Universal squib connector

Abstract: A universal squib connector (104) for automobile driver and passenger air bag collision protection systems includes a ferrite bead (122) having two holes in spaced relation with an electric terminal (106, 108) positioned in each hole for making electrical contact with an associated one of the protruding pins (46) of a pin type electric squib. The arrangement enables the use of a single configuration of gas generator and a single configuration of electric initiator or squib for the igniter system of the gas generator while providing EMI/RFI protection and the advantages realizable from both pin type and pig tail type connection of the collision sensor to the input conductors or lead wires (110, 112) to the squib and also the electrical system of the vehicle according to the preferences of individual automobile manufacturers.

Description: The present invention relates to an electrical connector for electroexplosive ignition devices commonly known as electric initiators or squibs. Such devices may be of the bridge wire type and have particular utility in igniter devices for the actuation of collision protection systems for motor vehicle drivers and passengers. Collision protection systems for motor vehicles, popularly known as "air bag" systems, involve the use of folded bags that typically are mounted on and fastened to the steering wheel and also to the dashboard of the vehicle and are inflated substantially instantaneously by a gas generator or inflator responsively to the onset of a collision, as sensed by a collision sensor. The sensor activates the igniter device of the gas generator by closing an electrical circuit to the bridge wire of the squib through an insulating plug provided at one end of the igniter device from a source of electrical energizing current. The plug is inserted in one end of a cylindrical steel casing that forms the outer casing for the igniter device. An explosive mixture contained in the casing surrounds the bridge wire of the squib. Typically, the electrical energizing current to the squib is derived from the electrical system of the motor vehicle and is conducted by input conductors or lead wires, referred to hereinafter as "sensor input conductors," that are connected to the sensor and which pass through the insulating plug of the igniter device to the bridge wire and causes the bridge wire to heat to the point of disintegration. The explosive mixture in proximity to the bridge wire is thus heated and caused to be ignited. Such ignition is effective to initiate the ignition of a gas generating charge which is positioned in surrounding relation to the igniter device, resulting in the generation of a volume of gas sufficient to inflate an associated folded air bag. A characteristic of electric squibs is that the bridge wire is susceptible of being heated and fired by extraneous radiant energy that tends to be induced in or picked up by the sensor input conductors to the squib from nearby radiation sources. Such radiant energy which may be of electomagnetic or radio frequency origin creates a hazard. Protection against such radiant energy interference is referred to hereinafter, for convenience, as "EMI/RFI protection." A solution for overcoming this hazard proposed in the prior art involves the use of an assembly of ferrite bodies or beads internally of the squib to absorb or attenuate the extraneous energy which is induced in or picked up by the sensor input conductors to the squib, thereby preventing such energy from reaching the bridge wire, as disclosed, for example, in US-A-3,572,247 and US-A-4,306,499. In US-A-3,572,247 the sensor input conductors extend from the plug of the squib as "pig tails," as also disclosed in Fig. 2 of the drawings hereof. In the Holmes patent, which is assigned to the assignee of the present invention, electrically conducting pins protrude from the squib, to which pins the terminals of an electrical connector are made to mate. Such a "pin type" squib is also shown herein in Fig. 1 of the drawings. US-A-4,271,453 on which disclosure the preamble of independent claim 1 is based, discloses an igniter with two projecting pins to engage the terminals of a female connector by means of which an ignition signal is conveyed to a heat generator. A conductor between the heat generator and one of the pins is provided with filter means comprising a ferrite core surrounding the conductor, a pair of metal electrodes on the core, a dielectric sleeve around the electrodes and the ferrite core and another electrode around the outside of the sleeve. Another solution for overcoming the radiant energy hazard, as embodied in the "Amphenol" connector commercially available from Amphenol Tuchel Elektronix Inc., August Hauser Str. 10, Heilbrohn, Germany, comprises an assembly including a wire coil wrapped around a cylindrical ferrite body that is connected in a series circuit with one of the input conductors or lead wires to one of the connector terminals. Such assembly in the connector for EMI/RFI protection replaces that provided internally of the igniter device in the Warshall and Holmes patents and that shown in Fig. 2 of the drawings hereof, thus simplifying the manufacture of the ingiter device as well as allowing a substantial reduction in the length thereof. Individual preferences of motor vehicle manufacturers in regard to the type of connector, pig tail or pin type, to be used for connecting the sensor input conductors or lead wires of the squib to the electrical system of the vehicle has introduced undesirable complexity in the manufacture of gas generators. This is because some vehicle manufacturers prefer the pig tail connector while others prefer the pin type connector. The pin type connector is a female connector that is assembled in cooperative mating relation with the protruding pins of the squib. There are various types of such connectors that are commercially available in addition to the aforementioned Amphenol connector. The Amphenol connector is difficult to permanently attach to the base of the gas generator. It includes an extended portion arranged at a right angle to the terminal portion thereof for enabling the sensor input conductors to run parallel and in close proximity to the base of the gas generator. The pig tail connector preferred by other vehicle manufacturers, as previously mentioned, has the input conductor assembled inside the squib-in cooperative relation with the elements that provide EMI/RFI protection. In this type of connector, as illustrated in Fig. 2 of the drawings, the sensor input conductors or lead wires extend out of the plug at the end of the squib as pig tails. A disadvantage with such a pig tail connector arrangement, from the standpoint of the manufacturer of the collision protection system, is that with the sensor input conductors assembled inside the squib to provide EMI/RFI protection, undesirable extension of the length of the squib results. The extension is sufficient to necessitate substantial modification