Abstract:
A vehicle seat includes a seat portion and an adjustable backrest portion which is movable between a forward operating position and a rearward operating position relative to the seat portion. Both the upper and lower sections of the backrest portion move upwardly relative to the seating portion when the backrest portion moves from the forward operating position to the rearward operating position. A lockable adjustment mechanism is included to enable a user to lock the backrest in a suitable position from the forward to the rearward operating positions.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to vehicle seats, and, more particularly, to adjustable vehicle seats for use in compact vehicles. 
     There is a demand for low and zero emissions commuter vehicles in areas with significant air pollution, such as large cities in California. In order to maximize efficiency, low and zero emissions vehicles frequently are designed with a streamlined contour. As a result, the cabin space is often quite limited. It would be useful to provide for such vehicles a vehicle seat which can be adjusted for users of various heights, and which takes up minimal space in the vehicle cabin. 
     It is an object of the present invention to provide a novel seat for use in compact commuter vehicles. 
     It is also an object to provide such a vehicle seat which can be adjusted for the comfort of drivers and/or passengers of various heights. 
     Another object is to provide such a vehicle seat which fits in a small cabin area and has a low center of gravity. 
     A further object is to provide such an adjustable vehicle seat which is sturdy and strong. 
     Yet another object is to provide a vehicle seat which can be quickly and conveniently adjusted by the user. 
     SUMMARY OF THE INVENTION 
     It has now been found that the foregoing and related objects may be readily attained in a vehicle seat comprising a seat portion having a forward end and a rearward end, support means for supporting the seating portion on a base wall of the vehicle, a backrest portion having an upper section and a lower section. The lower section is disposed adjacent the rearward end of the seating portion, and mounting means is provided for adjustably mounting the backrest portion on a generally vertical wall of the vehicle. The mounting means permits movement of the backrest portion between a forward operating position and a rearward operating position relative to the seat portion. Both the upper and lower sections of the backrest portion move upwardly relative to the seat portion when the seat moves from the forward operating position to the rearward operating position. The vehicle seat also includes adjustment means for adjusting the backrest portion into a desired position from the forward to the rearward operating position. 
     Desirably, the mounting means comprises first pivot means for pivotably connecting the lower section of the backrest portion to the generally vertical inner wall, and second pivot means for pivotably connecting the upper section of the backrest portion to the vertical inner wall. 
     Preferably, the adjustment means comprises spring means which may be a gas spring and, which most preferably is lockable in a multiplicity of adjusted positions. 
     Desirably, the adjustment means also includes lever means for adjusting the spring means. 
     Usually, the support means includes third pivot means for pivoting the seating portion between a seating position and a storage access position. 
     In one preferred form of the invention, the vehicle seat further comprises a headrest portion formed as a part of the backrest portion. The lower section of the backrest portion preferably includes a lumbar support portion. 
     In installing and using the seat of the present invention, there is provided an adjustable vehicle seat having a seat portion, and a backrest portion with upper and lower sections. The seat portion is supported in an operating position on a base wall in the vehicle, and the backrest portion is adjustably mounted on a vertical inner wall of the vehicle by providing a first pivot means connecting the upper section of the backrest portion to the vertical inner wall and a second pivot means connecting the lower section of the backrest portion to the vertical inner wall. The first and second pivot means permit movement of the backrest portion between a forward operating position and a rearward operating position relative to the seat portion. The method also includes mounting lockable spring means between the backrest portion and the vertical inner wall of the vehicle for locking the backrest portion in a selected position relative to the seat portion. 
     Desirably, the lockable spring means comprises a gas spring, and there is installed lever means for actuating the spring means. 
     Preferably, the seat portion is pivotally mounted, and this enables the seating portion to pivot between a seating position and a storage access position. 
