Abstract:
A docking system for securing a wheelchair into a vehicle in which a docking shoe is firmly attached to either the frame of the wheelchair or to the floor of the vehicle, or both. A firm anchor device, which may be a second docking shoe, is firmly attached to the other of the floor and wheelchair. A docking arm is mounted vertically in the anchor device and the wheelchair is positioned in the vehicle so that the docking shoe and the anchor device are vertically aligned one above the other so that the docking arm can be slidably and releasably locked into the docking shoe. Preferably, the docking shoe includes an electrically operated, spring loaded, release mechanism, and may also include a slide mechanism to allow limited forward and rearward movement of the wheelchair while under restraint.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a continuation-in-part of U.S. patent application Ser. No. 10/808,407 filed 10 Mar. 2004. 

   FIELD OF INVENTION 
   This invention relates to a system for securing wheelchairs and the like into a transport vehicle. 
   BACKGROUND OF INVENTION 
   The welfare and safety of persons being transported in wheelchairs, three wheeled scooters, power bases and the like is of ever increasing concern and many jurisdictions have enacted stringent safety requirements for devices to secure the wheelchair into the transport vehicle and the occupant into the wheelchair. Numerous structures, most of which are reasonably effective, have been suggested in the prior art, but they frequently require the attachment of a plurality of straps or the like to one or more anchor points in the vehicle. After attachment the straps have to be tightened either by the wheelchair occupant or by an attendant. Frequently, the wheelchair occupant has neither the physical strength nor the manual dexterity to manipulate the necessary straps and the like. This means that the attendant, or vehicle driver must spend several minutes securing each wheelchair in his/her charge into the vehicle. There have been some attempts to provide self attachment devices in the past and attention is directed to U.S. Pat. Nos. 4,690,364 and 6,474,916 in which a locking mechanism is secured either beneath or to the rear of a wheelchair and releasably locked to a post similarly mounted, either under or behind the wheelchair, on the floor of the vehicle. While reasonably effective in certain circumstances, problems of automatic unlocking and twisting or rotation of the wheelchair about the vertical post still remain. Thus there is a need for an automatic wheelchair tie-down system that can, if desired, be operated automatically by the attendant from a central location, or that can be operated manually by either the wheelchair occupant or by the attendant. It will also be appreciated that some wheelchair occupants may also be the driver of the vehicle, usually provided that the vehicle is equipped with hand controls. 
   OBJECT OF INVENTION 
   Thus, an object of the present invention is to provide a docking system for a wheelchair or the like in a vehicular conveyance that can be operated manually, or automatically from a central location, and in which a vertically oriented docking arm is either securely mounted beneath the seat of the wheelchair so that the free end can engage securely with a floor mounted docking shoe, or in which the vertical docking arm is either permanently or releasably mounted on the floor of the vehicle and is engagable with a docking shoe mounted securely on the wheelchair adjacent the underside of the seat thereof. Preferably, but not essentially, the docking shoe, whether it is on the floor or mounted beneath the wheelchair seat, or both, is provided with a power operated latch mechanism so as to secure and release the vertical docking arm. Conveniently, but not essentially, the vertical docking arm may include a power transmission cable to transmit power to a docking shoe secured beneath the seat of the wheelchair via complementary sliding contacts on the docking arm and the docking shoe. 
   Another object of the present invention is to provide a docking system for a wheelchair in a vehicular conveyance that, once locked into a docking shoe, provides limited forward and rearward position adjustment, to facilitate a comfortable driving position for the wheelchair occupant. 
   BRIEF STATEMENT OF INVENTION 
   By one aspect of this invention there is provided a wheelchair docking system for releasably securing a wheelchair to the floor of a vehicular conveyance, comprising:
     support frame means adapted for rigid attachment to said wheelchair;   docking shoe means, adapted for rigid attachment to either one of said support frame and said floor;   anchor means, adapted for rigid attachment to the other of said support frame and said floor; and   arm means adapted, when in operative position, for rigid mounting in a vertical plane on said anchor means and adapted for sliding and locking engagement in said docking shoe means.   

   By another aspect of this invention there is provided a method for securing a wheelchair to the floor of a vehicular conveyance, comprising:
     rigidly attaching a support frame means to said wheelchair;   rigidly attaching a docking shoe means, to either one of said support frame and said floor;   rigidly attaching anchor means to the other of said support frame and said floor;   rigidly mounting arm means on said anchor means so that, when in operative position, said arm means lies in a substantially vertical plane; and moving said wheelchair on said floor so as to vertically align said docking shoe and said anchor means one above the other and so that said docking arm moves into sliding and locking engagement in said docking shoe means.   

   By yet another aspect of this invention there is provided a wheelchair docking system for releasably and adjustably securing a wheelchair to the floor of a vehicular conveyance, comprising:
     support frame means adapted for rigid attachment to said wheelchair;   docking shoe means adapted for adjustable attachment to said floor;   anchor means adapted for rigid attachment to said support frame means; and   arm means adapted, when in operative position, for rigid mounting in a vertical plane on said anchor means and adapted for sliding and locking engagement in said docking shoe means.   

