Patent Publication Number: US-7219946-B2

Title: Stow in floor seat assembly with automatic lateral displacement

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a seat assembly for an automotive vehicle, and more particularly, to a riser assembly for automatically displacing the seat cushion laterally in response to pivotal movement of the seat cushion between a seating position and a forwardly dumped position. 
   2. Description of the Related Art 
   Automotive vehicles include seat assemblies for supporting occupants within the vehicle. Seat assemblies include a seat cushion and a seat back operatively coupled to the seat cushion by a recliner mechanism for allowing selective pivotal adjustment of the seat back relative to the seat cushion between a plurality of reclined seating positions. Typically, the seat back is also movable between any one of the reclined seating positions and a generally horizontal, forwardly stowed position to present a load floor surface on the back of the seat back. 
   It is known in the automotive seating art to mount a riser assembly between the seat cushion and the floor of the vehicle for moving the seat assembly between a seating position with the seat cushion spaced above the floor of the vehicle and a forwardly stowed position with the seat cushion disposed generally forward of the seating position and lying against the floor of the vehicle. It is also known for such a riser assembly to allow movement of the seat assembly between the seating position and a stowed position within a recess in the floor of the vehicle. However, it remains desirable to have a riser assembly that allows movement of the seat assembly between the seating position and a stowed position that is laterally offset from the seating position. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the invention a seat assembly is provided for supporting an occupant above a floor of an automotive vehicle. The seat assembly includes a seat cushion extending laterally between spaced apart side members. The seat cushion includes a front cross member extending between the side members. Front legs are pivotally assembled at one end to the front cross member for pivotal movement of the seat cushion relative to the front leg between a seating position and a forwardly dumped positions. A rod is connected at a first end to a spaced side member and at a second end to the front leg. The seat cushion is automatically laterally displaced relative to the front legs in response to pivotal movement of the seat cushion relative to the front legs due to changes in the effective length of the rod. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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: 
       FIG. 1  is a side view of a seat assembly incorporating a riser assembly according to one aspect of the invention; 
       FIG. 2  is a side view of the seat assembly; 
       FIG. 3  is a perspective view of the riser assembly; 
       FIG. 4  is a perspective view of a second embodiment of the riser assembly; 
       FIG. 5  is a perspective view of a third embodiment of the riser assembly; and 
       FIG. 6  is a front view of the third embodiment of the riser assembly. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to the figures, a seat assembly for an automotive vehicle is generally indicated at  10  in  FIG. 1 . The seat assembly  10  includes a seat cushion  12  for supporting an occupant above a floor in the vehicle and a seat back  14  for supporting the back of the occupant seated on the seat cushion  12 . A recliner assembly  16  is coupled between the seat cushion  12  and the seat back  14  for providing selective locking and pivotal adjustment of the seat back  14  relative to the seat cushion  12  between a plurality of generally upright seating positions and a forwardly folded flat position, indicated as A in  FIG. 1 , overlying the seat cushion  12 . Described in greater detail below, the seat assembly  10  includes a riser assembly  20  coupled between seat cushion  12  and the floor of the vehicle that allows movement of the seat assembly  10  between a seating position and a forwardly dumped position, indicated as B in  FIG. 2 , offset laterally inboard in the vehicle relative to the seating position. The riser assembly  20  also allows movement of the seat assembly between the forwardly dumped position B and a forwardly stowed position, indicated as C in  FIG. 2 , preferably nested within a recess in the floor that is offset laterally inboard in the vehicle relative to the seating position. Alternatively, the forwarding stowed position may be resting against the upper surface of the floor. 
   Referring to  FIGS. 2 and 3 , the seat cushion  12  includes generally parallel inboard  22  and outboard  24  side members. Front  26  and rear  28  cross members are fixedly secured to and extend axially between the inboard  22  and outboard  24  side members. Preferably, the front cross member  26  is cylindrical. 
   The riser assembly  20  includes generally parallel inboard  30  and outboard  32  front legs extending between the front cross member  26  and pivot pins  31  fixedly supported by brackets  33 . The brackets  33  are fixedly secured to the floor of the vehicle by bolts  35 , or other suitable fastener or methods, such as welding. Each front leg  30 ,  32  extends between an upper end  34 ,  36  and an opposite lower end  38 ,  40 . The lower end  38 ,  40  of each front leg  30 ,  32  is pivotally coupled to one of the respective pivot pins  31  in the floor of the vehicle for movement of the front legs  30 ,  32  between a support position extending generally vertically between the front cross member  26  and the floor of the vehicle and a forwardly folded position generally aligned with the floor of the vehicle, or alternatively, nested within recesses formed in the floor of the vehicle. 
