Patent Publication Number: US-6217388-B1

Title: Low profile SIR connector and terminal

Description:
TECHNICAL FIELD 
     The present invention relates to matable electrical connection systems, and more specifically, to an electrical connector for use in a supplemental inflatable restraint (SIR) system. 
     BACKGROUND OF THE INVENTION 
     It is well known in the art to provide a supplemental inflatable restraint (SIR) system for the protection of vehicle occupants. A typical SIR includes a housing, an airbag normally stored in the housing, and an inflator for discharging gas to inflate the airbag. Typically, the inflator is activated in response to a predetermined amount of vehicle deceleration. 
     It is known to mount an air bag of a SIR system in an instrument panel, a door panel, as well as within a steering wheel. Air bag inflation in triggered by a device known as an initiator. The initiator is connected to an electrical connector which is operatively coupled to a pair of wires leading from a controller. The space available for an airbag is generally limited, especially for steering wheel mounted air bags. Therefore, it is desirable to minimize the size of any component within a SIR system, including the electrical connector. 
     U.S. Pat. No. 5,586,902 to Hopf et al, discloses an electrical connector for coupling wires to an initiator. The &#39;902 patent teaches a connector having a pair of 90° terminals coupled to wires leading through a ferrite filter element disposed longitudinally within a connector housing. The geometry of the connector of the &#39;902 patent requires the wires to be inserted through the filter element before being crimped to the 90° terminals. Although the &#39;902 patent discloses a good electrical connector for an SIR system, it has a number of deficiencies. The location of the filter element results in a larger connector that requires more space. Furthermore, the location of the filter element substantially burdens the manufacturing process of the connector. 
     Therefore, it is desirous to provide an electrical connector for an SIR system having a reduced size. It is further desirous to provide an electrical connector for an SIR system which allows more efficient manufacturing of the connector and its components. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide an electrical connector for use in a SIR system having a controller and an initiator comprising a connector housing which has a plug portion with a filter cavity disposed therein. A pair of apertures are disposed within the plug portion of the connector housing which are in communication with the filter cavity. A filter element is disposed within the filter cavity. The filter element has a pair longitudinally disposed receptacles, which when installed in the filter cavity align with the pair of apertures. A pair of terminals, each of which has a barrel portion and a crimp portion, are disposed within the connector housing. The crimp portion is provided to receive a wire leading from the controller. The barrel portions of each terminal is disposed within one of the receptacles within the filter element, whereby the barrel portions are aligned with the pair of apertures so is to receive initiator pin terminals. 
     A feature of the present invention is that the connector housing has a reduced size as a result of locating the filter element within the plug portion of the connector housing. 
     Another feature of the present invention is that the barrel portions of the terminals are located within the filter element to reduce the cost of producing an SIR system. By locating the barrel portions of the terminals in receptacles of the filter element, the terminals may be processed on automatic cutters. Furthermore, installation of the filter element into the connector housing may be automated as well. 
     Another feature of the present invention is the connector housing has a wire shelf portion which has a pair of laterally disposed wire channels for guiding each of a pair of wires to one of the pair of terminals. 
     Another feature of the present invention is that the connector housing articulates with a retaining cap which has a connector position assurance (CPA) portion and a cover portion connected by a pair of flexible straps. 
     Another object of the present invention is to provide a method for assembling an electrical connector for use in a SIR system having a controller and an initiator, comprising the steps of providing a connector housing which has a plug portion with a filter cavity. The housing also has a pair of apertures disposed within the plug portion, and in communication with the filter cavity. The filter element has a pair of longitudinally disposed receptacles inserted within the filter cavity, where each of the receptacles are aligned with one of the pair of apertures. A pair of terminals having a barrel portion disposed generally perpendicular to crimp portion is also provided. The crimp portion of the terminal is crimped to a wire. Each of the terminals are inserted in the housing where the barrel portion of each of the pair of terminals is inserted into each of the pair of receptacles within the filter element. 
     It is another object of the present invention to provide a terminal for an electrical connector, comprising a barrel portion generally perpendicular to a crimp portion, the barrel portion having a contact end and a open end that is adjacent to the crimp portion. The barrel portion is provided to receive a pin terminal, while the crimp portion is provided to receive and secure the terminal to a wire. A generally U-shaped terminal transition area is disposed between the barrel portion and the crimp portion. The terminal transition area has a smaller diameter section, a neck down portion and a formed transition. The neck down portion is disposed between the open end of the barrel portion and the smaller diameter section. The formed transition is disposed between the smaller diameter section and the crimp portion. A position tab is disposed adjacent to the barrel portion for locating the terminal within the electrical connector. 
