Abstract:
A module that is adapted to be situated between a base and a seat. The module has ends that are independently adjustable to selectively raise the seat, lower the seat, and tilt the seat. The module is particularly suitable for use with a wheelchair to selectively raise, lower, and tilt the wheelchair seat.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application No. 60/621,526, filed on Oct. 22, 2004. 
     
    
     BACKGROUND OF INVENTION  
       [0002]     This invention relates in general to personal mobility vehicles and more particularly, to accessories for personal mobility vehicles. Most particularly, this invention relates to the seating aspect of wheelchairs and like vehicles.  
         [0003]     It is known to provide a lifting device for adjusting the height of the seat of a wheelchair. Such a device enables a person seated in the seat to be raised or lowered. However, known lifting devices are of limited use in that the devices are usually permanently fixed to the wheelchair and may encumber the same.  
         [0004]     To address the foregoing deficiencies, there has been provided a device, which serves as a height adjustable seat for a conventional wheelchair, and which is removable in nature. However, this device has a motor, which adversely affects the minimum height of the seat. Moreover, the motor requires power, and thus is not suitable for use with a manual wheelchair. Further, the device functions only to lift the wheelchair seat, not to tilt the wheelchair seat, as is often desired.  
         [0005]     Thus, while a current device enables a disabled person to adjust the height of the wheelchair seat, there is no simple way to change a conventional manual wheelchair to permit its seat to be tilted or lifted without adversely affecting the minimum height of the wheelchair. What is need is a lifting device for adjusting the tilt angle or height of the seat of a manual wheelchair without adversely affecting the minimum height of the seat.  
         [0006]     The present invention is directed towards a lifting device that meets the foregoing needs. The device comprises a module that is adapted to be situated between a base and a seat. The module has ends that are independently adjustable to selectively raise, lower, and tilt the seat.  
         [0007]     The present invention is also directed towards a wheelchair comprising a base, a seat, and a module between the base and the seat. The module has ends that are independently adjustable to selectively raise the seat, lower the seat, and tilt the seat.  
         [0008]     Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0009]      FIG. 1  is a side perspective view of a adjustable manual tilt/lift module of the present invention at its maximum height.  
         [0010]      FIG. 2  is a side elevational view of the module shown in  FIG. 1 .  
         [0011]      FIG. 3  is a side elevational view of the module at its intial or minimum height.  
         [0012]      FIG. 4  is a bottom plan view of the module shown in  FIG. 3  with a bottom plate removed to shown threaded engagement of adjustment shafts.  
         [0013]      FIG. 5  is a side elevational view of the module at its maximum negative angle.  
         [0014]      FIG. 6  is a side elevational view of the module lowered and at a negative angle.  
         [0015]      FIG. 7  is a side elevational view of the module at its maximum positive angle.  
     
    
     DETAILED DESCRIPTION  
       [0016]     Referring now to the drawings, there is illustrated in  FIG. 1  an adjustable manual tilt/lift module  10 , which is adapted to support a wheelchair seat (not shown) relative to a wheelchair base (also not shown).  
         [0017]     As seen in  FIGS. 1-4 , the module  10  includes a bottom support member, such as the bottom plate  12  shown, intermediate support members, such as the primary links  14 ,  16  shown, and a top support member, such as the top plate  18  shown. Top ends of the primary links  14 ,  16  are pivotally connected to opposing ends of the top plate  18 . Bottom ends of the primary links  14 ,  16  are slidably and pivotally connected to the bottom plate  12 . Interconnecting members, such as the secondary links  20 ,  22  shown, interconnect ends of the bottom plate  12  to the intermediate portions of the primary links  14 ,  16 . At the bottom ends of the primary links  14 ,  16  are adjustable drive or nut bars  24 ,  26 , which are provided with threaded openings. At the bottom ends of the secondary links  20 ,  22  are slide bars  28 ,  30 , which are provided with non-threaded openings. At opposing ends of the bottom plate  12  are end bars  32 ,  34 , which are fixed relative to the bottom plate  12 , and which are provided with non-threaded openings. Adjustment shafts, such as the threaded bars  36 ,  38  shown, pass through the non-threaded openings in the end bars  32 ,  34 , the non-threaded openings in the slide bars  28 ,  30 , and thread to threaded openings in corresponding nut bars  24 ,  26 . It should be appreciate that one of the threaded bars  36  passes through a non-threaded opening in one of the nut bars  26  and threads into the threaded opening in the other nut bar  24 . Similarly, the other threaded bar  38  passes through a non-threaded opening in one of the nut bars  24  and threads into the threaded opening in the other nut bar  26 .  
         [0018]     A knob  40 ,  42  is associated with an end of each threaded bar  36 ,  38  and a collar  44 ,  46  is associated with an opposing end of each threaded bar  36 ,  38 . The knobs  40 ,  42  and collars  44 ,  46  hold the threaded bars  36 ,  38  in a substantially fixed axial position with respect to the end bars  32 ,  34  and the bottom plate  12 . The knobs  40 ,  42  can be independently hand operated to independently turn the threaded bars  36 ,  38 . Turning each knob  40 ,  42  in one direction raises a corresponding end of the top plate  18 , as shown in  FIGS. 1 and 2 , and turning each knob  40 ,  42  in a opposite direction lowers a corresponding end of the top plate  18 , as shown in  FIG. 3 . From an initial position shown in  FIG. 3 , turning one knob  42  raises one end of the top plate  18  to produce a negative tilt angle, as shown in  FIG. 7 , and turning the other knobs  40  raises one end of the top plate  18  to produce a positive tilt angle, as shown in  FIG. 6 . It should be appreciated that the knobs  40 ,  42  can be turned as desired to produce a combination of a desired tilt and lift, as shown in  FIG. 5 .  
         [0019]     A seat (not shown) is adapted to be supported by the top plate  18 . The seat preferably includes a bottom made of rigid material to support a person when seated thereon as well as a soft cushion disposed on top of the bottom. The seat may be formed in any variety of configurations. For example, the seat may be formed with a central raised edge portion, the purpose of which is to aid in leg comfort and support to the user. By raising and lowering the top plate  18 , the seat is lifted or tilted accordingly.  
         [0020]     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.