Abstract:
A seat belt system for a vehicle having a seat belt mounted to a vehicle seat or a portion of a vehicle structure, a tongue which can slide is attached to the seat belt, and a buckle that receives and locks the tongue in an attached state such that the seat belt restrains an occupant in the vehicle seat. A primary coil is included in the buckle and is electrically connected to at least one primary circuit. At least one secondary coil is included in the tongue and is electrically connected to at least one secondary circuit. The primary coil and the at least one secondary coil are configured to be electromagnetically coupled when the buckle and tongue are in the attached state.

Description:
BACKGROUND 
       [0001]    Conventional seat belt systems for vehicle seats include two components, the buckle assembly and the tongue assembly. If an occupant is not present in the vehicle seat, the buckle and the tongue are not physically attached. After an occupant enters the vehicle seat, the occupant inserts the tongue into the buckle, where a mechanical actuator in the buckle locks the tongue rigidly in an attached state, thereby restraining the occupant in the vehicle seat. To break the mechanical attachment and return to the unattached state, the occupant presses a button on the buckle, which disables the attached state. Often the tongue and mechanical actuator are formed of metal. In addition, a switch is generally included within the buckle to detect when the buckle assembly is properly buckled. 
         [0002]    Electromechanical devices and sensors also may be integrated into the seat belt in order to support additional safety functions. Currently, belt-integrated sensors and actuators require wiring through the entire belt assembly from the retractor or the belt base in order to receive power from a power supply or receive and transmit data from a control unit. Such wiring, however, adds additional cost and complexity to the system. 
       SUMMARY 
       [0003]    One disclosed embodiment relates to a seat belt system for a vehicle. The seat belt system has a seat belt mounted to a vehicle seat or a portion of a vehicle structure and a tongue which can slide attached to the seat belt. The seat belt system further includes a buckle configured to receive and lock the tongue in an attached state such that the seat belt restrains an occupant in the vehicle seat. The tongue and buckle have the capability to be released or separated from the locked condition. A primary coil is included in the buckle and is electrically connected to at least one primary circuit. At least one secondary coil is included in the tongue and is electrically connected to at least one secondary circuit. The primary coil and the at least one secondary coil are configured to be electromagnetically coupled when the buckle and tongue are in the attached state. 
         [0004]    Another disclosed embodiment relates to a seat belt system for a vehicle seat having a seat belt with a tongue which can slide attached and a buckle configured to receive and and lock the tongue in an attached state. The tongue and buckle have the capability to be released or separated from the locked condition. A primary circuit is included in the buckle. At least one secondary circuit is included in the tongue. The primary circuit and the at least one secondary circuit are configured to be electromagnetically coupled when the buckle and tongue are in close proximity. 
         [0005]    Yet another disclosed embodiment relates to a seat belt system for a vehicle seat having a seat belt with a tongue which can slide attached and a buckle configured to receive and lock the tongue in an attached state. The tongue and buckle have the capability to be released or separated from the locked condition. The buckle and the tongue are further configured to be electromagnetically coupled when the buckle and tongue are in the attached state such that power and/or data may be transmitted between the buckle and tongue. 
         [0006]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below. 
           [0008]      FIG. 1  is a perspective view of an occupant restraint system, according to an exemplary embodiment. 
           [0009]      FIG. 2  is a perspective view of a tongue and a buckle of the occupant restraint system of  FIG. 1 . 
           [0010]      FIG. 3  is a block diagram of the tongue and the buckle of  FIG. 2  in an uncoupled state, according to an exemplary embodiment. 
           [0011]      FIG. 4  is a block diagram of the tongue and buckle of  FIG. 2  in a coupled state, according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below,” etc.) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure. 
         [0013]      FIG. 1  illustrates a portion of a vehicle interior  10 , including a vehicle occupant restraint system, such as a seat belt system  20  for use in a passenger vehicle. The seat belt system  20  generally includes a belt  22  (e.g. a webbing, a strap, etc.), a tongue  24 , and a mateable buckle  26 . Upon attaching the tongue  24  to the buckle  26 , the belt  22  is latched across the occupant to secure the occupant to the vehicle seat  12 . Sensors and various electromechanical devices may be integrated into the seat belt system  20  to enhance safety functions of the system. For example, a sensor  78  may be integrated with the belt  22  to collect data regarding the physiological state of the occupant or general use of the system by the occupant. In addition, actuators may be incorporated into the seat belt system  20  that provide tensioning adjustment to the belt  22  in certain events, such as, for example, pre-crash, crash, or other threat conditions. The use of such sensors and electromechanical devices in connection with the seat belt system  20  is described in more detail below. 
