Electrical connection system with interlock

Abstract: An electrical connection system comprises a first component carrying a pair of male connector elements releasably mated with a pair of female connector elements carried by a second connector component. A shorting clip is associated with the first component for providing an electrical short between the male connector elements. The shorting clip is moved to a non-shorting position when the first component is mated with the second component. An interlock is associated with the system and includes a lock element which is inserted into the connection to prevent separation of the first and second components while the lock element is in position.

Description: Background of the Invention The subject invention is directed toward the art of electrical connection systems and, more particularly, to an electrical connector arrangement wherein the electrical contacts of one component are shorted together when proper electrical connection to a second component has not been made. The invention is particularly suited for use in vehicle occupant inflatable restraint ("airbag") systems and will be described with reference thereto; however, the invention is capable of broader application and could be used in many different environments and for a variety of purposes. Vehicle inflatable restraint, or "airbag", systems each include an airbag assembly mounted in a hidden compartment within the cab of the vehicle and an electrical or electronic control system. The control system is connected to the airbag assembly by means of a wiring harness which typically is provided with an electrical plug and jack connector arrangement to permit an easy method of electrically joining the airbag assembly and the control system after they have been installed separately. U.S. Patent Nos. 4,988,307 (Muzslay), 4,906,203 (Margrave, et al.), 4,369,707 (Budde), and 4,170,939 (Hoheisel, et al.) each discloses a connection system for use in an airbag system. Each connection system incorporates a so-called shorting clip. Shorting clips are small metal elements arranged to electrically short together the leads within the plug or jack before the plug and jack are mated. Such shorting clips are included as a safety feature, to preclude stray electrical charges and inadvertent misconnections from accidentally triggering the airbag assembly during the manufacturing process. Attention is also drawn to GB 2 025 711 which relates to a protection arrangement for an electric ignitor. In accordance with the present invention an electro-mechanical connector for use with an electrical apparatus as set forth in claim 1 is provided. Preferred embodiments of the invention are disclosed in the dependent claims. Summary of the Invention The subject invention provides an electro-mechanical connector including a locking element. The locking element may be designed for insertion into the connected components to provide a positive mechanical interlock and thereby prevent inadvertent disconnection of the components. The connector of the invention is simple and effective and provides a ready visual indication as to whether or not proper mechanical and electrical connection has been made. As can be seen from the foregoing, a primary object of the invention is the provision of an electrical connector of the type described wherein an interlocking means is provided which is an integral part of the connector and that functions to prevent inadvertent disconnection of the primary connector components. Yet another, more limited object of the invention is the provision of an interlocking system of the general type described wherein the locking element enters into the connected components to prevent inadvertent disconnection. A further object of the invention is the provision of a system of the type described wherein a shorting element functions to automatically short out the connector elements upon disconnection of the components. Brief Description of the Drawings The above and other objects and advantages will become apparent from the following description when read in conjunction with the accompanying drawings wherein: FIGURE 1 is an electrical schematic of a vehicle occupant restraint system; FIGURE 1A is an isometric view of the connection system of the FIGURE 1 schematic with the component elements in their electrically and mechanically interconnected relationship; FIGURE 2 is an isometric exploded view showing the components of the connection system in proper relative physical orientation but in a mechanically separated and electrically disconnected condition; FIGURE 3 is a vertical cross-sectional view taken on line 3-3 of FIGURE 1A; FIGURE 4 is a vertical cross-sectional view taken on line 4-4 of FIGURE 1A; FIGURE 5 is a plan view of the shorting element of the connector system; FIGURE 5A is an isometric view of the shorting clip used in the shorting element of FIGURE 5; FIGURE 6 is a side elevational view of the component shown in FIGURE 5 (the view is taken on line 6-6); FIGURE 6A is a cross-sectional view taken on line 6A-6A of FIGURE 5; FIGURE 7 is a top plan view of the second connector component of the system shown in FIGURE 1A; FIGURE 8 is a side elevational view of the second connector component shown in FIGURE 7; FIGURE 9 is a bottom plan view of the component shown in FIGURE 7; FIGURE 10 is a cross-sectional view taken on line 10-10 of FIGURE 7; FIGURE 11 is a cross-sectional view taken on line 11-11 of FIGURE 9; FIGURE 12 is a cross-sectional view taken on line 12-12 of FIGURE 9; FIGURE 13 is a top plan view of a cover provided