Abstract:
A seat assembly includes a seat cushion and seat back for supporting an occupant above a floor in a motor vehicle. The seat back is operatively mounted for pivotal movement relative to the seat cushion between an upright seating position and a rearwardly folded bed flat position. A guide link slidably engages the seat cushion for guiding and supporting the seat cushion between a seating position and a raised position. A drive link couples the seat back to the seat cushion for automatically moving the seat cushion between the seating and raised positions, wherein the seat cushion is aligned horizontally level with the seat back, in response to pivoting the seat back between the upright seating position and the rearwardly folded bed flat position.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a seat assembly for a motor vehicle. More particularly, the invention relates to a drive link for automatically moving a seat cushion horizontally level with a seat back in response to pivoting the seat back from an upright seating position to a rearwardly folded bed flat position. 
       BACKGROUND OF THE INVENTION 
       [0002]    Automotive vehicles include seat assemblies for supporting occupants within the vehicle. Seat assemblies include a generally horizontal seat cushion having an upper seating surface and a generally vertical or upright seat back having a front supporting surface. Typically, a lower end of the seat back is operatively coupled to a rear end of the seat cushion by a recliner mechanism allowing for selective pivotal adjustment of the seat back relative to the seat cushion between a plurality of reclined seating positions. 
         [0003]    Oftentimes, the seat back is movable between any of the plurality of reclined seating positions and a forwardly folded stowed position in which the front supporting surface of the seat back is overlying the upper seating surface of the seat cushion. When the seat back is in the forwardly folded stowed position a back surface of the seat back defines a cargo load floor surface. 
         [0004]    Additionally, the seat back may be movable between any of the plurality of reclined seating positions and a rearwardly folded bed flat position in which the front supporting surface of the seat back is generally horizontal. In the rearwardly folded bed flat position, the upper seating surface of the seat cushion and the front supporting surface of the seat back define a bed surface. 
         [0005]    As currently practiced in the seating art, however, the recliner mechanism operatively coupled between the lower end of the seat back and the rear end of the seat cushion results in a step condition between the seat back and seat cushion when the seat back is in the rearwardly folded bed flat position. In other words, when the seat back is moved into the rearwardly folded bed flat position, the lower end of the seat back is disposed higher than or upward of the rear end of the seat cushion resulting in an offset or step condition between the seat back and seat cushion. 
         [0006]    It is therefore desirable to provide a drive link operatively coupled between the seat back and seat cushion to align the upper seating surface of the seat cushion with the front supporting surface of the seat back when the seat back is in the rearwardly folded bed flat position. It is also desirable that the drive link move the seat cushion forward and downward when the seat back is in the forwardly folded stowed position. 
       SUMMARY OF THE INVENTION 
       [0007]    According to one aspect of the invention, a seat assembly is provided for supporting an occupant above a floor in a motor vehicle. The seat assembly includes a seat cushion having an upper seating surface and a seat back having a front supporting surface. The seat assembly also includes a front link that extends between a first end pivotally coupled to the seat cushion and a second end adapted to be pivotally coupled to the floor. The seat assembly includes a guide link slidably couples the seat cushion for guiding and supporting the seat cushion between a forwardly fold flat position, a seating and a raised position. The seat back is operative for selective pivotal movement relative to said seat cushion between a folded forward position, an upright seating position and a rearwardly folded bed flat position generally horizontal. The seat assembly further includes a drive link that extends between a first end pivotally coupled to the seat back and a second end pivotally coupled to the seat cushion. The drive link automatically moves the seat cushion between the forwardly fold flat position, the seating position and the raised position, wherein the upper seating surface of the seat cushion is aligned horizontally level with the front supporting surface of the seat back, in response to pivotal movement of the seat back between a forwardly fold flat position, an upright seating position and a rearwardly folded bed flat position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
           [0009]      FIG. 1  is a side view of a seat assembly in a seating position according to the invention; 
           [0010]      FIG. 2  is a side view of the seat assembly in a stowed position; and 
           [0011]      FIG. 3  is a side view of the seat assembly in a bed flat position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0012]    Referring to  FIG. 1 , a seat assembly for an automotive vehicle is generally shown at  10 . The seat assembly  10  is shown in a seating position and includes a generally horizontal seat cushion  12 . The seat cushion  12  includes an upper seating surface  14  for supporting a seat occupant above a floor  16  of the vehicle, an opposite bottom surface  18 , and side surfaces  20  (one shown). The seat cushion  12  extends between a front end  22  and a rear end  24 . The seat assembly  10  also includes a generally vertical seat back  26 . The seat back  26  includes a front supporting surface  28  for supporting a back of the seat occupant, an opposite back surface  30 , and side surfaces  32  (one shown). The seat back  26  extends between a lower end  34  and an upper end  36 . 
