DE20003224U1 - Electrical connector - Google Patents

Description

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Patent Attorneys ''/"- ^: ■'-'''*'''' ^Telephone < ⁰²⁰² > ²⁵⁹⁰⁶ -°

Dipl.-lng. Harald Ostrigä*'"

Dipl.-lng. Bernd Sonnet*

Dipl.-lng. Jochen-Peter Wirths f ^JSanschrift _{&Lgr; R}

^{r &} Stresemannstr. 6-8

* Authorized by the European Patent Office 42275 Wuppertal-Barmen

Ostriga, Sonnet & Wirths ■ PO Box 20 16 53 ■ D-42216 Wuppertal
_

Applicant: Karl Lumberg GmbH & Co

Hälverstr. 94
10

58579 Schalksmühle

Designation

of the invention: Electrical connector

The invention relates to an electrical connector, in particular for proximity switches, with a union nut rotatably mounted on a contact carrier for screwing to a plug counterpart, wherein the union nut and the contact carrier are assigned a substantially snap-fit securing device for vibration-proof attachment to one another and the securing device comprises at least one radial projection on the outer circumference of the contact carrier and a corresponding radial projection on the union nut.

- To secure the plug connection between two interconnected connectors, it is known to mount a union nut on one of the two connector parts so that it can rotate and which is screwed onto a thread provided on the connector counterpart. Such screw connections ensure a secure contact connection between the connector parts as long as they are not exposed to vibrations during operation. In this case, there is a risk that the union nut will loosen and perfect contact can no longer be guaranteed.

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VAT ID No.

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(BLZ 360 100 43) 445 04-431 (BLZ 330 600 98) 301 891 024 (BLZ 330 400 01) 4 034*823 *** DE 121068676

Karl Lumberg

DE 42 05 440 C2 discloses a connector in which such a vibration protection against the plug connection being unscrewed is created in a simple manner. The safety device intended for this purpose comprises a radial toothing on the contact carrier and a radial counter toothing on the union nut as projections. These toothings are arranged and assigned to one another in such a way that a positive toothing connection only occurs towards the end of the axial coupling screw connection of the union nut. This means that the union nut can initially be easily screwed onto the thread of the plug counterpart without the safety device being activated, but then the thread arrangement comes into positive engagement and thus secures the screw connection against loosening.

The essence of the well-known connector is that no measures are required on the connector counterpart to secure the screw, since the union nut secures itself on the contact carrier, on which it is mounted so that it can rotate and move longitudinally to a limited extent. The design is also particularly simple, since the teeth, which are usually small, can be easily attached to the contact carrier and union nut.

As far as DE 42 05 440 C2 states that the teeth are not subject to any particular wear, this is true insofar as the teeth are only briefly in positive engagement with each screwing process. However, if inexpensive and, above all, soft materials such as PVC are used for the contact carrier, signs of wear on the safety device can certainly be seen after prolonged use.

Based on this, the invention is based on the object of providing a connector of the type assumed to be known, the safety device of which is designed to be particularly low-wear. In addition, importance is attached to the fact that the connector should still be very simple in design.

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The invention solves this problem with the features of claim 1 and is accordingly characterized in that a gap is formed between the radial projections, which gap is lined by a rubber-elastic ring whose strand diameter in the relaxed state is larger than the gap width of the gap.

In principle, the projections here also form a type of toothing in the broadest sense, which in the simplest case has one tooth each on the contact carrier and the union nut. The principle underlying the invention, however, is based on the fact that the projections themselves do not come into direct positive engagement, which is how they differ from real toothing. The essence of the rubber-elastic ring is, on the one hand, to keep the projections at a distance and, on the other hand, to bring about a "further locking" when the union nut is turned on the contact carrier.

Because the strand diameter of the rubber-elastic ring is larger than the gap width in the relaxed state, there is always a significant radial compression of the rubber-elastic ring when the projections on the contact carrier and union nut pass each other in the circumferential direction of rotation. The forces used to compress the rubber-elastic ring are approximately proportional to the forces that secure the union nut in place. In addition, the circumferential friction forces between the contact carrier and the rubber-elastic ring and/or between this and the union nut also act to prevent loosening.

