Scoop-proof plug connector system

The present invention relates to a scoop-proof connector assembly according to the precharacterizing clause of Patent Claim 1.

Such connector assemblies are used in automobile technology, for example, in order to produce an electrical connection on which high demands are to be made. On the one hand, this concerns the reliability with which such a connection needs to be made, and, on the other hand, it relates to protecting against incorrect handling of the plug connector system.

The document <patcit id="pcit0001" dnum="WO9741623A"><text>WO 97/41623</text></patcit> discloses a plug connector having a secondary locking mechanism and the outgoing cable at the side, said plug connector with a plug-in projection being inserted into a coupling piece which is situated in a mating connector and which has a shorting bridge and is situated in an igniter receptacle having contact pins. To effect secondary locking of the plug connector in the coupling piece, a clip is pushed in along the latching arms on the plug connector, with the result that they cannot escape from their holders made in the igniter receptacle. From <patcit id="pcit0002" dnum="EP0902506A2"><text>EP 0 902 506 A2</text></patcit> a connector with a secondary locking element is known. However, the secondary locking element is not fixed in its released position.

When such plug connectors are assembled, it is quite possible for the plug-in projection to be incorrectly oriented with respect to the coupling piece. A disadvantage of this is that, despite being incorrectly oriented, this plug-in projection can reach the contact pins on the igniter receptacle, can touch them, possibly bend them and can even break them off. To actuate the secondary locking mechanism, it is necessary to move either a blocking slide or even the secondary locking mechanism itself such that the latter can be pressed down into the plug connector. A disadvantage of this is that the fitter can release and even press down the secondary locking mechanism without the plug connector needing to be in the coupling piece or in the mating connector.

The object of the invention is to present a connector assembly which protects the contact pins on an igniter against the connector being plugged on incorrectly.

The object of the invention is achieved by the features of Patent Claim 1.

The scoop-proof connector assembly according to the invention comprises a plug connector which has a pair of contact sockets contained in the plug-in projection and a connector housing, a mating connector or receptacle which is a part of the casing of an igniter mechanism which has a pair of contact pins situated in one plane for insertion into the contact sockets and a holder, and an essentially cylindrical coupling piece which is situated in the mating connector, has a recess, which is complementary to the plug-in projection, and whose sleeve is shaped so as to be complementary to the holder. In addition, at least one guide shoulder which runs parallel to the contact pins in the coupling piece and essentially over the full height of the sleeve and which projects above the contact pins is integrally formed in the recess.

The invention affords the advantage that, when the plug connector system is assembled, the contact pins on the igniter can no longer be damaged by the plug-in projection on the connector.

Further, when the connector is inserted into the mating connector, a free end of a guide shoulder passes into a window in the connector and acts against an elastic element, with the result that the secondary locking mechanism can be transferred from a released position into a locked position. This particular design affords the advantage that the secondary locking mechanism can be pushed into the connector only if said connector is located in the mating connector or in the coupling piece. In addition, apart from the insertion operation, no additional action by the fitter is necessary in order to release the secondary locking mechanism. This effectively prevents incorrect operation of the secondary locking mechanism.

The dependent claims specify further preferred embodiments of the invention.

Preferred illustrative embodiments of the plug connector according to the invention are described in detail below with reference to the drawing, in which: <dl id="dl0001" compact="compact"><dt>Figure 1</dt><dd>shows an angled view of a connector according to the invention and of a coupling piece according to the invention;</dd><dt>Figures 2a,2b</dt><dd>show two different embodiments of a coupling piece according to the invention with guide shoulders of different lengths;</dd><dt>Figures 3a,3b</dt><dd>show a plan view of the coupling pieces from <figref idref="f0002">Figures 2a and 2b</figref> with a plug-in projection inserted, said plug-in projection being in transverse section with respect to the insertion direction;</dd><dt>Figures 4a,4b and 4c</dt><dd>show a section along the plane G, with the various insertion phases being shown; and</dd><dt>Figures 5ab,5b</dt><dd>show an angled view of the plug-in projection's connector face with the secondary locking mechanism pushed in partially and fully, respectively.</dd></dl>