   A bore  42 ,  44  is formed in the upper end  34 ,  36  of each front leg  30 ,  32 . The bores  42 ,  44  of each front leg  30 ,  32  are aligned coaxially for receiving the front cross member  26  therethrough and allowing relative pivotal movement between the front legs  30 ,  32  and the seat cushion  12 . The front cross member  26  is also axially slidable within each bore  42 ,  44  for allowing lateral inboard and outboard displacement of the seat cushion  12  relative to the front legs  30 ,  32 . 
   A guide flange or tube  50  is fixedly secured to the upper end  34  of the inboard front leg  30 . The guide tube  50  is preferably cylindrical and aligned axially with the bores  42 ,  44  for rotatably and slidably receiving the front cross member  26  therethrough. A guide slot  52  is formed in the guide tube  52 . The guide slot  52  is defined by spaced apart and generally helical first  54  and second  56  cam surfaces. A boss  58  protrudes generally radially from the front cross member  26  through the guide slot  52 . The boss  58  rotates with the front cross member  26  and engages the first cam surface  54  during movement of the seat cushion  12  from the seating position to the forwardly dumped position. The engagement between the boss  58  and the first cam surface  54  causes the seat cushion  12  to move laterally inwardly in response to the pivotal movement of the seat cushion  12  between the seating and forwardly dumped positions. Similarly, the boss  58  rotates with the front cross member  26  and engages the second cam surface  56  during pivotal movement of the seat cushion  12  from the forwardly dumped position to the seating position. The engagement between the boss  58  and die second cam surface  56  causes the seat cushion  12  to move laterally outwardly in response to the pivotal movement of the seat cushion  12  between the seating and forwardly dumped positions. 
   An assist spring  60  is coupled between a bracket  62  fixedly secured to the front cross member  26  and the outboard front leg  32  for assisting movement the seat cushion  12  between the seating and forwardly dumped positions. 
   The riser assembly  20  further includes generally parallel inboard  64  and outboard  66  rear legs each extending between an upper end  68 ,  70  and an opposite lower end  72 ,  74 . The upper ends  68 ,  70  of the inboard  64  and outboard  66  rear legs are pivotally assembled to the respective inboard  22  and outboard  24  side members by pivot pins  65 ,  67  for pivotal movement of the rear legs  64 ,  66  between a support position extending generally vertically between the seat cushion  12  and the floor of the vehicle and a stowed position aligned with the side members  22 ,  24 , as best illustrated by the seat cushion  12  in the forwardly dumped position B in  FIG. 2 . The lower end  72 ,  74  of each rear leg  64 ,  66  is selectively latchable to a respective striker bar fixedly secured to the floor of the vehicle and releasable therefrom by a release lever, as understood by persons of ordinary skill in the art. A link  76  extends between each rear leg  64 ,  66  and a respective front leg  30 ,  32  for moving the rear legs  64 ,  66  between the support and stowed positions in response to movement of the seat cushion  12  between the seating and forwardly stowed positions, respectively. Alternatively, a single link interconnects one of the rear legs  64 ,  66  to one of the front legs  30 ,  32  and a rod interconnects the rear legs  64 ,  66  together so that both rear legs  64 ,  66  move between the support and stowed positions in response to the movement of the seat cushion  12  between the seating and forwardly stowed positions, respectively. 
   A plurality of braces or stands  80 , preferably one corresponding to each front leg  30 ,  32  and bracket  33 , each extend between a hook-shaped lower end  82  selectively engaged with a slot  84  formed in one of the respective brackets  33  and an upper end  86  pivotally coupled to the front cross member  26  for moving the lower end  82  in and out of engagement with the slot  84 . While engaged with the slot  84 , the stands  80  maintain the seat cushion  12  in the seating position. A biasing member  88 , such as a clock spring or other suitable biasing means, extends between each front leg  30 ,  32  and one of the corresponding stands  80  for biasing the lower end  82  of the stand  80  toward engagement with the slot  84 . The seat cushion  12  engages the stands  80  during movement between the seating and forwardly dumped positions to move the lower ends  82  of the stands  80  in and out of engagement, respectively, with the slots  84  against the force applied by the biasing member  88 . 
   In use, the front  30 ,  32  and rear  64 ,  66  legs extend generally vertically in the support position to support the seat cushion  12  in the seating position. The lower end  82  of each stand  80  is engaged with the slot  84  in the bracket  33  to maintain the seat cushion  12  in the seating position. The biasing member  88  maintains the lower end  82  engaged with the slot  84 . 
