Abstract:
A folding seat system includes a lower seat portion and a seat back pivotally coupled thereto such that the seat back collapses towards the lower seat portion and opens away from the lower seat portion. Coupled to the seat back is a lumbar support basket including an upper pivot rod pivotally coupled widthwise across the seat back and a lower push rod generally parallel to the pivot rod. The lumbar support basket extends outwardly when the push rod moves upwardly in response to engaging a platform on the lower seat portion and flattens when the push rod moves downwardly in response to disengaging the platform.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to seating in automotive vehicles and, more particularly, to an automobile folding seat system having an automatic lumbar support system.  
       BACKGROUND OF THE INVENTION  
       [0002]     In vehicles, such as vans, mini-vans and sport utility vehicles, folding passenger seating arrangements are constantly being sought for providing large, unimpeded areas for carrying cargo. It is a constant goal to provide folding passenger seating arrangements including comfortable seats. It is also a constant goal to provide cargo areas having increased volume when the seating is stowed for facilitating loading and carrying large sized cargo.  
         [0003]     A number of approaches have been taken to provide this additional cargo room through including folding seating designs. For example, one current solution includes seats detachable from the vehicle. A further example includes seats movable or foldable in a forward direction for creating additional cargo space.  
         [0004]     Currently, however, folding seats are generally flat to allow thin folded thickness. Folding seats are generally required to be as flat as possible, when folded, to maximize storage space within the vehicle. This flatness requirement means the seat, when in the upright position, gives little or no support to the lumbar region of the occupant and may therefore be uncomfortable. Further, those current folding seats having substantial lumbar support also generally have a folded thickness not allowing maximum storage space.  
         [0005]     It is a known objective of all vehicle manufacturers to maximize the available storage area within the vehicle without significantly increasing its size. Increasing the size of the vehicle can be disadvantageous in that it can increase its cost as well as its weight and thereby decrease its fuel efficiency. It is also a known objective of these manufacturers to provide vehicles having increased seating capacity. A delicate balance must therefore be struck between increasing the storage capability of a vehicle and increasing the seating capacity of the vehicle. Further, while increasing seating capacity, it is a constant goal to improve comfort of vehicle seats. The present invention is directed to these ends.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention overcomes the above-stated disadvantages. In one embodiment of the present invention, a folding seat system includes a lower seat portion and a seat back pivotally coupled thereto such that the seat back is collapsible towards the lower seat portion. Coupled to the seat back is a lumbar support basket including an upper rod pivotally coupled widthwise across the seat back and a lower rod generally parallel to the upper rod. The lumbar support basket extends outwardly when the lower rod moves upwardly in response to engaging a section of the lower seat portion and flattens when the lower rod moves downwardly in response to disengaging the section of the lower seat portion.  
         [0007]     This embodiment of the present invention provides several advantages. One such advantage is that it maximizes vehicle space usage. A further such advantage is that it maximizes user comfort by providing a folding seat with lumbar support.  
         [0008]     The present invention itself, together with further objects and attendant advantages, will be best understood by reference to the following detailed description, taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying figures and described below by way of examples of the invention wherein.  
         [0010]      FIG. 1  is a partial cutaway view of an automotive system including a folding seat system in accordance with one embodiment of the present invention.  
         [0011]      FIG. 2  is a perspective view of the folding seat system of  FIG. 1 .  
         [0012]      FIG. 3  is a perspective view of the folding seat system of  FIG. 1  in operation.  
         [0013]      FIG. 4  is a side view of the folding seat system of  FIG. 1  in a collapsed position.  
         [0014]      FIG. 5A  is a close-up view of a push rod system for the folding seat system of  FIG. 1  in accordance with another embodiment of the present invention.  
         [0015]      FIG. 5B  is a close-up view of the push rod system for the folding seat system of  FIG. 1  in operation in accordance with another embodiment of the present invention.  
         [0016]      FIG. 5C  is a close-up partial view of the seat back of the folding seat system of  FIG. 5A .  
         [0017]      FIG. 5D  is a partial side view of the seat back of the folding seat system of  FIG. 5A .  