The top part of <figref idref="f0001">Figure 1</figref> shows an angled view of a connector 1 having a housing 2, a plug-in projection 3 integrally formed thereon at right angles, and two tongues 4 which are likewise integrally formed at right angles to the housing 2. Integrally formed on the back 7 of the housing 2 is a cable exit 8 having two cables 9 crimped onto contact elements 10 and 11. These contact elements 10 and 11 run essentially longitudinally in the housing 2 and merge into contact sockets in the connector which have been fully accommodated in the plug-in projection 3 in appropriate compartments. Integrally formed on the bottom 15 of the housing 2 and in the housing 2 close to the front 18 of the connector 1 are two pins 16 and 17 for fixing a U-shaped elastic element 20. In addition, the front 18 of the housing 2 has, essentially in the centre, a shoulder 19 projecting into the interior of the housing. Furthermore, the connector 1 comprises a U-shaped elastic element 20 having a base, which is situated between the pins 17 and 16 and the shoulder 19 and has two limbs 21 and 22 which are integrally formed at right angles to it and are connected to one another by a cross brace 23. Above the open housing 2 and partially inserted therein is a secondary locking mechanism 5 having a base 6 and two arms 25 and 26 which are integrally formed at right angles to said base and are obstructed by the cross brace 23.

The bottom part of <figref idref="f0001">Figure 1</figref> shows an essentially cylindrical coupling piece 30 according to the invention.

The coupling piece 30 will be explained more precisely with the aid of <figref idref="f0002">Figure 2a</figref>, which shows an angled view of the coupling piece from <figref idref="f0001">Figure 1</figref> with a plug-in projection 3 positioned at an angle. The coupling piece 30 has a cylindrical sleeve 31 with a collar 32 formed outwards on the front of said coupling piece. The sleeve contains a through <b>recess</b> 34 running from the front to the back (running in the plugging direction) to hold the plug-in projection 3. Integrally formed on the edge of the <b>recess</b> 34 are two guide shoulders 35 and 36 which are opposite the opening 34 and run at least over the full height of the coupling piece in the insertion direction, as can be seen in <figref idref="f0002">Figure 2b</figref>. In the embodiment in <figref idref="f0002">Figure 2a</figref>, the guide shoulders project beyond the collar 32. A common feature of the two embodiments of the coupling piece 30 is that the guide shoulders 35 and 36 are connected to the sleeve 31 by means of a coding rib 37 and 38. Two cutouts 33 for holding the latching tongue 4 on the plug-in projection 3 are arranged diametrically opposite in the sleeve 31 at right angles to the guide ribs 35 and 36. As already mentioned, the guide ribs 35 and 36 in the first embodiment, shown in <figref idref="f0002">Figure 2a</figref>, project above the collar 32, with the outwardly pointing edges 39 and 40 of the two guide shoulders 35 and 36 being bevelled. Likewise, the coding ribs 37 and 38 project above the collar 32, but these end below the bevelled edges 39 and 40.

In contrast to this, the second embodiment, shown in <figref idref="f0002">Figure 2b</figref>, has a slight elevation 41 with respect to the collar 32. Both the guide shoulders 43 and 44 and the coding ribs 45 and 46 in the second embodiment, shown in <figref idref="f0002">Figure 2b</figref>, end flush with the elevation 41. (Both embodiments have, on each guide shoulder 35, 36, 43, 44, a guide lug 42 which runs over the full height and in the plugging direction and projects inwards essentially in the centre of the guide shoulder.) Beneath the collar 32, semicircular coding lobes 70 can be seen. The collar 32 in the second embodiment, shown in <figref idref="f0002">Figure 2b</figref>, is cut off essentially parallel to the insertion direction, so that an edge 47 is produced. The contact pins 51 and 52 project into the opening 34, these contact pins being situated in the insertion direction and in a plane which is parallel to the extension of the guide shoulders.

On each of its two opposite side faces 61 and 62, the essentially rectangular plug-in projection 3 has two essentially L-shaped arms 63a, 63b, 64a and 64b, and one limb 65a of each of the two arms is integrally formed on the side face 61 at right angles such that the other two limbs 65b point towards one another, so that the arms 63a and 63b engage around the guide shoulder 36, for example, when the connector 1 is inserted into the coupling piece 30. As <figref idref="f0003">Figures 3a and 3b</figref> clearly show, when the connector is inserted, the limbs 65b of the two arms 63a and 63b are situated between the guide shoulder 36 and the inner wall of the sleeve 31. The same also applies to the L-shaped arms 64a and 64b. The rectangular plug-in projection has two plug-in compartments running in the plugging direction for holding contact sockets 66 and 67. In addition, a respective groove 68 and 69 for holding the guide lugs 61 and 62 over the full length of the plug-in projection 3. These grooves 68 and 69 divide the plug-in projection 3 into halves of essentially the same size, each half containing precisely one of these contact sockets 66 and 67.