         [0013]    The seat back  26  is operatively coupled to the seat cushion  12  for movement between an upright seating position at A, as shown in  FIG. 1 , a forwardly folded stowed position at B, as shown in  FIG. 2 , and a rearwardly folded bed flat position at C, as shown in  FIG. 3 . The seat assembly  10  is movable between a seating position, shown in  FIG. 1 , a stowed position, shown in  FIG. 2 , and a bed flat position, shown in  FIG. 3 . In the seating position, the seat back  26  is in the upright seating position A and the seat cushion  12  is in a seating position spaced above the floor  16 . In the stowed position, the seat cushion  12  is in a lowered position, downward and forward of the seating position, lying generally along the floor  16  and the seat back  26  is in the forwardly folded stowed position B such that the front supporting surface  28  of the seat back  26  is overlying the upper seating surface  14  of the seat cushion  12 . Finally, in the bed flat position, the seat back  26  is in the rearwardly folded bed flat position C and the seat cushion  12  is in a raised position such that the upper seating surface  14  of the seat cushion  12  is generally horizontally aligned with the front supporting surface  28  of the seat back  26 . 
         [0014]    It will be appreciated that while only one side of the seat assembly  10  is shown in the Figures, both an inboard side and an outboard side are substantially the same. In the embodiment shown, a track assembly, generally indicated at  38 , is provided for adjusting the seat assembly  10  fore and aft within the vehicle. The track assembly  38  includes a lower fixed track  40  that is adapted to be mounted to the vehicle floor  16  and an upper movable track  42  that is selectively slidable with respect to the fixed track  40 . The track assembly  38  is well known in the art and includes assemblies such as disclosed in U.S. Pat. No. 5,741,000 to Goodbred. A front riser  44  and a rear riser  46  are spaced apart and fixedly mounted to the upper movable track  42  for mounting the seat assembly  10  to the track assembly  38 . 
         [0015]    A recliner mechanism  48  is disposed between the lower end  34  of the seat back  26  and a seat back bracket  50  for providing selective angular adjustment of the seat back  26  relative to the seat cushion  12 . The seat back bracket  50  is fixedly mounted to the upper movable track  42 . The recliner mechanism  48  allows the seat back  26  to be adjusted between a plurality of reclined seating positions, one of which is the upright seating position A shown in  FIG. 1 . In addition, the recliner mechanism  48  allows the seat back  26  to be adjusted between any of the plurality of reclined seating positions, the forwardly folded stowed position B, and the rearwardly folded bed flat position C. The recliner mechanism  48  is actuated between a locked condition and an unlocked condition by a release lever (not shown). In the locked condition, the recliner mechanism  48  maintains the seat back  26  in one of the plurality of reclined seating positions. In the unlocked condition, the seat back  26  may be freely adjusted between any of the plurality of reclined seating positions and the forwardly folded stowed position B or the rearwardly folded bed flat position C. 
         [0016]    A front link  52  is disposed adjacent to the side surface  20  of the seat cushion  12 . The front link  52  extends linearly between a first end  54  and a second end  56 . The first end  54  is pivotally coupled to the side surface  20  of the seat cushion  12 , at the front end  22 , by pivot pin  58 . The second end  56  is pivotally coupled to the front riser  44  by pivot pin  60 . 