on the component shown in FIGURE 7; and FIGURE 14 is a cross-sectional view taken on line 13-13 of FIGURE 12. Detailed Description of the Preferred Embodiment Referring more particularly to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting same, FIGURE 1 is a general electrical schematic of a vehicular occupant restraint system in which the connector of the present invention will find utility. As shown in this FIGURE, the system comprises an airbag igniter A (sometimes referred to as a squib) which must be electrically coupled to a control system B. The igniter A is a pyrotechnic device which will combust when sufficient electrical energy is applied to it via its two electrical leads. Combustion of the igniter causes ignition of a gas generant material and consequent deployment of the airbag. The control system is an arrangement of mechanical, electrical, and/or electronic elements designed to discern when the airbag should be deployed, and to then promptly apply electrical energy to the igniter to initiate the deployment. Electrical energy is coupled between the control system and the igniter via a pair of wires 1 and a connector system C. The connector system C includes plug and jack components which may be mated to complete the electrical connection between the wires 1 and igniter A. FIGURE 1A shows the overall arrangement of the connector system C of the subject invention in a connected and mated condition and comprising a first component 10 into which a second component 12 is mechanically and electrically connected. Referring in particular to FIGURE 2, it will be seen that the first component 10 is a jack which comprises a main body 14 which defines an inwardly extending cylindrical socket 16. The component 10 can be a separate element which is subsequently mechanically and electrically connected to an associated structure or, of course, it can be integrally formed as part of the associated structure such as, for example, an electric igniter or the like. In any event, the body 14 includes a radially extending cylindrical shoulder 18 and the previously-mentioned socket 16. Carried within the socket 16 are a pair of centrally located male electric connector elements or pins 20 that extend perpendicular to the bottom wall 22 of socket 16. The pins are formed of electrically conductive material, but are mounted in electrically insulating material so as to be electrically isolated from one another. The two pins are coupled in any conventional fashion to respective leads of an airbag igniter (not shown) such that the coupling of electrical energy to the igniter through the pins will cause the igniter to fire. Associated with the socket 16 is a circumferentially extending locking groove 24 which has the cross-sectional configuration best seen in FIGURES 3 and 4. The multiple functions of the locking groove 24 will subsequently be described. It should also be noted that the bottom wall 22 includes three inwardly extending circular recesses 26. These recesses provide means for orienting the associated structures in the socket 16. Closely received in socket 16 and releasably retained therein is a shorting insert 30 that functions to electrically short the male connector elements 20 to one another when component 12 is not in the mated position. Insert 30 generally comprises a plastic cylindrical disk-like main body 32 having a circular through-opening 34 formed therein. As best seen in FIGURES 3 and 4, the shorting insert 30 is positioned in the bottom portion of the socket 16 and includes radially extending locking tabs or latch elements 36 which are positioned to resiliently engage the latch groove 24. These latch tabs 36 thus act to retain the shorting insert in proper position within the socket. In order to assure correct orientation of the shorting insert and proper relationship relative to the male connector elements 20, downwardly extending legs or extensions 38 are provided. The legs or extensions 38 enter into the previously-mentioned recesses 26. For reasons which will subsequently be described, the upper surface of the body 32 is provided with arcuate cutouts 40 which extend downwardly substantially halfway (axially) through body 32. A shorting clip 42 is retained within the body 32 of the shorting insert 30. The clip 42 is formed of a resilient, electrically conductive material such as spring steel. Portions of the shorting clip 42 are resiliently biased toward engagement with both of the male connector pins 20 establishing an electrical short circuit therebetween. As best seen in FIGURES 5 through 7, the shorting clip 42 comprises a base 44 and upwardly extending legs 46. Legs 46 are each bent back towards the base as best shown in FIGURE 5A and act to bias into engagement and make respective electrical connection with the sides of both of the connector pins 20. The legs 46 extend generally parallel to the connector pins 20. The base 44 is generally planar and is oriented parallel to the plane of the connector pins 20. The transverse ends of base 44 are serrated and are folded at right angles to thereby form catches. Catches 48 engage the groove 50 on member 30 to retain the shorting clip 42 in position. Positioned within the central opening or through-opening 34 is an axially extending rib 52. The rib 52 mates with a complementary groove in the second component 12 to assure proper orientation of the second component 12 when connection is made. The overall construction and arrangement of the second connection component 12 can best be understood by reference to FIGURES 2, 4, and 7 through 11. As shown