Abstract:
A wheelchair system is provided for use with conventional passenger vehicles. The system includes a wheelchair frame for supporting a conventional seat of the vehicle thereon for rolling movement along the ground. The wheelchair frame includes a lift frame which permits the seat to be supported thereon at various heights and inclinations relative to the ground. A portable ramp permits the wheelchair frame to be rolled in and out of the vehicle. A docking system mounts in place of conventional existing floor anchors in the floor of the vehicle for securing the wheelchair frame thereon in a transport position. The use of the wheelchair frame and the docking system permits a vehicle such as a mini-van to be adapted to transport a disabled person requiring the use of a wheelchair, with no structural modification required to the vehicle while providing a comfortable and aesthetically pleasing seat for the disabled person.

Description:
FIELD OF THE INVENTION 
     This invention relates to a wheelchair system for use with conventional passenger vehicles and more particularly to a wheelchair frame for adjustably supporting a seat thereon. 
     BACKGROUND 
     When disabled persons requiring the use of a wheelchair desire transportation in a vehicle it is often awkward and difficult without the use of an expensive system adapted for large traditional sized vans or without significant modification to smaller vans due to the arrangement of conventional wheelchairs. 
     A known reference point when discussing mobility aids such as wheelchairs is the Point-P. The Point-P is defined as the centre of a circle being 100 millimetres in diameter lying in the plane of symmetry of the wheelchair, that is in side elevation tangent to both the backrest and upper surface of the wheelchair seat with any padding depressed as if it were occupied and the wheelchair backrest pulled taut. 
     Conventional wheelchairs have a Point-P which is approximately twenty two inches above the ground. This is much higher than the equivalent Point-P found on conventional seats of most passenger vehicles. The result is a raised seating position for a person in a wheelchair in a vehicle relative to the other occupants of the vehicle. The problem which results is a significant lack of headroom for the person in the wheelchair relative to the other occupants. 
     The known systems for transporting disabled persons in wheelchairs thus generally require a large vehicle for creating enough headroom that the person in the wheelchair can sit upright when rolled into the vehicle. In the case of smaller vans and mini-vans a modified roof or floor structure is generally required for creating the desired headroom. Such wheelchair systems are quite expensive. 
     In order for a disabled person to sit in a conventional vehicle without the use of an in vehicle wheelchair system, the person requires being assisted by someone capable of lifting the person from their wheelchair and awkwardly placing them in one of the existing seats of the vehicle. The wheelchair must then be collapsed and stored separately in the trunk or elsewhere in the vehicle. The process of transferring to the vehicle seat and the storing of the wheelchair requires significant strength on the part of the disabled person as well as the person assisting them. The task of transporting a person requiring the use of a wheelchair is thus made quite difficult without the use of a wheelchair system designed for the task. 
     SUMMARY 
     According to one aspect of the present invention there is provided a wheelchair system for use with a mini-van having a plurality of passenger seats each with a Point-P seating reference point and floor anchors in a floor of the mini-van for securing at least one of the passenger seats on the floor of the mini-van, the wheelchair system comprising: 
     a wheelchair having: 
     a frame arranged to mount a seat thereon such that a Point-P seating reference point of the seat is substantially in a common plane with the Point-P of the passenger seats when the frame is positioned on the floor of the mini-van in a transport position; and 
     a set of wheels supporting the frame for rolling movement along the ground; 
     a docking system for securing the wheelchair to the floor anchors in the transport position; and 
     a portable ramp system for rolling the wheelchair in and out of the mini-van. 
     The wheelchair system of the present invention provides a wheelchair which allows a disabled person to sit upright while having enough headroom in a mini-van with no structural modification to the mini-van being required. The wheelchair has a Point-P which is positioned close to the ground by positioning the seat of the wheelchair such that it is inclined downward toward the rear of the seat, similarly to passenger seats in conventional passenger vehicles. 
     The frame may be adjustable such that the seat is movable from the transport position to an alternative seating position wherein the seat is spaced vertically from the transport position. 
     The seat preferably extends at a downward incline from a front end to a rear end of the seat in the transport position. The seating position of a person in the seat thus resembles the seating position of other occupants in the vehicle, while providing sufficient headroom to the person in the wheelchair. 
     The frame may be arranged to mount one of the passenger seats thereon while the docking system may comprise a docking plate arranged to mount on the existing floor anchors of the mini-van, the docking plate being arranged to engage the frame in the transport position for securing the frame thereon. The docking plate may further include adjustable mounting means for mounting on various floor anchor configurations. In this arrangement, the wheelchair system makes use of an existing seat of the vehicle for improved appearance and for minimal installation cost of the system by using as many existing parts of the vehicle as possible. 