in the structure of the gas generator, particularly in the structural arrangement of the base thereof, for the elongated squib to be employed therewith, as is readily apparent from a comparison of the gas generator of Fig. 2 hereof with that of Fig. 1. It is evident, therefore, that in order to satisfy the individual preferences of the vehicle manufacturers in regard to the type of connectors to be used, the manufacturer of the collision protection system has found it necessary to provide two different configurations of squibs, two different configurations of bases for the gas generator, and two different squib assembly processes. This not only introduces undesirable complexity into the manufacture and assembly of the collision protection system but adds substantially to the cost thereof. Thus, there is a need and a demand for an improved connector for connecting the sensor input conductors to the squib and to a source of electrical current such as the electrical system of a vehicle in order to eliminate the need for such duplication of squibs, gas generator bases, and squib assembly process while providing the necessary EMI/RFI protection and satisfying the individual preferences of the vehicle manufacturers in regard to the type of connector, pig tail or pin type, to be used. The present invention consists in a universal squib connector for providing a permanent pig tail connection to a pin type electric initiator or squib comprising, connecting terminals, a bead having holes therethrough in spaced relation, each of said holes having a first end and a second end, with one of said terminals positioned in one of said holes and another of said terminals positioned in another of said holes, the spacing of said holes being such as to allow protruding pins of the pin type electric initiator or squib each to enter the first end of a respective individually associated one of said holes to make electrical contact with an individually associated one of said terminals, and a plurality of electrical input conductors for connecting an electrical circuit to the electric initiator or squib with each of said input conductors having an end positioned in the second end of an associated one of said holes in said bead and connected to the terminal positioned therein, characterised in that said bead is a ferrite bead providing EMI/RFI protection in a region surrounding said terminals. There can thus be provided a universal squib connector for vehicle driver and passenger air bag collision protection systems that enables the use of a single configuration of gas generator and a single configuration of squib for the igniter system thereof while providing the necessary and desirable EMI/RFI protection and the advantages realizable from both pin type and pig tail type connection of the collision sensor input conductors to the squib and also to the electrical system of the vehicle according to the preferences of individual vehicle manufacturers. The universal squib connector in accordance with a preferred embodiment of the invention comprises an integral connector and connector lock containing EMI/RFI protection in a region surrounding two electrical terminals that are configured and positioned to mate with the two protruding pins of a pin type electric initiator or squib. Automotive lead wires may be attached to each of the terminals by soldering or welding for transmitting electric current, which is supplied to fire the squib, with the terminals being protected from corrosion tending to result from the potential environment to which the connector may be exposed over long periods of time that may be as long as ten years or more. The two terminals are physically and electrically isolated from each other. The EMI/RFI protection that is provided is characterized in that it does not provide an electrical path between the two terminals or the two terminals and insulating material that is provided. The EMI/RFI protection is so located as to provide protection against electromagnetic interference and radio frequency interference that is extraneously induced in the terminals. The connector may be permanently secured in the proper location to the gas generator with which it is associated by suitable means which may comprise a crimp, a locking ring or a mechanical lock which spans between the connector and the socket or cavity of the generator in which the connector is mounted. There is further provided a gas generator which may be of the type disclosed in US-A- 4,943,086. Incorporated in the gas generator is a squib of the pin type wherein the pins are sealed against the environment by a glass to metal seal, and with the base of the generator having a socket or cavity into which the pins protrude and which is adapted to snugly receive and to securely retain the universal squib connector according to the invention for connecting the pins and thereby the bridge wire of the squib to sensor input conductors or automotive lead wires and thereby to a collision sensor and to an electrical energizing source such as the electrical system of the vehicle in which the collision protection system is installed. With this description of the invention, a detailed description follows with reference being made to the accompanying figures of drawings which form part of the specification, in which like parts are designated by the same reference numbers, and of which: Fig. 1 is an elevation view, in cross section, illustrating a gas generator such as that disclosed in patent 4,943,086 and incorporating a squib of the pin type; Fig. 2 is an elevation view, in cross section, illustrating a gas generator such as that disclosed in Adams et al. U. S. patent 4,561,675 and incorporating a squib of the pig tail type; Fig. 3 is an elevation view, in cross section, of an igniter system containing a squib of the pin type that may be employed in the gas generator of Fig. 1, which igniter system is commercially available from Davey Bickford Siege Social, 37, Rue Saint-Maur, 76000 Rouen, France; Fig. 4 shows a bottom view of the igniter system of Fig. 3; Fig. 5 is an elevation view, partly in section, showing the squib of Fig. 3 and an enlarged fragment of the base of the generator of Fig. 1 with the universal squib connector positioned in and securely retained in a socket in the generator base, and with pig tail conductors or lead wires extending downwardly from the connector; Fig. 6 is a top view of the universal squib connector showing the openings for receiving the mating pins of the squib of Fig. 5; Fig. 7 is an elevation view, partly in section, illustrating a modification of the universal squib connector of Fig. 5 for enabling the pig tail conductors or lead wires to extend at a right angle to the connector parallel to the bottom surface of the generator base, and incorporating locking and anti-rotation features; Fig. 8 is a top view of the connector of Fig. 6 showing an anti-rotation rib and also the openings into which the pins of the squib are received; Fig. 9 is a cross sectional elevational