CA2174382A1 - Retractable lift/ramp apparatus - Google Patents

Abstract

A retractable lift/ramp apparatus is disclosed for moving a load between two vertically spaced surfaces.
The apparatus includes a load supporting platform which is movable between a storage and operating position and one or more lever arms which are pivotally coupled to the platform. When the platform is moved to the operating position, each lever arm is pivotable relative to the platform about a pivot point, so that one end of each lever arm may be selectively moved along an arcuate path beneath the platform and into contact against the lower surface to raise or lower at least part of the platform. A pivot actuator mechanism, such as a scissor jack is provided to engage both the platform and a portion of the lever arm and is extensible or retractable to rotate the lever arm about the pivot point. Lifting is achieved by activating the pivot actuator to move one end portion of the lever arms selectively and progressively along its arcuate path against the lower surface. As the end of the lever arm moves against the lower surface, its opposite portion which is hingely coupled to the platform biases the platform upwardly or permits it to fall depending on the direction of lever arm movement.

Description

~ 21 74382 ~.
-RETRACTABLE LIFT/RAMP APPARATUS

The present invention relates to a retractablelift/ramp apparatus, and more particularly to a compact lift/ramp apparatus which may be easily and inexpensively mounted to a vehicle or building without requiring extensive structural and mechanical vehicle modifications.

BACKGROUND OF THE INVENTION

Apparatus for lifting loads into and out of vehicles are well known. Conventional apparatus which are used in vehicles, for example to lift wheelchairs, are disclosed in U.S. Patent No. 4,958,979 to Svensson, which issued September 25, 1990, and U.S. Patent No. 5,308,214 to Crain et al, which issued May 3, 1994. These lift apparatus typically include a load supporting platform which is lowered to and raised from the ground while suspended horizontally in a cantilever position by a frame mounted to the vehicle. In raising and lowering the platform, the entire weight of the load and platform is supported by the frame. Conventional lift apparatus suffer the disadvantage that they typically require bulky structural frames and large hydraulic or pneumatic lift mechanisms to provide the necessary support and lifting forces to raise and lower the cantilevered platform.

Another disadvantage of conventional lift apparatus of the type disclosed in U.S. Patent Nos.
4,958,979 and 5,308,214 exists in that in lifting operation, the entire load which is to be lifted is supported by the vehicle. During lifting, therefore, the load exerts a cantilever force on the vehicle which, after repeated use, unevenly weakens the vehicle suspension.

Another disadvantage with conventional lift apparatus used in vehicles exists in that because of their ~ . 21 74382 large frames, their installation typically necessitates extensive modifications to the vehicle. Necessary modifications may, for example, include reinforcing the vehicle undercarriage, lowering floors or even enlarging vehicle doorways and raising vehicle roofs to provide adequate clearance for the lift apparatus.

Because of their large frame, prior art lift apparatus frequently weigh in excess of 300 lbs. When installed in vehicles, the added weight of the lift apparatus adversely affects vehicle handling in mini-van class and smaller vehicles.

Conventional wheelchair lift apparatus of the type disclosed in U.S. Patent No. 5,308,214 suffer the further disadvantage in that when the apparatus is not in use it is stored within the vehicle passenger compartment, occupying space which may otherwise be used for cargo or passengers.

In an attempt to overcome the disadvantages of prior art, U.S. Patent No. 4,909,700 to Fontecchio et al, which issued March 20, 1990, discloses a wheelchair lift which moves for storage to a retracted position housed entirely concealed between the top of the frame and floor deck of a van, requiring the vehicle step riser to be cut away. In addition to installation cost and difficulties, the Fontecchio lift apparatus suffers the disadvantage in that many of today's vehicles are manufactured with a unibody-type construction and do not have separate frame and floor deck panels which would permit a wheelchair lift ramp to be housed therebetween.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present ~ ~ 21 74382 invention to at least partially overcome the disadvantages of the prior art by providing a light weight lifting/ramp apparatus which incorporates a retractable load supporting platform which, in use, is lowered or raised relative to an underlying surface by the extension of a lever arm against the underlying surface.

Another object of the invention is to provide a lift/ramp apparatus having a load supporting platform comprised of a number of telescoping sections which can be collapsed to a stacked or nested orientation for storage and extended to an outstretched orientation for a lifting or a ramping operation.

Another object of the invention is to provide a retractable lift or ramp apparatus for use in moving a wheelchair into and out of a vehicle, and which may be quickly and easily mounted in place on the undercarriage of the vehicle without requiring extensive vehicle modifications.

A further object of the invention is to provide a lift/ramp apparatus for use in moving a load between upper and lower vertically spaced surfaces and which incorporates a load supporting platform having a number of guide channels formed therein, which assist in maintaining the load in a centred position on the platform during lifting.

Another object of the invention is to provide a low-profile concealed lift/ramp apparatus for the mini-van class of vehicle which may be installed in current production vehicles without resorting to lowered floors, raised roofs or other such permanent alterations which may otherwise reduce the utility or resale of the vehicle.

-~ 21 74382 Another object of the invention is to provide a light weight lift/ramp apparatus for the smaller mini-van class of vehicle which may be installed below either driver or passenger side doors, front or rear doors without creating steering or suspension problems for the user or the vehicle manufacturer.

Another object of this invention is to provide a lift/ramp apparatus which may be installed, removed and/or transferred between vehicles or residences with ease and m;n;m~l cost, thereby permitting the apparatus to follow the owner if changes in health, residence or vehicle do occur.

Another object of the invention is to provide an apparatus for moving a load between vertically spaced surfaces which allows the user to select either the option of operating the apparatus in a ramp mode or in a lift mode.

In furtherance of these objects, the present invention provides an apparatus for moving a load between two vertically spaced surfaces. The apparatus includes a load supporting platform and one or more lever arms which are pivotally coupled to the platform. At least part of the platform is raised and lowered between two vertically spaced surfaces by the selective engagement of one or more lever arms against the lower of the two surfaces. Each lever arm is pivotable relative to the platform about a pivot point so that one respective end may be selectively moved along an arcuate path beneath the platform and into contact against the lower surface. A pivot actuator mechanism, such as an electric motor, extensible pneumatic or hydraulic cylinder, a screw feed, scissor jack or the like may be provided engaging both the platform and a portion of the lower arm. The pivot actuator mechanism may ~ 21 74382 be extended or retracted to rotate the lever arm about the pivot point.

In the simplest embodiment, the apparatus functions as a movable ramp, whereby a front end portion of the platform is raised and lowered between the vertically spaced surfaces by the selective engagement of one or more lever arms against the lower most surface. Lifting of the end of the platform is achieved by activating the pivot actuator to move one end portion of the lever arms selectively and progressively along the arcuate path. As the end of the lever arm moves against the lower surface, the opposite portion of the lever arm which is hingely coupled to the platform propels the platform upwardly or permits it to fall depending on the direction along which the lever arm pivots.

If the upper surface to grade distance is not too large because of curbing, sidewalks or lawns, the ramp mode can be utilized. This is especially beneficial if the user of the apparatus has a powered wheelchair, or electric scooter.

The apparatus may use llOV AC motors or 12V DC
motors with battery reserve and, for example, can be permanently installed at a particular site to move a load between the outside ground and first floor surfaces of homes or offices. The primary advantage of the present invention, however, resides in vehicle use incorporating 12V DC motors to load and offload either cargo or wheelchairs.

In vehicle use, the apparatus preferably also includes a storage housing having a front opening. The platform is movable through the front opening of the housing in a longitudinal direction between a retracted ~ ~ 21 74382 storage position, at least partially positioned within the housing, and an operating position wherein the platform is moved forwardly substantially outwardly therefrom. A
rearward inner portion of the platform is coupled to the housing so as to permit pivotal movement of part of the platform relative to the housing as the front end portion of the platform is raised and lowered.

