Abstract:
In a metal/glass base or feedthrough of an ignition device for personal safety systems in motor vehicles, including a ring manufactured from a metal material, having at least one insulating body provided in a ring opening of the ring and tightly sealing said opening, and including at least one pin forming an electrical conductor and leading tightly sealed through the insulating body and electrically insulated from the ring, the ring is manufactured from a metal material by means of cold forming.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a metal/fixing-means base or socket, metal/fixing-material lead-through. 
         [0002]    A metal/fixing-means base or socket, also known as metal/fixing-material lead-through, for ignition devices for personal safety systems, namely airbags, especially those designed as metal/glass feedthroughs, are known in the art (DE 10 2005 009 644 A1, EP 1 061 325 A1). These bases consist essentially of a ring-shaped base body or ring with a ring opening sealed tightly by the fixing-means or fixing material in form of an insulating body made of glass or a glass plug and of at least one pin or lead leading through the insulating body and sealed by melting, which (pin or lead) forms an outer electrical connecting element (plug) as an electrical conductor on the outer side of the metal/glass feedthrough forming the ignition device and is connected in the interior of the ignition device with an electrical ignition element, which serves to activate the ignition device for igniting the ignition fuse containing a suitable initiator or explosive. 
         [0003]    It is an object of the invention is to present a metal/fixing-means base or socket that features a simplified manufacturing process. 
       SUMMARY OF THE INVENTION 
       [0004]    According to a first aspect of the invention, the ring or ring body of the metal/fixing-means base or socket is manufactured from a metal material, preferably of high-grade steel by cold forming from a suitable starting material. In addition to inexpensive production, the advantage of this process is that the cold forming or the high deformation pressure applied gives the ring high strength and also high density. 
         [0005]    According to another aspect of the invention, the ring or ring body is provided in the area of its at least one opening or ring opening with at least one projection protruding into said ring opening, on which (projection) a pin serving as a ground conductor or ground connector is suitably fastened. This design makes it possible to pre-mount the ring with the pin fastened on the projection during the manufacture of the metal/fixing-means base and then to use this pin as an assembly aid during assembly of the insulating body, e.g. to thread a glass bead forming said insulating body and provided with a further pin and then to heat the array thus formed to the required temperature, for example to melt the glass bead or the glass plug forming the insulating body. This process significantly simplifies the handling during the manufacture of the metal/fixing-means base. 
         [0006]    The fixing-means in the invention is at least one element made of at least one fastening material. The fastening material in the invention is an electrically insulating material, for example in the form of glass, ceramic, glass-ceramic composite or plastic. 
         [0007]    Further embodiments, advantages and possible applications of the invention are disclosed by the following description of the embodiments and the drawings. All characteristics described and/or depicted alone or in any combination are fundamentally the subject of the invention, regardless of any summarization. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The invention is described in more detail below based on an exemplary embodiment with reference to the drawings, in which: 
           [0009]      FIG. 1  is a simplified depiction in cross section of an ignition device for personal safety systems or airbags for motor vehicles; and 
           [0010]      FIG. 2  is a simplified depiction in top view of a metal/fixing-means base in the form of a metal/glass feedthrough of the device in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0011]    The ignition device generally designated  1  in the drawings and intended for airbags or similar personal safety systems, in particular in motor vehicles, includes essentially two leads or pins  2  and  3  made of an electrically conductive material or metal material, for example of nickel-iron and with suitable surface corrosion protection, for example in the form of a nickel layer,
       a metal/fixing-means socket or base in the form of a metal/glass base  4  or in the form of a hermetically sealed electric metal/glass lead-through for the pins  2  and  3 ,   a sleeve-like housing  5  enclosing an inner space of the ignition device  1 ,   an ignition fuse  6  within said inner space made of a suitable initiator or explosive that is suitable for such ignition fuses,   a cover  7 , and   an electrical ignition element  8  provided within the ignition fuse  6  and connected there with the ends of the pins  2  and  3 , for example in the form of an ignition or wire bridge or in the form of another electrical ignition element.       
