Abstract:
A wheelchair has a reclined configuration and an upright configuration. In the upright configuration, the seat of the wheelchair is at least substantially perpendicular to a back support and located at a first elevation. An actuator is useful to lift the seat during the movement to the reclined configuration to a second elevation higher than the first elevation. Outriggers move to load bearing position in the reclined configuration to assist in supporting weight on the back support. An installed litter is useful in assisting patient movement to and from the wheelchair.

Description:
CLAIM OF PRIORITY 
   This application claims the benefit of U.S. Provisional Patent Application No. 60/545,209 filed Feb. 18, 2004. 

   FIELD OF THE INVENTION 
   The present invention relates to wheelchairs and more particularly to a reclining wheelchair which facilitates transfer of a patient from the wheelchair to a bed or for otherwise providing increased comfort to a patient in a wheelchair. 
   DESCRIPTION OF RELATED ART 
   Numerous efforts have been directed toward providing reclining wheelchairs such as U.S. Pat. No. 6,799,770 which shows a wheelchair configured to cooperate with a bed. This wheelchair locks to the bed during patient transfer from the wheelchair to the bed. This wheelchair provides a reclining back, but does not have a traditional self-operable set of wheels so that an individual with the use of their hands could propel themselves. 
   U.S. Pat. No. 6,715,784 shows a much more user friendly wheelchair which operates by motor-driven wheels. The disclosure appears to focus more on a reclining aspect of the back but does not appear to provide an ability to easily transfer a patient from this wheelchair to a bed. 
   Accordingly, even though similar efforts have been made to provide a patient friendly reclining back wheelchair, improvements are still believed to be desirable. 
   SUMMARY OF THE INVENTION 
   A need exists for a wheelchair capable of reclining for either patient comfort and/or either to transfer a patient from a wheelchair to a hospital bed. 
   Another need exists for a reclining wheelchair which provides the seat of a patient at a higher elevation when the patient is reclined than when sitting. 
   Another need exists for a reclining wheelchair which resists tipping over when in the reclining position. 
   Accordingly, a wheelchair according to the presently preferred embodiment of the present invention provides a seat operably coupled to a frame and a back support operably coupled to the seat. An actuator is useful to transition the wheelchair from an upright configuration wherein the back support is at least substantially perpendicular to the seat to a reclined position in which the seat and back support are at least substantially parallel. 
   In the preferred embodiment, during the transition from the upright configuration to the recline configuration the seat is elevated from a lower sitting position to a higher position so that the transfer to the hospital bed may be easier. Additionally, in the reclined position, outriggers are useful to stabilize the back support relative to a surface that the wheels of the wheelchair are transported over. Finally, a litter is useful when used in combination with the wheelchair. The litter is at least flexible if not hinged at key locations such as where the back support and the seat meet as well as where the seat support and the leg support meet so that the litter is unobstructed when utilized in conjunction with the wheelchair. When the wheelchair is placed in the reclined position, the litter can then be detached from the wheelchair and be utilized to transfer a patient to a hospital bed. 

