Patent Publication Number: US-6663421-B1

Title: Igniter shorting contact

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical connectors and, more particularly, to a shorting contact used in an electrical connector. 
     2. Brief Description of Prior Developments 
     It is known to protect a vehicle occupant by inflating an air bag with inflation fluid from an air bag inflator. The inflation fluid is released from a container in the inflator and/or generated by ignition of combustible gas generating material in the inflator. 
     The inflator may use an electrically actuatable initiator to open the container and/or to ignite the gas generating material. A typical initiator has two terminals. The terminals are in electrical contact with an electrical connector which is part of vehicle electric circuitry. To actuate the inflator, the vehicle electric circuitry sends an electric signal through the electrical connector and the terminals to the initiator. The electric signal actuates the initiator, resulting in actuation of the inflator. 
     U.S. Pat. No. 5,733,135 describes an inflator having an initiator that includes a metal retainer onto which a shorting clip is crimped. Prior to connection of an electrical connector with terminals of the initiator, the shorting clip has electrically conductive portions connected between the terminals to prevent accidental actuation of the initiator. The shorting clip has an opening to receive the electrical connector when the inflator is connected with vehicle electric circuitry. The shorting clip physically maintains the electrical connector in electrical contact with the terminals of the initiator. 
     There is a need for an initiator to dissipate static electricity. Dissipating static electricity prevents the initiator from accidentally discharging because of static electricity. In the past, one solution for preventing static electricity from accidentally discharging the initiator was to dissipating static electricity by making the housing partially conductive. An electrically conductive carbon filler was added to plastic of the initiator housing. However, the housing still needs to be electrically insulating in order to housing the electrical terminals of the initiator. A disadvantage with this type of solution was that it resulted in a relatively expensive manufacturing process. 
     Another solution used in the past it dissipate static electricity was the use of an electrically conductive ring which was used to connect a shorting contact to the outer metal can. However, this increased the cost of manufacture because of the assembly process and cost of an addition piece for the initiator. 
     There is a need to provide an initiator which can dissipate static electricity, but which is less expensive to manufacture than a plastic housing having electrically conductive carbon filler. There is also a need to provide an initiator which can dissipate static electricity, but which is less expensive to manufacture than an initiator having an additional metal ring connecting the shorting contact to the outer metal can. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, an igniter shorting contact for an igniter connector is provided including a base, at least one deflectable contact arm, and a contact leg. The base is adapted to be mounted to an insulating housing member of a housing of the igniter connector. The deflectable contact arm(s) extending from the base and are adapted to contact electrical terminals of the igniter connector. The contact leg extends from the base. The contact leg is adapted to extend radially outward on the insulating housing and contact an outer electrically conductive housing member. 
     In accordance with another aspect of the present invention, a gas generator igniter connector is provided comprising a housing having an inner electrically insulating member and an outer electrically conductive member; electrical terminals mounted to the insulating member; and a shorting contact connected to the housing. The shorting contact comprises a first deflectable contact section adapted to contact the electrical terminals and a second contact section directly electrically connected to the outer electrically conductive member of the housing. The shorting contact directly connects the terminals to each other and to the outer electrically conductive member. 
     In accordance with one method of the present invention, a method of assembling a gas generator igniter connector is provided comprising steps of inserting a shorting contact into an insulating housing member of the connector; contacting electrical terminals of the connector with first deflectable contact sections of the shorting contact; and contacting an electrically conductive housing member of the connector with a second contact section of the shorting contact, wherein the shorting contact electrically connects the terminals to each other and to the electrically conductive housing member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects and other features of the present invention are explained in the following description, taken in connection with the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a gas generator igniter having a connector incorporating features of the present invention; 
     FIG. 2 is an exploded perspective view of the gas generator igniter connector shown in FIG. 1; 
     FIG. 3 is a cross sectional view of the igniter shorting contact of the connector shown in FIG. 2; 
     FIG. 4 is a rear side elevational view of the igniter shorting contact shown in FIG. 3; 
     FIG. 5 is a partial cross sectional view of the igniter shorting contact shown in FIG. 3 shown mounted to the housing of the connector; 
     FIG. 6 is a rear side elevational view of another embodiment of a shorting contact; 
     FIG. 7 is a top plan view of the contact shown in FIG. 6; and 
     FIG. 8 is a side elevational view of the contact shown in FIG.  6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, there is shown a perspective view of a gas generator igniter  10  (also referred to as a molded initiator assembly) incorporating features of the present invention. Although the present invention will be described with reference to the exemplary embodiments shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used. 