     Desirably, the method also includes providing a headrest portion on the backrest portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a vehicle seat embodying the present invention, the backrest being shown in full line in the rearward position and in phantom line in the forward position; 
     FIG. 2 is a front elevational view of the vehicle seat with the bracket system for adjusting the backrest being shown in broken lines; 
     FIG. 3 is a front elevational view of the vehicle seat showing the upward pivoting of the seat cushion; 
     FIG. 4 is a top plan view of the vehicle seat with the seat cushion in the operating position; 
     FIG. 5 is a side elevational view of the vehicle seat with the seat cushion pivoted upwardly; and 
     FIG. 6 is a top plan view of the vehicle seat with the seat cushion in the storage access position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning first to FIGS. 1-4 of the attached drawings, therein illustrated is a vehicle seat with an adjustable backrest and generally designated by the numeral  10 . The vehicle seat  10  is comprised of a seat cushion  12  which is pivotably connected to a base wall  14  in the vehicle cabin  15  by first and second hinge assemblies  16  and  17 . The vehicle seat  10  also includes a backrest  18  which is connected to the rear wall  20  of the vehicle cabin  15  by a bracket system generally designated by the numeral  22 . 
     Turning now in detail to the seat cushion  12 , it has a forward end  24 , a rearward end  26 , a left side  27 , a right side  28 , a top  29 , and a bottom  30 . The bottom  30  of the seating cushion  12  has a vapor seal  31  affixed thereto to prevent battery vapors from entering the vehicle cabin  15 . The first and second hinge assemblies  16  and  17  pivotably connect the left side  27  of the seat cushion  12  along the bottom  30  to the base wall  14 . 
     As shown in FIGS. 4-6, the first and second hinge assemblies  16 ,  17  include first and second bosses  32 ,  33  on the base wall  14  of the cabin  15 , and corresponding first and second brackets  34 ,  35  mounted on the bottom  30  of the seating cushion  12 . A first tubular member  36  is provided in a passageway through the first boss  32  and a first pivot pin  38  extends through the ears on the first bracket  34  and first tubular member  36  to provide a pivotal connection. Similarly, a second tubular member  37  is provided in a passageway through the second boss  33  and a second pivot pin  39  extends through the ears on the second bracket  35  and second tubular member  37  to provide a pivotal connection. 
     The seat cushion  12  can be pivoted upwardly, as is shown in FIG. 3, by releasing a latch  40 , part of which is disposed on the bottom  30  of the seat cushion  12  at the forward end  24 . A storage compartment  61  is positioned under the base wall  14  for storage of batteries  42  or other equipment. The storage compartment  61  is accessed by pivoting the seat cushion  12  upwardly. 
     The latch  40 , shown in detail in FIGS. 1,  3  and  6 , includes a first locking pin  41  depending from the bottom  30  of the seat cushion  12 . The first locking pin  41  has an aperture  42  which receives the end of a horizontal, spring loaded second locking pin  43  which has a pull knob  44  at the front of the seat  10 . The second locking pin  43  extends horizontally through a vertical portion of the base wall  14  and into the storage compartment  61  where it engages the aperture  42  in the first locking pin  41  in order to hold the seating cushion  12  in an operating position. 
     The seat cushion  12  is aligned in a seating or operating position by a front alignment pin  45  and a rear alignment pin  46 , which are formed on the right side  28  along the bottom  30 . The front alignment pin  45  is received in a bore  47  formed in a front pin alignment pad  48  in the base wall  14 . The rear alignment pin  46  is received in a bore  49  formed in a rear pin alignment pad  50  in the base wall  14 . 
     Turning now to the backrest  18 , it has an upper section generally designated by the numeral  51 , a lower section generally designated by the numeral  52 , a rear side  54  and a front side  56 . The lower section  52  includes a rounded projection  53  configured to support the lumbar region of the driver&#39;s back. In the illustrated embodiment, the backrest  18  also includes an integral headrest  58  at the top of the upper section  51 . 
     The bracket system  22  which mounts the backrest  18  on the rear wall  20  of the vehicle cabin  15  includes a first upper pivot rod  60  pivotably mounted on the rear side  54  of the upper section  51  by a first upper mounting plate  62 . First and second connecting arms  63 ,  64  are pivotably connected to opposite ends of the first upper pivot rod  60  at their upper ends  65 ,  66  respectively. The lower ends  67 ,  68  of the first and second upper connecting arms  63 ,  64  are pivotably mounted to the rear wall  20  by a second upper pivot rod  69  which is mounted on rear wall  20  by a pair of second upper mounting plates  70 ,  71 . 