The load supporting platform may further be comprised of a number of telescoping platform sections.
The platform sections slide relative to one another between a telescoped configuration in which the platform sections are moved to a collapsed or substantially nested orientation, and an outstretched configuration in which the platform sections are moved to an extended or outstretched position spaced at positions longitudinally offset relative to each other. An actuator mechanism, such as a rack and motor driven pinion, a tape drive, or hydraulic or pneumatic cylinder, is provided to slide the platform sections to the telescoped configuration when the platform is moved to the storage position and to the outstretched configuration when the platform is moved to the operating posltlon .

More preferably, the apparatus functions as a lift apparatus whereby the entire portion of the platform which supports the load is raised or lowered vertically.
A rear portion of the platform which is spaced towards the housing may be vertically moved between raised and lowered positions by additional lever arms movable therebeneath, or by a screw or scissor lift, hydraulic cylinder or other lifting device. The inventor has appreciated that a rearwardmost platform section which has front and rear halves hingely coupled together and a pivot mechanism for pivoting the halves relative to each other, advantageously may be used to maintain the portion of the platform which ~ 21 74382 , supports the load in a substantially horizontal position.
The hinge may, for example, comprise a continuous hinge.
The pivot mechanism may be a hydraulic or pneumatic plunger or, in a simplified embodiment, the pivot mechanism may include a threaded rod which engages a threaded nut rotatably mounted to each side of the rear half of the platform section. By coupling the rod to a drive gear or other torque converter which is pivotally mounted to the front half of the platform section, the rod may be selectively rotated to pivot the halves about the hinge.
In this manner, as the forward end portion of the platform is raised or lowered and the rear half pivots about the housing, each threaded rod may be turned in its associated pivotable nut to either increase or decrease the spacing between the gear box and nuts so as to maintain the front half of the rearward platform section in a generally level orientation with the forward end of the platform.

Accordingly, in one aspect the present invention resides in a retractable apparatus for use in moving a load between upper and lower vertically spaced surfaces, the apparatus comprising, a housing having a front opening, a load supporting platform movable in a longitudinal direction relative to said housing through said front opening between a retracted storage position wherein said platform is at least partially located within said housing and an operating position, wherein the supporting platform is moved substantially outwardly therefrom, in the operating position the platform extending longitudinally from a rear end portion spaced towards the housing to a front end portion, the front end portion being vertically movable between a raised position spaced above the lower surface, and a lowered position moved theretowards, ~ 21 74382 .

li~t means carried by the platform for selectively moving the front end portion between the raised and lowered positions when said platform is in the operating position, the lift means including a lever member having first and second ends, the lever member being coupled to the platform and pivotable about a pivot point to selectively move the first end below the platform along an arcuate path into engagement with the lower surface, wherein the engagement of the first end with the lower surface as the first end moves along the arcuate path raises and lowers the distal end of the platform relative to the lower surface, drive means including first actuating means for selectively moving the platform between the storage and operating positions, and second actuating means to reciprocally pivot the lever member about the pivot point for moving the first end into and out of contact with the lower surface.

In a another aspect the present invention resides in a retractable lift/ramp apparatus for lifting a load between upper and lower vertically spaced surfaces, the apparatus comprising, or creating a ramp to minimize the force necessary to move a load between two vertical spaced surfaces, a lift housing, a load supporting platform movable horizontally in a longitudinal direction between a retracted storage position wherein said platform is substantially located within said housing, and a lifting position wherein said platform is moved out of said lift housing, the platform comprising a plurality of interlocking telescoping platform sections which are longitudinally slidable relative to each other between a telescoped configuration, with said platform sections moved to a substantially nested orientation, and an outstretched ~ 2 1 74382 configuration with said sections moved to an orientation longitudinally offset relative to each other, in the operative position, the platform extending longitl~in~lly from a rearward platform section spaced towards the lift housing to a forward platform section, lift means for raising and lowering the forward platform section between a raised position at said upper surface and a lowered position at said lower surface, the lift means comprising an elongated lever arm coupled to one of said platform sections, the lever arm having first and second ends and being pivotable about a pivot point spaced towards the second end to move the first end along an arcuate path extending below the platform, the lever arm having a length selected such that its pivotal movement about the pivot point moves the first end into engagement with the lower surface to raise or lower the platform, drive means for moving said platform including, first actuator means for selectively moving said platform between said storage and lifting positions, and second actuator means for selectively pivoting said lever arm to move said first end along the arcuate path.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will appear from the following description together with the accompanying drawings in which:

Figure 1 shows a perspective schematic view of a vehicle mounted lift/ramp apparatus having a retractable telescoping platform moved to an outstretched starting lift position in accordance with a preferred embodiment of the lnvention;

~ 21 74382 -Figure 2 is a schematic side view of the apparatus shown in Figure 1;

. Figure 3 shows a schematic side view of the apparatus of Figure 1 with the platform moved to a fully raised lift position;

Figure 4 shows a schematic side view of the apparatus of Figure 1 with the platform moved to a fully lowered lift position;

Figure 5 shows a schematic side view of the apparatus of Figure 1 with the platform moved to a fully retracted storage position;

Figure 6 shows a schematic end view of the apparatus shown in Figure 5;

Figure 7 shows a schematic top view of the housing shown in Figure 5;

Figure 8 shows a perspective front view of the front end of the housing shown in Figure 7;

Figure 9 shows a schematic top view of the rearward section of the platform shown in Figure 2 when moved to fully outstretched start lift position;

Figure 10 shows a cross-sectional view of the platform section of Figure 9 taken along lines lo-lo';

Figure 11 shows a partial schematic side view of the platform section of Figure 9;

Figure 12 shows a schematic top view of the intermediate section of the platform shown in Figure 1;

- ~ 2174382 -Figure 13 shows a cross-sectional view of the platform section of Figure 12 taken along line 13-13';

Figure 14 shows a schematic top view of the forwardmost section of the platform shown in Figure 6 in the fully lowered offloading position;

Figure 15 shows a cross-sectional view of the platform section of Figure 14 taken along line 15-15'; and Figure 16 shows a schematic side view of the apparatus shown in Figure 1 moved to a ramp/grade position.

DETAILED DESCRIPTION OF THE DRAWINGS

Reference is first made to Figures 1 and 2 which show a retractable lift apparatus 10 which is mounted to the undercarriage 11 of a vehicle 12 and used to raise and lower a wheelchair or other load between the interior passenger compartment floor 6 of the vehicle 12 and the ground 8. The apparatus 10 includes a housing 14, a telescoping load supporting platform 16 which, as will be described hereafter, is movable into and out of the housing 14, and lift and drive mechanisms 18,20 for raising and lowering the platform 16.

As will be described hereafter, the housing 14 is formed having a compact construction which enables it to be secured in place to the vehicle undercarriage 11, regardless of whether or not the vehicle 12 is formed by unibody or conventional frame construction, and without requiring extensive modifications to the vehicle 12. The housing 14 is coupled to the undercarriage 11 of the vehicle 12 beneath a chosen access door 17 (shown in Figure 1 as a passenger side door) through which the wheelchair is to move into and out of the vehicle 12.

, ~ 21 74382 .

The housing 14 is provided as a protective casing for the platform 16 and the lift and drive mcch~n;~ms 18,20 when the apparatus 10 is not in use. Figures 7 and 8 show the housing 14 best as having a generally rectangular box-like construction having a top panel 22, bottom panel 23, sidewalls 24a,24b, and a rear inner panel 25; and which opens to a front open end 26. Although not essential, in the embodiment shown the sidewalls 24a,24b project forwardly beyond the front open end 26 to deflect precipitation and soil away from the platform 16, as well as acting as running board brackets.

A pair of guide tracks 28a,28b are provided on the interior of the housing 14 along the centre of the respective sidewalls 24a,24b. Two racks 30a,30b project upwardly from the bottom panel 23 at equally inwardly spaced locations from each sidewall 24a,24b and extend in a longitudinal direction from the rear panel 25 to the front open end 26. Pivot shaft locks 32a,32b are provided adjacent the front open end 26 at the forward most end of each respective racks 30a,30b, which as will be described hereafter, permit pivotal movement of platform 16 relative to the housing 14.