view of the universal squib connector modification taken along the lines 9-9 of Fig. 7; Fig. 10 is an elevation view, partly in section, illustrating a modification of the universal squib connector of Fig. 7; Fig. 11 is a top view of the universal squib connector of Fig. 10; Figs. 12, 13 and 14 are elevation, side and bottom views, respectively, illustrating a modification of the base of the squib used with the universal squib connector of Figs. 10 and 11; Fig. 15 is a fragmented elevation view, partly in section, illustrating another modification of the universal squib connector incorporating locking and anti-rotation features, positioned in and securely retained in a socket of the gas generator base, with pig tail connectors extending parallel to the bottom surface of the generator base; Figs. 16, 17 and 18 are elevation, side and bottom views, respectively, illustrating a modification of the base of the squib used with the universal squib connector of Fig. 15; Figs. 19, 20 and 21 are elevation, side and top views, respectively, of the universal squib connector of Fig. 15; Fig. 22 is a cross sectional view taken on the lines 22-22 of Fig. 19; Fig. 23 is a cross sectional view taken on the lines 23-23 of Fig. 20; and Fig. 24 is an enlarged fragmented cross sectional view of one of a plurality of axially extending elongated sharp edged projections or ribs that are provided on the exterior surface of the universal squib connector of Fig. 15 for taking up slack or tolerance in making the connector fit tightly in the socket of the gas generator. In Fig. 1 of the drawings, there is shown at 10 a gas generator which is operable when initiated to provide gas for rapidly inflating a vehicle inflatable air bag. The generator 10 has a generally cylindrical outline and includes a housing structure 12 comprising two components. These structural components comprise a lower or base component 14 and an upper component 16. Each of the components 14 and 16 may be composed of aluminum to minimize the weight of the generator. Components 14 and 16 are joined by two concentric inertia welds indicated at 18 and 20 to form the housing structure 12. Welds 18 and 20 are performed simultaneously in a single inertia welding operation. The base 14 may be formed by forging or impact extruding and includes a cylindrical wall 22 which is mated with and is inertia welded to a circular surface 24 on the upper structural component 16 at the weld 18 to define a combustion chamber 26. The upper component 16 may be formed by forging or impact extruding and includes a cylindrical wall 28 which is concentric with wall 22 and is mated with a mating surface 30 of the base 14 and is welded by weld 20 to define an annular diffuser chamber 32 between the inner and outer walls 22 and 28, respectively, in which the gas generated by generator 10 is cooled and filtered. The base component 14 includes, centrally thereof, an inwardly protruding post 34 on which an electric igniter system 36, including a squib 37 therein, is mounted, being retained thereon by a portion 38 of the post 34 which is crimped over a flange 40 on the lower end 42 of igniter system 36. Protruding downwardly through a central aperture 44 of the post 34 are spaced parallel pins 46 comprising electric input terminals of the squib 37 of the igniter system 36. Contained within the igniter system 36, as best seen in Fig. 3, to be ignited by electric current introduced through pins 46, is an ignition bead 48 of the squib 37 comprising a priming charge that is positioned in firing relation to a bridge wire (not shown). Surrounding the ignition bead 48 is pyrotechnic material 50 which may comprise QVB powder (quick velocity burn). Igniter system 36 includes an outer shell 52 that may be made of steel. An insert 54 which also may be made of steel is assembled in closing and sealing relation to the lower end of shell 52, being laser welded to the flared lower end 56 thereof, as illustrated at 58. A rubber inner seal 60 is provided on the inner wall of shell 52. A plastic member 62 having a centrally located aperture 64 therein, and which is molded to the insert 54, extends between the upper end of insert 54 and the ignition bead 48. An aperture 66 is provided in the insert 54. Inwardly thereof aperture 66 is closed in sealing relation by a member 70 in the form of a glass plug that forms a glass to metal seal with the insert 54 and also with pins 46 that extend through member 70 to the bridge wire provided in the aperture 64 of plastic member 62. Upon an initiating flow of electric current through the bridge wire of the squib 37, the ignition bead 48 is ignited and fires directly into the pyrotechnic material 50. Outer shell 52 is serrated, as illustrated at 72, for explosive separation thereby allowing the resulting hot ignition gases to expand and flow into the combustion chamber 26. Contained within the combustion chamber 26, as shown in Fig. 1, are uniformly distributed pellets 74 of the gas generant composition, which pellets are held in place by a retainer disk 75 and are ignited for the production of inflation gas by the flow therein of ignition gases from the igniter system 36. A plurality of apertures 76 are provided in the inner cylinder 22 around the circumference thereof for distributing the flow of gas generated in the combustion chamber 26 into the diffuser chamber 32. An aluminum foil or other suitable material (not shown) may be provided on the inner surface of cylinder 22 for hermetically sealing the combustion chamber 26 against moisture and other constituents of the environment to which the generator 10 is exposed that could tend to be deleterious to the desired operability thereof. A generally cylindrical cooling and filtering screen 78 is positioned in the combustion chamber 26. The screen 78 may be positioned adjacent the aforementioned aluminum foil that is provided for forming a hermetical seal for the combustion chamber 26, and provides cooling and filtering of the generated gas prior to entry thereof into the diffuser chamber 32. Contained within the outer cylinder 28 are a plurality of apertures or ports 80 that are spaced around the circumference thereof and through which the generated gas is directed into an air bag (not shown) that is to be inflated. An auto ignition device 82 is disposed in a cavity 84 that is provided in the inner wall of the upper component 16, centrally thereof. The purpose of the auto ignition device is to ignite the gas generating pellets 72 and the pyrotechnic material 50, in the event of a fire while the gas generator 10 is being shipped, in storage, or installed in a vehicle, at a temperature which is lower than the ignition temperatures of pellets 72 and material 50 but which is substantially higher than the ambient temperature range to which the generator 10 normally is subjected. This prevents ignition of the pyrotechnic material 50 and 72 when, due to a fire, the generator housing is at a temperature at which the aluminum of the housing has degraded and