Patent Publication Number: US-2007114846-A1

Title: Power supply circuit for removable automotive interior systems with integrated position sensor system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      Not Applicable  
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
      Not Applicable  
     REFERENCE TO A SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX  
      Not Applicable  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates in general to a vehicle interior power supply connections for interior trim members of a vehicle, and more specifically, to a disconnectable power supply circuit for a detachable interior trim member of a vehicle such as a seat.  
      2. Description of the Related Art  
      Vehicle interior systems such as passenger seats are removable from a vehicle and/or stowable in the vehicle. Vehicle seats which include electrical load devices such as heating elements or motors for moving portions of the seats require power be supplied to the vehicle seat through an electric connection. Typically the floor area is the only suitable location for making the electrical connection between a power supply connector and a releasable connector incorporated within the vehicle seat. For vehicle seats that are removable, stowable, or pivotal to a tilt forward position, a mating portion of the electrical connection must also be detachable to allow the vehicle seat to be removed, stowed, or pivoted fully forward.  
      While providing an electrical connection which automatically connects and disconnects the mating connectors when the vehicle seat is removed from its position, power is still supplied to an exposed power supply connector. The exposed electrical contact is susceptible to a short circuit caused by the electrical contacts coming into contact with a foreign object or by a person, in addition by damage caused by impacts to the contact from the person or object. Furthermore, being that the electrical connection to a vehicle seat is typically made at the floor level, an exposed connector may be susceptible to debris and liquids spilled on the floor which may lead to the corrosion or damage to the electrical contact.  
     BRIEF SUMMARY OF THE INVENTION  
      This invention has the advantage of determining whether an electrical connection is made between two mating connectors of an electrical supply circuit for supplying power to an electric device within an interior trim member of a vehicle. The electrical supply circuit disconnects power to the power supply connector when the proximity of the releasable connector relative to the power supply connector is outside of a predetermined range that indicates that the connectors are disconnected.  
      In one aspect of the present invention, an electrical power supply system is provided that includes a vehicle interior trim member selectably mountable to a vehicle interior. The vehicle interior trim member includes an electrical load device and a releasable connector for receiving electrical energy for powering the electrical load device. The releasable connector includes a high impedance element having an impedance within a predetermined range less than an open circuit impedance. A power supply connector is fixedly mounted to the vehicle interior and adapted to be electrically coupled to a power supply. The power supply connector is also releasably attachable to the releasable connector for supplying electrical energy from the power supply to the electrical load device. A switching circuit determines a position of the power supply connector relative to the releasable connector and selectively energizes the power supply connector in response to the sensed position. The releasable connector is connected to the power supply connector when the vehicle interior trim member is selectively attached to the vehicle and is disconnected from the releasable connector when the vehicle interior trim member is selectively detached from the vehicle. The switching circuit disconnects power from the power supply connector when a proximity of the releasable connector relative to the power supply connector is outside of the predetermined range. The switching circuit connects power to the power supply connector when the proximity of the releasable connector relative to the power supply connector is within the predetermined range.  
      Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a view of a interior compartment of a vehicle illustrating detachable interior trim members according to a preferred embodiment of the present invention.  
       FIG. 2  is a perspective view of the power supply connector according to a first preferred embodiment of the present invention.  
       FIG. 3  is a perspective view of the male terminal contacts of the power supply connector according to a first preferred embodiment of the present invention.  
       FIGS. 4   a  and  4   b  are perspective views of the releasable connector according to a preferred embodiment of the present invention.  
       FIG. 5  is an illustration of the connection of the power supply connector and the releasable connection preferred embodiment of the present invention.  
       FIG. 6  is an electrical schematic of the electrical supply system circuit according to a preferred embodiment of the present invention.  
       FIG. 7  is a method for powering on and off the power supply connector according to a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring now to the drawings, there is illustrated in  FIG. 1  an interior of a vehicle shown generally at  10 . The interior of the vehicle  10  includes a driver&#39;s seat  12 , a front passenger&#39;s seat  14 , a rear passenger seat  16 , and a front center console  18  that are mounted to a vehicle floor shown generally at  20 .  
      The rear passenger seat  16  includes a latch mechanism  22  disposed on a bottom corner of the rear passenger seat  16 . The latch mechanism  22  includes a latch  24  and latch release lever  26 . The latch mechanism  22  is typically spring-loaded to allow the latch to move into position for engaging a catch  28  mounted in the vehicle floor  20 . The latch  24  is unlatched for allowing the rear passenger seat to be moved. For example, the rear passenger seat  16  may be pivoted forward to allow a person access to the rear of the rear passenger seat  16 , stowing the rear vehicle seat  16  in a stowable compartment (not shown), or removing the rear passenger seat  16  from the vehicle interior.  