As is apparent from Figures 1, 2 and 5, the platform 16 is movable in the longitudinal direction along axis A1. The platform 16 moves along the Axis A1 between the retracted storage position shown in Figure 5, wherein the platform 16 is driven horizontally rearward into the housing 14 through the open end 26 to a position where most of the platform 16 is located within the housing 14, and an extended operating position, wherein the platform 16 is driven horizontally forward along the axis A1 outward from the housing 14 to the position shown in Figure 2 with the platform 16 moved substantially out of the housing 14.

- ~ 21 74382 Figures 1 to 5 show best the platform 16 as having three separate telescoping sections 38,40,42. The sections 38,40,42 are telescopically movable relative to each other and the housing 14 between a telescoped or collapsed configuration, with the sections 38,40,42 positioned in a nested orientation shown in Figures 5 and 6, and an outstretched configuration shown in Figures 1 to 4. In the outstretched configuration, the platform sections 38,40,42 assume positions which are longitudinally offset along the axis A1 relative to each other. As will be described in detail hereafter, when the platform 16 is in the outstretched configuration the rearward platform section 38 which is spaced closest to the housing 14, is pivotally coupled at its rear edge 44 (Figure 9) to the housing 14. The forward edge of the rearward platform section 38 is positioned partially overlapping approximately 6 inches of the platform section 40 which locates in an intermediate position between the rearward platform section 38 and the outermost forward platform section 42 which locates furthest from the housing 14.

The rearward platform section 38 is shown best in Figures 9 to 11 as being divided laterally into an outer front deck section 46, and an inner rear deck section 48 which are pivotally coupled by a continuous hinge 50. The front section 46 includes downwardly extending sidewalls 68a,68b which are generally square C-shaped for increased rigidity. The sidewalls 68a,68b of the front deck section 46 are integrally formed with a corrugated top panel 72 and are fabricated from a solid sheet of bent .040" stainless steel. The sidewalls 68a,68b curve inwardly and upwardly along their bottom edges to provide increased structural integrity to the front deck section 46.

Figure 11 shows the rear deck section 48 as having split sidewalls, each with respective longitudinally -.

extGn~;ng top rail 69a,69b which is integrally formed with a top panel 74, and a generally U-shaped bottom rail 70c,70d. The separate bottom rail 70c,70d of each sidewall 69a,69b curves inwardly and upwardly along its bottom inner edges in substantially the same cross-sectional profile as the bottom edges of sidewalls 68a,68b.

The bottom inner edge of each sidewall are provided as a longitudinally extending rack 70a,70b on deck 46 and rack 70c,70d on deck 48, which extends the length of the platform section 38 and, as will be described hereafter, is engaged by a motor driven pinion in sliding the platform sections 38,40,42 longitudinally in and out of the housing 14.

Preferably, the top panel 74 is formed from .040"
steel, and is embossed with ribbing 75 for enhanced rigidity. The sidewalls 68a,68b,69a,69b are also formed of .040" gauge for increased rigidity.

Two pair of pivot wheels 61a,61b are rotatably provided at each end of a shaft 60. Each pivot wheel 61a,61b consists of a respective outer roller 59a,59b and an inner cam 58a,58b. The inner cams 58a,58b are rotatably secured to each top rail 69a,69b and bottom rail 70c,70d adjacent the rear edge 44 of the deck section 48 by pins 84 (Figure 11) on each inner cam 58a,58b.

As previously noted, the front deck section 46 is coupled to the rear deck section 48 by a continuous hinge 50 (shown in Figure 9). Figures 9 and 11 show the decks 46 and 48 as also connected along each side by a mechanical pivot 51a,51b. Each pivot 51a,51b is comprised of a respective gear box 52a,52b (or other torque converter), a threaded nut 54a,54b and a threaded rod 56a,56b. The gear boxes 52a,52b are rotatably coupled at their centres to the - ~ 21 74382 ..

rear deck 46 in alignment with the continuous hinge 50.
The bottom rail 70c,70d is additionally rotatably coupled to each respective gear box 52a,52b by a pin 86 whereby the rotational movement of the inner cams 58a,58b and gear boxes 52a,52b permit the bottom rails 70c,70d to move relative to the top rails 69a,69b. The threaded nuts 54a,54b are rotatably mounted towards the rearward edge portion of each bottom rail 70c,70d.

The threaded rods 56a,56b are rotatably mounted at one end within a respective gear box 52a,52b. The rods 56a,56b are provided in threaded engagement with threaded nuts 54a,54b, whereby the rotation of the rods 56 through the nuts 54 diagonally along the sides of top rails 69a,69b permits the front deck section 46 to pivot along the hinge 50 relative to the rear deck section 48. By rotating the threaded rods 56a,56b through the nuts 54a,54b upon activating the respective gear boxes 52a,52b, the spacing between the pairs of gear boxes and nuts 52a,54a and 52b,54b may be varied and the angular position between the front and rear deck sections 46,48 may thereby be changed.

Figure 11 shows the ramp 76 as being perforated by a series of 0.25 inch diameter holes 77 provided on 1.0 inch centres. Although not shown in the remaining Figures for clarity, the upper surface of all of the platform sections 38,40,42 contain similar sized and spaced holes.
In addition to reducing the overall weight of the platform 16, the holes 77 provide enhanced traction, reducing the chance that the wheelchair or attendant may accidentally slip on the platform 16.

The rollers 59a,59b of the pivot wheels 61a,61b are rotatable in a respective guide track 28a,28b on housing 14, to couple the platform section 38 to the housing 14 while permitting its movement through the front ~ 2 1 74382 open end 26. In this manner, when the platform 16 is moved to the storage position, the rearwardmost three quarters of the platform section 38 is moved through the open end 26 to a position within the housing 14. In a forwardmost position with the platform section 38 moved to the operating position, the roller shaft 60 o~ the pivot wheels 61a,61b engage a respective pivot shaft lock 32a,32b shown in Figure 7 to lock the platform section 38 in place while permitting pivotal movement of the rear deck section 48 about a lateral axis co-axial with the shaft 60.

Figures 9 and 11 shows the platform section 38 as further carrying a rear safety ramp 76 which is also coupled to deck section 46 by the continuous hinge 50. As will be described in detail hereafter, the safety ramp 76 is selectively pivotable about the hinge 50 by rotating telescoping control rods 64a,64b which are used to activate a respective cam 66a,66b to move the safety ramp 76 between a storage position, a position level with vehicle floor 6 with the ramp 76 in a generally horizontal position, and a vertical load safety position.

Figures 12 and 13 show best the intermediate platform section 40 which has a cross-sectional profile which is complementary to that of section 38, so as to permit its sliding insertion therein. Like the platform section 38, the intermediate platform section 40 has a downwardly open generally square C-shape and is characterized by integrally formed sidewalls 78a,78b and a corrugated and perforated top panel 82. The platform section 40 is formed of .020" gauge perforated stainless steel with each sidewall 78a,78b formed by double folding the steel for increased strength. The sidewalls 78a,78b also curve inwardly and upwardly along their bottom edges, with the lower open edge of each sidewall 78a,78b provided with a respective rack 80a,80b extending longitudinally the ~ 2 1 74382 length of the platform section 40.

Pairs of wedge shaped nylon slide locks 85a,85b and 87a,87b are provided along the bottom rails of 78a,78b adjacent the respective front and rear ends of the platform section 40. The slide locks 85a,85b are positioned downward on a lower interior surface of the sidewalls 78a,78b and engage and lock in place the platform section 42 on outward movement of the section 40 from the housing 14. The slide locks 87a,87b are positioned rearward on a lower interior surface of the sidewalls 78a,78b and engage and lock the platform section 40 in place relative to the platform section 38 when the platform 16 is moved to the outstretched position. Each pair of slide locks 85a,85b,87a,87b is provided so as to lock the platform sections 38,40,42 in a rigid orientation when the platform 16 is extended and release the respective platform sections 42,40 and 40,48 on the return movement of the platform 16 to the storage position.

