Abstract:
A seat belt assembly is provided for an occupant seated in a seat that includes a seat back portion and a seat base portion having an outboard side. The seat belt assembly includes a continuous seat belt having a lap belt and shoulder belt. The lap belt has an inboard portion, an outboard portion, and an anchor portion. The anchor portion is fixed to an anchor member positioned below, rearward, and inboard relative to the outboard side of the seat base portion. An actuator assembly is selectively engageable with the outboard portion of the lap belt and is operable to selectively release the lap belt. A pre-tensioner is operatively connected to the shoulder belt. The pre-tensioner is configured to tension the shoulder belt and the lap belt thereby applying force in an inboard direction when the lap belt is released from the actuator assembly.

Description:
TECHNICAL FIELD 
     The present invention pertains generally to a seat belt assembly for a vehicle. 
     BACKGROUND OF THE INVENTION 
     It is well known in motor vehicles to restrain a seated occupant with a seat belt assembly such as a conventional three-point seat belt. The three-point seat belt typically includes a lap belt and a shoulder belt, which reach around and thereby secure the occupant to the car seat. The seat belt assembly may also include a seat belt tensioning device or pre-tensioner, which forcibly tensions the seat belt in response to a vehicle condition such as vehicle deceleration or an impact. 
     SUMMARY OF THE INVENTION 
     A seat belt assembly for an occupant seated in a seat that includes a seat back portion and a seat base portion having an outboard side is provided. The seat belt assembly includes a continuous seat belt having a lap belt and shoulder belt. The lap belt has an inboard portion, an outboard portion, and an anchor portion. The anchor portion is fixed to an anchor member positioned below, rearward, and inboard relative to the outboard side of the base portion. An actuator assembly is selectively engageable with the outboard portion of the lap belt and is operable to selectively release the lap belt. A pre-tensioner is operatively connected to the shoulder belt and is configured to selectively tension the shoulder belt and the lap belt, thereby applying force in an inboard direction when the lap belt is released from the actuator assembly. 
     A control device operatively connected to the actuator assembly may be provided. The control device is preferably configured to actuate the actuator during a side impact event to release the lap belt and to prevent actuation of the actuator during a frontal impact event to retain the lap belt. An anchor pre-tensioner may be disposed between the anchor portion of the lap belt and the anchor member and is operable to selectively tension the lap belt. A buckle assembly may be mounted with respect to the inboard portion of the lap belt, while a buckle pre-tensioner may be mounted with respect to the buckle assembly and is operable to selectively tension the lap belt and the shoulder belt. 
     The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic front view of a portion of a vehicle illustrating a seat belt assembly of the present invention; 
         FIG. 2  is a schematic side view further illustrating aspects of the seat belt assembly of  FIG. 1 ; 
         FIG. 3  is a schematic front view of the seat belt assembly of  FIGS. 1 and 2  illustrating an actuated state during a side impact event; 
         FIG. 4  is a schematic front view of a seat belt assembly in accordance with an alternate embodiment of the present invention; and 
         FIG. 5  is a schematic front view of a seat belt assembly in accordance with another alternate embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, wherein like reference numbers refer to like components throughout the several figures,  FIG. 1  shows a portion of a passenger vehicle  10  having a passenger side door panel  12 . A seat  14  including a back portion  16  and a base portion  18  is disposed within the vehicle  10 . The base portion  18  of the seat  14  includes an inboard side  20  and an outboard side  22 . A seat belt assembly  24  is applied to an occupant  26  seated in the seat  14  and includes a three-point seat belt  28 , a belt tensioning device or pre-tensioner  30 , a buckle assembly  32  and an actuator  34  in accordance with the present invention. 
     The three-point seat belt  28  includes a shoulder belt  36  and a lap belt  38 . The lap belt  38  includes an inboard portion  40 , an outboard portion  42  and an anchor portion  44 . The three-point seat belt  28  is generally continuous such that the shoulder belt  36  is connected to the inboard portion  40  of the lap belt  38 . When the seat belt assembly  24  is in the applied position, as shown in  FIG. 1 , the lap belt  38  is defined between an outboard anchor  46  and an inboard anchor  48  to which the three-point seat belt  28  is attached with the buckle assembly  32 . Similarly, when the seat belt assembly  24  is in the applied position, shown in  FIG. 1 , the shoulder belt  36  is defined between an outboard anchor  50  and the inboard anchor  48 . The seat belt assembly  24  is shown with a three-point seat belt  28  for illustrative purposes; however, it should be appreciated that the present invention may also be applied to alternate seat belt configurations. 
