Abstract:
A height adjustable seat for wheelchair having a frame, wheels, a wheelchair seat and back operably connected thereto includes a base with connector for connecting the base to the frame of the wheelchair, a seat, and an elevator operably connecting the base and the seat for adjustably elevating the seat to a selectable height, a remote control therefor, and wherein there are provided an anti-pinch point covers and torsion spring mechanisms to aid the elevation of the seat.

Description:
BACKGROUND OF INVENTION  
         [0001]    This invention concerns improvements in or relating to a height adjustable seat primarily for use on a wheelchair and like apparatus for raising and lowering a seat of a wheelchair.  
           [0002]    The present invention is an improvement over the teachings in U.S. Pat. No. 5,695,248 which pertained to a retrofit adjustable seat for connection to a conventional wheelchair having a frame, wheels, a wheelchair seat and back operably connected thereto. Such a seat comprised a base with releasable connector for connecting the base to the frame of the wheelchair, a retrofit seat, and an elevator operably connecting the base and the retrofit seat for adjustably elevating the retrofit seat to a selectable height.  
           [0003]    Even with the improvements made to the art, there remains a need to improve the art. Particularly, the height adjustable seats for a wheelchair may expose a person to certain pinch-points during operation of the seat and or wheelchair. Accordingly, the present invention aims to improve on the art to overcome the problem of pinch-point exposure thus making a device for adjusting seat height of a conventional wheelchair in a safer manner.  
         BRIEF SUMMARY OF INVENTION  
         [0004]    It is an object to improve wheelchairs.  
           [0005]    It is another object to provide an improved height adjustable seat for a wheelchair while minimizing pinch-point exposure to the user  
           [0006]    It is yet another object to provide a height adjustable seat for a wheelchair having improved elevation apparatus.  
           [0007]    Accordingly, the invention is directed to an anti-pinch point cover connectable to a seat for adjustably elevating the seat to a selectable height with respect to a wheel chair. In a preferred embodiment, the anti-pinch point cover includes a pair of side arm flaps and a leg flap which are associated with the height adjustable seat to extend over side arms and leg supports of a wheelchair, respectively, during operation of the height adjustable seat. The cover also includes a back support panel. There is also provided improved elevation spring based apparatus to ease the elevation of the seat. Further, a remote control is provided. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0008]    [0008]FIG. 1 is a perspective view of the retrofit adjustable seat of the present invention.  
         [0009]    [0009]FIG. 2 is a perspective view of a wheelchair with the retrofit adjustable seat of the present invention.  
         [0010]    [0010]FIG. 2 a  is a perspective view of another embodiment wheelchair with the retrofit adjustable seat of the present invention.  
         [0011]    [0011]FIG. 3 is a side view of the retrofit adjustable seat of the present invention.  
         [0012]    [0012]FIG. 3 a  is a side view of the retrofit adjustable seat of the present invention.  
         [0013]    [0013]FIG. 4 is a front view of retrofit adjustable seat of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]    Referring to the drawings, the adjustable seat  10  which is here shown to include a base  12  which is connected to the side frame member  14  of a wheelchair W through use of brackets  16  which are fixably slidably connected to the base  12 . The base  12  may be formed of any resilient and strong material, preferably a light weight plastic, providing ease of portability along with strength. It is also contemplated that the present invention may be integrally formed as part of the wheelchair W or as a retrofit seat therefor.  
         [0015]    In the case of a retrofit, FIGS. 3 and 4 depict the brackets  16  as generally planar and elongated having an open surface  18  therein and a terminal end  20  which is slightly arcuate. Screws  22  are provided of a size such that the threads thereof are less in diameter than the open surfaces  18  and are received within threaded open surfaces  24  of the base  12  to enable connection of the brackets  16  to the base  12  When the screws  22  are loosened, the brackets  16  may be lengthwise positioned and then fixed in place by tightening screws  22  to the base  12 .  
         [0016]    When the wheelchair W is opened the wheelchair side frame members  14  typically open to a first predetermined spacing The wheelchair side members  14  open to a second maximum spacing when a person sits on the wheelchair W. The wheelchair side members  14  return to the first spacing when the person gets off the wheelchair W.  
         [0017]    The brackets  16  are positioned such that a distance between the ends  20   a  and  20   b  are slightly greater than the second distance to accommodate the side members  14  in their maximum spaced relation The arcuate terminal ends  20   a  and  20   b  are in a fixed contact with the wheelchair side members  14  to hold the adjustable seat  10  in place until the person gets off of the wheelchair W, at which time the wheelchair side members  14  return to their first spaced relation to permit removal of the retrofit adjustable seat  10 . Also, the screws  22  can be loosened to aid the removal of the retrofit adjustable seat.  