may tend to rupture or burst. The auto ignition device 82 includes a suitable pyrotechnic material 86, a suitable gun powder, for example, enclosed in a pouch 88 shaped to fit the cavity 84 and covered by a suitable foil (not shown) such as aluminum foil. The structural component or base 14 includes an attachment flange 90 having a plurality of apertures 92 therein spaced circumferentially thereabout for the attachment of the generator 10 to a vehicle the occupants of which are to be protected. The attachment flange 90 may be of any suitable configuration depending upon the interface requirements with the vehicle. Functioning of the gas generator 10 begins with an electrical signal from a collision sensor (not shown) to the igniter system 36. The resulting heating of the bridge wire (not shown) to the point of disintegration fires the ignition bead 48 igniting the pyrotechnic material 50. The material 50 burns and the hot gases produced thereby tend to expand, building up pressure until the outer shell 52 of the igniter system 36 explosively separates to allow the hot gases to flow into combustion chamber 26 to ignite the gas generant pellets 74 therein. The gas produced by ignition of the pellets 74 flow through the cooling and filtering screen 76 where they are initially cooled and filtered after which they burst through the combustion chamber aluminum foil seal and pass through the apertures 76 into the diffuser chamber 32. The generated gases are cooled and filtered after which they flow out of the apertures or ports 80 into an air bag for the inflation thereof. The gas generator 94 illustrated in Fig. 2 differs in a number of respects from that shown in Fig. 1 including the addition of a third internal cylinder 96 which separates the combustion chamber 98 from an ignition chamber 100 in which an electric igniter or squib 102 is contained. Additionally, as shown, the squib 102 is of the pig tail type. A wire connector shown at 99 connects input conductors 101 and 103 from the squib 102 to the electrical system of the vehicle. Inasmuch as the gas generator 94 of Fig. 2 is disclosed and described in the aforementioned Adams et al . U. S Patent No. 4,561,675 and neither that gas generator nor the squib 102 of the pig tail type disclosed in Fig. 2 form part of the present invention, further detailed description thereof will not be provided herein. Patent 4,561,675 is assigned to the assignee of the present invention; the disclosure thereof, by reference, is incorporated herein. One embodiment of a universal squib connector incorporating EMI/RFI protection, according to the invention for providing a permanent pig tail connection to a pin type electric initiator or squib, is illustrated in Figs. 5 and 6. As there shown, a universal squib connector 104 includes two or four contacts or terminals 106 and 108 that mate with a respectively associated one of the protruding pins 46 of the squib 37 of the igniter system 36 of Fig. 1. Automotive lead wires 110 and 112 are attached to the terminals 106 and 108, respectively. Such attachment may be by soldering, crimping and/or welding, as indicated at 114 and 116. Each terminal and associated lead wire attachment 106, 114 and 108, 116 is positioned and retained in a separate aperture or hole 118 and 120, respectively, in a ferrite bead 122, with the spacing between the holes being such as to allow mating engagement of the pins 46 with the terminals 106 and 108, as shown. The terminals 106 and 108, the lead wire attachments 114 and 116, and the ferrite bead 122 (which provides EMI/RFI protection) are encapsulated in electrical insulating material 124 which may comprise a suitable plastic with the terminals 106 and 108 physically and electrically isolated from each other. The ferrite bead 122 does not provide an electrically conductive path between the two terminals 106 and 108 or the two terminals 106 and 108 and the insulating material 134. The ferrite bead 122 provides protection from electromagnetic and radio frequency interference that may tend to be extraneously induced in the terminals 106 and 108. The universal squib connector 104 may be firmly secured in a socket or cavity 126 that is provided in the base component 14 of the generator 10 by any suitable means which, as shown in Fig.5, may comprise a non-structural crimp 128. Another embodiment of the universal squib connector according to the invention, indicated by the reference numeral 130, is illustrated in Figs. 7, 8 and 9. The universal squib connector 130 differs from that shown in Figs. 5 and 6 in several respects. Specifically, as shown, the length of the connector 130 is extended sufficiently to allow the automotive lead wires 110 and 112 to be bent through an angle of 90° to run parallel and in close proximity to the base component 14 of the gas generator 10. To this end, the connector 130 includes a portion 132 at the outer end that extends at a right angle thereto for determining the direction in which the lead wires emerge therefrom. In addition, the portion 132 is provided with an anti-rotation rib 134. The rib 134, in cooperation with a cutout 136 in the outer end of socket 126 of base component 14, permits insertion of the connector 130 into the socket 126 in cooperative engagement with the pins 46 of the squib 37 in one angular position only, thereby determining the orientation of the universal squib connector 130 with respect to the base component 14 and squib 37 of the gas generator 10. To that end the cutout 136 matches the geometrical configuration of the rib 134. Additionally, the rib 134 prevents rotation of the squib 37 and of connector 104 in socket 126 relatively to the base component 14. For the retention of the universal squib connector 130 in the socket 126, there is provided an expansible locking means or ring 138 that may be made of steel or other suitable material and is positioned in a groove 140 in the outer surface of the universal squib connector 130. When the connector 130 is properly fully inserted in the socket 126, the locking ring 138 expands out of the groove 140 into locking relation with a groove 142 provided on the interior wall of the socket 126 thereby to retain the connector 130 in the socket 126 with each of the terminals 106 and 108 in engagement with a respectively associated pin 46 of the squib 37. Desirably, a rubber sealing ring 144 positioned in a groove 146 on the outer surface of the connector 130 may be provided for sealing the terminals 106 and 108 from the external environment. A further embodiment of the universal squib connector according to the invention, indicated by the reference numeral 148, is illustrated in Figs. 10 and 11. The connector 148 differs from the connector 130 shown in Figs. 7 and 8 in that the anti-rotation rib 134 has been eliminated and a generally rectangular cavity or groove 150 has been provided instead. Elimination of the anti-rotation rib 134 on the universal squib connector makes unnecessary the formation of the cutout 136 in the wall of the socket 126 