   To move the seat cushion  12  between the seating and forwardly dumped positions, the lower end  72 ,  74  of each rear leg  64 ,  66  is released from latching engagement with the striker bars fixedly secured to the floor of the vehicle. As the seat cushion  12  is pivotally moved from the seating position toward the forwardly dumped position, the boss  58  rotates with the front cross member  26  and engages the first cam surface  54  of the guide tube  50 ; in response, the first cam surface  54  acts upon the boss  58  and displaces the seat cushion  12  laterally inwardly relative to the front legs  30 ,  32 . At the same time, the link  76  pulls the rear legs  64 ,  66  from the support position to the stowed position in response to movement of the seat cushion  12  from the seating position to the forwardly dumped position. 
   When the seat cushion  12  is returned from the forwardly dumped position to the seating position, the boss  58  rotates with the front cross member  26  and engages the second cam surface  56  of the guide tube  50 ; in response, the second cam surface  56  acts upon the boss  58  and displaces the seat cushion  12  laterally outwardly relative to the front legs  30 ,  32 . At the same time, the link  76  pushes the rear legs  64 ,  66  from the stowed position to the support position in response to tie movement of the seat cushion  12  from the forwardly dumped position to the seating position. The lower ends  72 ,  74  latchingly engage the striker bars fixedly secured to the floor of the vehicle to lock the seat cushion  12  in the seating position. 
   Instead of returning the seat cushion  12  to the seating position, the seat back  14  may be moved to the forwardly folded flat position overlying the seat cushion  12  and the seat cushion  12  may be moved between the forwardly dumped position and forwardly stowed position. The seat cushion  12  in the forwardly dumped position engages the stands  80  at the top ends of the stand and pivots the lower ends  82  of the stands to disengage from the slots  84 . Then, the front legs  30 ,  32  are freely movable about the pivot pins  31  to allow movement of the seat cushion  12  together with the seat back  14  between the forwardly dumped position and the forwardly stowed position nested within the recess in the floor of the vehicle. 
   Referring to  FIG. 4 , a second embodiment of the riser assembly  120  is shown for laterally displacing the seat cushion  12  outwardly and inwardly in response to movement of the seat cushion  12  between the seating and forwardly dumped positions, respectively. A guide flange  150  is fixedly secured to the upper end of the inboard front leg  30 . The guide flange  150  includes a helically shaped cam surface  154  formed therein for cammingly engaging the boss  58  during movement of the seat cushion  12  between the seating and forwardly dumped position. An energized biasing member  160  extends between the seat cushion  12  and one of either the outboard  32  or inboard  30  front legs for biasing the seat cushion  12  laterally outwardly. 
   It should be appreciated that the profiles of the first cam surface  54 , the second cam surface  56 , and the cam surface  154  are preferably helical, but can be any suitable shape necessary to achieve a predetermined amount of lateral displacement of the seat cushion  12  in response to a predetermined range of pivotal movement of the seat cushion  12 . 
   Referring to  FIGS. 5 and 6 , a third embodiment of the riser assembly  220  is shown. The riser assembly  220  includes a rod  222  extending generally laterally between the inboard front leg  30  and the outboard side member  24 . The rod  222  pulls and pushes the seat cushion  12  laterally inwardly and outwardly relative to the front legs  30 ,  32  in response to the pivotal movement of the seat cushion  12  between the forwardly dumped and seating positions, respectively. More specifically, the rod  222  extends axially between inboard  224  and outboard  226  ends. The inboard end  224  of the rod  222  is rotatably coupled to the inboard front leg  32 . Similarly, the outboard end  226  of the rod  222  is rotatably coupled to the outboard side member  24 . The effective length of the rod  222  shortens as the seat cushion  12  rotates about the front legs  32 ; thereby resulting in the lateral displacement of the seat cushion  12 . As the seat cushion  12  is moved to the forwardly dumped position from the seating position, the effective length of the rod  222  decreases forcing the seat cushion  12  laterally inward. Conversely, as the seat cushion  12  is returned to the seating position from the forwardly dumped position the effective length of the rod  22  is increased resulting in the outward lateral displacement of the seat cushion  12 . 
   An abutment bracket  228  is fixedly secured to the front cross member  26 . A biasing member  230  is energized in compression between the inboard front leg  30  and the abutment bracket  228  for biasing the seat cushion  12  laterally outwardly. Alternatively, the biasing member  230  may be tensioned between the inboard front leg  30  and the abutment bracket  228  for biasing the seat cushion  12  laterally inwardly and pivotally toward the forwardly dumped position B. 
   The invention has been described in an illustrative manner, and it is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of 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 described.