2. Description of the Related Art Use of airbag systems in motor vehicles has become virtually universal in recent years and is mandatory in many jurisdictions. Such systems normally include an airbag assembly mounted in a hidden compartment beneath the dashboard and an electrical or electronic control system for activating the assembly upon occurrence of a crash. The airbag assembly is generally connected to the control system by a wiring harness provided with a plug with socket contacts and a socket that receives pin contacts of the initiater.

A connector system of this type is shown, for example, in EP 0 591 947, in which the system is associated with an interlock including a locking element that is inserted into the connection to prevent separation of a pair of male connector elements carried by a first component from a pair of female connector elements carried by a second component and releasably mated therewith. A shorting element is associated with the first component and includes a pair of contact elements each biased into electrical contact with one of the pair of first connector elements for producing a short therebetween. The second component has a body comprising a portion contoured to enter between the pairs of connector elements for disconnecting the short upon mating of the first and second components, which are mechanically latched together. The locking element prevents release of the latch and hence separation of the two components while in the locked position.

U. S. Patent No. 5,435,742 shows an electrical connector position assurance system (CPA) in which one of two mating connectors includes a projection which is at a first location when the connectors are fully mated and at a second location when they are less than fully mated. The projection blocks movement of a CPA from its first to its second position when the projection is in its second location. A latch holds the connectors in mated condition when the CPA is in its second position.

SUMMARY OF THE INVENTION The invention comprises an airbag igniter plug including a housing, a removable cover which is latched onto the housing, and a secondary locking clip having secondary locking arms which are inserted into insertion grooves provided in the cover and extending from sliding grooves which permit the locking clip to slide longitudinally in a reception cavity in the cover, from a rear unlocking position to a front locking position. The locking clip comprises a resilient finger or latch arm which cooperates with a boss or ramp on the cover so as to assure that the locking clip is stably retained in the locking or unlocking position. Guide surfaces projecting from the arms of the locking clip prevent it from becoming disengaged from the cover.

In the rear unlocking position of the secondary locking clip, its secondary locking arms are positioned in grooves of the plug housing and are not in contact with the locking arms of the plug. In this position, the plug is hence free to be mated in an igniter socket, and to be unmated therefrom by pressing the ends of the plug locking arms, which may be configured as push buttons.

When the secondary locking plug is slid forwardly into its locking position, the secondary locking arms come into contact with the locking arms of the plug and prevent unmating of the plug and socket.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood, it will now be described with reference to the accompanying drawings, in which an embodiment of the invention is shown for purposes of illustration.

Figure 1 is a perspective view of the plug housing.

Figure 2 is a perspective view of the plug cover.

Figure 3 is a perspective view of the secondary locking clip according to the invention.

Figure 4 is a perspective view of the housing, cover and secondary locking clip in assembled condition.

Figure 5 is a detail section view showing the secondary locking clip in its rear unlocking position.

Figure 6 is a detail section view showing the secondary locking clip in its front locking position.

Figure 7 is a perspective view showing the interaction of an arm of secondary locking clip 3 with locking arms 5 of the plug.

DESCRIPTION OF PREFERRED EMBODIMENT As shown in Figure 1, plug body 1 has a generally rectangular shape with longitudinally extending, parallel contact receiving chambers 21 and 22. Side latches 11 are provided on both sides of the plug, and a transversely extending latching arrangement 13 is provided at the front end of the plug. Plug locking arms 5 extend downwardly on both sides of the front end, and these comprise horizontally extending locking catches 6

and horizontally extending, outwardly projecting unlocking push buttons 7 at their upper edges.

As shown in Figure 2, cover 2 has a generally rectangular shape corresponding to that of plug 1. Near the rear ends of its sides, it has downwardly extending loops 10 which engage side latches 11 of the plug body. At its front end, cover 2 has a transversely extending latch member 12 which latches underneath latching arrangement 13 of the plug body.

As shown in Figure 3, secondary locking clip 3 has two downwardly extending secondary locking arms 18 which are inserted downwardly into insertion grooves 15 in cover 2. These insertion grooves 15 are laterally widened portions of longitudinally extending sliding grooves 14 which permit front-to-rear sliding of secondary locking clip 3 along reception cavity or recess 20 in the upper surface of cover 2. The width L of secondary locking arms 18 is slightly greater than that of insertion grooves 15, to enable force-fitting of secondary locking clip 3. A resilient finger 17 provided on secondary locking clip 3 cooperates with a boss 16 on cover 2 to assure that the clip remains stable in either the locking or unlocking position, and guide rails 19, which engage underneath an overhang 23 of the lateral walls of grooves 14, prevent secondary locking clip 3 from exiting from cover 2.

In the rear unlocking position of secondary locking clip 3, arms 18 rest in grooves in the housing of plug 1 and do not engage locking arms 5 of plug 1. In this position, the plug can be mated with an igniter socket (not shown), and can be unmated therefrom by pushing in push buttons 7 projecting outwardly from the upper ends of locking arms 5.

When locking is to be effected, secondary locking clip 3 is slid forwardly in grooves 14, bringing its arms 18 into engagement with locking arms 5 of plug 1 (Figure 7), forcing them outwardly, and thereby preventing unmating of the plug from the socket.