         [0017]    A guide link  62  is disposed adjacent to the side surface  20  of the seat cushion  12 . In the embodiment shown, the guide link  62  is generally L-shaped and extends between a first end  64  and a second end  66 . An elbow  68  is disposed between the first  64  and second  66  ends. The guide link  62  includes a slot  70  extending along the length of the guide link  62  between the first  64  and second  66  ends. A slide pin  72  is fixedly secured to the side surface  20  of the seat cushion  12 , at the rear end  24 . The slide pin  72  extends laterally from the side surface  20  and is disposed in the slot  70  slidingly coupling the guide link  62  to the seat cushion  12  for guiding and supporting the seat cushion  12  between the seating, lowered, and raised positions. The first end  64  of the guide link  62  is coupled to the seat back bracket  50  by tab  73 . The second end  66  is coupled to the rear riser  46  by fixed pin  74 . When the seat assembly  10  is in the seating position, the slide pin  72  is disposed in the slot  70  at the elbow  68  of the guide link  62 . When the seat assembly  10  is in the stowed position, the slide pin  72  is disposed in the slot  70  at the second end  66  of the guide link  62 . When the seat assembly  10  is in the bed flat position, the slide pin  72  is disposed in the slot  70  at the first end  64  of the guide link  62 . Although not shown, it will be appreciated that the guide link  62  may include a latch for engaging and securing the slide pin  72  in the slot  70  at the elbow  68 , second end  66 , and first end  64  depending on the respective position of the seat assembly  10 . 
         [0018]    A drive link  76  is disposed adjacent to and outboard of the guide link  62 . The drive link  76  extends between a first end  78  and a second end  80 . In the embodiment shown, the drive link  76  has a curvature or bend between the first end  78  and the second end  80 . The first end  78  is pivotally coupled to the side surface  32  of the seat back  26 , adjacent the lower end  34 , by pivot pin  82 . The second end  80  is pivotally coupled to the side surface  20  of the seat cushion  12 , adjacent the rear end  24 , by pivot pin  84 . 
         [0019]    In operation, starting with the seat assembly  10  in the seating position, as shown in  FIG. 1 , the release handle is actuated to unlock the recliner mechanism  48 . The seat back  26  is then pivoted forward toward the forwardly folded stowed position B. The forward pivotal movement of the seat back  26  urges the first end  78  of the drive link  76  forward and the second end  80  of the drive link  76  downward and forward. In response, the seat cushion  12  moves downward and forward. At the same time, the second end  56  of the front link  52  pivots about pivot pin  60  in a counterclockwise direction (when viewed from  FIG. 1 ) and the slot  70  in the guide link  62  guides the slide pin  72  from the elbow  68  to the second end  66  such that the seat cushion  12  moves from the seating position to the lowered position. When the front supporting surface  28  of the seat back  26  abuts the upper seating surface  14  of the seat cushion  12  the seat assembly  10  is in the stowed position, as shown in  FIG. 2 . In the stowed position, the back surface  30  of the seat back  26  is disposed generally horizontal to the floor  16  defining a cargo load floor surface. 
         [0020]    Starting again with the seat assembly  10  in the seating position, the release handle is actuated to unlock the recliner mechanism  48 . The seat back  26  may also be pivoted rearward toward the rearwardly folded bed flat position C. The rearward pivotal movement of the seat back  26  urges the first end  78  of the drive link  76  downward and rearward and the second end  80  of the drive link  76  upward. In response, the rear end  24  of the seat cushion  12  moves upward and the slot  70  in the guide link  62  guides the slide pin  72  from the elbow  68  to the first end  64  such that the seat cushion  12  moves from the seating position to the raised position. When the upper seating surface  14  of the seat cushion  12  is horizontally aligned with the front supporting surface  28  of the seat back  26 , the seat assembly  10  is in the bed flat position, as shown in  FIG. 3 . In the bed flat position, the upper seating surface  14  of the seat cushion  12  and the front supporting surface  28  of the seat back  26  are disposed horizontally relative to the floor  16 . 
         [0021]    The invention has been described here in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of words of description rather than limitation. Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically enumerated within the description.