     The docking plate may include a plurality of lugs mounted thereon while the frame may include a plurality of channels mounted thereon in respective alignment with the lugs on the docking plate in the transport position, the channels being arranged to secure the lugs therein. 
     According to a second aspect of the present invention there is provided a wheelchair system for use with a vehicle having a plurality of occupant seats supported by respective seat frames on respective existing floor anchors on a floor of the vehicle, the wheelchair system comprising: 
     a wheelchair frame arranged to support one of the occupant seats of the vehicle thereon; 
     a set of wheels supporting the wheelchair frame for rolling movement along the ground; 
     a docking system for securing the wheelchair frame to the floor of the vehicle in a transport position; and 
     a portable ramp system for rolling the wheelchair frame with an occupant seat supported thereon in and out of the vehicle. 
     In this arrangement, the wheelchair system makes use of an existing seat of the vehicle for improved appearance of the wheelchair and for minimal installation cost of the system by using as many existing parts of the vehicle as possible. 
     The docking system preferably comprises a docking plate arranged to mount on the existing floor anchors of the vehicle, the docking plate being arranged to engage the frame in the transport position for securing the frame thereon. 
     The wheelchair frame may include adjustable mounting means for mounting various seat configurations thereon. 
     It is preferred that a handle frame be mounted adjacent the rear end of the seat for supporting a pair of handles thereon. 
     The handles may be slidably mounted on the handle frame for adjusting a relative height of the handles in relation to the seat. 
     According to a further aspect of the present invention there is provided a wheelchair for supporting a person thereon, the wheelchair comprising: 
     a seat having a front and rear end, the seat being arranged to support the person thereon; 
     a docking plate frame supported for rolling movement along the ground; 
     a lift frame pivotally mounted on the docking plate frame, the lift frame pivotally mounting the seat thereon; 
     a forward actuator associated with the front end of the seat for controlling a height of the front end of the seat in relation to the docking plate frame; and 
     a rearward actuator associated with the rear end of the seat for controlling a height of the rear end of the seat in relation to the docking plate frame, the forward and rearward actuators being operative independently of one another. 
     The arrangement of the lift frame permits the seat to be positioned at be various heights and inclinations as desired for the comfort of the person supported in the seat. These positions may include a lowered seating position for headroom in a vehicle and a raised position for ease of standing up from the seat or for sitting at an appropriate height at a table for instance. 
     The seat is preferably movable between an inclined seating position in which the seat extends at a downward incline from the front end to the rear end thereof, a raised seating position in which the seat is raised in relation to the inclined seating position and a standing assistance position in which the seat extends at a downward incline from the rear end to the front end thereof. 
     When using the wheelchair for vehicular transport, the lift frame is preferably pivotally mounted on a front end of the docking plate frame with the seat being pivotally mounted on the lift frame at the rear end of the seat. A docking lock can thus be mounted on a rear end of the lift frame for securement to a floor of the vehicle in a transport position wherein the docking lock insures that the seat is adequately secured to the floor regardless of the condition of the actuators. 
     One of the actuators is preferably coupled between the docking plate frame and the lift frame with the other actuator being coupled between the lift frame and the seat. 
     The actuators may comprise air spring cylinders. When using air spring cylinders, a pair of cable operated mechanisms may be mounted adjacent the rear end of the seat wherein the mechanisms are operatively associated with the actuators respectively for selectively locking the respective actuators independently of one another at various positions of the actuators. 
     The seat may comprise a seat frame arranged to mount a conventional vehicle seat thereon wherein there may be provided a docking system arranged to mount the docking plate to existing floor anchors in a floor of a conventional passenger vehicle. 
     It is preferred that there be provided a rear seat cushion pivotally mounted on the seat for movement between an upright position and a reclined position wherein the rear seat cushion extends substantially horizontally rearward from the seat. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings, which illustrate an exemplary embodiment of the present invention: 
     FIG. 1 is a side elevational view of the wheelchair according to the present invention in an inclined seating position. 
     FIG. 2 is a side elevational view of the wheelchair of FIG. 1 showing the chair in respective raised, reclined and standing assistance positions. 
     FIG. 3 is a bottom plan view of the wheelchair of FIG.  1 . 
     FIG. 4 is an isometric view of the docking plate for use with the wheelchair of FIG.  1 . 
     FIG. 5 is a rear elevational view of the wheelchair of FIG.  1 . 
     FIG. 6 is an isometric view of the wheelchair system as it is used on a conventional mini-van. 
    
    
     DETAILED DESCRIPTION 
     Referring to the accompanying drawings, there is illustrated a wheelchair system  10  arranged for use in a conventional passenger vehicle  12 , for example a mini-van as shown in FIG.  6 . The wheelchair system  10  generally comprises a wheelchair  14  having a frame  16  which is arranged to mount an occupant seat  18  of the vehicle thereon and support the seat,for rolling movement across the ground. A pair of portable ramps  22  are additionally provided for rolling the wheelchair  14  from the ground onto the floor of the vehicle. The ramps  22  are commercially available type ramps for use with wheelchairs. 