         [0018]      FIG. 6A  is a close-up view of a lumbar adjuster system for the folding seat system of  FIG. 1  adjusted to provide decreased lumbar support, in accordance with another embodiment of the present invention.  
         [0019]      FIG. 6B  is a close-up view of a lumbar adjuster system for the folding seat system of  FIG. 1  adjusted to provide increased lumbar support, in accordance with another embodiment of the present invention.  
         [0020]      FIG. 7  is a perspective view of the folding seat system in accordance with another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0021]     While the present invention is described primarily with respect to a folding seat for an automotive vehicle, the present invention may be adapted to various application requiring folding seating, as will be understood by one skilled in the art. For example, the present invention may be applied to stadium seating, airplane seating, seating for aerospace or aeronautical vehicles, or any other vehicle or structure requiring folding seating.  
         [0022]     In the following description, various operating parameters and components are described for a number of constructed embodiments.  
         [0023]     The specific parameters and components are included as examples and are not meant to be limiting.  
         [0024]     Referring to  FIG. 1 , a folding seat system  10  within a vehicle  12  is illustrated in accordance with one embodiment with the present invention. The vehicle  12  also includes three other folding seat systems (second folding seat system  14 , third folding seat system  16 , fourth folding seat system  18 ), thereby illustrating that any of the vehicle seats may be stowed for providing increased cargo space in the vehicle  12 . Important to note is that the seat system  10  is upholstered in  FIG. 1 , whereas  FIGS. 2-6B  illustrate unupholstered seat frames  19  for an upholstered seat system  10 .  
         [0025]     Referring to  FIGS. 2-4 , a component view of the interior support structure of the folding seat system  10  of  FIG. 1  is illustrated.  FIG. 2  illustrates a fully opened or upright folding seat system  10 ,  FIG. 3  illustrates a partially opened folding seat system  10 , and  FIG. 4  illustrates a fully closed or collapsed folding seat system  10 .  
         [0026]     The folding seat system  10  includes a seat frame  19  having a seat back  26  pivotally coupled to a lower seat portion  28  through a pivot  30  or pair of pivots. The folding seat system  10  includes a lumbar support system  33  coupled to the seat back  26 , which will be discussed in detail herein. The seat back  26  and lower seat portion  28  are designed such that the seat back  26  folds towards the lower seat portion  28  for stowing the seat system  10 .  
         [0027]     One embodiment of the seat system  10  includes a spring mechanism or reactive member (seat actuator system) for springing the seat back  26  into its upright position when the seat frame  19  is opened. However, any known mechanism may be used for unfolding the seat.  
         [0028]     The seat back  26  includes an upper portion  41 ; a middle portion  44 ; a lower portion  46 ; a lumbar region  45  between the upper portion  41  and the lower portion  46 ; an inner edge  47 , such that said upper portion  41 , the middle portion  44 , and the lower portion  46  have the inner edge  47  in common; and a base portion  48  extending outwardly and at an angle relative to said lower portion  46 .  
         [0029]     Coupled or welded to the lower portion  41  is a push rod tube  51  through which the push rod  52  of the lumbar support system  33  translates, which will be discussed later. Important to note is that, although embodied as having a tube on one side of the seat back, the present invention includes alternate embodiments having tubes on both sides such that the ends of the push rod  52  translate through both tubes.  
         [0030]     The seat back  26  is foldable in an upright position  49 , illustrated in  FIG. 2 , and a collapsed position  53 , illustrated in  FIG. 4 . The seat frame  19  deploys the lumbar support system  33 , which is mechanically activated as the seat back  26  is moved to the upright position  49 . The lumbar support system  33  flattens when the seat back  26  is moved to the collapsed position  53 .  
         [0031]     The lumbar support system  33  includes a collapsible lumbar basket  42  including an upper pivot rod  50  (first rod or upper rod) pivotally attaching to the middle portion  44  of the seat back  26 , a lower push rod  52  (second rod or lower rod), which is substantially parallel to the upper pivot rod  50 , having perpendicular ends  55 , received within the push rod tubes  51 . Between the upper pivot rod  50  and the lower push rod  52  are, in accordance with one embodiment of the present invention, a plurality of substantially parallel rods  56  having ends  58  linked together by a plurality of fasteners  59  (e.g. clamps or crimped fasteners). The ends  58  may be bent such that an end of one of the parallel rods  56  and the end of a lower or upper rod are pivotally coupled within a fastener  59 .  