therein, the second connection component 12 is a plug which includes a main body 55 having a cylindrical extension 56. The cylindrical outer surface of the extension 56 is sized and shaped to be complementary to the size and shape of the cylindrical inner surface of the central opening 34 of the shorting element 30 whereby the extension 56 can be inserted into, and will be closely received by, the central opening 34. The extension 56 carries a pair of female contacts 58. Each of the contacts 58 is a generally cylindrical contact formed of resilient, electrically conductive metal. The contacts 58 are sized and spaced to each receive a corresponding one of the two pins 20 of the jack 10. As shown in FIGURE 3, each contact 58 has a folded, generally L-shaped attachment section 59 for attachment to a corresponding one of two conductors 61. The conductors 61 are insulation-sheathed wires whose ends are stripped for electrical and mechanical joining to the attachment section of the corresponding contact. The wires are attached to the cylindrical contacts in any conventional manner, usually through crimping of a portion of the attachment section around the bare end of the wires. The conductors pass through a ferrite bead 65 disposed within a cavity 67 in the main body 55 of plug 12. The bead 65 is a generally box-shaped solid and is pierced by two parallel, cylindrical through-holes through which the conductors 61 pass. The conductors emerge from the main body 55 through openings in the rear wall of the cavity 67. As mentioned above, the extension 56 includes an axially extending groove or recess 63 (see FIGURE 9) which is adapted to receive the axial rib 52 within the opening 34. The rib and groove arrangement properly orients the plug 12 with the jack 10. Additionally, the rib and groove arrangement, in conjunction with the previously-mentioned recesses 26 and tabs 38, prevents relative rotation of the connection elements after they are mechanically and electrically mated. Also extending downwardly from the main body 55 of plug 12, generally parallel to extension 56, is latch means in the form of a pair of spaced legs 62. The legs are each joined at one end to the main body 55 and are at the other end free. The free end of each leg is radially flexible. Further, the free ends of the legs 62 are provided with radial projections or catches 64 located so as to be received in the latch recess 24 of the socket 16. The relationship of the catches 64 to the recess 24 can best be seen in FIGURES 3 and 4. Referring again to FIGURES 8 and 9, it will be seen that the legs 62 are positioned on diametrically opposite sides of the plug extension 56 and have a generally arcuate or curved configuration so as to closely engage in the socket 16. Plug extension 56 includes a relatively flat side wall 68 that terminates in chamfer 70 best seen in FIGURES 9 and 12. As illustrated in FIGURE 3, when the extension 56 is received in opening 34 of the element 30, first the chamfer 70 and then the side wall 68 engages each of the shorting clip legs 46 and forces them away from the respective connector pins 20. This forced retraction of the legs 46 breaks the electrical contact between the clip and the pins, thus removing the short and electrically enabling the connection. Thus, when plug 12 is plugged into jack 10, the electrical short is automatically eliminated. The removal of the short permits electrical energy to be coupled between the pins of the jack 10, the corresponding sockets of plug 12, and conductors 61. When the components are in the connected position, the flexible legs 62 and their catches 64 are engaged in the latch groove 24 as best seen in FIGURE 4. Preferably, and in accordance with one aspect of the invention, means are provided to lock the legs 62 in their latch position so as to prevent inadvertent disconnection of the connection components 10 and 12. In the subject embodiment, the locking means comprises a locking clip 70 that is connected with the second component 12 by a tether or flexible connecting element 72. The locking clip includes a base 74 and a pair of flexible legs 76 which project from base 74. The legs 76 are sized and shaped so as to extend into openings 78 formed through body 55 and enter between the latch legs 62 and the central portion of plug extension 56. This relationship is best seen in FIGURES 4, 9, and 11. As shown therein, when the locking clip legs 76 are in position, flexure of the legs 62 is blocked and thus it is not possible to disengage the catches 64 from the groove 24. Thus, plug 12 is mechanically interlocked with jack 10 and the risk of inadvertent detachment is reduced. Additionally, when in this interlocked position, the locking clip 70 is located as illustrated in FIGURE 1 and provides a visually perceptible indication that the components are properly locked together. Preferably, small latch tabs 82 are formed at the ends of the legs 76 to resiliently retain locking clip 70 in position. The latch tabs 82 are positioned and sized so as to engage in suitable latch recesses 84 formed at the inner lower ends of the latch legs 62 (see FIGURE 4). The plug 12 has its housing or main body 55 completed by a cover 90 (see FIGURES 13 and 14) which is of generally U-shaped configuration and includes downwardly extending resilient sides 92 provided with latches 94. The cover element 90 is sized and arranged to enclose the right-hand end of body 55 as viewed in FIGURE 1 and thereby capture the ferrite bead 65 within the cavity 67. The latches 94 engage in suitable recesses 96 located as shown in FIGURE 