The corrugated overall shape of the top panel 82 is complementary to the shape of the top panel 72. More particularly, the complementary shapes of the intermediate platform section 40 and rearward platform section 38 are selected to permit the intermediate platform section 40 to be slid under and within the platform section 38. In this manner, the section 40 is movable between a telescoped configuration, with the platform section 40 moved within the platform section 38 to the nested orientation shown in Figures 5 and 6, and an outstretched orientation, with the platform section 40 moved to a position shown in Figure 2, offset longitudinally and extending forwardly from the platform section 38. In the outstretched orientation, approximately 6" of the rearwardmost edge of the intermediate platform section 40 is overlapped by the front deck 46 of platform section 38. The complementary square -~ 2174382 C-shape of the sections 38,40 in conjunction with the slide locks 87a,87b secures the sections 38,40 in place and provides sufficient safety factor rigidity between the front deck 46 and the intermediate platform section 40 to support the wheelchair.

Figures 14 and 15 show the forward platform section 42 as having an overall downwardly open square C-shape which is marginally smaller than and complementary to that of the intermediate platform section 40.

The forward platform section 42, like the intermediate platform section 40 is made from a sheet of .020" thick stainless steel and includes sidewalls 88a,88b which are integrally formed with a perforated and corrugated top panel 92. The sidewalls 88a,88b, like sidewalls 78a,78b, are formed by double folding the steel sheet, and curve inwardly and upwardly along their bottom edges in an open square channel construction for increased rigidity.

The complementary shape of the front panel section 42 to that of the section 40 permits the front panel section 42 to be moved longitudinally along the axis A1 relative to the rearward and intermediate sections 38,40.
In the telescoped configuration the front panel section is moved rearwardly into the intermediate section 40 then inwardly into the panel 38 to the nested orientation shown in Figures 5 and 6. In the outstretched configuration the front panel section 42 is slid forwardly and outwardly from the panel section 40 to a position shown in Figure 2, with the intermediate panel section 40 overlapping approximately 6" of section 42. As with the panel sections 38,40, the overlapping complementary shape and nylon locks 85a,85b provide sufficient safety factor integrity to the platform 16 to support the wheelchair or other load thereon.

~ 21 74382 .

The corrugations of the top panels 72,82,92 are such that when the platform 16 is moved to the outstretched position, the corrugated upper surfaces 72,82,92 define three longitudinally extending channels 94,96,98 (seen best in Figure 1). Each of the channels 94,96,98 is formed having a size and a relàtive spacing chosen so that the outer channels 94,98 permit the movement of the wheels of a wheelchair therein; with channels 94, 96 and 98 spaced to receive therein the wheels of a three wheeled scooter.
With the foregoing construction, the channels 94,96,98 act to assist in maintaining a wheelchair or scooter in the correct position on top of the platform 16, without requiring complicated folding handle structures or the like.

The platform section 42 further is provided with a laterally extending barrier 100 which extends downwardly beneath the top panel 92 about one quarter of the distance from the front end of the platform section 42 towards its rear edge. The barrier 100 may be formed as a rigid plastic or metal plate, but preferably comprises a curtain of fibrous bristles. As will be described later, the barrier 100 acts as a weathershield which closes the housing front open end 26 when the platform 16 is moved to the retracted position to protect the apparatus 10 when the vehicle 12 is in motion.

Figure 14 shows the forward platform section 42 best as carrying a forward ramp 102. The ramp 102 is hingely coupled to the top panel by a continuous hinge 103.
The forward ramp 102 is pivotable about the hinge 103 for both loading and safety by means of the telescoping control rods 64a,64b and cams 104a,104b. By rotating the control rods 64a,64b, the ramp 102 may be moved between a horizontal position shown in Figure 5, where the ramp 102 is moved flush against top panel 92 and acts as a running ~ 21 74382 board; a vertical load retaining position shown in Figures 2 and 3; and a forwardly oriented generally horizontal ramp position shown in Figure 4. It is to be appreciated that the telescoping construction of the control rods 64a,64b enables their collapse to a reduced length when the platform 16 is moved to the storage position, and their extension full length as the platform sections 38,40,42 are returned to the outstretched orientation.

Figures 1, 6, 14 and 15 show best the lift mechanism 18 and drive mechanism 20 as being mounted to and carried on the underside of the forward platform section 42.

The lift mechanism 18 includes a pair of laterally spaced lever arms 110a,110b, which are actuated in movement by a corresponding scissor jack 118a,118b. The lever arms 110,110b have a length selected greater than the height which the platform is to be raised above the ground 8. One end of each lever arm 110a,110b is pivotally coupled by a respective hinge llZa,112b to the underside of top panel 92 under corrugations forming the respective channels 94,98, and at positions adjacent the rear edge of the forward platform section 42. Each lever arm 110a,110b consists of a channel defining U-shaped steel beam 114a,114b and a polyethylene roller 116a,116b. The polyethylene rollers 116a,116b are rotatably mounted to the end of the beams 114a,114b opposite the end coupled to the panel 92.

The scissor jacks 118a,118b are activatable to move between the extended and retracted positions by the rotational movement of threaded rods 120a,120b. In this regard, each rod 120a,120b is coupled at one end to, and is rotated by, a respective gear box 136a,136b or like torque converter.

~ 2 1 74382 The scissor jacks 118a,118b are sized for placement within the channel defined by the beams 114a,114b of each respective lever arm llOa,llOb. The scissor jacks 118a,118b are coupled to each of the underside of the top panel 92 and the associated beams 114a,114b, such that when each scissor jack 118a,118b is moved to a fully collapsed position, the associated beam 114a,114b and roller 116a,116b are pivoted about the hinges 112a,112b to a fully retracted, horizontal position shown in Figures 4, 5 and 6.
In the fully retracted position the lever arms llOa,llOb are moved upwardly flush against the underside of the forward platform section 42. Although not essential, the weathershield 100 may be provided with c~ose fitting gaps that have a size and shape complementary to that of the beams 114a,114b, so that when the platform 16 is returned to the storage position in the housing 14, the lever arms llOa,llOb form a substantially weather impermeable seal with the weathershield 100.

In the retracted position, the respective jacks 118a,118b locate within the channel defined by each beam 114a,114b. When the jacks 118a,118b are moved to the extended position shown in Figure 3, each lever arm llOa,llOb is pivoted about its associated hinge 112a,112b to move the rollers 116a,116b downwardly along an arc of a circle centred on the respective hinges 112a,112b, and against the ground 8.

It is to be appreciated, that by forcing the rollers 116a,116b of each lever arms llOa,llOb against the ground as the scissor jacks 118a,118b are extended, the end of the lever arms llOa,llOb which is hingely coupled to the platform section 42 forces the forward platform 42 section upwardly. Conversely, as the scissor jacks 118a,118b are collapsed, the spacing between the rollers 116a,116b and the upper surface 92 is reduced, lowering the forward - ~ 21 74382 platform section 42 to the ground.

Figure 14 shows best the drive m~h~n;sm 20 used to operate the apparatus 10 as comprising six 12 volt DC
reversible motors 122,124,126,128,130,132 mounted beneath the forward platform section 42. The motors 122,124,126,128,130,132 are coupled to the forward panel section 42 rearwardly from the weathershield 100, so that when the platform 16 is moved to the storage position, each of the motors 122,124,126,128,130,132 are located in an interior of ~the housing 14. The motors 122,124,126,128, 130,132 are independently controlled by a microprocessor 140 and may, for example, be similar to the type presently used in power seat assemblies used in automobiles. Each motor 122,124,126,128,130,132 powers an associated respective cable drive 123,125,127,129,131,133 for providing forward and reversing movement to various components of the apparatus 10.