      The rear passenger seat  16  further includes an electrical load device  30 , such as a vehicle seat warmer. The electrical load device  30  may further other types of electrical load devices such as a seat motor for adjusting a backrest or lumbar. A releasable connector  32  is mounted on a bottom portion of the vehicle seat  16  for receiving and supplying power to the electrical load device  30  and is moveable with the rear passenger seat  16  as the seat is moved.  
      The vehicle floor  20  includes a power supply connector  34  for providing power to the releasable connector  32  when electrically coupled. The power supply connector  34  is fixedly mounted in the vehicle floor  20 . Preferably, the power supply connector  34  is recessed below the floor  20  such as in a pilot hole  36 . Recessing the power supply connector  34  below the floor  20  prevents the power supply connector  34  from being damaged by impacts.  
      The releasable connector  32  of the rear vehicle seat  16  is in electrical contact with the power supply connector  34  when rear vehicle seat  16  is in a latched position. As the rear passenger seat  16  is moved to the latch position, the releasable connector  32  extends into the pilot hole  36  and mates the power supply connector  34  recessed below the floor  20 . This not only prevents the connection of the power supply connector  34  and the releasable connector  32  from being damaged by contact but also prevents a person or object from contacting the electrical connection when energized.  
       FIG. 1  further shows an interior trim member such as the front center console  18  that is detachable from the vehicle interior compartment  10 . The front center console  18  may include an electrical load device such as a multimedia device (i.e., DVD player for viewing movies or a CD magazine rack for playing audio). The front center console  18  or a portion thereof may be detachable to allow the electrical load device to be removed from the vehicle. The front center console  18  includes an electrical connection, shown generally at  38 , that is similar to the electrical connection described above. When the front center console  18  is mounted to the floor  20  or other adjacent structure, an electrical connection is made between the two mating connectors. When the front center console  18  is detached from the floor  20  or other adjacent structure, the center console power supply connector is recessed within the floor  20  to avoid contact or interference with any exterior objects or passengers.  
       FIG. 2  illustrates a perspective view of the power supply connector  34 . The power supply connector  34  includes a first male terminal contact  40  and a second male terminal contact  42  for supplying electrical energy from a power supply device (e.g., vehicle battery) to a female mating connector. The power supply connector  34  includes a circular base portion  44  integrally formed with a guide post  46 .  
      A position sensor  91  is disposed on a top surface  90  of the circular base portion  44 . Preferably the position sensor  91  is a Hall Effect sensor. Alternatively, the position sensor may include an inductive sensor or an RFID reader.  
      Referring to both  FIGS. 2 and 3 , the first male terminal contact  40  includes a longitudinal section  48  that is integrally formed to a ring portion  50  that is open ended. The ring portion  50  is retained about the circumference of the post  46 . The post  46  may include a notched portion in which the ring portion  50  is inserted therein. Alternatively, the open ended ring portion  50  may be insert-molded as part of the post  46 . The longitudinal section  48  extends axially along the post  46  and through the circular base portion  44 . An end  52  of the longitudinal section  48  protrudes from a bottom portion the circular base portion  44  for connecting to a wire or harness (not shown) for receiving voltage from the designated power source.  
      The second male terminal contact  42  includes a longitudinal section  58  that is integrally formed to a ring portion  60  that is open ended. The ring portion  60  is retained about the circumference of the post  46  and is spaced axially in relation to the first ring portion  50 . The post  46  may include a notched portion in which the ring portion  60  is inserted therein. Alternatively, the ring portion  60  may be insert-molded as part of the post  46 . The longitudinal section  58  extends axially along the post  46  and through the circular base portion  44 . An end  62  of the longitudinal section  58  protrudes from the bottom portion of the circular base portion  44  for connecting to a wire or harness (not shown) for receiving voltage from a designated power source.  
      An open end  64  of the ring portion  50  provides an axial passage for allowing the longitudinal section  58  of the second male terminal contact  42  to extend past the open ended ring portion  50  without contacting and shorting the first male terminal contact  40  to the second male terminal contact  42 .  