     The anchor portion  44  of the lap belt  38  extends from the outboard anchor  46  toward the actuator  34 . In the preferred embodiment, the outboard anchor  46  is positioned below, rearward, and inboard relative to the outboard side  22  of the base portion  18  and therefore an outboard hip  52  of the occupant  26 . The outboard anchor  46  may be disposed with respect to the base portion  18  of the seat  14 ; however, those skilled in the art will recognize that the outboard anchor  46  may be mounted with respect to a floor  54  of the vehicle  10 . The actuator  34  is selectively engaged with the outboard portion  42  of the lap belt  38  and operates to maintain the outboard portion  42  of the lap belt  38  with respect to the seat  14 . Additionally, the actuator  34  is operable to selectively release the outboard portion  42  of the lap belt  38  in response to a signal from a control device  56 . The control device  56  may be existing hardware mounted with respect to the vehicle  10  that would otherwise be implemented to deploy side airbags and/or roof rail airbags (not shown) during side impact events. The shoulder belt  36  is operatively connected to the pre-tensioner  30 . The pre-tensioner  30  is configured to selectively and rapidly retract at least a portion of the shoulder belt  36 , thereby tensioning the shoulder belt  36  and lap belt  38 . 
     Referring to  FIG. 2 , and with continued reference to  FIG. 1 , there is shown a side view of the seat  14  further illustrating aspects of the seat belt assembly  24 . As shown in  FIG. 2 , the actuator  34  is secured with respect to the floor  54  of the vehicle  10  via a cable  58  or other tethering device; however, alternate placement for securing the actuator mechanism  34 , such as to the base portion  18  of the seat  14 , may be envisioned while remaining within the scope of that which is claimed. The actuator  34  may be any device known in the art capable of selectively retaining the lab belt  38  with respect to the seat  14 . As shown in  FIG. 2 , the actuator  34  includes a D-ring  60  having a selectively movable pin  62 . The D-ring  60  and pin  62  define an opening  63  configured to slidably receive the lap belt  38  thereby enabling relative motion between the lap belt  38  and the actuator  34 . The pin  62  is movable with respect to the D-ring  60 , as indicated by the dashed lines, such that the pin  62  enables the selective release of the outboard portion  42  of the lap belt  38 . 
     Having described the structure in accordance with the preferred embodiment of the present invention, its operation will now be explained with reference to  FIG. 1  for a frontal impact event and  FIG. 3  for a side impact event. During the frontal impact event, the actuator assembly  34  will retain the lap belt  38  with respect to the seat  14 , while the pre-tensioner  30  will retract thereby pulling or tensioning the three-point seat belt  28  to substantially prevent the forward movement of the occupant  26 . 
     During the side impact event, the actuator  34  is commanded to actuate by the control device  56  thereby releasing the outboard portion  42  of the lap belt  38 , as shown in  FIG. 3 . The pre-tensioner  30  will retract thereby pulling or tensioning the three-point seat belt  28  such that the outboard portion  42  of the lap belt  38  is pulled inboard from the outboard side  22  of the base portion  18  of seat  14  and into engagement with the outboard hip  52  of the occupant  26 . As the pre-tensioner  30  continues to tension the three-point seat belt  28 , the occupant  26  is pulled or urged both inward, as indicated by arrow  64 , toward the interior of the vehicle  10  and downward, as indicated by arrow  66 , into the seat  14 . Advantageously, the seat belt assembly  24  of the present invention allows the three-point seat belt  28  to bias the occupant  26  inboard and away from the door panel  12  thereby obviating the need for devices such as, for example, pelvic pusher blocks, pelvic airbags, etc. By mounting the outboard anchor  46  below and rearward relative to the outboard side  22  of the base portion  18  and the outboard hip  52  of the occupant  26 , the forces acting on the occupant  26  by the lap belt  38  are directed such that the occupant  26  is biased downward and rearward into the seat  14 , thereby increasing the frictional forces between the occupant  26  and the seat  14 . Additionally, by mounting the outboard anchor  46  inboard relative to the outboard side  22  of the base portion  18  and the outboard hip  52  of the occupant  26 , the forces acting on the occupant  26  by the lap belt  38  are directed such that the occupant  26  is biased inward toward the interior of the vehicle  10  and away from the point of impact. 
