rear aperture 32 of the tubular portion 18.

As can be seen in particular in Figure 3, on the front face of one of the sectors 26 there is formed a stop projection 34. Another sector 26 has on its front face a ramp-shaped projection 36 the function of which will become clear hereinafter.

Referring now to Figures 2 and 4, the contact-carrier body 14 is constituted by a single piece of injection moulded plastics material in which are formed a plurality of

cavities indicated 38 in Figure 2, for receiving respective contacts indicated 40 in Figure 4. The contact-carrier body 14 has a flat front surface 42 on the edge of which are formed a plurality of perimetral lugs 44. In a posicion slightly back from the perimetral lugs 44 the contact-car¬ rier body 14 has an annular stop collar 46. Between the perimetral lugs 44 and the stop collar 46 is defined a groove the axial dimension of which is about equal to the thickness of the sectors 26 of the casing 12.

The contact-carrier body 14 of the casing 12 is assernbled in the following manner.

First, as illustrated in Figure 5, the contact-carrier body 14 is introduced into the tubular part 18 of the casing 12 starting from the rear aperture 32 by aligning the perime¬ tral lugs 44 with the passage zones 28 provided between each pair of adjacent sectors 26. The axial movement of the contact-carrier body 14 with respect to the casing 12 stops when the annular collar 46 comes into contact against the rear faces of the sectors 26.

At this point the contact-carrier body 14 is caused to rotate in the sense indicated by the arrow 48 in Figure 5. To perform this rotation it is necessary to overcome a predetermined resistant couple because the ramp projection 36 must be made to pass over the perimetral lug 44 and to achieve this it is necessary to cause a slight flexing of the perimetral lug 44.

As is illustrated in Figure 6 the rotation of the con¬ tact-carrier body 14 ends when the perimetral lug 44a comes into contact against the stop projection 34. In this position the perimetral lug 44b has passed completely over the ramp-shaped projection 36 (see also Figure 7) which

constitutes an abutment stop against rotation of the contact-carrier body 14 in the opposite sense from that in which assembly takes place.

Dismantling of the contact-carrier body 14 can be effected simply by making the contact-carrier body 14 rotate in the sense indicated by the arrow 50 in Figure 6 and by applying a couple sufficient to allow the perimetral lug 44b to pass over the ramp projection 36.

Another advantageous characteristic of the plug according to the invention is that the contact-carrier body 14 has an annular rear wall 52 (Figures 2 and 7) which, when the plug is assembled, remains slightly spaced from the front edge of the rear aperture 32 of the tubular part 18. In this way the annular groove defined between the wall 52 and the edge 32 (Figure 7) can advantageously be utilised for engagement of an anchoring rib 54 of the protective cap 16.