     Other objects and features of the present invention will become apparent to those skilled in the art in light of the following detailed description of the preferred embodiment of the present invention, setting forth the best mode of the invention contemplated by the inventors and illustrated by the accompanying sheets of drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded isometric view of the electrical connector of the present invention; 
     FIG. 2 is an isometric view of a shorting clip assembly shown in FIG. 1; 
     FIG. 3 is an isometric view of a connector housing shown in FIG. 1, 
     FIG. 4 is an upside-down isometric view of the connector housing shown in FIG. 3; 
     FIG. 5 is an isometric view of a retaining cap shown in FIG. 1; 
     FIG. 6 is an upside-down isometric view of the retaining cap shown in FIG. 5; 
     FIG. 7 is a isometric view of a terminal shown in FIG.  1  and shown crimped to a wire; 
     FIG. 8 is a isometric view of the terminal as shown in FIG. 7 prior to crimping; and 
     FIG. 9 is a partial section view of the terminal shown in FIG.  8 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, and more particularly to FIG. 1, a connector  1  is shown in an exploded isometric view. The connector  1  comprises a connector housing  10  which has a plug portion  12  and wire shelf portion  22 . A filter cavity  14  is disposed within the plug portion  12  along a vertical axis. 
     A filter element  8  is provided and disposed within the filter cavity  14 . A pair of apertures  16  extend through the wall of the plug portion  12  of the connector housing  10  at the bottom of the cavity  14  so that the apertures  16  are in communication with the filter cavity  14 . The filter element  8  has a pair of longitudinally disposed receptacles  9  that are aligned with the pair of apertures  16  when the filter element  8  is disposed within the filter cavity  14 . 
     Referring now to FIG. 5 a retaining cap  30  having a connector position assurance (CPA) portion  40  and a cover portion  50  is shown in an isometric view. The CPA portion  40  is attached to the cover portion  50  by a pair of flexible straps  32 . A plurality of lock arms  54  extend from the cover portion  50  to fasten the retaining cap  30  to the connector housing  10 . 
     The CPA portion  40  has a pair of disengagement tabs  44  extending from a CPA body  42 . Referring now also to FIG. 2, a shorting clip assembly  70  is shown. The pair of slots  79  cooperate with a pair of alignment tabs  48  extending from the CPA body  42  of the retaining cap  30 . The shorting clip assembly  70  includes a shorting clip housing  72  which has a shorting clip cavity  74  with a pair of slots  79 . A shorting clip  76  which has a pair of tabs  78  is disposed within the shorting clip cavity  74 . 
     The shorting clips assembly  70  mates with an initiator  60  which has a socket portion  62  for receiving the shorting clip housing  72 . The initiator  60  has a pair of initiator pins  64 , also referred to herein as terminal pins  64  extending within the socket portion  62 . 
     The initiator  60  has a groove  66  that cooperates with a ridge  19  formed at the perimeter of a pair of retaining tabs  18  which can be seen in FIG.  4 . An index rib  17  disposed along the plug portion  12  aligns the connector housing  10  with the shorting clip housing  72 . The shorting clip assembly  70  is inserted into the socket portion  62  of the initiator  60 . The terminal pins  64  project into the shorting clip cavity  74  where contact is made with the shorting clip  76 , thereby providing a shunt between the initiator pins  64 . 
     The plug portion  12  of the connecting housing  10  engages shorting clip housing  72 . The index rib  17  aligns the connector housing  10  to the shorting clip assembly  70  by cooperating with an index groove  75  disposed within the shorting clip housing  72 . 
     The connector housing  10  is secured to the shorting clip housing  72  by locking the ridges  19  formed at the perimeter the retaining tabs  18  into the groove  66  within the initiator  60 . The receptacles  9  within the filter element  8  disposed within the plug portion  12  of connector housing  10  are aligned with the initiator pins  64 . The barrel portion  82  of each of the pair of terminals  80  engages each of the pair of receptacles  9  to contact the initiator pins  64 . Each wire  5  is connected to a crimped portion  94  of one of the terminals  80 . The wire shelf portion  22  of the connector housing  10  has a pair of wire channels  24  separated by a longitudinal rib  26 . A plurality of retaining ribs  28  are disposed within wire channels  24  for retaining and strain relieving wires  5  during assembly and operation of the connector  1 . 
