There are prior art wheelchair lifts which require modification to the floor of the vehicle, wherein a well open to the rear or side of the vehicle has to be cut into the floor of the vehicle and additional bracing, and, in some cases, modification to the suspension, required. See for example US patent no. 4,804,308-Hamblin.

In another form, such as US patent no. 3,887,092-Leet, the tailgate in its lowered position acts as the lift and is raised and lowered between the ground engaging position and the floor height on roller assemblies running along channels at the rear of the vehicle. Such a structure is not readily useable with small"people mover"vans due to the extensive modifications required.

In a further form, such as shown in US patent 4,930,969-Langer, the lift is located at the rear of the vehicle and is raised and lowered between the ground engaging position and the floor height on roller assemblies running along channels at the rear of the vehicle, but in its storage position is folded underneath the vehicle. This method is

not readily suitable for small"people mover"vehicles, as it interferes with the road clearance of the vehicle and usually requires alteration to the exhaust system.

The present invention seeks to ameliorate these disadvantages, by providing a lifting tray apparatus adapted to be fitted to the floor of a vehicle, whereby a lift tray is slide externally from the vehicle and lowered to the ground for access to the lift tray and raised to the level above the floor of the vehicle and slide into the vehicle to its transportation position, said lifting tray apparatus comprising: a pair of opposed first slides, adapted to be connected to the floor of the vehicle; a pair of swing arms, each adapted to slide along a respective first slide and having a free end; a pair of second slides, each connected adjacent the free end of a respective swing arm; a lift tray adapted to slide along and between said second slide, whereby each swing arm is in the form of a parallelogram linkage, and has operating means connected across one of its diagonals, such that with the lifting tray slid externally of the vehicle, by altering the length the diagonal, the swing arm moves the lifting tray between a ground engaging position and a position above the floor of the vehicle.

In another form the invention comprises a lifting tray apparatus adapted to be fitted to the floor of a vehicle, whereby a lift tray is slide externally from the vehicle and lowered to the ground for access to the lift tray and raised to the level above the floor of the vehicle and slide into the vehicle to its transportation position, said lifting tray apparatus comprising: a pair of opposed first slides, adapted to be connected to the floor of the vehicle; a pair of carriages, each adapted to slide along a respective first slide a pair of lifting arms, each pivotally connected to a respective carriage and having a free end; a pair of second slides, each connected adjacent the free end of a respective swing arm; a lift tray adapted to slide along and between said second slides, and having a rear end a first bowden cable having one end connected adjacent the end of one of the first slides, remote from the rear of the vehicle, the cable passing through a rigid sheath secured to the respective carriage and the other end passing around a pulley, which is connected to said carriage or free end of said lifting arm, and secured to said lift tray;

a second bowden cable having one end connected adjacent the end of the other of the first slides, remote from the rear of the vehicle, the cable passing through a rigid sheath secured to the respective carriage and the other end passing around a pulley, which is connected to said carriage or free end of said lifting arm, and secured to said lift tray ; a third bowden cable having one end connected to the lift tray, the cable passing through a rigid sheath secured to the respective carriage and around a pulley thereon, with the other end secured adjacent the rear end of the one of the first slides, a fourth bowden cable having one end connected to said lift tray, the cable passing through a rigid sheath secured to the respective carriage and around a pulley thereon, with the other end secured adjacent the rear end of the other of the first slide, whereby as the carriages are driven along the first slides towards the rear of the vehicle, the first and third bowden cables pull around their respective pulleys and pull the lift tray along the second slides to an rearwardly extended position, and whereby when the carriages are driven along the first slides, away from the rear of the vehicle, the second and third bowden cables pull the tray along the second slides into the vehicle, and whereby each lifting arm is in the form of a parallelogram linkage, and has operating means connected across one of its diagonals, such that with the lifting tray slid externally of the vehicle, by altering the length the diagonal, the swing arm moves

the lifting tray between a ground engaging position and a position above the floor of the vehicle.

The present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows schematically a plan view of the lifting tray connected to one half of the track arrangement of a lifting tray apparatus according to one embodiment of the present invention; Figure 2 shows schematically an end view of the track arrangement of the lifting tray arrangement shown in figure 1; Figure 3 shows schematically a plan view of the lifting tray apparatus illustrated in figure 1 in its fully extended position; Figure 4 illustrates one embodiment of a bearing carriage for the swing arm; Figure 5 illustrates a cut away end view of the view shown in figure 4 Figure 6 the shape of one component of the swing arm according to one embodiment of the present invention;

Figure 7 illustrates the swing arm as formed by two of the components shown in figure 6, in its horizontal mode; Figure 8 shows the swing arm in its lowered position with the lift tray in its ground engaging position; Figure 9 shows schematically the engagement of the swing arm operating means on the components of the swing arm; Figures 10 and 11 illustrates schematically the arrangement of one of the bowden cables to drive the lifting tray to its extended position; Figures 12 and 13 illustrate schematically the arrangement of the other bowden cable to drive the lifting tray to its retracted position; Figure 14 illustrates another embodiment of a bearing carriage for the lifting arm; and Figure 15 illustrates a cut away end view of the view shown in figure 14.