     At The seat  18  of the wheelchair  14  is a standard vehicle seat similar to that which is normally anchored to the floor  24  of the vehicle by a standard seat frame secured to existing floor anchors in the floor  24 . 
     The seat  18  includes a bottom cushion  26  which extends from a front end  28  to a rear end  30  of the seat. A back cushion  32  is pivotally mounted on the rear end of the bottom cushion for movement between an upright position shown in solid line in FIG. 2 and a reclined position shown in dashed line in FIG. 2 in which the back cushion extends substantially horizontally rearward from the bottom cushion. 
     The frame  16  includes a base frame  34  which is supported for rolling movement along the ground. A lift frame  36  is pivotally mounted on the front end of the of the base frame to extend generally rearward therefrom. A seat frame  38  is pivotaily mounted at a rear end of the seat adjacent a rear end of the lift frame. 
     In this arrangement the seat is movable between an inclined seating position as shown in FIG. 1 in which the bottom cushion extends at a downward incline from the front end to the rear end thereof; a raised seating position as shown in solid line in FIG. 2 in which the seat is raised in relation to the inclined seating position; and a standing assistance position as shown in dashed line in FIG. 2 in which the bottom cushion extends at a downward incline from the rear end to the front end thereof. 
     A docking system in the form of a docking plate  40  is arranged to mount on the existing floor anchors in the floor of the vehicle using bolts  42  which extend through mounting apertures in the plate. The location of the holes for receiving the bolts  42  can be selected according to the type of vehicle in which the plate  40  is to be installed such that the plate  40  can be adjustably mounted on different configurations of existing floor anchors. 
     The docking plate  40  includes a plurality of mounting posts  44  extending upwardly therefrom. A forwardmost post  44  is centrally located on the plate while a pair of rearward posts  44  are spaced apart across the rear end of the plate. The plate  40  further includes a seatbelt mount  46  for mounting the female end of a seatbelt coupling thereon. Each mounting post  44  includes a lug  48  on a top end thereof having a diameter which is greater than a diameter of the post, 
     The base frame  34  includes a front cross bar  50  which extends laterally across a front end of the base frame. A pair of side rails  52  extend rearwardly and downwardly from respective front corners of the front cross bar. 
     A pair of castor wheels  54  are pivotally mounted on the front corners of the front cross bar  50  so as to support the respective side rails  52  thereabove. A rear wheel  56  is mounted on the rear end of each side rail  52  so as to be oriented for rolling movement in a forward direction with the castors. The rear wheels are equipped with conventional wheel stops  58  which assist in keeping the wheels from rotating when engaged thereon. 
     A rear cross bar  60  is coupled between the side rails  52  adjacent a rear end thereof for structural support. A central portion of the rear cross bar  60  is curved downwardly to accommodate the lift frame  36  between the side rails  52  in a lowered position of the frame. A pair of longitudinal supports  62  are spaced apart across a central portion of the front cross bar  50  to extend downwardly and then rearwardly therefrom for connection to the rear cross bar  60  at a rearward end thereof. 
     The longitudinal supports  62  mount a docking channel  64  therebetween adjacent the front end of the base frame for alignment with a forwardmost mounting post  44  of the plate  40  of the docking system. The docking channel  64  includes a slot therein for receiving the lug  48  at the top of the post  44  therein. The slot includes a wide mouth for ease of alignment of the post with the slot in the docking channel wherein the slot tapers rearwardly to an apex arranged to secure the mounting post therein. 
     A pair of foot supports  66  are pivotally mounted on respective support arms  68  similarly to conventional wheelchair foot supports. 
     The lift frame  36  includes two pairs of parallel arms  70  which extend longitudinally with the frame. Each pair of arms is coupled at respective front and rear ends for structural support. The arms  70  are pivotally mounted at the front end thereof at spaced apart locations on the front cross bar  50  of the base frame to extend generally rearward therefrom. 
     A center cross bar  72  and a rear cross bar  74  are coupled between the pairs of arms adjacent a respective central and rearward location. A pair of spaced apart pivot mounts are located on the rear cross bar  74  in alignment with the longitudinal supports  62  for mounting a pair of rear actuators  76  on the respective pivot mounts. The rear actuators  76  are a piston-cylinder arrangement mounted at a cylinder end on the rear cross bar to extend generally downwardly and forwardly to a piston end mounted on the respective longitudinal supports  62 . The lift frame further includes a pivot mount located centrally on the center cross bar  72  for mounting a piston end of a front actuator  78  thereon. 