     The bracket system  22  also includes a first lower pivot rod  72  which extends horizontally across the rear side  54  of the backrest  18  at the lower section  52 . The pivot rod  72  is pivotably mounted on the backrest  18  by a first lower mounting plate  73 . First and second lower connecting arms  74 ,  75  are pivotably connected to opposite ends of the first lower pivot rod  72  at their upper ends  76 ,  77 . The lower ends  78 ,  79  of the first and second lower connecting arms  74 ,  75  are connected to opposite ends of a second lower pivot rod  80  which is mounted on the rear wall  20  of vehicle cabin  15  by a pair of second lower mounting plates  82 ,  83 . 
     In a preferred form of the invention, the upper and lower connecting arms  63 ,  64 ,  74  and  75  are attached to a roll bar portion of the vehicle, resulting in a strong and lightweight structure. When viewed from the side, the upper and lower connecting arms,  63 ,  64 ,  74  and  75 , in conjunction with portions of the rear wall  20  and the rear side  54  of backrest  18 , form a quadrangle that generally resembles a parallelogram when the backrest  18  is in the forward position. This quadrangle is shown in FIG. 1 by segments a, b, c, and d. It is noted, however, that each segment of the quadrangle has a different length in the preferred embodiment of the invention, thereby resulting in a slightly non-parallel arrangement. 
     The backrest  18  can be pivotably adjusted from a forward and low position, shown in broken lines in FIG. 1, to a rearward and elevated position, shown in solid lines in FIG.  1 . Elevation of the backrest  18  as it is moved rearwardly elevates the headrest to a accommodate a taller operator. In accordance with the preferred embodiment of the invention, the backrest  18  also can be releasably fixed at any desired pivoted position between the forward and rearward positions. This important feature of the invention enables the seat  10  to be adjusted for the comfort of a particular user. 
     More specifically, the desired position of the backrest  18  relative to the rear wall  20  is fixed by a gas spring  90  which is housed in a spring support compartment  92  which extends rearwardly through the rear wall  20  of the vehicle cabin  15 . The gas spring  90  has a cylinder  94  which houses a piston (not shown) connected to a rod  100  that extends outwardly from the cylinder  94 . As is shown in FIG. 5, the outer end of the rod  100  is pivotably connected to the first and second lower connecting arms  74 ,  75  by a horizontally extending gas spring support rod  102 . Rod  100  moves rearwardly into the cylinder  94  when the backrest  18  is pivoted to a rearward and elevated position, as is shown in solid line in FIG.  1 . The rod  100  extends outwardly from the tube or cylinder  94  when the backrest  18  is pivoted to a forward and lower position, as is shown in broken lines in FIG.  1 . The rearward end  104  of gas spring  90  is mounted in the spring support compartment  92  on a support rod  106 , the end of which is shown in FIG.  5 . 
     A release valve  108  is positioned toward the lower end of the cylinder  94  for adjusting the gas spring, thereby causing pivotal movement of the backrest  18 . When release valve  108  is opened, the piston is movable within cylinder  94  in either direction. When the release valve  108  is closed, the piston rod  100  is fixed in whatever position it assumed at the time of valve closure. In this manner, a user can open the release valve  108  in order to adjust the backrest  18  to a comfortable position, and subsequently close release valve  108  to maintain the backrest  18  in that desired position. 
     In a particularly preferred embodiment of the invention, control of gas spring  90  by a user is facilitated by a valve adjustment lever  110  which is conveniently positioned beside the seat cushion  12 . The valve adjustment lever  110  includes a lever arm  114  which can be moved manually forwardly and backwardly by an operator in order to open and close release valve  108 , by the cable  116  which connects the lever  110  to the release valve  108 . 
     While in the preferred embodiment pivotal movement of backrest  18  is effected by a gas spring, other mechanical and electromechanical adjustment mechanisms can also be used, including a hydraulic spring, a coil spring or an electric linear actuator. 
     One of the significant advantages of having a fixed operating position for the seat cushion  12  in accordance with the preferred embodiment of the invention is that no seat cushion adjustment mechanism, e.g., sliding track or the like, needs to be positioned beneath the seat cushion. By eliminating such an adjustment mechanism, the seat cushion can be designed lower in the vehicle, thereby lowering the center of gravity and providing more room in the driver compartment. Furthermore, the use of a compact seat adjustment mechanism enables the vehicle to be designed with an aerodynamically efficient configuration. 
     Thus, it can be seen from this foregoing detailed description and attached drawings that the vehicle seat of the present invention is one that provides multiple advantages when used in a compact vehicle, such as an electric car.