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a front isometric view of one embodiment of a wheelchair according to the present invention; 
       FIG. 2  is a close up view of the attachment frame mounted on the wheelchair of  FIG. 1 ; 
       FIG. 3  is a side view of one embodiment of the docking arm of the present invention; 
       FIG. 4  is an isometric view of a floor mounted docking shoe according to one embodiment of the present invention; 
       FIG. 5  is a side sectional view of the docking shoe of  FIG. 4 , in the loading or release position; 
       FIG. 6  is a side sectional view of the docking shoe of  FIG. 4  in the locked position; 
       FIG. 7  is a side view of an alternative embodiment of the docking arm of the present invention; 
       FIG. 8  is a perspective view of an alternative embodiment of a docking shoe, shown mounted on the floor; 
       FIG. 9  is a sectional side view of the docking shoe of  FIG. 8 ; 
       FIG. 10  is an end view of the docking shoe of  FIG. 8 ; 
       FIG. 11  is an isometric view of an alternative embodiment of a floor mounted docking shoe according to the present invention; 
       FIG. 12  is an isometric view of the shoe of  FIG. 11  in the forward slide position; 
       FIG. 13  is an isometric view of the shoe of  FIG. 11  in the rearward slide position; and 
       FIG. 14  is a front view of a dash control console for use with the embodiment of  FIG. 11 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   In  FIG. 1  there is shown a wheelchair  1  having a quadrilateral frame  2  securely mounted to the side frame members  3 , 4  of the wheelchair  1 . Frame  2  supports a central post mount  5  (as seen more clearly in  FIG. 2 ). A docking arm  6  (seen most clearly in  FIG. 3 ) is securely mounted in post mount  5  in any conventional manner such as screwing or clamping. Arm  6  is provided with a hammer headed like foot having a sloping leading edge  7  and a squared trailing face  8  and is of sufficient length to provide normal ground clearance but to engage a floor docking shoe  9  which is securely bolted, at any selected position on the floor of a vehicular conveyance (not shown), by means of bolts  16 . Shoe  9  is provided with a flared and sloped entry  10  at one end thereof for sliding engagement with the leading edge  7  of arm  6  when the wheelchair is positioned thereabove. Edge  7  then rides over a spring loaded wedge shaped member  11  thereby compressing spring  12  ( FIG. 5 ) and allowing the arm to fully enter the shoe  9  until the front  13  thereof abuts the face of the docking shoe  9 , as seen in  FIG. 6 , whereupon the arm  6  clears wedge member  11  and allows spring  12  to extend and drive wedge member  11  upwardly so that the vertical face  14  thereof abuts the rear face  8  of arm  6 , thereby locking the arm and shoe together and securely fastening the wheelchair in the vehicle without any possibility of the wheelchair swiveling or twisting about the central axis thereof and without any need to tighten or adjust restraining straps and the like by either the wheelchair occupant or the attendant. 
   In order to release the wheelchair from the locked position it is merely necessary to raise the free end of the lever  15 , pivotally mounted about a fulcrum  16  and engaging with wedge member  11 , from the locked position shown in  FIG. 6  to the unlocked position shown in  FIG. 5 . This may be accomplished manually if necessary but it will be appreciated that this is impossible for a wheelchair occupant and somewhat awkward and inconvenient for the attendant. It is preferred, therefore, that the release be effected by the attendant from a central location such as the driver&#39;s seat. To facilitate release, a conventional solenoid switch  17  is mounted beneath end of lever  15  with the end of plunger  18  thereof in contact with lever  15 . Upon activation of solenoid  17 , plunger  18  extends from the retracted position shown in  FIG. 6  to the extended position shown in  FIG. 5 , thereby forcing wedge member  11  down to the unlocked position shown in  FIG. 5  and releasing arm  6 . Power for solenoid  17  may be provided in any conventional manner such as wires from the control position and the vehicle battery, or from an internal power source which may be actuated by any conventional remote control system such as a radio signal. 
   It will be appreciated that the floor docking shoe  9  may equally well be mounted on the quadrilateral frame  2  on wheelchair  1  and the post mount  5  and arm  6  may be mounted on the floor of the vehicle. This arrangement has the advantage that the arm  6  is in the vehicle at a fixed position and this facilitates accurate location of a plurality of wheelchairs in the vehicle. It also allows for somewhat greater ground clearance for the wheelchair when it is not in the vehicle. Power to actuate solenoid  17 , now located on wheelchair  1 , may be provided from the wheelchair power supply if so equipped, an internal power supply or by leads passing internally through arm  6  and contact shoes (not shown) on docking shoe  9 . 
   In a third embodiment, docking shoes  9  may be provided on both the floor of the vehicle and on the quadrilateral frame on the wheelchair so as to provide for maximum ground clearance for the wheelchair and an uncluttered floor in the vehicle. In this embodiment it is, of course, necessary to modify the arm  6  to provide a sloped leading edge  7  and a squared trailing face  8  at each end thereof, as seen in  FIG. 7 , so that the arm  6  can be detached from both the wheelchair and the floor. 