     Each pair of arms  70  mounts a docking channel  80  therebetween at a rearward end thereof. The docking channels  80  are arranged for alignment with the rearwardmost posts  44  of the docking system and include a tapered slot similar to the docking channels  64  for receiving respective lugs  48  of the mounting posts  44  at their end. A locking clamp  82  is pivotally mounted on each docking channel  80  and includes a respective actuator lever for pivoting the clamp  82  into a locked position wherein the respective lug  48  is secured therein. 
     Strap mounts  84  provide an alternate mounting arrangement to the docking system for anchoring the frame  16  to the floor of the vehicle using straps. These strap mounts are located at spaced apart locations on the front cross bar  50  and at rear end of each pair of arms  70 . 
     The seat frame  38  includes a mounting plate  86  arranged to mount one of the seats  18  thereon. The plate includes a plurality of mounting apertures therein for accommodating various seat configurations to be mounted thereon. A pivot mount is located centrally on the plate  86  adjacent a front end thereof for mounting the cylinder end of the front actuator  78  thereon. A further pair of pivot mounts are spaced apart adjacent a rear end of the mounting plate  86  for pivotally mounting the rear end of the seat on the lift frame adjacent a rear end thereof but spaced forwardly of the docking channels  80 . 
     A handle frame  90  is mounted on a rear face of the back cushion  32  of seat. The handle frame  90  includes a pair of cross supports  92  having adjustable mounting locations thereon for mounting at vertically spaced positions to extend laterally across the back cushion. A guide block  94  is mounted on each cross support  92  to support a pair of upright channels  96  thereon. The channels  96  are coupled by a cross bar  98  at a top end thereof and are arranged to face inwardly for longitudinal sliding movement along the respective ends of the guide blocks  94  which are received within the channels. 
     A pair of handles  100  extend laterally outward from the top end of the respective channels  96 . The sliding movement of the channels along the guide blocks permits a height of the handles in relation to the seat to be adjusted. A pair of cam locks  102  are pivotally mounted in the uppermost guide block  94  for selectively engaging the respective channels  96  such that the channels are fixed in position when the cam locks  102  are engaged. 
     The front and rear actuators  78  and  76  each comprise an air spring in a piston-cylinder arrangement to assist in lifting the seat when adjusting a relative height of the seat. The forward actuator Is associated with the front end of the seat for controlling the relative height of the front end while the rearward actuators are associated with the rear end of the seat for controlling the relative height of the rear end as the respective actuators are extended and contracted. A pair of cable operated locking mechanisms  104  are associated with the respective front and rear actuators for locking the respective pistons within their cylinders until release by respective levers located adjacent the handles  100 . 
     The wheelchair frame  16  and the docking system can be used with any suitable seat or be permitted to use an existing occupants seat of a vehicle in which the system to be installed. When installing a wheelchair system  10  a selected occupant seat is removed from its standard seat frame in the vehicle and mounted on the seat frame  38  of the wheelchair. The standard seat frame of the vehicle is then removed and replaced with the plate  40  of the docking system which can be adjustably mounted on the existing floor anchors in the floor of the vehicle. 
     When used on a mini-van the portable ramps  22  may be aligned with either the side doors of the van as shown in solid line in FIG. 6 or the rear doors of the van as shown in dashed line in FIG. 6 to permit the wheelchair  14  to be rolled up the ramp and into the van. Once inside the van the wheelchair is aligned with the plate  40  of the docking system by using the tapered slots on the respective docking channels which are aligned to engage the respective mounting posts  44  on the plate  40 . The locking clamps  82  on the rearward pair of docking channels may thus be pivoted and locked into a transport position of the wheelchair. The ramps  22  may subsequently be stored in the vehicle. The existing seatbelt of the vehicle may be used and coupled to the seatbelt mount  46  of the docking system. In order to exit the vehicle the reverse steps are used. 
     Using the wheelchair frame  16  of the present invention the height of the seat may be adjusted such that a point P reference point of the seat lies substantially in a common plane with the point P of the other occupant seats in the vehicle regardless of the seat type used. The design of the wheelchair frame  16  is further useful in accommodating the various desired seating positions of a person supported in the wheelchair. 
     In further arrangements the docking plate or the mounting plate  86  of the seat frame may be replaced with other suitable adjustable mounting means. The seat frame in particular may comprise a set of crossbars which are mounted across the bottom of an existing vehicle occupant seat at an adjustable location. The mounts on the seat frame would thus be located on the crossbars instead of being located on the mounting plate  86 . 
     While one embodiment of the present invention has been described in the foregoing, it is to be understood that other embodiments are possible within the scope of the invention. The invention is to be considered limited solely by the scope of the appended claims.