         [0018]    Means  26  for elevating are provided and include a base support member  28  connected to the base  12 , side support members  30  and  31 , and a top support member  32 . An end  33  of side support member  31  is hingedly connected to an end  35  of side support member  30 . An end  36  of side support member  31  is hingedly connected to top support member  32  and an end  37  of side support member  30  is hingedly connected to base support member  28 . Interconnecting members  38  are also provided, which interconnect ends  33  and  35  and each have a threaded open surface  40  which coaxially align. A threaded bar  42  has opposite threaded ends and threads to open surfaces  40 . In this way, the side support members  30  and  31  performs scissors like function of opening and closing upon the threading and unthreading of the bar  42 .  
         [0019]    The elevating means  26  includes a motor  48  which is slidably connected to a linear race track  50  which in turn is connected to the base  12 . The motor  48  includes a jointed rotatable shaft  60  extends from the motor  48  and fixably connects to the end of the threaded shaft  42 . A stop  61  limits translational movement such that the threaded bar  42  does not thread beyond and out of the threaded open surfaces  40 . The motor  48  can be powered by a battery  49  or other energy source, for example, which can be connected to the base  12 . Further, torsion springs  58  are fixably connected at their ends to support members  30  and  31  such that they are normally in a relaxed state when the support members  30  and  31  are in an extended position and seat  44  is in a raised position. Thus, the springs  58  aid to normally bias the seat  40  toward a raised position which in turn reduces the amount of work to be done by the motor  48 . It is contemplated that other springs such as extension springs can be employed, for example, interconnecting the interconnecting members  38  to further aid in raising the seat  44 .  
         [0020]    The seat  44  is connected to the top support member  32 . The seat  44  preferably includes a bottom made of rigid material to support an individual when seated thereon as well as a soft cushion disposed on top of the bottom. The seat  44  may be formed in any variety of configurations. For example, the seat  44  may be formed with a central raised edge portion  46  the purpose of which is to aid in leg comfort and support to the user as well as provide additional space therebeneath for accommodating the motor  48 .  
         [0021]    An electronic controller receiver  70  is operably connected to the motor  48  and battery  49  to cause activation of the motor  48  in forward and reverse directions A remote control transmitter  71  is provided with an internal battery power source and equipped to send signals to the receiver  70  to cause rotation forward, backward or to stop rotation. Optionally, a control can operably connect to the motor  48  and battery  49  and can be disposed adjacent the seat  44  or on the wheelchair W. The control may be a hand operated switch or a joy stick mounted on a cord, for example, wherein moving the switch or joy stick one direction raises the seat  44  and moving the switch or joy stick in another direction lowers the seat.  
         [0022]    A flexible expandable boot cover (side cover)  64  can be optionally included to cover the seat  10 , elevating means  26  and base  12 . The cover  64  can be of any suitable cloth or synthetic material.  
         [0023]    An anti-pinch point cover  100  and is intended to compliment the adjustable seat  10 . The anti-pinch point cover  100  can be fabricated from a polymer, polyfoam and or cloth material for example. The cover  100  may be formed of any flexible or resilient and strong material, preferably a light weight plastic and which provides ease of portability. The cover  100  includes a pair of side flaps  112  which can be connected to the base  12  and are of a sufficient length and flexibility to remain draped over a side arm members  114  of wheelchair W. Further a leg flap  116  can be connected to the base  12  and is of sufficient length and flexibility to remain draped over leg supports  118  of the wheelchair W. A back panel  120  can also be provided to connect to the seat  44  and extend upwardly to form a back rest therefor.  
         [0024]    Finally, it is now contemplated by the inventor that the ends  20   a  and/or  20   b  can be formed in with a slot  21   a , for example, and the side member  14  include a threaded bores  124  to receive locking wing nuts  23   a . Thus, this provides for a substitute seat of the wheelchair W. In this embodiment, the end  20   b  of the brackets  16  can be loosened and slid inwardly such that the adjustable seat  10  can swing or pivot to a vertical position and hang by ends  20   a . The present invention now provides a compact means for either retrofitting a conventional wheelchair or providing an integral wheelchair which includes the features of an improved height adjustable seat and means for collapsing the wheelchair with the eight adjustable seat attached thereto in a conventional manner, i.e, inwardly from the wheelchair&#39;s sides.  
         [0025]    While the present invention has been set forth above in a preferred embodiment, it is contemplated that other modifications, improvements and derivations will be readily apparent to those skilled in the art. For example, it is contemplated that the support members  30  and  31  could be alternatively designed as shown in FIG. 3 a . Accordingly, the appended claims hereto should be accorded the full scope of protection of any such modifications, improvements and derivations.