in the base component 14 of the gas generator 10. Cavity 150, as shown, adjoins in a symmetrical manner the apertures or holes 118 and 120 that receive the mating pins 46 of the squib of the gas generator 10. The squib provided for use with the universal squib connector 148, as indicated at 37' in Figs. 12, 13 and 14, includes a projection or projecting part 152 on the base thereof. The projection 152 extends in the direction of the pins 46, being positioned symmetrically with respect thereto, and is disposed to fit into the groove 150. The contour or configuration of the projection 152 matches that of the cavity 150, being slightly smaller, however, to allow easy insertion of the projection 152 into the cavity 150 as the universal squib connector 148 is positioned in the socket 126 of the base component 14 of the gas generator 10. The projection 152 permits such positioning of the connector 148 in socket 126 in two angular positions that are spaced 180° apart. It will be understood that, if desired, and as described hereinafter in connection with the embodiment of the invention illustrated in Figs. 15-24, the contours of the cavity 150 and the projection 152 may be such that there is only one angular position in which the projection 152 will fit in the cavity 150, and hence, only one angular position in which the universal squib connector 148 properly may be fully inserted into the socket 126. Whether arranged to permit one or two angular positions, and hence, predetermined oriented positions of the universal squib connector squib 148 with respect to the squib 37' and gas generator 10, it will be apparent that the cavity 150 and projection 152 preclude any relative angular movement between the squib 37' and the universal squib connector 148. This prevents angular forces or torques to which the universal squib connector 148 might be subjected from being transmitted directly to the protruding pins 46 possibly resulting in damage to the squib 37'. It is noted that this advantageous feature is also inherent in the universal squib embodiment 130 of Figs. 7-9. For the retention of the universal squib connector 148 in the socket 126, there is provided a first circumferential groove 154 on the outer cylindrical surface of the connector 148 and an expansible locking ring 156 that may be made of steel or other suitable material, which locking ring may be positioned in the groove 154. When the connector 148 is fully inserted in socket 126 with the projection 152 in proper cooperative and fitting relation with the cavity 150, the locking ring 156 expands out of the groove 154 into locking relation with a second circumferential groove 158 that may be provided on the interior wall of the socket 126 thereby to retain the connector 148 in the socket 126 with each of the terminals 106 and 108 in engagement with a respectively associated pin 46 of the squib 37'. Such cooperative relation of locking ring 156 and groove 158 on the interior wall of the socket 126 may be substantially identical to that of the locking ring 138 and groove 140 as shown in Fig. 7. If desired, a rubber sealing ring similar to the sealing ring 144 of Fig. 7 may be positioned in a groove on the outer cylindrical surface of the universal squib connector 148 for sealing the terminals 106 and 108 from the external environment. As those skilled in the art will understand, the cavity 150 provided in the universal squib connector 148 may be disposed non-symmetrically, if desired, with respect to the holes 118 and 120 that receive the protruding pins of the squib 37'. In such modification the projection 152 on the base of the squib 37' would be similarly positioned non-symmetrically with respect to the protruding pins 46, with the contour of the projection 152 matching that of the cavity 150 in the universal squib connector 148. It is contemplated herein that, in such modification, the cavity 150 may be positioned in either contact or non-contact relation with the holes 118 and 120 of the universal squib connector, and similarly, that the projection 152 on the squib may be positioned in either contact with or non-contact with the protruding pins 46. Thus, as used herein, the terms "adjoin" and "adjoining" are used in a broad sense to mean either "lying next to and in contact" or "lying next to and not in contact". Another and preferred embodiment of a universal squib connector incorporating EMI/RFI protection, according to the invention, indicated by the reference numeral 160, is illustrated in Figs. 15-24. Similarly to the universal squib connectors 130 and 148 illustrated in Figs. 7-9 and 10-14, respectively, the length of the universal squib connector 160 is sufficient to allow the automotive lead wires 110 and 112 to be bent through an angle of 90° to run parallel to and in close proximity to the base 14 of the gas generator 10. The universal squib connector 160 differs, however, from the connectors 130 and 148 in several important respects, foremost of which is that the connector 160 is a single piece universal squib connector. A separate expansible locking means such as the ring 138 and the ring 156 which are associated with the connectors 130 and 148, respectively, is not required for firmly securing the universal squib connector 160 in the generator socket 126. The connector 160 differs, additionally, from the other universal squib connectors disclosed herein, including the connector 104 of Fig. 5, in that there is only one angular position in which the connector 160 properly may be fully inserted into the socket 126. A further difference in the connector 160 over the connectors 104, 130 and 148 is the provision of a structural configuration, as hereinafter described, that facilitates the execution of a "pull test" for providing assurance that, when inserted in the generator socket 126, the connector 160 is firmly secured therein. The means provided in the preferred embodiment of the invention for securely retaining the universal squib connector 160 in the socket 126 of the gas generator comprises a locking means 162 including a first latch member 164 provided on one side of the connector 160 and a second latch member 166 provided on the other side thereof. Each of the latch members 164 and 166 may be moulded in electrical insulating material 168 in which the terminals 118 and 120 of the connector 160 are encapsulated, and comprises an integrally formed outwardly and downwardly extending flexible member. The electrical insulating material 168 may comprise a plastic material that is identical to the material 124 in which the universal squib connectors 104, 130 and 148 are encapsulated. As best seen in Figs. 21 and 23, the curvature of each of the latch members 164 and 166 shapes into a circumferential groove of the cylindrical wall 127 of the generator socket 126. When connector 160 is inserted in socket 126, each of the flexible members 164 and 166 is compressed against an associated recessed wall portion 170 and 172, respectively, of the connector 160. When connector 160 is