         [0014]    The belt  22  is configured to extend and retract across the occupant when seated. The belt  22  may be formed of a woven nylon material, which is threaded through the tongue  24  via an opening  33  in a striker portion  42 . The tongue  24  slides with respect to the belt  22  when in an unbuckled position, allowing the seat belt  22  to be utilized for a wide range of occupant sizes and seating positions. The belt  22  is connected to a belt retractor  28  that is configured to guide the belt  22  between winding and unwinding. The retractor  28  may include a mechanism configured to pretension the belt  22  in the winding direction. The mechanism may include a plurality of springs, for example. The buckle  26  may be fixed with respect to the vehicle, such as the vehicle floor, vehicle seat, or any other appropriate vehicle structure. For example, the buckle  26  may be anchored to the vehicle frame so that the seat belt  22  is secured or locked in place when it is attached to the buckle  26 . When the tongue  24  and the buckle  26  are secured, the belt  22  extends from a floor anchor  32 , crosses the waist of the occupant, and passes through the tongue housing  34  to form a lap portion  36  of the occupant restraint system  20 . The belt  22  crosses diagonally across the torso of the occupant to a shoulder anchor  30  (e.g., a ring assembly, a D-ring, etc.) to form a shoulder portion  38  of the occupant restraint system  20 , and then leads into the retractor housing  28  where it terminates in a spool which rotates relative to the fixed housing. 
         [0015]    As shown in  FIG. 2 , the buckle  26  includes a latch  40  to prevent unwanted disengagement of the tongue. The latch  40  may be formed, for example, from a metal or metal alloy. The latch  40  is configured to secure the striker portion  42  of the tongue  24 . The striker portion  42  also may be formed from a metal or metal alloy. In addition, the striker portion  42  may be partially covered by a tongue housing  34 , which may be formed, for example, as a hollow plastic member that partially frames the striker portion  42 . The latch  40  is further configured to selectively release the striker portion  42  of the tongue  24 , either manually or automatically, such as with the depression of a user interface, which is shown in  FIG. 2  as a button  44 . The button  44  may be provided on the distal end of the buckle  26  and defines an opening  45  into which the striker portion  42  is inserted to engage the latch  40 . The buckle  26  may further include an internal switch  46  included within a housing  48  of the buckle  26  that is configured to detect when the striker portion  42  and the latch  40  are engaged or disengaged. The switch  46  may, for example, be an electromechanical switch. The switch  46  may communicate to the vehicle whether the latch  40  of the buckle  26  and the striker portion  42  of the tongue  24  are in an “attached” or “unattached” state via electrical wiring contained in the buckle  26 . 
         [0016]    As shown in  FIGS. 3 and 4 , the buckle  26  may communicate with the vehicle via signals passing through electrical wires (represented as double arrows) coupling the buckle  26  to an electrical system  50 . Electromechanical devices may then be integrated into the buckle  26 , including, but not limited to, lighting elements, vibrating actuators, and electromechanical motors, all of which may facilitate ingress and egress movement of the buckle or general use of the occupant restraint system  20 . The electrical system  50  further may include a power source  52 , configured to provide electrical power, and a control circuit  54  (e.g., a controller, a processor circuit, etc.), configured to provide control signals. 
         [0017]    The power source  52  may provide electrical power to the components of the buckle  26  and, as described in more detail below, other components of the seat belt system  20 . The power source  52  may be connected (e.g., wired) to a vehicle power supply system. The power source  52  may be integrated into the vehicle power supply system or may be independent of the vehicle power supply system. For example, the power source  52  may be a dedicated battery or other electrical storage device that provides power only to the buckle  26 . 
         [0018]    The control circuit  54  may contain circuitry, hardware, and/or software for facilitating or performing a variety of functions. The control circuit  54  may handle inputs, process inputs, run programs, handle instructions, route information, control memory, control a processor, process data, generate outputs, communicate with other devices or hardware, or otherwise perform general or specific computing tasks. The control circuit  54  may, for example, be an electronic control unit for a vehicle. The control circuit  54  also may include a processor  56 . The processor  56  may be implemented as any suitable electronic processing component, such as, for example, a general-purpose processor, an application-specific integrated circuit (“ASIC”), one or more field-programmable gate arrays (“FPGAs”), a digital-signal-processor (“DSP”), or a group of processing components. The control circuit  54  may include a further connection to another vehicle communication system such as, for example, a CAN bus. 
         [0019]    The control circuit  54  may include memory  58 , which may be one or more devices (e.g. RAM, ROM, flash memory, hard disk storage, etc.) for storing data and/or computer code for facilitating the various processes performed by the control circuit  54 . The memory  58  may be, or include, non-transient volatile memory or non-volatile memory. The memory  58  also may include any type of information structure for supporting the various activities and information structures performed by the system, such as database components, object code components, and script components. The memory  58  is in direct communication with the processor  56  and provide computer code or instructions to processor for executing the processes described herein. 