       FIGS. 4   a  and  4   b  illustrate perspective views of the releasable connector  32 . The releasable connector  32  includes a main body  66  made from a nonconductive material. The main body  66  includes an inner bore  67  that extends axially through the main body  66 . The releasable connector  32  includes a first female terminal contact  70  that includes a conductive circular member  74  that in electrical contact with a conductive longitudinal member  78 . The releasable connector  32  further includes a second female terminal contact  72  which includes a conductive circular member  80  in electrical contact with a conductive longitudinal member  84 . The first female terminal contact  70  and second female terminal contact  72  are insert-molded into the main body  66  and are exposed to the inner bore  67 .  
      An end portion  88  includes magnet  93 , preferably a permanent magnet. The magnet  93  may be insert molded to the main body  66  or coupled to the main body  66  by another method. The magnet  93  generates a magnetic field in the vicinity of the end portion  88  that is sensed by the position sensor  91  of the male terminal contact  34 .  
      Alternatively, if an inductive sensor is used, a metal shield is utilized in place of the magnet for expelling the magnetic field and changing the coil inductance of the inductive sensor. The changing of the coil inductance indicates the proximity of the power supply connector relative to the releasable connector.  
      In yet another alternative embodiment, an RFID circuit may be utilized to sense the proximity of the power supply connector relative to the releasable connector. The RFID circuit may be configured differently for sensing the electrical interconnection connection of two devices. The sensing of the interconnection of two devices using an RFID circuit is shown in co-pending application entitled “System and Method For Verifying Assembly Of Manufactured Parts Using RFID Tags”, Ser. No. 11/162,957 filed Sep. 29, 2005, which is incorporated by reference herein. An example of utilizing the RFID circuit is to dispose an RFID tag in the releasable connector and dispose the RFID reader in the power supply connector. The reader powers the tag when the tag is in close proximity to the reader. The tag when powered by the reader responds to an interrogation pulse, thereby identifying the proximity of the two mating connectors. Alternatively, the electrical connection between the power supply connector and the releasable connector may be used to perform an electromechanical switching function within an RFID tag portion of the circuit. The RFID tag portion includes an open loop antenna with a transponder. An open circuit in the antenna loop when the accessory is removed will prevent the reader from powering the tag (transponder) so that the tag is incapable of responding to the reader. A closed circuit in the RFID tag portion when the accessory is attached will allow the reader to power the tag (transponder) so that it may respond to the reader. A response from the tag to the reader would indicate an electrical connection is occurring between the power supply connector and the releasable connector whereas a non-response would indicate that some other conductive object is inadvertently making the connection. Power would be connected to the power supply connector if a response is received and power would be disconnected from the power supply connector if a non-response is received.  
      A circular seal  86  is disposed within the main body  66  near the end portion and is exposed to the inner bore  67 . The seal  86  prevents contaminants from entering the connection between the power supply connector  34  and the releasable connector  32  from the end potion  88 . The seal  86  also wipes the male terminal contacts as the post  46  is inserted within the inner bore  67 .  
       FIG. 5  illustrates the connection between the releasable connector  32  and the power supply connector  34 . The first female terminal contact  70  includes the conductive circular member  74  which is a spring-like member that has radial retention properties for contacting the post  46  when inserted within the conductive circular member  74 . The conductive circular member  74  and the conductive longitudinal member  78  may be integrally formed or may be held in electrical contact with one another by the main body  66 . The conductive longitudinal member  78  extends axially within the main body  66 . The conductive longitudinal member  78  protrudes through an end surface  82  for electrically coupling to a respective conduit for supplying voltage to the electrical load device  30  within the interior trim member.  
      The second female terminal contact  72  includes the conductive circular member  80  which is a spring-like member that has retention properties when the post  46  is inserted within the conductive circular member  80 . The conductive circular member  80  and the conductive longitudinal member  84  may be integrally formed or may be held in contact with one another by the main body  66 . The conductive longitudinal member  84  extends axially within the main body  66 . The conductive longitudinal member  84  protrudes through an end surface  82  for electrically coupling to a respective conduit for supplying voltage to the electrical load device within the interior trim member.  
      The seal  86  is seated within the main body  66  and is exposed to the inner bore  67  near an end portion  88  of the releasable connector  32  for preventing debris from entering the end portion  88  when the power supply connector  30  and the releasable connector  32  are coupled.  