Figure 14 shows best the motors 122,124 and their associated cable drives 123,125 as being coupled to the gear boxes 136a,136b, respectively. In this manner, the selective rotation of the motors 122,124 may be used to extend or retract the scissor jacks 118a,118b to actuate pivotal movement of the lever arms llOa,llOb. The independent operation of the motors 122,124 further permits each of the lever arms llOa,llOb to be independently pivoted relative to the other. The independent movement of the lever arms llOa,llOb advantageously permits the apparatus 10 to compensate for potholes, uneven terrain, curbs and other obstructions.

Figure 14 shows the motor 126, cable drive 127 and gear box 138 which are used to selectively rotate the control rods 64a,64b to move the safety ramps 102,76 to the desired position during lift operation. The gear box 138 -- ~ 21 74382 is coupled to a shaft 141 which in turn provides rotatable movement to the rods 64a,64b by the use of bevel or miter gearing 139 on the shaft 141. Preferably the microprocessor 140 provides control signals to the motor 126 to automatically actuate the control rods 64a,64b and move the front and rear safety ramps 102,76 to their appropriate positions when lift and pivot mechanisms reach their various storage loading and offloading positions.

Motor 128, cable drive 129 and gear box 145 are selectively operable to move the platform sections 38,40,42 between the telescoped orientation substantially located within the housing 14, and the outstretched orientation for lifting operation. The cable drive 129 is connected to the gear box 145 which in turn by the use of miter gearing 147 rotates a shaft 142 mounted along an innermost edge of the section 42. The shaft 142 has a pinion 144a,144b provided at each of its ends, which rotatably engage each of the racks 70,80 of the housing 14, section 38 and intermediate section 40. In this manner, the activation of the motor 128 selectively rotates the shaft 142 and pinions 144a,144b. As the pinions 144a,144b rotate, they engage the respective racks 30,70,80 causing the platform sections 38,40,42 to slide longitudinally inwardly or outwardly relative to each other and the housing 14, between the telescoped configuration housed shown in Figure 5 and the outstretched configuration shown in Figure 2.

It is to be appreciated that relative telescoping movement of the sections 38,40,42 may be achieved by providing gaps along portions of the racks, by providing racks having variable tooth profiles, or by using bevelled pinions to selectively engage each rack 30,70,80 as to rack height.

The cable drives 131,133 are coupled to each of ~ 21 74382 gear boxes 52a,52b (shown in Figure 9). In this manner, the activation of the motors 130,132 selectively activates each gear box 52a,52b to rotate the respective threaded rods 56a,56b. By controlling the activation of the motors 130,132, the threaded rods 56a,56b are moved through the respective threaded nuts 54a,54b to vary the angle between the front and rear deck sections 46,48 as the platform sections 40,42 are raised and lowered by the lever arms llOa,llOb. By varying the angle between the front and rear deck sections 46,48, the front deck section 46 may be maintained in a level co-planar orientation with the forward and intermediate platform sections 42,40 during lifting operations, maintaining the wheelchair or load in a position generally parallel with the ground 8 and vehicle floor 6.

Figures 14 and 15 show best the apparatus 10 as further including a spool bailer 146 mounted beneath the top panel 92. The bailer 146 engages and eliminates any slack in the cable drive 131,133, as the platform 16 is moved to a nested fully extended position. The bailer 146 thus ensures that the cable drives 131,133 will not inadvertently get caught between the moving platform sections 38,40,42 and result in the jamming of the apparatus 10.

Figures 6 and 14 show the apparatus 10 as further including a spring loaded power cable recoil mechanism 148 which eliminates any excess in the power supply (not shown) from the housing 14 to the motors in deck 42. Whether the apparatus 10 is powered by servo-mechanical or a hydraulic mechanism, the recoil 148 and bailers 146 will thus provide accurate power cable for different stages of operation of apparatus 10.

Figures 6 and 14 show the apparatus 10 as further ~ 21 7~382 including three levelling sensors 152a,152b,152c which are electronically connected to the microprocessor 140 and provide signals indicative of the angular orientation of the platform 16 relative to the housing 14, vehicle floor 6 and grade 8.

The levelling sensors 152a,152b,152c consist principally of level switches (ie. mercury or the like) and are used to maintain the platform 16 in a substantially level orientation relative to the vehicle 12 as the platform 16 is raised and lowered. When either sensor longitudinal 152a,152b or transverse 152c emits a signal indicative of one side of the platform sloping relative to the other, as for example when one roller 116 engages a pot-hole or other such depression, the microprocessor 140 receives the signal and actuates the appropriate drive motor 122,124 to move the associated scissor jack 118 and extend the corresponding lever arm 110 to compensate for the depression. More preferably, the sensors 152a,152b,152c provide a safety function as well whereby deployment or continued movement of the platform 16 is prevented when the level limit switches 152a,152b,152c sense that the angular orientation of the platform 16 is more than 5~ from horizontal.

Also, connected to the microprocessor 140 are light sensors 154a,154b mounted adjacent to each lift mechanism 18 at the rear edge platform section 42 (shown in Figure 15). The light sensors 154a,154b operate in conjunction with three pairs of reflectors to ensure the proper positioning of the platform 16 at its three points of travel, namely: one pair of reflectors 156a,156b (shown in Figure 7) which are positioned on the rear wall 25, on the housing 14; one pair of reflectors 156c,156d (shown in Figure 1) which are positioned on the step riser of the vehicle 12 adjacent the access door 17 and vehicle floor 6;

-- ~ 21 74382 and one pair of reflectors 156e,156f (shown in Figures 1 and 11) which are provided as downwardly ext~n~;ng tabs below the outward edge of deck 48. The light sensors 154a,154b operate to provide signals to the microprocessor control 140 indicative of whether platform 16 is opposite its programmed destination. In this manner, the sensors 154a,154b may signal the microprocessor control 140 to selectively operate the drive motors 122,124,130 and 132 to position and maintain the platform 16 in a substantially level orientation using reflectors 156a and 156b with the front open end 26 while the motor 128 moves the platform 16 between the storage and operating positions.

As indicated, the motors 122,124,126,128,130,132 are housed on the underside of the forward platform section 42, rearwardly from weathershield 100. The weathershield 100 is configured such that when the platform 16 is moved to the retracted storage position within the housing 14, the weathershield 100 engages and substantially seals the front open end 26 of the housing 14. In this manner, all of the electronic components and gearing of the apparatus lo are contained internally within the housing 14 for storage and are protected from dirt, corrosion by slush and winter road salt.

The applicant has appreciated that by forming the platform sections 38,40,42 and housing 14 of stainless steel or other such light weight metal or plastic. The apparatus typically will have a total overall weight of only about 125 pounds, and may be easily mounted to existing vehicles by conventional gas tank mounting straps, without requiring customization of the vehicle frame and/or shock absorber assembly.

In the preferred embodiment of the invention used to lift wheelchairs into and out of vehicles 12, such as ~ 217438~

mini-vans, the housing 14 has an overall width in the lateral direction of about 32 inches, a depth under the vehicle 12 of about 18 inches, and a height of between about three and five inches. The platform sections 38,40,42 have overall lateral widths of about 29-1/2 inches, 29-3/16 inches and 29 inches respectively, enabling their telescoping movement. Because of the placement of the drive mechanism 20 and motor placement on the forward platform section 42 rearwardly from the weathershield 100, each of the platform sections 38,40,42 need only be partially housed within the housing 14 during storage. As such, the platform sections 38,40,42 may be provided with a length of approximately 24 inches. The added length of the platform sections 38,40,42 is, for example, accommodated by mounting the housing 14 under the vehicle so that the portions of the platform sections 38,40,42 which extend outwardly from the housing 14 forms a useful 6" running board, or step when the platform 16 is fully retracted (see Figure 5).

The operation of the apparatus lo is best described with reference to Figures 2 to 5.

While the vehicle 12 is moving, each of the platform sections 38,40,42 is positioned in the telescoped configuration housed substantially within the housing 14 as shown in Figure 5. As part of 12 V connection to the battery, the vehicle 12 is provided with an ignition-type switch which prevents the apparatus 10 from operating if the vehicle 12 is not in the park/on or park/off position.
To move a wheelchair either into or out of the vehicle 12 once the vehicle is parked, the apparatus 10 is operated by remote control (not shown) which controls the microprocessor 140.