         [0032]     Alternately, the parallel rods  56  may extend within the fasteners  59 , and joining sections  61  may likewise pivotally couple within the fasteners  59  for joining the parallel rods  56  of the basket  42  together. Numerous other embodiments of the interconnected or mesh configuration of the parallel rods of the basket  42  are also embodied herein.  
         [0033]     The lower seat portion  28  includes a top  70 , a bottom  72 , a top rear  71 , a top front  73 , and a common side  74 . The top  70  is designed such that a passenger may sit thereon. The side  74  is designed with a thickness such that it may fit compactly within a stowage cavity or may occupy a minimal amount of room in a passenger compartment.  
         [0034]     Coupled to the top rear  71  are pivot holders  76  to which the pivot  30  attaches for pivoting the seat back  26  relative to the lower seat portion  28 . Coupled to the pivot holders are platforms  62  (sections of the lower seat portion  28 ), which lumbar basket push rod  52  presses against when the seat  19  is in the upright position  49 . The sections of the lower seat portion  28  are embodied herein as platforms  62 , however, they may further be embodied as latches, hooks, or other means for providing a counter resistance to movement of the lower push rod  52  in one direction as the seat is in the upright position.  
         [0035]     Referring to  FIGS. 5A-5D , an operational view of the seat frame  19  is illustrated including arrows demonstrating movement of components of the seat frame  19 . The lumbar support system  33  automatically changes from curved to flat when the seat back is moved.  
         [0036]     When the seat  19  is placed in the upright position, the lumbar basket push rod  52  presses against the platform  62  and resultantly translates upwards through the push rod tube  51 . Because the lumbar basket  42  is attached to the seat back  26  at the upper pivot rod  50 , the parallel rods  56  of the lumbar basket  42  are forced outwardly relative to the seat back  26  responsive to the translation of the push rod  52 .  
         [0037]      FIGS. 5C and 5D  illustrate that a lower side connector  90  is biased toward the lower seat portion  28  such that the lumbar basket  42  is forced outwardly in a proper manner. In other words, an upward force of the push rod  52  results in the proper outward force of the basket  42  in the lumbar region of the seat.  
         [0038]     Referring to  FIGS. 6A and 6B , an alternate embodiment of the seat frame  19  is illustrated in accordance with another embodiment of the present invention. In this embodiment, the seat frame  19  operates with a lumbar comfort adjuster  100 . One possible scheme for the adjuster  100  is shown.  
         [0039]     The adjuster  100  includes a ratcheting handle  102  rotating a lever system  104 , which raises or lowers the platform  62  on which the lumbar basket push rod  52  sits. This does not interfere with the folding of the seat frame  19 , and the lumbar comfort adjuster  100  adjustment will be retained when the seat frame  19  is brought back to the upright position. Further, the lever system  104  may include a plurality of predetermined positions such that the comfort adjustment of the system  10  may be tailored closely to an individual passenger or a variety of passengers.  
         [0040]     Referring to  FIG. 7 , an alternate embodiment of the seat frame  19  is illustrated in accordance with another embodiment of the present invention. In this embodiment, the basket is embodied as a single thin sheet basket  110  of flexible material, such that the sheet basket  110  bends to form a lumbar support as a function of the interaction of the platform  62  and the push rod  52  as discussed above. The sheet basket  110  defines openings  112  for facilitating bending and reducing stress on the sheet  110 . The sheet basket  110  may also include other design features, such as a recessed portion  114 , for adjusting flexibility of various portions thereof for providing increased passenger comfort. The sheet basket  110  may also include a combination of sheets including different materials, such as plastics, as will be understood by one skilled in the art.  
         [0041]     While the invention has been described in connection with one or more embodiments, it is to be understood that the specific mechanisms and techniques which have been described are merely illustrative of the principles of the invention, numerous modifications may be made to the methods and apparatus described without departing from the spirit and scope of the invention as defined by the appended claims.