      The post  46  of the power supply connector  30  positioned on a bottom portion of the rear passenger seat  16  is seated within the bore  67  of the releasable connector  32  when the rear passenger seat  16  is in a secured position to the floor  20 . When the post  46  enters the bore  67  from the end portion  88 , the post  46  as well as the first and second male terminal contacts  40  and  42  makes contact with the seal  86  as the post  46  moves through the bore  67 . As the first and second terminal male contacts  40  and  42  slidingly contact the seal  86 , fluid and debris are wiped from each respective contact. As the end portion  88  of the power supply connector  34  bottoms out against a top surface  90  of the circular base portion  44 , the first male terminal contact  42  is in electrical contact with the first female terminal contact  70  and the second male terminal contact  42  is in electrical contact with the second female terminal contact  72 . Both conductive circular members  74  and  80  exert and inward radial force against the ring portions  50  and  60  for maintaining an electrical connection when the electrical load device  30  is activated. Power is provided to the electrical load device  30  within the rear passenger seat  16  via the mating electrical contacts.  
      Power is connected to the power supply connector  34  when the releasable connector  32  is within a proximal position of the releasable connector  32 . The magnet  91  generates an electromagnetic field about an end portion  88  of the releasable connector  32 . This is accomplished by the position sensor  91  sensing the electromagnetic field of the magnet  93 . The position sensor  91  senses the intensity of the electromagnetic field generated by the magnet  93  as the releasable connector  32  is inserted over the power supply connector  34 . As the magnet  91  is moved closer to the position sensor  91 , the intensity of the electromagnetic field is increased. When the intensity of the electromagnetic field reaches a predetermined threshold as sensed by the position sensor  91 , power is connected to the power supply connector  34 . If the intensity of the electromagnetic field is outside of the predetermined threshold, then power is disconnected from the power supply connector  34 .  
       FIG. 6  illustrates a schematic of an electrical supply system  89 . The electrical supply system  91  includes a power supply circuit  92  and a releasable supply circuit  94 . The power supply circuit  92  includes a power supply source  95 , a switching circuit  96 , and the power supply connector  34 . The power supply source  95  may be an energy storage device such as a battery or an energy generating device such as an alternator. In the preferred embodiment, the power source  95  is electrically connected between the switching circuit  96  and the power supply connector  34 . The switching circuit  96  includes a position sensor  91  that senses the proximal position of the releasable connector relative to the power supply connector seen by the switching circuit  96 . The switching circuit  96  includes a re-settable controlled switch  97 , solid state fuse, or other device which be used connect or disconnect power between the power source  95  and the power supply connector  34 . Alternatively the controlled switch  97  or like device may be disposed in a power distribution box (not shown).  
      The releasable supply circuit  94  includes the releasable connector  32 , a device switch  98 , and the electrical load device  30 . The releasable connector  32  is selectively connectable with the power supply connector  34  for receiving power from the power supply circuit  92 . The releasable connector  32  also includes a magnet  93  for generating an electromagnetic field.  
      The position sensor  91  senses the electromagnetic field as generated by the magnet  93  when the releasable connector  34  is moved within a proximal distance of the power supply connector  32 . This distance correlates to the intensity of the electromagnetic field. The stronger the intensity of the electromagnetic field, the closer the proximity of the position sensor  91  to the magnet  93 , and as a result, the closer the releasable connector  34  is to being fully seated on the power supply connector  34 . When the position sensor  91  senses that the intensity of the electromagnetic field reaches a predetermined threshold, a presumption is made that the vehicle interior trim component  16  is attached to the vehicle interior  20  and that the releasable connector is seated or at least substantially seated on the power supply connector  34 . The switching circuit  96  connects power to the power supply circuit  34  which is thereby supplied to the electrical device  30  via the releasable connector  32  in response to the sensed electromagnetic field intensity being at or above the predetermined threshold.  
       FIG. 7  illustrates a method for connecting and disconnecting power to the power supply connector in response to the sensed electromagnetic field. In step  100 , the vehicle interior trim member is in either the latched or unlatched position. In step  101 , the position sensor senses the-position of the releasable connector relative to the power supply connector (e.g., by the intensity of the electromagnetic field). In step  102 , a determination is made as to whether the position of the releasable connector and the power supply connector are within a predetermined threshold. If the determination is made that the sensed position is within the predetermined threshold, then power to the power supply connector is connected in step  103 . If the sensed position is not within the predetermined threshold, then power to the power supply connector is disconnected in step  104 . It should be noted that the sensed position may be determined by the intensity of the electromagnetic field, the sensed inductance, or a interrogation response from a RFID tag.  
      In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.