fully inserted, the compressive force is released and each of the latch members 164 and 166 moves outwardly into a respectively circumferential groove 174 that is provided in the wall 127 of the socket 126, as indicated in Fig. 15. Groove 174 may have a rectangular cross section, or if desired, a cross section of triangular shape to match the outwardly flared configuration that the latch members 164 and 166 normally tend to assume. Thus, by use of the locking means 162 comprising latch members 164 and 166 formed in the encapsulating material 168 of the connector 160 and the respectively associated groove 174, the connector 160 is fixedly secured in the generator socket 126 simply by the insertion of connector 160 therein, in the proper angular position as described hereinafter. For assuring that there is one angular position only in which the connector 160 will properly fit in the generator socket 126, there is provided a T-shaped cavity 178 in the top portion of connector 160, as best seen in Fig. 21. Cavity 178 adjoins in a symmetrical manner the apertures or holes 118 and 120 that receive the mating pins 46 of the squib of the gas generator 10. The squib provided for use with the universal squib connector 160, as indicated at 37" in Figs. 16, 17 and 18, includes a T-shaped projection or boss 180 on the base thereof. The projection 180 extends in the direction of the pins 46 of the squib 37", being positioned symmetrically with respect thereto, and fits into the cavity 178 in the connector 160. The T-shape of the projection 180 matches that of the cavity 178, being slightly smaller, however, to allow easy insertion and snug fit of the projection 180 into the cavity 178 as the universal squib connector is inserted in the generator socket 126. For taking up slack or tolerance, that is, the small permissible allowance for variations from the specified dimensions in order to ensure a tight fit of the single piece universal squib connector 160 in the generator socket 126, four axially extending pointed or knife edge ribs or projections 182, 184, 186 and 188, as best seen in Figs. 19, 20 and 24, are provided around the cylindrical surface of the connector 160 at the lower portion thereof, being moulded therein. The ribs 182, 184, 186 and 188 are uniformly spaced around the connector 160. Two of the ribs 182 and 184 are shorter in length than the other two, 186 and 188, with the axial positions of all of the ribs being such, however, that they all engage the wall 127 of the generator socket 126 at substantially the same time and allow the connector 160 to be inserted therein in concentric relation therewith. In order to make more convenient the execution of a pull test to provide assurance that when inserted in the generator socket 126 the connector 160 is firmly secured therein, the electrically insulating plastic material 168 in which the connector 160 is encapsulated is so configured, as best seen in Figs. 15, 19 and 20, to facilitate gripping thereof by automated equipment performing the test. Specifically, as shown in Figs. 15, 19 and 20, the connector 160 includes a connector portion 190 that abuts against the bottom surface of the generator base member 14 when the connector 160 is fully and properly inserted in the socket 126, which connector portion 190 extends at a right angle to the connector 160 and in the direction of the electrical input connectors 110 and 112. Triangularly shaped edges 192 and 194 on the connector portion 190 makes gripping of the connector 160 more convenient in the performance of the pull test, as does also a connector portion 196 provided on the other side of the connector 160 which portion 190 extends away from the electrical input connectors 110 and 112, as shown in Figs. 19 and 21. The connector portion 196 is spaced somewhat from the base 14 of the generator 10 when the connector 160 is fully properly inserted in the generator socket 126. This spacing contributes also to facilitating the pull test. For the vehicle manufacturer that prefers a pin type connector, a universal squib connector 104, 130, 148 or 160 according to the invention, may be provided separately from the gas generator 10 with which it is to be associated and which incorporates a squib 37, 37' or 37" having protruding pins 46. Such vehicle manufacturer may then assemble the appropriate universal squib connector to the generator 10, inserting it in the socket 126 with the terminals 106 and 108 thereof in proper engagement with the pins 46 of the squib 37 and providing a non-structural crimp 128 to firmly secure the connector in place if of the first embodiment illustrated and designated by reference numeral 104; and if of an alternative embodiment designated 130 or 148, simply inserting the connector in the socket 126 and locking it in place by means of the locking ring 138 or 156 and the associated groove in the wall of socket 126 in the case of the embodiments designated 130 and 148. As described, the alternative and preferred embodiment designated 160 is a single piece universal squib connector and requires no locking means separate from the connector 160 to retain it in place once the connector has been fully and properly inserted in the generator socket 126. For the vehicle manufacturer that prefers a pig tail connector, the universal squib connector, whether of the embodiment designated 104, 130, 148 or 160 may be assembled with an associated gas generator 10 incorporating an appropriate squib of the pin type by the manufacturer of the collision protection system, with the universal squib connector 104, 130, 148 or 160 firmly secured in place in the socket 126 of the generator 10 and with the terminals 106 and 108 thereof in proper engagement with the terminals 106 and 108 of the associated squib 37, 37' or 37". Thus, in accordance with the invention, there has been provided a universal squib connector for vehicle driver and passenger air bag collision protection systems that enables the use of a single configuration of gas generator and a single configuration of squib for the igniter system of the gas generator while providing the necessary and desirable EMI/RFI protection and the advantages realizable from both pin type and pig tail type connection of the collision sensor input conductors or lead wires to the squib and also the electrical system for the vehicle according to the preferences of individual vehicle manufacturers. The universal squib connector is characterized in comprising an integral connector and connector lock containing, that is, incorporating EMI/RFI protection in a region surrounding two electrical terminals that are configured to mate with and make electrical engagement with the protruding pins of a pin type electric initiator or squib. A feature of the connector is that the terminals are protected from corrosion tending to result from exposure to the environment in which the connector is expected to be operative over long periods of time, with the terminals physically and electrically isolated from each other.