         [0020]    The seat belt system  20  includes an electromagnetic primary coil  60  that is provided in the buckle  26  and at least one electromagnetic secondary coil  62  that is provided in the tongue  24 , both of which are represented schematically in  FIGS. 3 and 4 . In an attached state (e.g., when the striker portion  42  of the tongue  24  engages the latch  40  of the buckle  26 ), the primary coil  60  and the secondary coil  62  are inductively coupled. The mechanical interconnection of the striker portion  42  and the latch  40  fix the relative positions of the primary coil  60  and the secondary coil  62 . The striker portion  42  may be positioned relative to the primary coil  60  and the secondary coil  62  to serve as a metal core linking the primary coil  60  and secondary coil  62  to improve power and/or communication coupling. For example, the primary coil  60  may be provided about the periphery of or within the housing  48  of the buckle, and the secondary coil  62  may be provided about the periphery of or within the tongue housing  34 . The striker portion  42  may extend into the tongue housing  34  such that, when the tongue  24  is coupled to the buckle  26 , one end of the striker portion  42  is surrounded by the primary coil  60  while the opposite end of the striker portion  42  is surrounded by the secondary coil  62 , as shown in  FIG. 4 . 
         [0021]    Once an electromagnetic coupling is established between the primary coil  60  and the secondary coil  62 , power and data may be transferred. Data may be exchanged between the primary coil  60  and the secondary coil  62  through various methods including, but not limited to, low-power Bluetooth, WiFi, near field communication (“NFC”), or simple controlled modulation of the primary and/or secondary coil circuits. Through the inductive coupling between the primary coil  60  and the secondary coil  62 , power and/or data may pass between the buckle  26  and the tongue  24  without direct physical contact of the power and/or data conducting members connected to the tongue  24  and the buckle  26 . 
         [0022]    To facilitate power and data transfer, the buckle  26  may include a power supply circuit  64  and/or a communications circuit  66 . The power supply circuit  64  and the communications circuit  66  may be included within the housing  48  of the buckle  26  such that they do not interfere with the coupling of the striker portion  42  and the latch  40 . The power supply circuit  64  is connected to the power source  52  and to the primary coil  60 . The power supply circuit  64  may be a simple connection that directly couples the primary coil  60  to the power source  52  or may include components to alter (e.g., rectify, invert, step-up, step-down, condition, etc.) the electrical power between the power source  52  and the primary coil  60 . The communications circuit  66  is connected to the control circuit  54  and to the primary coil  60 . The communications circuit  66  may be a simple connection that directly couples the primary coil  60  to the control circuit  54  or may include components such as additional processors to alter data passing between the primary coil  60  and the control circuit  54 . 
         [0023]    The tongue  24  may include a power storage device  70 , a power conversion system  72 , an electrical sensing system  74 , and/or an actuation circuit  76 . One or more of the power storage device  70 , the power conversion system  72 , the electrical sensing system  74 , or the actuation circuit  76  may be included within the tongue housing  34  or within a separate housing coupled to the tongue  24 . 
         [0024]    The power storage device  70  is connected to the secondary coil  62 . The power storage device  70  is charged with electrical power from the power source  52  through the inductive coupling between the primary coil  60  and the secondary coil  62 . The power storage device  70  may be any device suitable for storing electrical energy. For example, the power storage device  70  may a rechargeable electrochemical cell or battery (e.g., a suitable battery could include Ni—Cd, NiMH, Li-ion, Li polymer, etc.), a capacitor, supercapacitor, or any other device or combination of devices capable of storing electrical energy. 
         [0025]    The power conversion system  72  is connected to the secondary coil  62 . The power conversion system  72  may include components to alter (e.g., rectify, invert, step-up, step-down, condition, etc.) the electrical power between the secondary coil  62  and the power storage device  70 , the electrical sensing system  74 , the actuation circuit  76 , the sensor  78 , and other devices (e.g., sensors, actuators, lights, etc.) included in the tongue  24  or in other components connected to the tongue  24  (e.g., belt  22 , shoulder anchor  30 , retractor  28 , etc.). 
         [0026]    The power storage device  70  and/or the power conversion system  72  provide electrical power to components included on the tongue  14  or the belt  22  without direct contact being needed between conductive members coupled to the tongue  24  and the buckle  26 . Further, by providing power storage in the tongue  24  with the power storage device  70 , the power conversion system  72 , the electrical sensing system  74 , the actuation circuit  76 , the sensor  78  and other devices (e.g., sensors, actuators, lights, etc.) included in the tongue  24  or in the belt  22  coupled to the tongue  24  may receive power even when the tongue  24  is disengaged from the buckle  26 . 