To offload a wheelchair from the vehicle 12, the ~ 2 1 74382 platform 16 is initially moved from the storage position shown in Figure 5 to the operating starting position shown in Figure 2. To move to the starting position, the microprocessor 140 activates the motor 128 to rotate the gear box 145 which turns the miter gearing 147, the shaft 142 and pinions 144a,144b. As the pinions 144a,144b turn, they rotatably engage a respective rack 30a,30b along the edges of the housing 14, moving all of the platform sections 38,40,42 forwardly simultaneously out of the housing 14 through the front open end 26. With the forward movement of the platform sections 38,40,42, the microprocessor 140 activates the motors 122,124 to turn cable drives 123,125 to activate the gear boxes 136a,136b extending the scissor jacks 118a,118b and lowering the lever arms llOa,llOb so as to move each associated roller 116a,116b downwardly against the ground 8. The level switches 152a,152b,152c and sensors 154a,154b and reflectors 156a,156b provide signals to the microprocessor 140 to maintain the platform 16 level keeping the rack gears 30,70,80 aligned.

With the present apparatus lo, when the van 12 is parked on >5~ surface, the rollers 116a,116b preferably move forwardly from the open end 20 a distance of between about 18 and 30 inches before they are moved into engagement with the ground 8. This ensures that when the van 12 is parked next to sidewalks and medians (not shown), the platform 16 will tend to move above the sidewalk as it is extended. To ensure proper deployment of the platform 16, the microprocessor 140 may further be provided with an ampere load sensor or the like which automatically reverses the platform 16 when obstructions prevent its movement.

As the platform 16 moves forwardly from the housing 14, each pivot wheel 59a,59b turns along to the end of respective guide track 28a,28b until shaft 60 is brought ~ 2 1 74382 J

into engagement against the pivot shaft locks 32a,32b, pivotally locking the rearward platform section 38 in position relative to the front of the housing 14.

The shaft 142 and pinions 144a,144b continue to rotate to successively slide the intermediate platform section 40 longitudinally forward relative to the rearward platform section 38 by its engagement with the racks 70a,70b,70c,70d on top rails 69a,69b; and the forward platform section 42 longitudinally forward relative to the intermediate platform section 40 by the engagement with the racks 80a,80b on each sidewall 78a,78b. The forward movement of the pinions 144a,144b past the slide locks 87a,87b and 85a,85b engages and moves the slide locks 87a,87b and 85a,85b to a locked position.

As the platform sections 38,40,42 move to the outstretched orientation, the telescoping control rods 64a,64b also extend to maintain engagement between cams 104,66 and miter gearing 139a,139b. While the platform 16 moves, the levelling sensors 152a,152b provide signals to the microprocessor 140 to selectively control the motors 130,132 activating the gear boxes 52a,52b to maintain the platform 16 substantially level with the front open end 26 of the housing 14. In this manner, the platform 16 is maintained in a position aligned with and level to the front open end 26 until fully extended.

The microprocessor 140 additionally controls the motor 126 to activate the gear box 138 and miter gears 139a,139b to rotate the control rods 64a,64b, raising each of the safety ramps 76,102, and preventing use of the apparatus 10 during mid-point positioning. During extension and retractions, the reflectors 156a,156b respond to impulses from the sensors 154a,154b maintaining level alignment. The sensors 154a,154b operate in conjunction - ~ 21 74382 .

with the reflectors 156e,156f to feed back to platform 16 that it has reached the lower elevation or grade 8.

Correspondingly, reflectors 156c and 156d respond to light sensors 154a and 154b to inform the microprocessor 140 that platform 16 has reached the vehicle floor deck 6.

Once the pinions 144a,144b have moved the platform sections 38,40,42 to the fully extended position and the sections are locked in place by sliding locks 85a,85b,87a,87b, the motor 128 is deactivated. When the platform 16 is extended, the interlocking C-shape construction of all of the platform sections 38,40,42 and slide locks 85a,85b,87a,87b ensures that a rigid stable structure is provided.

Unloading and loading of a wheelchair is achieved next in precisely an opposite manner. To unload a wheelchair passenger, the remote control is used to activate the microprocessor 140 to move the platform 16 to the raised disembarking position shown in Figure 3. The motors 122,124 are first activated to extend each scissor jack 118a,118b and move the rollers 116a,116b of each lever arm 110a,110b downwardly along their arcuate paths of movement against the ground 8. As the lever arms 110a,110b are pivoted about their respective hinges 112a,112b, the downward force applied by the rollers 116a,116b against the ground 8 causes the forward end of the platform 16 to rise with the rotation of the lever arms 110a,110b.

As the forward end of platform 16 is raised vertically above the horizontal plane of the front open end 26, the levelling switches 152a and 152b and safety transverse switch 152c sense the inclination of the platform 16. The three levelling switches 152 then signal the microprocessor 140 to activate the motors 130,132 to - ~ 21 74382 -turn the respective cable drives 131,133 and gear boxes 52a,52b rotate the threaded rods 56a,56b to raise the front deck section 46. In raising the platform sections 40,42 and deck section 46, the rods 56a,56b are rotated to increase the distance between each gear 52a,52b and nut 54a,54b. The increased spacing between the gears 52a,52b and nuts 54a,54b causes the bottom rails 70c,70d to move rearwardly relative to the top rails 69a,69b while the rear deck section 48 pivots relative to the front deck section 46 about the hinge 50 and housing 14 about the shaft 60 to assume the upwardly inclined position shown in Figure 3.

With the platform 16 in the fully raised position using reflectors 156c,156d as electrical limit switches, the front deck section 46, intermediate platform section 40 and forward platform section 42 are all positioned in a substantially level orientation with the interior floor 6 of the vehicle 12. The motor 126 is then activated to rotate the control rods 64a,64b and lower the safety ramp 76, permitting the wheelchair rider to move his or her wheelchair on to the platform 16. As the ramp 76 is lowered to a horizontal position with permission from the reflectors 156c,156d and the sensors 154a,154b, the final positioning of the platform 16 relative to the floor 6 is complete.

During loading, the front safety ramp 102 remains vertical. In moving on to the platform 16, the corrugated surface of the platform 16 positions the wheelchair so that it is aligned with opposing pairs of wheels received in the outer two channels 94,98. In this position, the possibility that the wheelchair will accidentally slide off the sides of the platform 16 is virtually eliminated.

Once the wheelchair is moved onto the platform 16 in the loaded position, the down remote control uni't -, ~ 2 1 74382 signals the microprocessor 140 to first activate the motor 126 to again turn the control rod 64a,64b to raise the safety ramp 76 to a vertical safety position before giving commands to lift and pivot mechanism to lower platform 16.

The motors 122,124 are then activated to retract the respective scissor jacks 118a,118b. Simultaneously, the motors 130,132 are also activated on receiving signals from the levelling switches 152a,152b and transverse level switch 152c to rotate the threaded rods 56a,56b in the reverse direction, to decrease the distance between the respective gear boxes 52a,52b and nuts 54a,54b and pivot the rear deck section 48 to the horizontal starting orientation.

As the platform sections 40,42 are lowered below the start position shown in Figure 2, the microprocessor 140 through level switches 152 and 154a,154b sc~nn;ng continue to respond with motors 130,132 to further turn the threaded rods 56a,56b through the respective threaded nuts 54a,54b in the same direction and further pivot the deck 46, relative to the deck 48. As the front deck section 46 is lowered, the bottom rails 70c,70d move forward relative to the top rails 69a,69b with the rotation of the pivot wheels 58a,58b and gear boxes 52a,52b. As seen in Figure 11, the forward end of the bottom rails 70c,70d may be rounded so as not to bind against the front deck section 46 as it pivots. In this manner, the front deck section 46 is lowered parallel with the sections 40,42 and the ground until the lever arms 110a,110b fully retract against the underside of the top panel 92 of the platform section 42.
As platform nears ground 8, reflectors 156e,156f return light sensors 154a and 154b scan and the microprocessor halts platform 16 downward movement.