Claims: A universal squib connector (104) for providing a permanent pig tail connection to a pin type electric initiator or squib (37) comprising, connecting terminals (106, 108), a bead (122) having holes (118, 120) therethrough in spaced relation, each of said holes having a first end and a second end, with one of said terminals (106) positioned in one of said holes (118) and another of said terminals (108) positioned in another of said holes (120), the spacing of said holes being such as to allow protruding pins (46) of the pin type electric initiator or squib each to enter the first end of a respective individually associated one of said holes to make electrical contact with an individually associated one of said terminals, and a plurality of electrical input conductors (110, 112) for connecting an electrical circuit to the electric initiator or squib with each of said input conductors having an end positioned in the second end of an associated one of said holes in said bead and connected to the terminal positioned therein, characterised in that said bead (122) is a ferrite bead providing EMI/RFI protection in a region surrounding said terminals. A universal squib connector according to claim 1 further including means (138, 140, 165, 166) to retain each of said terminals (106, 108) in permanently electric contact with the individually associated one of the protruding pins (46) of an electric initiator. A universal squib connector according to claim 1 or claim 2 wherein said ferrite bead (122) and said terminals (106, 108) are encapsulated in a plastics molding (124, 168) with the holes in said ferrite bead being aligned with corresponding holes in the plastics molding to allow entry of each of the protruding pins (46) of an electric squib (37) to enter the associated first end thereof and an end of each of said electrical conductors to enter the associated second end thereof. A universal squib connector according to claim 3, wherein said plastics molding for said universal squib connector includes first and second portions that extend at substantially a right angle to said universal squib connector with said first portion (190) extending in the direction of the electrical input conductors (110, 112) and providing guidance therefor and with said second portion (196) extending away from the electrical input conductors, said first portion of said plastics molding having opposed triangular edges (192, 194) for facilitating gripping of said universal squib connector. A universal squib connector according to claim 4, wherein the shape of said universal squib connector (160) is cylindrical, and wherein a plurality of uniformly spaced axially extending ribs (182, 184, 186, 188) integral with said plastics molding (168) are provided on the cylindrical surface thereof. A gas generator having an electric initiator or squib (37) of the pin type with protruding pins and operative when electrically energised to provide ignition for said gas generator, said gas generator having an external wall (14) portion with a socket (126) formed therein into which the protruding pins of said squib extend, and a universal squib connector (104) according to any one of claims 3 to 5 for connecting said squib to a source of electrical current for initiating ignition, the shape of the plastics moulding (124) of the squib connector matching that of said socket, said universal squib connector being positioned in said socket (126) and including first holes therein into which said pins from said squib are received to engage respective ones of said terminals (106, 108), said universal squib connector providing a permanent pig tail connection to said squib and the gas generator including means for retaining the universal squib connector (104) permanently in the socket (126). A gas generator according to claim 6 wherein the plurality of electrical input conductors (110, 112) extend directly away from said universal squib connector (104). A gas generator according to claim 6 or claim 7, wherein the means to retain said universal squib connector permanently in said socket is a non-structural crimp (128) formed in the wall portion (14) of the generator. A gas generator according to claim 6 or claim 7 wherein the shape of said universal squib connector (130) and that of said socket (126) in the external wall portion (14) of the gas generator are both cylindrical, and wherein the means to retain said universal squib connector permanently in said socket in the external wall portion of said generator comprises a first circumferential groove (140) in the connector, an expansible locking ring (138) in said first circumferential groove, and a second circumferential groove (142) in the wall of the socket with the positions of said first and second circumferential grooves on said connector and socket, respectively, being such that said first and second circumferential grooves are positioned adjacent each other when said universal squib connector is substantially fully inserted in said socket whereby the locking ring is allowed to expand partially out of said first circumferential groove into said second circumferential groove thereby to lock said universal squib connector in said socket. A gas generator according to claim 9 further including a seal ring (144) provided in circumferential relation to said connector and positioned between said connector and the interior wall of the socket. A gas generator according to claim 9 or claim 10 wherein said plastics molding encapsulating said ferrite bead (122) and connecting terminals (106, 108) has a portion (132) that is adjacent the electrical input conductors (110, 112), which portion extends at a right angle to said universal squib connector to guide and allow the electrical input conductors to run parallel to the external wall (14) of the generator in which the socket is formed. A gas generator according to claim 11 further comprising an anti-rotation rib (134) which extends between the main body of said connector and the right angle portion (130) thereof, wherein the wall of said socket in the external wall portion of the gas generator includes a cutout portion (136) matching the