     The igniter  10  is preferably for use with a micro-gas generator (MGG). However, the igniter could be used with any suitable device. The igniter  10  generally comprises an electrical connector  12 , an outer housing or can  14 , and an initiator or ignition material  16 . The ignition material  16  is contained within the outer housing  14 . The outer housing  14  is mechanically wrapped around an annular outer ring of the connector  12 . The electrical connector  12  generally comprises an inner housing member  18 , electrical terminals  20  and a shorting contact  22 . 
     The inner housing member  18  is preferably comprised of a molded plastic or polymer material. The inner housing member  18  preferably also functions as a retainer; the retainer feature being molded into the inner housing member. In a preferred embodiment, the inner housing member  18  does not comprise an electrically conductive filler, such as a carbon filler. Instead, the inner housing member  18  can be comprised of merely dielectric material. 
     The inner housing member  18  generally comprises the annular outer ring  24 , a mating connector receiving area  26 , and a shorting contact receiving areas  28 . The rear end of the inner housing member  18  includes apertures  46  (see FIG. 5) for mounting the electrical terminals  22  therein. The front end of the electrical terminals  22  extend into the mating connector receiving area  26 . The annular outer ring  24  forms a ledge  30  facing the front side of the inner housing member  18 . The mating connector receiving area  26  is sized and shaped to receive a portion of a mating electrical connector (not shown) and allow contacts of the mating connector to make electrical connection with the electrical terminals  20 . 
     The shorting contact receiving area  28  is sized and shaped to receive the shorting contact  22  and allow portions of the shorting contact  22  to extend into the mating connector receiving area  26  and onto the ledge  30 . Referring also to FIGS. 3-5, the shorting contact  22  generally comprises a base section  32 , a first contact section  34  and a second contact section  36 . The shorting contact  22  is preferably comprised of sheet metal which has been stamped and formed into the shape shown. Portions of the shorting contact may be plated with suitable plating material. 
     The base section  32  is sized and shaped to fixedly attach the shorting contact  22  to the inner housing member  18 . In the embodiment shown, the base section  32  is substantially flat except for a mounting section  38 . The mounting section  38  comprises a deflectable tab. As seen with reference to FIG. 5, the shorting contact receiving area  28  comprises a snap lock ledge  40  therein. When the base section  32  is inserted into the shorting contact receiving area  28  the mounting section  38  is adapted to deflect and snap lock mount behind the snap lock ledge  40 . However, in alternate embodiments, any suitable type of system for mounting the shorting contact to the inner housing member could be provided. For example, the base section could comprise lateral mounting barbs for piercing into the inner housing member. 
     The first contact section  34  comprises two cantilevered deflectable arms  42 . However, in alternate embodiments, the first contact section  34  could comprise more or less than two cantilevered deflectable arms. The two arms  42  are substantially identical to each other. However, in alternate embodiments, the arms could comprise different shapes and/or sizes. The arms  42  extend upward from a top side of the base section  32  and are bent towards a downward direction. Bottom ends  44  of the arms  42  extend in an inward direction when mounted to the inner housing member  18 . End tips of the bottom ends  44  are adapted to contact the electrical terminals  20 . Thus, the shorting contact  22  is adapted to electrically connect the two electrical terminals  20  to each other. The cantilevered arms  42  are resiliently deflectable away from the electrical terminals  20  when the mating electrical connector (not shown) is inserted into the mating connector receiving area  26 . 
     The second contact section  36  comprises a contact leg which extends from the base section  32  in a general opposite direction relative to the first contact section  34 . The second contact section  36  extends from the top side of the base section  32  and is bent in a downward direction. An end  48  of the second contact section  36  is bent to extend in a really outward direction. Thus, the contact leg has a general L shape. The end  48  is located adjacent the ledge  30  of the inner housing member  18 . The second contact section  36  wraps around a portion  50  of the inner housing member  18 . The housing portion  50  provides structural support and positioning support for the second contact section  36 . 
     Gas generators, such as for vehicle safety air bags, are generally well known in the art. These well known gas generators comprise members such as the outer housing  14 , an electrical connector having the pin contacts  20  and a shorting contact, and the ignition material  16 . The present invention is directed to a new type of electrical connector for a gas generator. As shown best in FIG. 5, when the outer housing  14  is connected to the connector  12 , a front end of the outer housing  14  is wrapped in front of the ledge  30  and sandwiches the end  48  of the second contact section  36  against the ledge  30 . This connection provides two functions. First, the connection provides a mechanical connection of the shorting contact with the inner housing member  18  and the outer housing member  14 . Second, the connection provides an electrical connection between the outer housing member  14  and the shorting contact  22 . Thus, the shorting contact  22  electrically connects the electrical terminals  22  to each other and to the outer housing member  14 . In alternate embodiments, additional or alternative systems for connecting the second contact section to the outer housing member could be provided. 