The lifting tray apparatus (1) is attached onto the floor (2) of a rear opening "people mover", so as to be able to load and transport wheel chair passengers.

As shown in figures 1 & 2, a pair of first slides (3) is secured to the floor of the vehicle, a predetermined distance above the floor, in this case, with the openings (4) of the slides (3) facing inwardly. A suitable bearing carriage (5), as shown in figures 4 & 5, travels along each slide (3) on rollers (6). Attached to the bearing carriage (5) at end (7) is the first end (10) of the swing arm (8), which is hung below the slides (3). A second slide (9) is attached to the other end (11) of the swing arm (8), and extends back towards the first end (10) of the swing arm (8). The lifting tray (13) is connected adjacent its mid point on each side to a tray holder bearing carriage (12) which is adapted to travel along the respective slides (9).

The swing arm (8), preferably, comprises two identical components (16 & 17) as shown in figure 6, which are connected together, as shown in figure 7 such that each long side (14) overlays the short side (15) of the other component. The components (16 & 17) at the end (10) are pivotally connected to each other and the bearing carriage (5) and at the other end (11) are pivotally connected to each other and the tray holder bearing carriage (12), forming a parallelogram linkage such that the tray (13) retains the same substantially horizontal orientation during its raising and lowering to the ground.

A suitable operating means, in this case a hydraulic ram (18) is connected, as shown in figure (9) from the lower component (16) diagonally to the top component (17). Therefore when the hydraulic ram (18) is retracted, the swing arm (8) swings

downwardly as the distance across the diagonal is decreased, lowering the lifting tray (13) to the ground.

A pressure switch (not shown) is connected in the hydraulic line such that when the lifting tray (13) is lowered to the ground a piston causes the tailgate to be lowered to the ground, such that a wheel chair can be rolled onto the lifting tray (13).

Preferably the tailgate is connected to a pivot rod that is rotated by the piston, by means of wires connected to cams on the pivot rod.

The tray (13) is then raised, by extending the hydraulic ram (18), which lengthens the diagonal across the swing arm (8) causing the swing arm (8) to swing upwardly. As soon as the lifting tray (13) begins to rise, the tailgate pivots to an upright position, preventing the wheel chair from rolling rearwardly out of the tray (13). When the swing arm (8) reaches its upper position, the lifting tray (13) on its carriage (12) is slid along the slides (9). Further the swing arm (8) on its bearing carriage (5) is slide along the slides (3), to its transport position as shown in figure 1. Any suitable operating means such as worm drives, rack and pinion or hydraulically operated cylinders can be used to move the carriages (5 & 12) along their respective slides (3 & 9). Preferably once the tray (13) is in its transport position, the tray is lowered to the floor of the vehicle and a front flap is raised to prevent the wheelchair from rolling off the tray (13).

A further embodiment is shown in figures 14 & 15, in which the tracks of the slide (3) are in the form of v-tracks (19) with the rollers (6) having a complementary periphery. An off centred roller (20) can be attached between the rollers (6) to adjust the engagement between the rollers (6) and the tracks (19). The slides and swing arm operate in the same manner as described previously, except in the following manner.

As the tray (13) has to be lowered to the ground and the tray (13), naturally, is moved out of the plane of the slides (3 & 9), a problem arose in providing a reliable operating means to slide the various components along their respective slides, while allowing for the tray (13) to swing down to the ground. This problem was solved by the use of bowden cables, to slide the various components along their respective slides. As shown in figure 10 and 11, a first bowden cable (21) is connected at one end (22) to the lifting tray (13) and passes around a pulley (23) connected to the carriage (5) or the free end of said lifting arm (8) and through a fixed sheath (23), which is fixedly connected to the carriage (5). The other end (25) is secured to the vehicle. Thereby as the lifting arms (8) on their carriages (5) travel along the slides (3), the cable (21) pulls the tray (13) and its carriage (12) along the slide (9) on the lifting arms (8). A similar bowden cable arrangement is fitted to each side of the apparatus.

To retract the tray (13) a second bowden cable (26) is used as shown in figures 12 and 13, on each side of the apparatus. The cable (26) is connected at one end (27) to the tray (13) and though the fixed sheath (28), which is secured to the carriage (5). The other end (29) of the cable (26) passes around a pulley (30) and is secured to the vehicle or the slide (3). Thus as the carriage (5) slides into the vehicle along the slide (3) bowden cable (26) retracts the lifting tray (13) along the slide (9) on the lifting arms (8).

Preferably a spring (not shown) is connected to one end of each bowden cable to lessen any stretching of the cables. Further an adjustment can be located at the other end to overcome any stretching of the cables.

It should be obvious to people skilled in the art that modifications and alterations to the above embodiments can be made without departing from the scope and the spirit of the present invention.