As far as the screw connection is concerned, the invention guarantees absolute freedom from wear with regard to the contact carrier and union nut. The only part of the connector that is subject to wear, even if only slightly, is the rubber-elastic ring, which, however,

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can be easily renewed at any time, should the need actually arise.

In connection with a further feature of the invention, which consists in the fact that the gap width of the gap between projection-free peripheral sections of the contact carrier and the projections of the union nut essentially corresponds approximately to the strand diameter of the rubber-elastic ring in the relaxed state, areas arise in which no significant radial or circumferential forces occur in the screw system, so that the rubber-elastic ring is protected to the maximum.

Further advantageous embodiments and expedient developments of the subject matter of the invention are characterized in the remaining subclaims. They also emerge from the following description of an embodiment shown in the drawings. They show:

Fig. 1 a plug connector with a union nut mounted on its contact carrier in view and partial longitudinal section,

Fig. 2 a cross-section according to the section line ll-lll in a first locking position of the union nut,

Fig. 3 a corresponding representation in a different locking position rotated by 45°,

Fig. 4 is a cross-section through the contact carrier alone along the line ll-lll in Fig. 1, and

Fig. 5 is a cross-section through the union nut only, also following the section line ll-lll.

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A connector, designated as a whole with 10, comprises a connector body 11, into which an electrical cable 12 leads at the rear. The connector body 11, which is designed as a so-called handle body overmold, encloses a contact carrier 13, which is also made of insulating material and contains a number of plug contacts 14 corresponding to the number of poles of the connector 10. Finally, the connector 10 also comprises a union nut 15.

The union nut 15, which is arranged to be slightly axially displaceable, rests with its inner surface 16 on the outer collar surface 17 of an annular collar 18 formed on the contact carrier 13. On the side of the annular collar 18 facing away from the plug connection side, the contact carrier 13 has a circumferential groove 19 into which a rubber-elastic ring, namely an O-ring 20, is inserted. This O-ring 20 is opposite an inwardly drawn-in collar 21 of the union nut 15 on the outside.

The cross-sectional shape of the circumferential groove 19 of the contact carrier 13, which can be seen in Figs. 2 and 3, is not circular, but rather it has at least one projection 22. In the example shown, the cross-section of the groove 19 is essentially square, with four projections 22 being formed from the corners 23 of this square.

The union nut 15, or its inner circumferential collar 21, also has a number of projections 24 arranged at regular circumferential intervals. Since there are twice as many projections 24 on the union nut 15 as there are projections 22 on the contact carrier 13, this results in the wave-shaped circumferential profile of the inner contour 25 of the collar 21 of the union nut 15, as can be seen in particular in Fig. 5.

In principle, the number of projections depends on the desired fineness of the "locking" on the one hand, and on the other hand, the number

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The larger the diameter on which they are arranged, the larger they can be made.

It is important for the invention that the diameter of the groove 19 in the region of the at least one projection 22 on the contact carrier 13, which diameter is designated by d in Fig. 4, is smaller than the diameter designated by Di in Fig. 5 in the region of at least one projection 24 on the union nut 15.

In this way, an annular gap of the gap width Si=(D1-d)/2 is created between the union nut 15 and the contact carrier between two projections 22 and 24 directly opposite one another. This gap width Si is at least slightly smaller than the strand diameter 26 of the rubber-elastic O-ring 20 in its relaxed state.

"Relaxed state" means, with respect to the O-ring 20, its state as it exists when the O-ring 20 is received in the groove 19 of the contact carrier 13, but no significant external forces from the union nut 15 act on it.

If no projection 22 of the contact carrier 13 is located directly opposite a projection 24 of the union nut 15, i.e. in one of the positions according to Fig. 2 or Fig. 3, the gap width S2 between a projection 22 of the contact carrier 13 and a non-projecting circumferential section of the union nut 15 is essentially equal to the strand diameter 26. In these assignments according to Figs. 2 and 3 of union nut 15 and contact carrier 13, as can easily be seen from these figures, a locking mechanism takes place. This locking mechanism can be overcome by turning the union nut 15 relative to the contact carrier 13 when the union nut is moved from a first locking mechanism (Fig. 2) to the next locking mechanism (Fig. 3).