     The retaining cap  30  is fastened to the connector housing  10  by the plurality of lock arms  54 . Referring now also to FIG. 5, the pair of flexible straps  32  permit the CPA portion  40  of the retaining cap  30  to fold over and engage the cover portion  50 . A lock  46  fastens the CPA portion  40  to the connector housing  10 . The alignment tabs  48  pass through a pair of alignment tab apertures  59  disposed within the cover portion  50  as well as another pair of alignment tab apertures  25  disposed within the connector housing  10 . The alignment tabs  48  interlock with the pair of slots  79  at the opposite sides of the shorting clip housing  72 . The shorting clip housing  72  is aligned with the initiator  60  by engaging a pair of notches  68  disposed in the initiator  60  with a pair of tabs  73  extending from the perimeter of the shorting clip housing  72 . By facilitating alignment between the CPA portion  40  and the shorting clip housing  72 , proper alignment of the connector housing  10  and the initiator  60  is achieved. 
     A pair of disengagement tabs  44  extend from the CPA body  42  and pass through a pair of disengagement tab apertures  49  disposed within the cover body  52  when the CPA body  42  engages the cover portion  50 . The disengagement tabs  44  disconnect the shorting clip  76  from the initiator pins  64  when the CPA portion  40  folds over and engages the cover portion  50 , rendering the CPA portion  40  in a locked position. A spring arm  56  is operatively attached to the cover portion  50  and is in contact with the longitudinal rib  26  when the retaining cap  30  is connected to the connector housing  10 . The spring arm  56  provides tension to prevent rattling. 
     Referring now to FIGS. 7,  8 , and  9 , the terminal  80  for electrical connector  1  is shown in detail. The terminal  80  comprises a barrel portion  82  and a crimp portion  94 . The barrel portion  82  is disposed generally perpendicular to the crimp portion  94 . The barrel portion  82  has a contact end  85  and an open end  86  that is adjacent to the crimp portion  94 . The barrel portion  82  has one or more contacts  84  disposed therein. The barrel portion  82  of the terminal  80  is provided to receive a pin terminal such as one of the pin terminals  64  shown in FIGS. 1 and 2. 
     The crimp portion  94  is provided to receive and secure the terminal  80  to wire  5 . A generally U-shaped transition area  88  is formed between barrel portion  82  and crimp portion  94 . Transition area  88  has a smaller diameter section  90 , a neck down portion  91  disposed between the open end  86  of the barrel portion  82  and the smaller diameter section  90 . A formed transition  92  is disposed between the smaller diameter section  90  and the crimp portion  94 . A position tab  96  disposed adjacent to the barrel portion  82  is provided to locate the terminal  80  within an electrical connector (not shown). A carrier strip remnant  98  is at the end of the transition area  88  along the same axis as the barrel portion  82 . 
     The terminal  80  is formed from a unitary piece of metal. The carrier strip remnant  98  is part of a long carrier strip that transports the unitary piece of metal along various sequential manufacturing steps which may include progressive die stations. Furthermore, the carrier strip allows several terminals attached to the carrier strip to be wound on a reel, stored, delivered, and fed to an automatic termination machine. The U-shaped transition area  88  is formed to join the U shaped crimp portion  94 , as can be seen in FIG. 8, prior to crimping. The U-shaped transition area  88  allows for a smaller terminal  80  by forming a tighter band. The usual method to achieve a stamped right angle terminal is to provide a flat transition area, which will result in a increase in the overall size of the terminal. 
     Referring again to FIG.  1  and FIG. 2, the connector  1  of the present invention is assembled by providing a connector housing  10  with a filter cavity  14 . The filter element  8  is then disposed within the filter cavity  14  so that receptacles  9  of filter element  8  align with apertures  16 . Referring now also to FIG. 3, the connector housing  10  has a filter retaining ridge  20 , that prevents the filter  8  from coming dislodged during transport and assembly. A pair of terminals  80  are provided, each of which have a barrel portion  82  which is disposed generally perpendicular to the crimp portion  94 . A wire  5  is connected to the crimped portion  94  of each terminal  80 . The pair of terminals  80  are inserted into the connector housing  10  so that the barrel portion  82  are inserted into respective receptacles  9  of filter element  8  and the wires  5  are lodged in wire channels  24 . 
     The cover portion  50  of retaining cap  30  is then fastened to the top of connector housing  10 . CPA portion  40  is then folded over on top of cover portion  50  so that tabs  44  and  48  extend into the connector housing  10 . Connector housing  10  is then plugged into initiator  60  after shorting clip assembly  70  has been installed. Alignment tabs  48  slide into slots  79  to guide connector housing  10  into shorting clip assembly  70  while disengagement tabs  44  push shorting clip  78  away from terminal pins  64 . 
     The foregoing description discloses and describes the various embodiments of the present invention. One skilled in the art will readily recognize from such description, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the present invention, and also such modifications, changes and variations are intended to be included within the scope of the following claims.