<figref idref="f0003">Figures 3a and 3b</figref> show a plan view of the coupling piece 30a and 30b with a plug-in projection 3 inserted which is cut open at the level of the collar 32, so that the contact sockets 66 and 67 project out of the plug-in projection. In these contact sockets, the contact pins 51 and 52 on the igniter can be seen. When the connector has been inserted, as shown here, the latching arms 4 enter the cutouts 33.

<figref idref="f0004">Figures 4a to 4c</figref> show a section along the plane G in <figref idref="f0001">Figure 1</figref>, this section likewise passing through the coupling piece 30. The section plane passes through the two opposite coding ribs 37 and 38. These <figref idref="f0004">Figures 4a to 4c</figref> will be used to explain an illustrative embodiment of the coupling piece 30a. The top half of <figref idref="f0004">Figure 4a</figref> shows the housing 2 of the connector 1. Projecting from this housing 2 is the partially inserted secondary locking mechanism 5. It should be noted that <figref idref="f0004">Figure 4a</figref> reproduces the state in <figref idref="f0001">Figure 1</figref>. As already mentioned, the bottom 15 in the housing 2 holds the elastic element 20 with wings 21 and a cross brace 23, said cross brace having a finger 85 which is integrally formed at right angles, has a bevelled end 86 and projects into a window 12 made in the bottom 15. As can be seen in <figref idref="f0004">Figure 4a</figref>, the finger 85 rests against the side wall 62. The top edge of the cross brace 23 runs below the front edge 48 of the limb 25. This means that it is not possible to press the secondary locking mechanism 5 further into the housing 2. When the connector 1 is inserted into the coupling piece 30a, see <figref idref="f0004">Figure 4b</figref>, the plug-in projection 3 enters the <b>recess</b> 34, the guide lugs 42 enter the grooves 68 and 69, and the arms 63 and 64 engage accordingly around the guide shoulders 35 and 36. The contact pins 51 and 52 enter their corresponding contact sleeves 66 and 67. During this insertion operation, the guide shoulder 35 passes into the window 12, for example, so that the angled edge 39 reaches the bevelled end of the <i>cross</i> brace 23 and pushes it to the left, with the result that the finger 85 hits the bottom 15. The top edge of the cross brace 23 then releases the front edge 48. It is now possible to press the secondary locking mechanism 5 downwards, as can be seen in <figref idref="f0004">Figure 4c</figref>, so that the limbs pass between the plug-in projection 3 and the tongues 4 to prevent the latter from springing back. At the same time, the latching hook 80 integrally formed on the side of the limb 25 arrives underneath the bottom 15 and locks the secondary locking mechanism in a locked position. When the secondary locking mechanism and the coupling piece 30a are pulled out, the spring force of the elastic element 20 pushes the cross brace 23 underneath the front edge 48 of the secondary locking mechanism again, so that said secondary locking mechanism is protected against being unintentionally pressed downwards. There is nothing to stop it being used again.

As <figref idref="f0005">Figures 5a and 5b</figref> show, the protrusion 71 integrally formed on the front edge 48 can additionally release an essentially V-shaped shorting bridge 72 during the insertion operation. The shorting bridge 72 protects the ignition capsule against unintentional triggering, but it is necessary to ensure that it is raised from at least one contact pin 51 or 52 when the connector is inserted, so that the control electronics can ignite the primer as necessary. During the insertion operation or during locking, the limbs 25 and 26 on the clip-like secondary locking mechanism engage around the plug-in projection 3. (<figref idref="f0005">Figures 5a and 5b</figref> show the contact pins 51 and 52, inserted into the compartments in the plug-in projection 3, and the shorting bridge 72 in angled plan views of the plug-in projection's connector face. In addition, the clip-like secondary locking mechanism 5 engaging around the plug-in projection can be seen. <figref idref="f0005">Figure 5a</figref> shows that the shorting bridge touches both contact pins; in contrast to this, the shorting bridge in <figref idref="f0005">Figure 5b</figref> is raised from one contact pin. An outwardly pointing clip 75 on the shorting bridge 72, which clip projects over the plug-in projection and runs transversely with respect to the insertion direction, is raised by the protrusion 71 during insertion, so that this very bridge is opened.