At this point it should be noted that Fig. 2 and 3 show the union nut as a fixed reference body, so that here

Karl Lumberg GmbH

the contact carrier 13 of Fig. 2 appears to have been rotated one notch further in Fig. 3.

In the intermediate position between two such locking positions, a projection 24 of the union nut 15 is located on each projection 22 of the contact carrier 13. Since the gap width Si = (DI-d) / 2 is then smaller than the gap width S ₂ = (D2-d) / 2, a radial compression of the O-ring 20 takes place. The forces resulting from this do not hinder the turning of the union nut 15 by hand; it is perceived as relatively soft and pleasant. Nevertheless, the compression of the O-ring builds up forces which definitely prevent the union nut 15 from coming loose by turning back, even under the influence of considerable vibrations during operation. In addition to the compression forces which act essentially radially on the O-ring, there are also circumferential friction forces which can have different effects depending on the design and the existing tolerances between the O-ring 20 and the contact carrier 13 and/or between the O-ring 20 and the union nut 15.

Since the gap between the union nut 15 and the contact carrier 13 is lined with the O-ring, the union nut 15 and the contact carrier 13 do not touch in this area. These two parts of the connector 10 cannot therefore wear out. Only the O-ring 20 can do this, but it can be easily replaced at any time without any problems.

The entire design is also very simple in other respects. The contact carrier 13, usually an injection-molded part, can be given the non-circular groove 19 during its manufacture, whereas the wavy contour 25 can be incorporated into the collar 21 of the union nut 15, which is made of high-quality metal, during machining or pressing.

Claims (9)

1. Electrical plug connector ( 10 ), in particular for proximity switches, with a union nut ( 15 ) rotatably mounted on a contact carrier ( 13 ) for screwing to a plug counterpart, wherein the union nut ( 15 ) and the contact carrier ( 13 ) are assigned a substantially snap-fit securing device for vibration-proof attachment to one another and the securing device comprises at least one radial projection ( 22 ) on the circumference of the contact carrier ( 13 ) and a corresponding radial projection ( 24 ) on the union nut, characterized in that a gap is formed between these radial projections ( 22 , 24 ), which is lined by a rubber-elastic ring ( 20 ), the strand diameter ( 26 ) of which in the relaxed state is larger than the gap width (S ₁ ) of the gap. 2. Connector according to claim 1, characterized in that the gap width (S ₂ ) of the annular gap between projection-free peripheral sections of the union nut and the projections ( 22 ) of the contact carrier substantially corresponds approximately to the strand diameter ( 26 ) of the rubber-elastic ring ( 20 ) in the relaxed state. 3. Connector according to claim 1 or 2, characterized in that the rubber-elastic ring is an O-ring ( 20 ). 4. Connector according to one of claims 1 to 3, characterized in that the rubber-elastic ring ( 20 ) is received in a circumferential groove ( 19 ) of the contact carrier ( 13 ) which contains the at least one radial projection ( 22 ). 5. Connector according to claims 1 to 4, characterized by a plurality of projections ( 22 ; 24 ) arranged regularly distributed over an outer circumference of the contact carrier ( 13 ) and an inner circumference of the union nut ( 15 ). 6. Connector according to claim 5, characterized in that the number of projections ( 24 ) on the inner circumference of the union nut ( 15 ) is greater than the number of projections ( 22 ) on the contact carrier ( 13 ). 7. Connector according to claim 6, characterized in that the number of projections ( 24 ) on the inner circumference of the union nut ( 15 ) is at least twice as large as the number of projections ( 22 ) on the contact carrier ( 13 ). 8. Connector according to one of the preceding claims, characterized in that - in view of the cross section of the contact carrier ( 13 ) - the groove ( 19 ) has the shape of a preferably regular polygon, the corners ( 23 ) of which form the radial projections ( 22 ). 9. Connector according to claim 8, characterized in that the polygon is a square.