Once the platform section 16 is moved to the ~ ~ 21 74382 fully lowered position shown in Figure 4, the motor 126 is again activated to rotate the control rods 64a,64b to lower only the front safety ramp 102 and permit the wheelchair to move off of the platform 16.

Following disembarkation, the platform 16 is returned to a storage position within the housing 14 by the microprocessor 140 and information from switches 152a,152b and sensors 154a,154b reversing the motors 122,124,130,132 to raise the front deck 46 and intermediate and forward platform sections 40,42 to the operating start position.
Once the front and rear deck sections 46,48, and the intermediate and forward platform sections 40,42 are returned to a position horizontally aligned to the open end 26 of the housing 14, the motor 126 is activated to rotate the control rods 64a,64b and return both safety ramps 76,102 to a horizontal position. Once the ramps 76 and 102 are rotated to the running board position, the reflectors 156a,156b respond to the sensors 154a,154b, and final alignment of the platform 16 with the housing 14 is achieved. The platform 16 is next retracted to the storage position. The levelling switches 152a,152b are used to ensure that the sections 38,40,42 are oriented to the vehicle grade. During this operation, transverse 152c is bi-passed. The motor 128 is then again activated to reverse the rotation of a shaft 142 and pinions 144a,144b to sequentially move the platform 16 to the storage position.

In the opposite sequence to extension, the pinion 144a,144b movement first moves the forward platform section 42 into the intermediate platform section 40, and the intermediate platform section 40 into the rearward platform of section 38. As the pinions 144a,144b move towards the housing 14, they engage and release the slide locks 85a,85b,87a,87b to uncouple the platform sections 38,40,42.

~ 21 74382 The shaft 142 and pinions 144 are rotated until as a unit the platform sections 38,40,42 are moved into the housing 14. Preferably the pinion 144a,144b first releases the rotatable shaft 60 from pivot shaft locks 32a and 32b, and pinions 144a,144b engage the rack 30a,30b to move the platform 16 into housing 14 until the weathershield 100 is brought against and closes the front open end 26. The motors 122,124 initially keep the combined unit 38,40,42 level during initial retraction, and then simultaneously raise the lever arms llOa,llOb to their fully raised position.

As seen best in Figures 1 to S, it is to be appreciated that the compact 3" height arrangement of this particular model apparatus 10 advantageously permits its installation in almost any existing van, without the requirement of extensive modifications. The applicant has appreciated that the compact design of the present invention allows the apparatus 10 to be suspended from the undercarriage 11 of a vehicle 12 by conventional or stainless steel gas tank mounting straps (not shown) or the like. In addition, because lifting is performed by the levering of the weight of the load off of the ground 8 and not by cantilevered suspension, the combined weight of the lift and cargo is not carried by the vehicle 12. The present invention thereby eliminates the need for complex and costly hydraulic lift mechanisms, and therefore may incorporate comparatively small permanent magnet 12 volt DC
electrical or 110 volt AC motors.

While Figures 1 to 5 show the use of the apparatus 10 in a wheelchair lifting mode, it is to be appreciated that the apparatus lo may equally be used in a ramp mode as for example is shown in Figure 16.
.

In ramp mode operation, the platform 16 is moved ~ 21 74382 from the storage position shown in Figure 5 to the starting position shown in Figure 2. The remote control (not shown) is then pressed to select ramp operation, whereby the motors 122,124 are used to activate gear boxes 136a,136b by means of cable drives 123,125 to lower the forwardmost end of the forward platform section 42 to the ground 8.

Simultaneously with the retraction of the lever arms llOa,llOb to lower the front end of the platform 16, the motors 130,132 are activated to rotate the gear boxes 52a,52b and threaded rods 56a,56b to raise the forward edge of deck 48 to the height of the vehicle floor 6.

The motor 126 then activates gear box 138 to rotate the shaft 141 and control rods 64a,64b to adjust the ramps 102,76 from the vertical safety position to load positions, with the ramp 26 lowered onto the vehicle floor 6 and ramp 102 lowered onto the ground 8.

As previously mentioned, the corrugated shape of the platform sections 40,42 and front deck section 46 assists in guiding a wheelchair or other loads along the platform 16 as it is loaded or unloaded.

It is to be appreciated that when ramp mode is selected, the microprocessor 140 bypasses the signals received from the level sensors 152,154 to permit angled positioning of the platform section.

Upon completion of the ramp mode the reverse operation of the motors returns the platform to the starting position of Figure 2 and the platform 16 is retracted into the storage position by an engagement of the pinions 144a,144b in the same manner as in lift operation.

The preferred motors 122,124,126,128,130,132 are ~ 2174382 preferably low torque motors capable of high revolutions per minute. To produce the necessary torque to perform lifting operations, the gear boxes or other torque converters 136a,136b and 52a,52b are preferably reduction gear boxes which may reduce output revolution by up to 100 fold. Circuit breakers for controlling the power to the motors may additionally be provided either within the vehicle 12 or adjacent the power supply. To avoid short circuiting of the drive mechanism 20, the moisture sensor may be provided, which on sensing the presence of water under the platform 16 limits or prevents the platform 16 from being lowered into electrical hazards such as large puddles and the like.

While the use of levelling sensors 152,154 and reflectors 156 is disclosed, it is to be appreciated that other platform positioning devices may equally be used, including the use of stepping motors or matched gearing and the like.

If desired, the fibres of the weathershield 100 may be provided with hooked ends which engage pile fasteners about the open end 26 of the housing 14 to provide a more secure seal when the platform 16 is moved to the storage position.

While the preferred embodiment of the invention illustrates the apparatus 10 for use in lifting a wheelchair into and out of a vehicle 12, the invention is not so limited. The compact design of the present invention is equally adaptable to permit installation at the rear of a pick up or cargo truck, or as a load lift for permanent installation at either home or commercial locations.

While the preferred embodiment of the invention - ~ 21 74382 is to provide a retractable lift or ramp apparatus which may be quickly and easily mounted on the undercarriage of the vehicle without requiring extensive vehicle modification; the applicant is aware that different vehicle models will have different vertical distances from the undercarriage 11 to the finished vehicle floor 6 (Figure 1). Therefore platform 48 of deck 38 and pivot rack rails 70c and 70d (Figure 11) will be selected as to chosen vehicle to permit a full range of platform movement.

In a preferred embodiment of the invention, each of the drive motors, gears and threaded rods used in raising and lowering the platform may be provided with speed wrench fittings 166 (shown in Figure 6) which are accessible either outside the lift 10 or through the weathershield 100 to allow the manual return of the platform 16 to the storage position in the event of vehicle electrical failure.

Although not shown, it is to be appreciated that a temperature and moisture or ice sensor may be provided within the housing 14 which is connected to the DC motor 12 fans and a heater coil to automatically de-ice and preheat the lift and drive mechanisms 18,20 to prevent freezing.
It is to be appreciated that grease fittings may further be located on all threaded rods and gear boxes to permit lubrication by the use of low temperature lithium grease.

While the preferred embodiment of the invention discloses a platform 16 which includes three telescoping sections 38,40,42, it is to be appreciated that more or fewer telescoping sections could equally be provided depending on the overall size of the platform desired.

While the preferred embodiment of the invention discloses a pinion as the actuator for telescoping movement ~ 2174382 of the platform sections 38,40,42, the invention is not so limited. Other drive apparatus including hydraulics and/or belt or tape drive assemblies are also possible and will now become apparent. Similarly, while scissor jacks 118a,188b may advantageously be provided to selectively pivot the lever arms 110a,110b about their hinges 112a,112b, other types of jack extensions, hydraulic system and pivoting mech~n;sms are also possible and will now become apparent.

Although the detailed description describes and illustrates various preferred embodiments, the invention is not so limited. For a definition of the invention, reference may be had to the appended claims.