8. As can be seen from the foregoing, the subject invention provides an effective and simple structure which acts to provide a mechanical and electrical interlock between the various components to prevent inadvertent disconnection. Additionally, with the subject invention, when disconnection does take place, an automatically actuated short is achieved between the male connector elements. The claims define the scope of protection. It should be noted that the objects and advantages of the invention may be attained by means of any compatible combination(s) particularly pointed out in the items of the following summary of the invention and the appended claims. The invention, thus concerns an electro-mechanical connector for use with an electrical apparatus having a first pair of electrical contacts for electrical communication with said apparatus, said connector comprising: a first insulative housing of disk shape removably positioned about said first pair of electrical contacts and carrying electrical conducting means thereon for selectively electrically connecting said first pair of electrical contacts when in a first position and electrically disconnecting from said first pair of electrical contacts when in a second position; means on said first housing for biasing said electrical conducting means into said first position; a second housing adapted for releasable mating with said electrical apparatus and carrying a second pair of electrical contacts adapted to engage said first pair of electrical contacts for selective electrical communication with said electrical apparatus, a portion of said second housing being adapted for urging said electrical conducting means into said second position against said biasing means when said second housing is mated with said electrical apparatus; resilient latch means on said second housing adapted for providing a mechanical latch with said electrical apparatus; and, a locking element positionable into a lock position in said second housing for preventing release of said latch means and preventing separation of the first and second housings from said electrical apparatus. According to an embodiment said latch means comprises at least one resilient leg extending from the second housing. According to a further embodiment said second housing includes a plug insertable into a corresponding socket in said electrical apparatus for releasable connection therewith. According to another embodiment said latch means comprises a resilient leg element which extends into the plug into engagement with said electrical apparatus; and, said locking element includes an elongated element insertable into the second housing to prevent movement of said resilient leg out of engagement with said electrical apparatus. According to yet another embodiment said socket includes a latch groove about its interior, the resilient leg element having a latch portion which engages in the latch groove.

Claims: An electro-mechanical connector (C) for use with an electrical apparatus having a first pair of electrical contacts (20) for electrical communication with said apparatus, said connector comprising: a first insulative housing (32) of disk shape removably positioned about said first pair of electrical contacts (20) and carrying electrical conducting means (42) thereon for selectively electrically connecting said first pair of electrical contacts (20) when in a first position and electrically disconnecting from said first pair of electrical contacts (20) when in a second position; means on said first housing (32) for biasing said electrical conducting means into said first position; a second housing (55) adapted for releasable mating with said electrical apparatus and carrying a second pair of electrical contacts (58) adapted to engage said first pair of electrical contact (20) for for selective electrical communication with said electrical apparatus, a portion of said second housing being adapted for urging said electrical conducting means (42) into said second position against said biasing means when said second housing is mated with said electrical apparatus; resilient latch means (62) on said second housing adapted for providing a mechanical latch with said electrical apparatus; and, a locking element (70) positionable into a lock position in said second housing for preventing release of said latch means and preventing separation of the first and second housings from said electrical apparatus. The electro-mechanical connector of claim 1 wherein said latch means (62) comprises at least one resilient leg (64) extending from the second housing (55). The electro-mechanical connector of claim 1 or 2 wherein said second housing (55) includes a plug (56) insertable into a corresponding socket in said electrical apparatus for releasable connection therewith. The electro-mechanical connector of claim 3, wherein: said latch means (62) comprises a resilient leg element which extends into the plug into engagement with said electrical apparatus; and, said locking element (70) includes an elongated element (76) insertable into the second housing to prevent movement of said resilient leg out of engagement with said electrical apparatus. The electro-mechanical connector of any of claims 3-4, wherein said socket includes a latch groove (24) about its interior, the resilient leg element having a latch portion (64) which engages in the latch groove.

Inventors: CAHALY JAMES E, PITSTICK BRIAN R, CAHALY, JAMES E., PITSTICK, BRIAN R.
Applicants: TRW INC, TRW INC.
Application year: 1993
Main classification: H01R13
IPC codes: H01R13, H01R31