in fig1 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 fig2 ). a docking arm 6 ( seen most clearly in fig3 ) 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 ( fig5 ) 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 fig6 , 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 fig6 to the unlocked position shown in fig5 . 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 fig6 to the extended position shown in fig5 , thereby forcing wedge member 11 down to the unlocked position shown in fig5 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 fig7 , 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 fig8 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 fig1 ). 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 fig7 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 fig1 . as seen more clearly in fig1 and 13 , shoe 31 is slideably mounted on a base plate 32 for movement between a forward position as seen in fig1 and a rearward position as seen in fig1 , 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 ( fig1 ) 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 .
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 .