Claims (21)

1. A retractable apparatus for use in moving a load between upper and lower vertically spaced surfaces, the apparatus comprising, a housing having a front opening, a load supporting platform movable in a longitudinal direction relative to said housing through said front opening between a retracted storage position wherein said platform is at least partially located within said housing and an operating position, wherein the supporting platform is moved substantially outwardly therefrom, in the operating position the platform extending longitudinally from a rear end portion spaced towards the housing to a front end portion, the front end portion being vertically movable between a raised position spaced above the lower surface, and a lowered position moved theretowards, lift means carried by the platform for selectively moving the front end portion between the raised and lowered positions when said platform is in the operating position, the lift means including a lever member having first and second ends, the lever member being coupled to the platform and pivotable about a pivot point to selectively move the first end below the platform along an arcuate path into engagement with the lower surface, wherein the engagement of the first end with the lower surface as the first end moves along the arcuate path raises and lowers the distal end of the platform relative to the lower surface, drive means including first actuating means for selectively moving the platform between the storage and operating positions, and second actuating means to reciprocally pivot the lever member about the pivot point for moving the first end into and out of contact with the lower surface.

2. An apparatus as claimed in claim 1 wherein said second actuating means includes jack means spanning between and coupled to said platform and a portion of said lever member spaced from said pivot point, whereby the extension of the extension and retraction of the jack means moves the portion of the lever member relative to the platform to pivot the lever member about the pivot point.

3. An apparatus as claimed in claim 2 wherein said platform comprises a plurality of slidably connected telescoping platform sections and includes a forward platform section and a rearward platform section, the forward and rearward platform sections being slidable in the longitudinal direction relative to each other between a telescoped configuration with said forward and rearward platform sections moved to a substantially nested orientation, and an outstretched configuration wherein said forward platform section is moved longitudinally forward relative to the rearward platform section, the drive means moving the forward and rearward platform sections to the outstretched configuration when the platform is in the operating position, and moving the forward and rearward platform sections to the telescoped configuration when said platform is in the storage position.

4. An apparatus as claimed in claim 3 wherein both the lever member and jack means are coupled to the forward platform section for movement therewith.

5. An apparatus as claimed in claim 4 wherein the rearward platform section comprises, a front deck portion spaced towards said forward platform section, a rear deck portion spaced towards said housing hingely coupled to the front deck portions, and levelling means for maintaining the front deck portion of the rearward platform section in a generally level orientation with the forward platform section as said second actuating means reciprocally pivots the lever member.

6. An apparatus as claimed in claim 5 wherein when the platform is in to the operating position the rear deck portion of a rear end of the rearward platform section is pivotally coupled to the housing, the levelling means includes a hinge means pivotally coupling the front and rear deck portions, and means for pivoting the front deck portion relative to the rear deck portion.

7. An apparatus as claimed in claim 3 wherein when said platform sections are moved to the outstretched configuration, said platform sections define a plurality of longitudinally extending guide channel means for guiding said load on said platform.

8. An apparatus as claimed in claim 3 further including at least one intermediate platform section movable relative to the forward and rearward platform sections between the telescoped configuration substantially nested with said forward and rearward platform sections, and the outstretched configuration wherein the intermediate platform section assumes a position between the forward and rearward platform sections.

9. An apparatus as claimed in claim 8 wherein said lift apparatus comprises a wheelchair lift for use with a vehicle having an interior passenger compartment floor, an undercarriage extending beneath the passenger compartment floor, and an access door opening into the vehicle, the lift apparatus for lifting said wheelchair from said lower surface to said upper surface with said upper surface comprising said compartment floor, the housing means being mounted to said undercarriage with said front opening substantially aligned beneath said door opening.

10. An apparatus as claimed in claim 2 wherein said jack means comprises a scissor jack.

11. An apparatus as claimed in claim 3 wherein said drive means further comprises third actuator means for moving said forward and rearward platform sections relative to each other, the third actuator means comprising a rack extending longitudinally along said rearward platform section, and a motor driven pinion for engaging said rack rotatably mounted to said forward platform section.

12. An apparatus as claimed in claim 9 wherein when said platform sections are moved to the outstretched configuration, said platform sections define a plurality of longitudinally extending guide channel means for guiding said load on said platform.

13. An apparatus as claimed in claim 12 further including at least one intermediate platform section movable relative to said forward and rearward platform sections between the telescoped configuration substantially nested with said forward and rearward platform sections, and the outstretched configuration wherein the intermediate platform section assumes a position spaced longitudinally between the forward and rearward platform sections.

14. A retractable lift apparatus for lifting a load between upper and lower vertically spaced surfaces, the apparatus comprising, a lift housing, a load supporting platform movable horizontally in a longitudinal direction between a retracted storage position wherein said platform is substantially located within said housing, and a lifting position wherein said platform is moved out of said lift housing, the platform comprising a plurality of interlocking telescoping platform sections which are longitudinally slidable relative to each other between a telescoped configuration, with said platform sections moved to a substantially nested orientation, and an outstretched configuration with said sections moved to an orientation longitudinally offset relative to each other, in the operative position, the platform extending longitudinally from a rearward platform section spaced towards the lift housing to a forward platform section, lift means for raising and lowering the forward platform section between a raised position at said upper surface and a lowered position at said lower surface, the lift means comprising an elongated lever arm coupled to one of said platform sections, the lever arm having first and second ends and being pivotable about a pivot point spaced towards the second end to move the first end along an arcuate path extending below the platform, the lever arm having a length selected such that its pivotal movement about the pivot point moves the first end into engagement with the lower surface to raise or lower the platform, drive means for moving said platform including, first actuator means for selectively moving said platform between said storage and lifting positions, and second actuator means for selectively pivoting said lever arm to move said first end along the arcuate path.

15. A lift apparatus as claimed in claim 14 wherein said second actuator means comprises a scissor mechanism spanning between said platform and a portion of said lever arm between the pivot point and its lower end, the scissor mechanism movable between a retracted position wherein the spacing between the platform and the portion of the lever arm is minimized, and a lowered extended position wherein the spacing between the platform and the portion of the lever arm is increased.

16. A lift apparatus as claimed in claim 14 wherein said load comprises a wheelchair, each of said platform sections being generally corrugated in cross-section and defining a plurality of longitudinally extending channels, at least two of said channels spaced relative to each other to receive therein opposing pairs of wheels of said wheelchair.

17. A lift apparatus as claimed in claim 16 wherein said apparatus comprises a wheelchair lift for use with a vehicle having an interior passenger compartment floor, an undercarriage extending beneath the passenger compartment floor, and an access door opening into the vehicle, and wherein the upper surface comprises said compartment floor, the housing means being mounted to said undercarriage with said front opening substantially aligned beneath said door opening.

18. A lift apparatus as claimed in claim 14 wherein the rearward platform section comprises a front deck portion spaced towards said forward platform section, and a rear deck portion spaced towards said housing hingely coupled to the front deck portions, levelling means for maintaining the front portion of the rearward platform section in a generally level orientation with the forward platform section as said second actuating means reciprocally pivots the lever member.

19. An apparatus as claimed in claim 18 wherein when the platform is moved to the operating position the rear deck portion is pivotally coupled along its rear edge to the housing, the levelling means includes a hinge means pivotally coupling the front and rear deck portions, and means for pivoting the front deck portion relative to the rear deck portion activatable to vary the angle between the front and rear deck portions as the forward platform section is moved towards the lower surface, so as to maintain the front deck portion in a substantially coplaner orientation with the forward platform section.

20. A lift apparatus as claimed in claim 19 wherein said housing includes a pair of opposed longitudinally extending horizontal track forming members, and the rear deck portion further comprises a pair of guide members spaced to slidably engage said track forming members, the guide members movable in the track forming members between a position rearwardly spaced from the front opening when the platform is in the storage position and a forwardly spaced position adjacent the front opening when the platform is in the lifting position, in the forwardly spaced position the rear deck portion being pivotable about the guide members to move relative to the housing.

21. A lift apparatus as claimed in claim 20 wherein said apparatus comprises a plurality of apertures formed through said platform.