     Referring to  FIG. 4 , an alternate embodiment of the seat belt assembly  24  is shown, generally indicated at  24 A. The seat belt assembly  24 A includes an anchor pre-tensioner  68  preferably positioned within the base portion  18  of the seat  14  and disposed between the anchor portion  44  of the lap belt  38  and the outboard anchor  46 . The anchor pre-tensioner  68  is selectively controlled by the control device  56 . In operation, during a frontal impact event, the pre-tensioner  30  will operate thereby retracting at least a portion of the shoulder belt  36  to tension the three-point seat belt  28 . Similarly, the anchor pre-tensioner  68  is commanded to operate by the control device  56  thereby retracting at least a portion of the anchor portion  44  of the lap belt  38  to further tension the three-point seat belt  28 . As described hereinabove with reference to  FIG. 1 , the actuator  34  will retain the outboard portion  42  of the lap belt  38  with respect to the seat  14  during the frontal impact event. 
     During a side impact event, the actuator  34  is commanded to actuate by the control device  56  thereby releasing the outboard portion  42  of the lap belt  38 . Simultaneously, the control device  56  commands the anchor pre-tensioner  68  to retract at least a portion of the anchor portion  44  of the lap belt  38 . Additionally, the pre-tensioner  30  will retract thereby pulling or tensioning the three-point seat belt  28 . As discussed above with reference to  FIG. 3 , the outboard portion  42  of the lap belt  38  is pulled inboard with respect to the outboard side  22  of the base portion  18  and into engagement with the outboard hip  52  of the occupant  26 . As the pre-tensioners  68  and  30  continue to tension the three-point seat belt  28 , the occupant  26  is pulled or urged both inward toward the interior of the vehicle  10  and downward into the seat  14 . Advantageously, the seat belt assembly  24 A of the present invention allows the three-point seat belt  28  to bias the occupant  26  inboard and away from the door panel  12  during the side impact event. Additionally, by including the anchor pre-tensioner  68  within the seat belt assembly  24 , the “pull in” (i.e., the amount of slack within the three-point seat belt  28  to be retracted) required for the outboard portion  42  of the lap belt  38  to contact the outboard hip  52  of the occupant  26  by each of the pre-tensioners  30  and  68  is reduced. This reduction in pull-in results in reduced response time of the seat belt assembly  24 . Additionally, the pre-tensioners  30  and  68  cooperate to provide simultaneous pulling of the outboard hip  52  of the occupant  26  during the side impact event. 
     Referring to  FIG. 5 , another alternate embodiment of the seat belt assembly  24  is shown, generally indicated at  24 B. The seat belt assembly  24 B includes a buckle pre-tensioner  70  positioned between the inboard anchor portion  48  and the buckle assembly  32 . The buckle pre-tensioner  70  is selectively controlled by the control device  56  and is preferably commanded to operate during both frontal and side impact events. 
     The pre-tensioner  30 , of  FIGS. 1 through 5 , anchor pre-tensioner  68 , of  FIG. 4 , and the buckle pre-tensioner, of  FIG. 5 , may be of any type known in the art, such as those that include a pyrotechnic charge device that may be ignited to retract or tension the three-point seat belt  28 . Alternately the pre-tensioner  30 , anchor pre-tensioner  68 , and buckle pre-tensioner  70  may include a mechanical energy storage device, such as a spring, which may be actuated to retract or tension the three-point seat belt  28  in the event of an impact event. Advantageously, a typical mechanical energy storage device is re-settable such that servicing the device after actuation is less expensive than with a pyrotechnic device which is typically deployable only once. 
     While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.