configuration of said anti-rotation rib, and wherein said anti-rotation rib is so arranged as to fit in the matching cutout portion in the wall of said socket when each of the protruding pins (45) of said squib are in operable electrical contact with an associated one of said terminals. A gas generator according to claim 11 further including anti-rotation means comprising a cavity (150) adjoining the holes (118, 120) that are provided for the insertion therein of the protruding pins of an electric squib (37') with which the universal squib connector (148) is to be used, which cavity is arranged to receive a projection (152) on the electric squib when the universal squib connector is brought into operative relation with the electric squib, with the contour of the cavity matching that of the projection on the electric squib. A gas generator according to claim 13 wherein said cavity (178) is T-shaped whereby there is only one angular position in which the cavity is arranged to receive the projection (46) on the electrical squib (37"). A gas generator according to claim 6 or claim 7 wherein the means to retain the universal squib connector (160) permanently in said socket (126) comprises latch means (164, 166) attached to said universal squib connector and extending outwardly and downwardly from a side wall portion thereof, said latch means being compressed inwardly against the side wall of said universal squib connector upon insertion of said universal squib connector in said socket, said socket having a groove (174) in the wall (127) thereof into which said latch means moves and is captured when said universal squib connector is fully inserted in said socket. A gas generator according to claim 15 wherein the shape of said universal squib connector (160) and that of said socket (126) in the external wall portion of the gas generator are generally both cylindrical, and said latch means comprises at least one latch member (164, 166) that is integrally formed with a plastics molding (168) encapsulating the terminals of said universal squib connector, the latch member extending outwardly and downwardly from its connection to the molding. A gas generator according to claim 15 or claim 16, wherein said means to permanently retain said universal squib connector (160) in said socket (126) comprises first and second latch members (164, 166) attached to said universal squib connector and extending outwardly and downwardly from respectively opposed side wall portions thereof, said socket having a circumferential groove (174, 176) in opposed side wall portions thereof into which each of said first and second latch members, respectively, moves and is captured when said universal squib connector is fully inserted in said socket. A gas generator according to any one of claims 6 to 17 wherein the shape of said universal squib connector (160) and that of said socket (126) in the external wall portion (14) of the gas generator are both cylindrical, and further including, a plurality of uniformly spaced axially extending ribs (182, 184, 186, 188) on the cylindrical surface of said universal squib connector, each of said ribs having a pointed edge that engages the wall (127) of said socket, allowing said universal squib connector to be inserted therein but providing substantial resistance to movement to which said universal squib connector may be subjected. A gas generator according to claim 18 wherein said axially extending ribs are knife-edge ribs. A gas generator according to any one of claims 6 to 19 wherein the shape of said universal squib connector (160) and that of said socket (126) in the external wall portion (14) of the gas generator are both cylindrical, wherein said encapsulating plastics molding (168) includes first and second connector portions that extend at substantially a right angle to said universal squib connector, with said first portion (190) extending in the direction of the " electrical input conductors (110, 112) in contact with the wall portion (14) of the gas generator to guide and allow the electrical input conductors to run in a direction parallel to said wall portion, and with said second portion (196) extending away from the electrical input conductors and spaced somewhat from the wall portion of the gas generator. A gas generator according to claim 20 wherein said first connector portion (190) of said plastics molding has opposed triangular edges (192, 194) which together with said second connector portion (196) thereof facilitate gripping of said universal squib connector to pull thereon when installed in the socket of the gas generator to provide assurance that said universal squib connector is securely retained therein. A gas generator according to claim 20 or claim 21 wherein a plurality of uniformly spaced axially extending ribs (182, 184, 186, 188) are provided on said plastics molding surrounding said universal squib connector, ribs (182, 184) positioned adjacent said first connector portion (190) having a shorter length than ribs (186, 188) spaced further away from said first connector portion but the'axial position of all said ribs being such that upon insertion they all engage the wall (127) of the generator socket (126) at substantially the same time. A gas generator according to any one of claims 6 to 22 wherein said socket (126) is formed in a housing (12) comprising: an inner central chamber (100) in which is placed said squib for ignition, said squib being positioned such that said pins thereof extend into said socket, an intermediate chamber (26) containing a gas generant pyrotechnic composition (74), and an outer chamber (32) containing means (78) for filtering and for communicating externally of the housing by way of said outer orifices, with at least said intermediate and outer chambers communicating through intermediate orifices (76).

Inventors: ALLARD JOHN E, CHANDLER VIRGINIA E, CUNNINGHAM DONALD J, MONK DAVID B, SMITH BRADLEY W, ALLARD, JOHN E., CHANDLER, VIRGINIA E., CUNNINGHAM, DONALD J., MONK, DAVID B., SMITH, BRADLEY W.
Applicants: MORTON INT INC, MORTON INTERNATIONAL, INC.
Application year: 1992
Main classification: F42B3
IPC codes: B60R21, F42B3