 
         [0017]    The ignition device  1  is, in the known manner, part of an electrically controllable gas generator for generating a gas to activate a personal safety element (airbag). The metal/glass lead-through or metal/glass base  4  in the depicted embodiment consists of a ring body or ring  9 , which is manufactured from a metal material, preferably from a high-grade steel by means of cold forming, namely as one piece with a projection  9 . 2 , which protrudes radially from the ring wall  9 . 1  into the ring opening on the lower front side of the ring  9  facing away from the inner space of the ignition device  1 . A fixing or insulating body  10  is held in the ring  9 , through which (body) the two pins  2  and  3  lead parallel to each other and parallel to the axis of the ring  9  and therefore also parallel to the axis of the sleeve-like housing  5 , hermetically sealed and electrically insulated from each other, thus producing the ends of the pins  2  and  3  that protrude into the interior of the ignition device  1  and are connected with the ignition element  8  and the ends of the pins  2  and  3  that project out of the ignition device  1  or the metal/glass base  4  and serve as connecting plugs. The insulating body  10  is made of a suitable material for such insulating bodies and is for example embodied as a glass plug, which is connected with the ring  9  by a glass/metal melt bond and into which the pins  2  and  3  are melted. Other electrically insulating materials are also conceivable for the insulating body  10 , for example ceramics, ceramic-glass composites, plastics, for example epoxy resin, etc. 
         [0018]    The pin  2  forms the mass or ground connection and for this purpose is also electrically connected with the free end  9 . 2 . 1  of the projection  9 . 2 , for example by soldering, e.g. hard soldering, or by welding, for example resistance welding or laser welding. Further, the projection  9 . 2  also forms an additional mechanical or form-fitting support for the insulating body  10 . 
         [0019]    The metal/glass base  4  in the depicted embodiment is inserted into an end of the sleeve-like housing  5  and connected with its ring  9  with the housing  5  on this end to form a seal, namely for example by force-fitting through deformation or pressing of the housing  5  on the ring  9  or by welding, for example resistance or laser welding. Other means of connecting the metal/glass base  4  with the housing  5  are also possible. 
         [0020]    One of the distinguishing features of the ignition device  1  described above is that the ring  9  is manufactured by cold forming, which results in economical use of material and reduced manufacturing times due to significant savings in costs for the manufacture of the ignition device  1 . The use of high-grade steel materials for the ring  9  also results in sufficiently high stability of the metal/fixing-means base or for the metal/glass base  4 , especially against the insulating body  10  being inadvertently pressed out of the ring  9 . 
         [0021]    The metal materials used for the pins  2  and  3 , the metal/glass base  4  and the housing  5  can be nickel plated in a controlled production process. The projection  9 . 2  enables a simplified connection of the metal/glass base to the ground conductor, namely to the pin  2 . This simplified connection of the ground conductor especially makes it possible to use simple and identical pins  2  and  3  for both conductors. The assembly of the pins  2  and  3  and the insulating body  10 , in particular also the assembly of the glass bead(s) used for manufacturing the insulating body  10  is simplified considerably, namely by the fact that in the case of the pin  2  being pre-mounted on the projection  9 . 2 , the insulating body, e.g. the glass beads forming the insulating body  10  can be placed together with the pin  3  onto the pin  2  held on the ring  9  so that the elements forming the metal/glass base  4  are reliably held together during the further process. 
         [0022]    The connection of the pin  2  with the projection  9 . 2  can be achieved by soldering with low consumption of solder material, or it is possible as described above to connect the pin  2  with the projection  9 . 2  by welding, in which case optimum temperature can be achieved with short process times during welding due to the reduced mass in the area of the projection  9 . 2 . 
         [0023]    The invention was described above based on an exemplary embodiment. It goes without saying that modifications and variations are possible without abandoning the underlying inventive idea on which the invention is based. 
       REFERENCE LIST 
       [0000]    
       
           1  ignition device 
           2 , 3  metal pin or lead 
           4  metal/glass base or metal/glass lead-through 
           5  housing 
           6  ignition fuse 
           7  cover 
           8  electric ignition element 
           9  ring 
           9 . 1  ring wall 
           9 . 2  projection 
           9 . 2 . 1  end 
           10  insulating body