         [0027]    The electrical sensing system  74  may communicate with one or more sensors  78  included on the tongue  24  or on the belt  22  coupled to the tongue  24  to monitor the use of the occupant restraint system  20  and/or collect data concerning the occupant using the occupant restraint system  20 . The sensor  78  communicates collected data to the control circuit  54  via the inductive coupling between the primary coil  60  and the secondary coil  62 . While the sensor  78  is shown schematically in  FIGS. 3 and 4  as a single sensor included on the belt  22  coupled to the tongue  24 , the sensor  78  alternatively may be included on the tongue  24  (e.g., on the striker portion  42  or the tongue housing  34 ). The sensor  78  also may include multiple sensors included in various locations on the tongue  24 , the belt  22  or any other component associated with the seat belt system  20  (e.g., the refractor  28 ). 
         [0028]    The sensor  78  may be utilized to estimate the stature of the occupant based on the occupant&#39;s use of the seat belt system  20 . For example, the sensor  78  may be one or more accelerometers included within the tongue housing  34 . The accelerometer may track the movement of the tongue  24  by the occupant&#39;s hand, during ingress, from a stowed position to engaging the buckle  26  to estimate the occupant&#39;s stature. Alternatively, the sensor  78  may be an encoder (e.g., an optical encoder) that is configured to monitor belt payout through the tongue housing  34  to estimate occupant stature (e.g., through absolute and/or relative encoded information on the belt  22 ). Alternatively, the sensor may be composed of a gear system (which steps down the turn ratio of the refractor) attached to a rotational potentiometer. 
         [0029]    The sensor  78  also may be utilized to collect other biological data from the occupant. For example, the sensor  78  may be included on a portion of the belt  22  that is positioned over the chest of the occupant and may be configured to collect a variety of data, including, but not limited to, occupant physiological data, such as movement, heart rate, respiration rate, or detect or measure biochemical analytes through respiration, perspiration or other physiological processes. 
         [0030]    In addition, the sensor  78  may be utilized to monitor the tongue  24  and the buckle  26  or the proper use of the seat belt system  20 . For example, the sensor  78  may be configured to detect the electromagnetic coupling levels when the tongue  24  is properly locked into the buckle  26 . The sensor  78  may therefore replace the switch  46  as a means for detecting the state of the buckle assembly. The sensor  78  also may be utilized to detect misuse of the seat belt system  20 , such as by detecting belt placement behind or under the occupant. The sensor  78  additionally may be utilized to detect due care situations, such as the presence or positioning of a car seat or whether the buckle  26  and the tongue  24  are in a non-occupant attached state. 
         [0031]    The actuation circuit  76  is configured to actuate a portion of the seat belt system  20  based on control signals from the control circuit  54  that are transmitted to the actuation circuit through the inductive coupling between the primary coil  60  and the secondary coil  62 . 
         [0032]    The actuation circuit  76  may be coupled to an actuator, indicator, or other device included on the tongue  24  and configured to act upon the tongue  24 . For example, the actuation circuit  76  may be configured to activate a motor to vibrate the tongue  24  as a warning device, or may be configured to activate a light or sound device to provide a warning or indicator to the occupant (e.g., if the tongue  24  is not properly coupled to the buckle  26 ). Alternatively, the actuation circuit  76  may be coupled to an actuator, indictor, or other device that is configured to act upon another body. For example, the actuation circuit  76  may be configured to activate an actuator in the tongue housing  34  to lock the belt  22  in the tongue housing  34  to provide enhanced restraint during pre-crash, crash, or other threat conditions. Such an actuator may be utilized in combination with other active belt functions, such as a motorized seat belt function. 
         [0033]    The actuation circuit  76  may be coupled to an actuator, indicator, or other device in another portion of the seat belt system  20 . For example, the actuation circuit  76  may be configured to activate an actuator in the shoulder anchor  30  to adjust tension (e.g., looser or tighter) to achieve a target belt tension. The actuation circuit  76  may activate any other electromechanical reversible and/or non-reversible features embedded in the seat belt or other components of the occupant restraint system  20 , such as in response to pre-crash, crash, or other threat conditions detected by other sensors and communicated to the actuation circuit from the control circuit  54  through the inductive coupling between the primary coil  60  and the secondary coils  62 . 
         [0034]    The electromagnetic coupling of the seat belt system  20  allows for wireless sensors and/or actuators to be integrated into the tongue housing or in other components of the seat belt system  20  without the requirement of extensive wiring through the entire belt assembly. The system allows for use of existing power and communications wiring in the buckle assembly to provide additional features and functions and may also replace the switch as a means to detect proper attachment of the buckle and tongue, thereby reducing parts while adding functionality. 
         [0035]    The construction and arrangement of the elements of the electromagnetic coupling system as shown in the exemplary embodiments are illustrative only. Although only a few embodiments of the present disclosure have been described in detail, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements. Some like components have been described in the present disclosure using the same reference numerals in different figures. This should not be construed as an implication that these components are identical in all embodiments; various modifications may be made in various different embodiments. It should be noted that the elements and/or assemblies of the enclosure may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations.