The invention relates to a locking strap for a plug-and- socket device according to the preamble of Claim 1 or 4, respectively, and a connector according to claim 12.

From DE 30 07 978 C2 a locking strap for a plug-and-socket device is known which comprises a leg with a recess, with the recess comprising a mouth and a closed end and being adapted to accommodate a section of a journal of the plug-and-socket device, and which is provided with a securing component which is attachable to the leg and which comprises a blocking sec¬ tion. The blocking section of the securing component extends between the journal and the mouth of the recess in a trans¬ verse direction over the recess thereby completely blocking same. The securing component is adapted for attachment to the leg only after sliding the leg with its recess onto the journal .

A locking strap of this type is also known from EP 0 405 168 Al . There, a securing component in the form of a detent spring is provided which is firmly connected with a leg of the locking strap during its manufacture. The securing com¬ ponent is inserted at one end into holders and at the other end is provided with a -shaped spring fork which is capable of encompassing a journal of a mounting housing, which serves as a pivot axis.

From DE 26 32 338 C2 a housing half cover for multipole elec¬ trical connectors is known. This connector has a U-shaped closing strap the two legs of which comprise an overlapping part each which can slide over journals at the housing. Opposite each journal an elongated hole is formed which con¬ stitutes the centre of rotation of the U-shaped closing strap. In order to hold the U-shaped closing strap so as to

be rotatable about the respective journal, a V-shaped bent wire spring s pivotably attached at the inner side of each lateral part. For this purpose, the attachment point at the lateral part of the U-shaped closing strap is provided with a punched sheet metal lug which penetrates the eye bent at each wire spring and is riveted to same m a tubular rivet fashion.

From DE 29 14 929 C2 a similar locking device for electrical connectors is known, wherein wire springs are provided with a hook-shaped end and hooked into a closing strap, with the other end contacting the journal under spring tension. With this arrangement it is no longer necessary to attach the wire spring at the closing strap, e.g. by riveting.

Several problems exist with locking straps according to the state of the art. In some cases, they are permanently assem¬ bled at the plug-and-socket device so that it is impossible to replace them or alternatively to attach them to one of the two housings (plug or socket housing) of the plug-and-socket device. Replaceable locking straps as they are known, e.g. from the already mentioned EP 0 405 168 Al, sometimes fail to reliably hold the locking strap at the plug-and-socket de¬ vice. Moreover, their manufacture is often expensive because, for example, they have an intricate shape, consist of high- gauge and therefore hard-to-work spring wire, or must be fastened in an expensive way at the leg of the locking strap.

The invention is based on the object to provide a locking strap which can be manufactured economically, can be readily attached and replaced at a plug-and-socket device and which is secured reliably at the plug-and-socket device.

According to the invention, this object is solved by a lock¬ ing strap with the characteristics of Claim 1 or 4, respect¬ ively.

The aspect of the invention as described in Claim 1 is based on the basic idea that a reliable attachment of the locking strap at the plug-and-socket device is possible if a securing component is employed which is not fitted to the locking strap already during the manufacture but is pushed onto the locking strap only after the latter has been attached to the plug-and-socket device. A securing component can then be in¬ serted which reliably blocks the journal m a recess or a cutout of a leg of the locking strap. In this context, the term "blocking" means that the recess of the leg is complete¬ ly secured against a penetration of the journal, irrespective of whether the journal is to be pushed into the recess or to be removed from same.

In the configuration according to the invention of the lock¬ ing strap the securing component need not comprise a snap or detent function for the journal of the plug-and-socket device as is the case, for example, with the spring fork according to EP 0 405 168 Al . Accordingly, there is no risk that the locking strap detaches itself (e.g. during shipment) un¬ intentionally from the plug-and-socket device. Moreover, an essentially rigid securing component can be manufactured in a particularly economical way, for example, as a plastic injec¬ tion moulded part.

The securing component is preferably attachable to the leg of the locking strap m an engaging manner (e.g. to be clipped on) as well as removable so that the locking strap can be replaced. The securing component can be reusable several times or be designed as a one-way component which must be destroyed in order to remove the locking strap.

The securing component which is preferably made from plastic material is preferably disk-shaped and comprises a hole for a section of the journal. Thus the securing component need not exclusively have a blocking function but can also serve as a bearing for the journal. In this case, the recess in the leg of the locking strap may have relatively great dimensional tolerances. This facilitates the machining of the leg which is normally made of metal. The securing component which is preferably made of plastic material can, for example, be manufactured by the injection moulding process, thus inher¬ ently giving it sufficiently small tolerances for accommod¬ ating the journal with the desired friction.

Another aspect of the invention according to Claim 4 is based on the basic idea that the manufacture of the securing compo¬ nent and its assembly at the locking strap are simplified if the securing component is not only fastened on one side but on both sides of the recess at the leg of the locking strap. Fastening "on both sides" of the recess in this context means a fastening at the right-hand and left-hand side of the re¬ cess, based on an orientation of the leg as shown in Fig. 7.

In this configuration according to the invention the securing component need not be located exactly. Rather, it may be sufficient to hook the securing component relatively loosely into two eye-shaped end sections. This simplifies the assemb¬ ly. Due to the two-sided mounting the securing component need not be dimensioned so as to be particularly strong, thus enabling it to be manufactured economically even from metal. In addition, the securing component (e.g. contrary to the W- shaped spring fork known from EP 0 405 168 Al) needs only relatively few and no "sharp" bends.

The securing component which is formed as a metal detent spring preferably comprises a spring section which extends

transversely to the recess, i.e. a section which is arranged approximately horizontally in the orientation of the leg as shown in Fig. 7. This spring section causes a contacting sec¬ tion which is in contact with the journal to be resilient m the direction of the recess. The journal is then elastically held m the recess, while the contacting section must be arranged at a distance from the closed end of the recess.

Preferably, the locking strap is intended for the attachment to plug-and-socket devices which consist of two cooperating housings. One of these housings can be a mounting housing. Preferably, identical journals are provided at both housings, each of which optionally serving as a bearing for the locking strap or as a detent component which engages a detent opening or recess of the locking strap for locking the housings to one another. In this configuration, it is possible to attach the locking strap optionally to one of the two housings.

In the following, two embodiments of the invention will be described in more detail with reference to the schematic drawings m which:

Fig. 1 shows a front view of a mounting housing with an assembled locking strap m a first embodiment;

Fig. 2 shows a front view of the leg of the locking strap illustrated m Fig. 2 in the unassembled condition;

Fig. 3 shows an enlarged front view of the securing com¬ ponent illustrated in Fig. 1;

Fig. 4 shows the Section A-A in Fig. 3;

Fig. 5 shows a side view of the mounting housing illustrated in Fig. 1 with the assembled locking strap;

Fig. 6 shows a side view of the mounting housing with an assembled locking strap in a second embodiment of the invention;

Fig. 7 shows a front view of the mounting housing illustrat¬ ed in Fig. 6, at which two locking straps according to the second embodiment of the invention are attach¬ ed; and

Fig. 8 shows a detailed view of a securing component illus¬ trated in Fig. 7.

The mounting housing 10 shown m Fig. 1 of the connector for the locking strap according to the invention comprises a lower flange 12 and can be screwed onto a base 16 via fasten¬ ing holes 14 provided in the flange 12. At the side of the mounting housing 10, which is opposite the flange 12 a rubber gasket 18 is provided. A plug-in housing (not shown) can be attached onto the mounting housing 10 and is sealed by the rubber gasket 18.

The mounting housing 10 comprises a journal 20 which has a mushroom-shaped form with a thinner neck 22 (Fig. 5) and a thicker, cylindrical head 24 (Fig. 5) .

A securing component 30 which consists of plastic material and which is shown m more detail in Figs. 3 and 4 comprises a disk 32 with a blocking section 34 and a central hole 36. The diameter of the central hole 36 approximately corresponds to the outer diameter of the head 24 (Fig. 5) of the journal 20. Two curved walls which project vertically with respect to the disk 32 are formed as detent hooks 38. The securing component 30 can be colour-coded.

The locking strap 40 comprises a handle part 70 which in Fig. 1 extends vertically to the drawing plane away from the viewer, at the ends of which one leg 50 each is arranged at right angles to the handle part 70. In order to securely hold the plug-in housing (not shown) at the mounting housing 10 the leg 50 is provided with an overlapping part 52, a nose 54 and a detent opening 56. A detent component (not shown) of the plug-in housing (not shown) can be brought into engage¬ ment with the latter.

The leg 50 additionally comprises a recess 60 with an open mouth 62 and a closed end 64. The recess 60 has the shape of an elongated hole and, in the embodiment shown in Fig. 2, is curved approximately to the shape of a quarter circle. It has a uniform internal diameter which approximately corresponds to the outer diameter of the neck 22 (Fig. 5) .

The closed end 64 of the recess 60 has a semi-circular shape and a diameter which is approximately identical to the outer diameter of the neck 22 so that the end 64 partially serves as a bearing for the journal 20. Near the end 64 and on both sides of the recess 60 two circular arc-shaped detent open¬ ings 66 are arranged into which the detent hooks 38 of the securing component 30 engage.

Fig. 5 shows the locking strap 40 and the two legs 50 which are arranged on one end each of the handle part 70. The legs 50 are arranged at a distance and approximately parallel to each other and engage one journal 20 each on one side each of the mounting housing 10. The recess 60 of each leg 50 en¬ compasses the neck 22 of the associated journal, while the head 24 of said journal 20 is arranged in the hole 36 of the associated securing component 30. The disk 32 of the securing component 30 is in contact with one side of the leg 50, and the detent hooks 38 extend through the detent openings 66 to

the other side of the leg 50 where they engage behind the detent openings 66.

In order to attach the locking strap 40 to the mounting hous¬ ing 10, the legs 50 are first pushed onto the journals 20 via their recesses 60, with the recesses 60 serving as link guides. Only then, the securing components 30 which are form¬ ed as plastic clips are attached onto the legs 50. The block¬ ing sections 34 of the securing components 30 block the re¬ cesses 60 so that the locking strap cannot detach itself from the mounting housing 10. In addition, the holes 36 in the se¬ curing components 30 serve as bearings for the heads 24 of the journals 20. The plastic material of the securing com¬ ponents 30 is in intimate contact with the journals 20 and provides a sufficient friction with the circumferential sur¬ face of the heads 24 so that the locking strap can be moved easily and neither fits too loosely nor too tightly.

The plug-in housing (not shown) can be locked after its placement on the mounting housing 10 by pivoting the locking strap 40 (Fig.l) upwards. Thereby, a detent component (not shown) of the plug-in housing (not shown) initially contacts the overlapping part 52 of the leg 50, then overcomes the snap point formed by the nose 54, and finally engages the de¬ tent opening 56. Due to the curved surface of the overlapping part 52 the plug-in housing (not shown) is pulled towards the mounting housing 10 during the upwards pivoting movement of the locking strap 40. The elastic effect of the rubber gasket 18 provides for a firm seat of the locking strap 40 in its engaged position.

In order to disassemble the locking strap 40 the securing component 30 is removed first. The locking strap 40 can only then be removed from the mounting housing 10.

According to the second embodiment of the invention shown in Figs. 6 to 8, the recess 60 in the leg 50 of the locking strap 40 is formed as a straight elongated hole which at its mouth 62 is expanded approximately at right angles. An area of the recess 60 which is terminated by the end 64 is corres¬ pondingly shaped as a slot with a uniform inner diameter and serves as a guide for the neck 22 of the journal 20. On both sides (in Fig. 7 on the right-hand and left-hand side) of the recess 60 the leg 50 comprises one fastening pin each 80 and 82, respectively.

In this second embodiment the securing component 30 shown in Fig. 8 is formed as a detent spring which, for example, can be bent from spring wire with a circular cross-section. The securing component 30 comprises an eye-shaped bent end sec¬ tion 90 which is followed in the orientation of Fig. 7 by an approximately horizontal or slightly declining spring section 92. In the continuation of the spring section 92, a curved detent section 94 forms a detent nose which partially pro¬ trudes into the recess 60. A section 96 which is bent to a quarter circle encompasses approx. 90° of the neck 22 of the journal 20 and changes into a straight declining contacting section 98. The latter is followed by an approximately ver¬ tically upwards extending section 100 which in turn is fol¬ lowed by an eye-shaped bent end section 102.

The securing component 30 is attached with its two end sec¬ tions 90 and 102, respectively, at the fastening pins 80 and 82, respectively, of the leg 50, which are designed as rivets.

With the locking strap 40 attached to the mounting housing 10, as shown in Fig. 7, the journal 20 contacts the contact¬ ing section 98 with its lower side, is laterally encompassed by the curved section 96 and is retained in the recess 60

from above by the detent section 94. Upon placing and locking the plug-in housing (not shown) onto the mounting housing 10, the leg 70 is pulled upwards in Fig. 7. Since the journal 20 does not contact the closed end 64 of the recess 60 but the contacting section 98, an upward movement of the leg 50 is possible, whereby it is primarily the spring section 92 of the securing component 30, which extends transversely to the recess 60, which exerts a spring action.

The spring force of the securing component 30 is selected in such a manner that, firstly, the locking strap 40 is held re¬ liably (through the action of the detent nose formed by the detent section 94) at the journal 20; secondly, that it can be removed and relaced without the aid of tools and, thirdly, the above-described spring action is sufficient to provide for a safe locking of the plug-in housing (not shown) on the mounting housing 10. Due to the two-sided support of the securing component 30 at the fastening pins 80 and 82, therefore no excessively strong detent spring is for this purpose.

It can finally seen from Fig. 7 that two (or more) locking straps 40 may be provided at a single plug-and-socket device.

The two illustrated embodiments of the invention can be com¬ bined. In particular, each of the two configurations of the recess may be employed with each of the two configurations of the securing component 30. A locking strap according to the invention may also comprise both securing components shown or one securing component which comprises the characteristics of the two independent claims.

The invention also relates to a connector which comprises one of the two locking straps.