     Because the inner housing member  18  is preferably comprised of merely dielectric material, the inner housing member  18  can be manufactured at a less-expensive cost than a conventional inner housing member with an electrically conductive filler material to dissipate static electricity. With the present invention, static electricity can be dissipated by the electrical connection of the shorting contact  22  with the outer housing member  14 . Thus, providing the inner housing member with an electrically conductive filler material is no longer necessary to prevent static electricity buildup. The inner housing member can be manufactured less expensively than the prior art inner housing member having electrically conductive material and, thus, the gas generator igniter of the present invention can be manufactured less expensively than the conventional part gas generator igniter, but still provide the same static electricity dissipation feature. 
     The present invention can provide relatively easy assembly because the second contact section  36  is merely captured between the front end of the can  14  and the inner housing member  18 . No extra assembly step is required. The molded initiator assembly or igniter  10  is more compact than a conventional igniter when fit into an initiator head. The molded initiator assembly  10  provides an assembly having three components all assembled into one unit; the retainer molded into the initiator head, the shorting clip, and the initiator. Thus, the present invention can be provided as a single unit rather than three separate pieces which need to be assembled latter on. The present invention can be manufactured less expensively than the prior art initiator which had an additional metal ring connecting the shorting contact to the outer metal can. 
     In alternate embodiments, the second contact section  36  could comprise any suitable size and shape. In addition, the second contact section  36  could comprise more than one cantilevered leg. Any suitable type of mechanical connection between the shorting contact and the inner housing member could be provided. Any suitable shape or size of first contact section could also be provided. Features of the present invention could be used in any suitable type of gas generator igniter. In addition, the shorting contact of the present invention could be used in any suitable type of electrical connector. 
     Referring now also to FIGS. 6-8, an alternate embodiment of a shorting contact is shown. In this embodiment the shorting contact  60  generally comprises a base section  62  and a first contact section  64 . The shorting contact  60  is preferably comprised of sheet metal which has been stamped and formed into the shape shown. Portions of the shorting contact may be plated with suitable plating material. 
     In this embodiment the shorting contact  60  does not comprise a second contact section  36 . However, it could be provided as illustrated in FIG.  8 . In the embodiment shown, the base section  62  is substantially flat except for a mounting section  68 . The mounting section  68  comprises a deflectable tab. As noted above, the shorting contact receiving area  28  comprises a snap lock ledge  40  therein (see FIG.  5 ). When the base section  62  is inserted into the shorting contact receiving area  28  the mounting section  68  is adapted to deflect and snap lock mount behind the snap lock ledge  40 . However, in alternate embodiments, any suitable type of system for mounting the shorting contact to the inner housing member could be provided. The outer housing  14  could comprise a tab for contacting the shorting contact  60 . 
     The first contact section  64  comprises two cantilevered deflectable arms  72 . However, in alternate embodiments, the first contact section  64  could comprise more or less than two cantilevered deflectable arms. The two arms  72  are substantially identical to each other. However, in alternate embodiments, the arms could comprise different shapes and/or sizes. The arms  72  extend upward from a top side of the base section  62  and are bent towards a downward direction. Bottom ends  74  of the arms  72  extend in an inward direction when mounted to the inner housing member  18 . End tips of the bottom ends  74  are adapted to contact the electrical terminals  20 . Thus, the shorting contact  60  is adapted to electrically connect the two electrical terminals  20  to each other. The cantilevered arms  72  are resiliently deflectable away from the electrical terminals  20  when the mating electrical connector (not shown) is inserted into the mating connector receiving area  26 . 
     The mounting section  68  is formed by a slot aperture  76  through the base section  62  and a semi-dome shaped projection  78  at the bottom of the slot  76 . The top surface  80  of the semi-dome shaped projection  78  forms a latching surface for latching with the housing. However, the semi-dome shaped projection  78  can still resiliently deflect inward when being mounted to the inner housing member  18 . The semi-dome shaped projection  78  provides more surface area for latching with the inner housing member  18  and provides a ramp shaped bottom surface for easier mounting with the inner housing member  18 . 
     It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.