   It will be appreciated that many modifications may be made without departing from the spirit and scope of the present invention. For example, numerous variations of the docking shoe are possible and one such variation is illustrated in  FIGS. 8 and 9 , which show a docking shoe  19 , having a flared and sloped entry ramp  20 , similar to entry  10 , which may be secured to the floor of the vehicle or to the wheelchair as described above. A circular pin  21 , having a circular flange  22 , is mounted vertically on shoe  19  and is provided with an axial, spring loaded, locking pin  23 , which may be electrically actuated from a central location by the driver or by the wheelchair occupant, by a solenoid switch. Vertical locator pins  25 , 26  may also be mounted on shoe  19  and positioned so as to permit limited rotation of arm  6  or to prevent any rotation of arm  6 , as described in more detail below. In order to cooperate with the modified shoe  19 , the end of arm  6  must similarly be modified to provide a part-circular button  27  having a top  28  secured to arm  6  and a lower flange  29 , the top surface of which is adapted to slidably engage the lower surface of flange  22  (as seen in  FIG. 10 ). When fully engaged, spring loaded pin  23  extends through the axial bore so as to releasably lock button  27  and arm  6  to the docking shoe  19 . It will be appreciated that the position of pins  25 , 26  is a matter of choice so as to either permit limited rotation of arm  6  and hence of the wheelchair, or to preclude angular rotation when pins  25 , 26  abut flat face  30  of button  27 . In order to release the wheelchair, the pin  23  is retracted by actuation of solenoid switch, either by the wheelchair occupant or by the attendant. In order to facilitate smooth mating of button  27  with flange  22 , the edge  30  of button  27  and the circumferential rim of flange  22  are preferably bevelled. 
   It will, of course, also be appreciated that the docking shoe  19  may equally well be mounted on the wheelchair and the arm  6  mounted on the floor, as previously described with reference to the previous embodiment. Or, docking shoe  19  may be provided on both the floor and the wheelchair and a double-ended arm  6  having a button  27  at each end thereof, similar to  FIG. 7  may be provided. 
   As noted hereinbefore, in certain circumstances a wheelchair occupant may be the driver of the vehicle in which the docking system is installed adjacent and immediately behind the steering wheel. Usually, in such circumstance the vehicle is provided with hand controls and the regular driver&#39;s seat is removed. A docking shoe  31 , similar in concept to the docking shoe  19  previously described herein, is mounted on the vehicle floor in a suitable position rearwardly of the vehicle steering wheel (not shown), as seen in  FIG. 11 . As seen more clearly in  FIGS. 12 and 13 , shoe  31  is slideably mounted on a base plate  32  for movement between a forward position as seen in  FIG. 12  and a rearward position as seen in  FIG. 13 , when a lock (not shown) located between shoe  31  and base plate  32  is actuated by adjustment lever  33 , generally but not essentially, located on the dashboard or sidewall of the vehicle and accessible to the wheelchair occupant. Lever  33  is generally operatively connected to the lock by actuating cable  34 . 
   It will be appreciated that some wheelchairs have very little ground clearance and frequently catch on obstructions on the floor. For this reason, it is preferred that the docking shoes  19  and  31  are provided with sloping top covers so as to facilitate the wheelchair riding smoothly thereover. 
   In operation, the wheelchair occupant docks the wheelchair into the docking shoe and a green light  38 , on dash console  36  ( FIG. 14 ) lights. When the green light is on, the occupant may either prepare to drive or may adjust his position relative to the steering wheel. In order to adjust position, the adjust lever  33  is depressed to temporarily disengage shoe  31  from base  32 . This deactivates green light  38  and activates flashing amber light  39 , to indicate that the wheelchair is not disengaged from the locking shoe but is not fully locked in position either. The wheelchair occupant can then either slide the shoe forwards or backwards by about 2″–4″ from a neutral central position so as to attain a desired and comfortable driving position. When the desired position is located, the adjust lever  33  is raised and the shoe  31  and base  32  are locked together. The amber light  39  will cease to flash and the green light  38  will relight. In order to disengage the wheelchair and occupant from the docking shoe completely, the occupant may press the release button  35  on console  36  so as to release the docking arm  6  from the shoe  31 . Upon pressing button  35 , red light  40  will flash and upon release of arm  6 , will remain on constantly to indicate that the wheelchair is not secured. 
   While this embodiment has been described thus far with reference to placement of the wheelchair adjacent the driving position, it will be appreciated that the invention is not limited thereto. The docking shoe may equally well be placed at any one or more of the seating positions in the vehicle, both front and rear. 
   It will be further appreciated that the adjustable feature of this invention has been described with reference to forward and rearward motion when the wheelchair is in the operative position. However, there may be situations when limited lateral movement or vertical movement of the docking shoe is desired. Lateral movement can be easily achieved by loosening the securing bolts of the slide mechanism in elongated boltholes so as to effect the required adjustment and retightening by the installation technician. Similarly, vertical movement can be achieved by careful placement of shims or by adjustment of lifting bolts.