   
     DESCRIPTION OF THE DRAWINGS 
     The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which: 
       FIG. 1  is a side plan view with the wheels shown in phantom of a wheelchair constructed in accordance with the presently preferred embodiment of the present invention in an upright configuration; 
       FIG. 2  is the wheelchair of  FIG. 1  shown in a reclined configuration; 
       FIG. 3  is a top plan view of the litter shown in  FIG. 1  removed from the wheelchair; and 
       FIG. 4  shows the litter shown in  FIG. 1  in operation. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  shows a side plan view of a wheelchair  10  of the presently preferred embodiment of the present invention. The wheelchair  10  provides a seat  12  and a back support  14 . Arm rests  16  as shown in an in use position in  FIG. 1  which allows a user to rest his or her arms thereupon. Large wheels  18  are disposed on left and right sides of seat  12  to allow an individual sitting in the wheelchair  10  to grab the large wheels  18  to propel his or herself. Note that the top of the wheel  20  extends a distance above the seat  12  in the upright configuration. 
   The arm support  16  is illustrated hinged to the back support  14  and stanchion  22 . Although only one side is illustrated, it will be obvious to one skilled in the art that another side could be similarly or dissimilarly constructed. Stanchion  22  is illustrated hinged to the arms support  16  as well as the seat  12 . The back support  14  is rotatable relative to the seat  12  as will be described below. The seat  12  is connected at a pivot to leg support  24  which is shown in the extended position in  FIG. 2  and in the unextended position in  FIG. 1 . The back support  14  is connected to grips  26 . It will be understood to one skilled in the art that two grips  26  are normally utilized to allow another individual to push a patient sitting in the wheelchair  10  on the seat  12  in a normal operation. 
   The wheelchair  10  is preferably constructed so that the back support  14  is at least substantially perpendicular to the seat  12  in an upright configuration. The back support  14  is positionable relative to the seat  12  as will be explained in further detail below in reference to other drawings so that the seat  12  and the back support  14  can be made to be substantially parallel and even more preferably at least about collinear with one another. A plurality of reclined positions may also be obtained. 
   Another portion of the wheelchair  10  is the frame  28  which provides a connection for axle  30  which allows rotation of the large wheels  18  relative to the seat  12  and other components of the wheelchair  10  as well as a connection point for axle  32  for small wheels  34  so they can also be similarly rotated relative to the seat  12 . Large and small wheels  18 , 34  are known in the art of wheelchairs. 
   Of course, large and small wheels  18 , 34  are utilized with manually operable wheelchairs  10  such as the embodiment as shown. Other wheelchairs may be electronically driven and/or may use other sized wheels or even more or fewer wheels than illustrated in the preferred embodiment. Litter  36  is illustrated atop the seat  12  and over the back support  14  and connected at the grip  26 . The litter  36  also preferably extends down over at least a portion of the leg support  24 . Operation of the litter  36  will be described in further detail in reference to other drawings. 
   While transitioning the wheelchair  10  from the upright configuration shown in  FIG. 1  to a reclined position as shown in  FIG. 2 , a number of mechanisms are useful. First, a linear actuator  38  which may be driven from an electric power supply such as battery  40  operated by first switch  42  has been found useful. The linear actuator  38  extends from a contracted position shown in  FIG. 1  to the extended position shown in  FIG. 2  with push rod  44  extending a greater distance from cylinder  46  in  FIG. 2  than shown in  FIG. 1 . It is also possible to hae intermediate positions between the reclined and upright configurations. Other actuator mechanisms as is known in the art could also be utilized such as electric motors, hydraulic pumps, chain drive, etc. . . . 
   The seat  12  is connected to the frame  28  by legs  50 , 52 . The top of the legs  50 , 52  is illustrated connected to the seat  12 . The bottom of the legs  50 , 52  is shown connected to the frame  28 . Upon extension of the rod  44  from the cylinder  46  by the activation of switch  42  driving the linear actuator  38  or other appropriate mechanism, the legs  50 , 52  rotate as illustrated from  FIG. 1  to  FIG. 2  thereby elevating the seat  12  relative to the top  20  of the wheel  18 . As shown in  FIG. 2 , the seat  12  is now a distance above the top  20  of the big wheel  18  in the reclined position. This prevents the wheel  18  from interfering with the transfer of a patient to a bed. 
   Meanwhile, while the seat  12  is being elevated, the arm  54  connected to the frame  28  is hingedly connected to the back support  14 . Accordingly, as the seat  12  rotates upwardly, the back support  14  rotates to the position shown in  FIG. 2  so that it is now substantially parallel to if not coplanar with the seat  12 . Furthermore, link  56  pushes outrigger in the form of a post  58  into position so that foot  60  contacts the ground  62  when in the prone position so that weight located on the back support  14  towards the grips  26  can be assisted in support by the post  58  to prevent rotation about the axle  30 . Basically this ensures the wheelchair  10  doesn&#39;t flip over when loaded. The arm rests  16  also rotate preferably out of the way. When going from reclined to upright, the outrigger is lifted by back support  14  off of the ground  62  and rotated by link  56  towards the back support  14  out of the way. 
   The outrigger(s) could be provided as a single support in some embodiments. Furthermore, instead of being hingedly brought into a supporting position on the ground and retracted position when the wheelchair is in an upright configuration with a linking mechanism, other mechanisms could also be utilized to transition the outrigger(s) into position. Hydraulic pumps, linear actuators, chain driven devices, etc. as known in the art could at least assist in the transition. 
   While these features are enough to make a person prone from their knees up, it has been helpful to extend the legs of a person below the knees to complete the prone positioning of a patient on the wheelchair  10 . Leg support  24  can be extended as shown in  FIG. 2  by the operation of a driver  64  which pushes extension  66  outwardly to lift the leg support  24  as shown in  FIG. 2 . In  FIG. 1 , the leg extension  66  is in a retracted position allowing the leg support  24  to rotate so that it would not be supporting the weight of the lower legs of the person. 
   A second switch  68  is useful to control the driver  64 . In some embodiments, the ability to make the legs support  24  copoint substantially planar with the seat  12  parallel to the seat  12  in back support  14  may be done by a single switch in a single coordinated motion or through multiple switches and movements. Battery case  70  is useful to store battery  40  to drive the linear actuator  38  and/or driver  64 . Furthermore, the battery  40  may be utilized to drive motorized wheelchairs in other embodiments. More than battery  40  may be utilized. 
   The litter  36  as shown in  FIG. 1  is shown removed in  FIG. 2  and from a top view in  FIG. 3 . The litter  36  is hinged or at least flexible at the intersections of a first section  72 , second section  74  and third section  76 . First section  72  cooperates with a head and a back of an individual. A second section  74  may be located below the seat of an individual. Lower section  76  may be utilized at least partially under the legs of an individual. By providing a hinged or flexible litter  36 , the litter  36  can be stored connected in position as shown in  FIG. 1  on the wheelchair  10 . The litter  36  may be constructed of similar or dissimilar material as materials utilized with the remainder of the wheelchair  10 . High strength polyethylene, urethane and/or reinforced fabric is a possibility for the litter  36  as well as for portions of the seat  12 , etc. 
   When the wheelchair  10  is extended in the reclined configuration shown in  FIG. 2 , the litter  36  may be prone as shown in  FIG. 4 . One or more individuals can utilize the litter  36  to assist in moving a patient from the wheelchair  10  to a bed such as a hospital bed or other desired location. Handholds  78 , 80  are useful at either end of the litter  36  as shown in  FIG. 3  for either moving the head or the legs of an individual on the litter  36  either one at a time or together. 
   In order to return the wheelchair  10  from its reclined position shown in  FIG. 2  to its upright position shown in  FIG. 1 , the switch  42  or switches  42 , 68  may be operated in the opposite direction to retract the leg extension  66  and/or to withdraw the rod  44  relative to the cylinder  46  to allow the seat  12  to lower back into its position which, in the preferred embodiment, is assisted by gravity. Furthermore, while the seat  12  is lowering to its position relative to the frame  28 , the back support  14  is rotated back into the upright position as shown in  FIG. 1 . The arm rests  16  rotate back into position and the outrigger is moved to the position shown in  FIG. 2 . One skilled in the art will understand that with telescoping members for the back support  14  or otherwise, the back support  14  may be adjustable for a user&#39;s height. 
   Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.