Wheelchair lift with slidable support arm

A wheelchair lift for use in conjunction with a vehicle having a floor. The lift includes a power actuating system, a platform assembly having first and second platform sections, and a linking assembly connecting the power actuating system to the platform assembly. The linking assembly includes first and second vertical arms connected to the platform assembly. The platform assembly is movable between a fully extended configuration, a pre-stowed position and a stowed position. The first and second vertical arms are a first distance apart when the platform assembly is in the fully extended configuration and the pre-stowed position and a second distance apart when the platform assembly is in the stowed position. The second distance is less than the first distance.

FIELD OF THE INVENTION

The present invention relates to a lift assembly for aiding users of wheelchairs to get into and out of a van or the like.

BACKGROUND OF THE INVENTION

A lift assembly of this type comprises a platform laterally supported by an armature and carried from a vertical stored position inside the vehicle to a horizontal position exteriorly of the vehicle and level with the vehicle floor and to a ground position.

The user wheels himself onto the platform and actuates means to displace the platform from the vehicle level to the ground or inversely.

This type of known lift assembly (see U.S. Pat. No. 3,651,965 dated May 28, 1972 to Clever Industries) is stored in the vehicle but uses a relatively large percentage of the floor area and, moreover, the platform4, when in stored position, obstructs the door opening, thus preventing a non-invalid person from using it. Also, the hydraulic systems used to raise or lower the platform are generally bulky and complex.

Other types of lifts have attempted to solve these problems. See, for example, U.S. Pat. Nos. 6,802,095, 6,379,102, 6,585,474, 6,086,314, 6,062,805, 5,944,473, 5,605,431, 5,556,250, 5,445,488, all of which are incorporated herein in their entireties by reference.

Therefore, a need exists for a lift assembly mounted in a vehicle and foldable into a compact position within the latter.

SUMMARY OF THE INVENTION

In accordance with a preferred embodiment of the present invention there is provided a wheelchair lift for use in conjunction with a vehicle having a floor. The lift includes a power actuating system, a platform assembly having first and second platform sections, and a linking assembly connecting the power actuating system to the platform assembly. The linking assembly includes first and second vertical arms connected to the platform assembly. The platform assembly is movable between a fully extended configuration, a pre-stowed position and a stowed position. The first and second vertical arms are a first distance apart when the platform assembly is in the fully extended configuration and the pre-stowed position and a second distance apart when the platform assembly is in the stowed position. The second distance is less than the first distance. In a preferred embodiment, the second vertical arm is movable inwardly toward the first vertical arm along a horizontal path. Preferably the first and second platform sections are adjacent to one another when the platform assembly is in the stowed position.

In accordance with another preferred embodiment of the present invention there is provided a wheelchair lift for use in conjunction with a vehicle having a floor and a door opening. The lift includes an anchoring plate fixedly secured to the floor inwardly of the door opening, a platform movable between an upstanding stowed position and an upstanding pre-stowed position inside the vehicle, and a pair of vertical arms pivotally connecting the platform to the anchoring plate. At least one of the arms is movable in a horizontal direction. The platform is further pivotal relative to the anchoring plate between the upstanding pre-stowed position and an outside floor level position, and is movable from that position to a ground level position and inversely. The platform includes first and second platform sections movable between a position where they lie in the same plane to form a flat surface and a stowed position where they do not lie in the same plane.

In accordance with yet another preferred embodiment of the present invention there is provided a method of stowing a wheelchair lift. The method includes the steps of providing a wheelchair lift having a power actuating system, a platform assembly and a linking assembly with two vertical arms connecting the power actuating system to the platform assembly, moving the platform assembly from a floor level position to a pre-stowed position, and shortening the distance between the two vertical arms. In a preferred embodiment, the step of shortening the distance between the first and second vertical arms is accomplished by moving the second vertical arm towards the first vertical arm along a horizontal path. The platform preferably includes first and second platform sections that are pivotally connected.

DETAILED DESCRIPTION OF THE INVENTION

Although specific embodiments of the present invention will now be described with reference to the drawings, it should be understood that such embodiments are by way of example only and are merely illustrative of but a small number of the many possible specific embodiments which can represent applications of the principles of the present invention. Various changes and modifications obvious to one skilled in the art to which the present invention pertains are deemed to be within the spirit, scope and contemplation of the present invention as further defined in the appended claims.

With reference to the drawings, and in particular toFIG. 1, the lift assembly is secured at the doorway of a vehicle1, such as a van or the like, and comprises an anchoring plate3secured to the vehicle floor C and partially engaging in the cavity forming the floor board cavity4, a transverse shaft6having a length comparable to the length of the anchoring plate3, is rotatably supported in front of the latter alongside the section engaging in the floorboard cavity4by means of three brackets7,8,9, (FIGS. 1,2) respectively positioned at each of the extremities of the bar6and at an intermediate position near the double acting hydraulic cylinder11which is connected to the transverse shaft6by means of two parallel radial arms10secured to shaft6.

The lift assembly is movable by a power actuating system. The actuating system may be controlled electrically, hydraulically or in any other conventional means known to one skilled in the art. For demonstration purposes only, a hydraulic actuating system is described herewith. The hydraulic actuating system includes a hydraulic pump (not shown), a hydraulic power unit (not shown), and a hydraulic cylinder11. In an alternative embodiment the hydraulic actuating system can include a pair of opposed hydraulic cylinders.

The radial arms10are pivotally connected to the hydraulic cylinder piston rod2at a first extremity and welded to the transverse shaft6at the other extremity.

The hydraulic cylinder11is pivotally supported at its upper extremity by two bracket plates12upstanding from and secured to anchoring plate3. In the present embodiment, the hydraulic cylinder11is located on the left side of the lift assembly (however, it could be located on the right side) and is used in conjunction with a fluid pump and tank (not shown) which can be installed anywhere in the vehicle.

A platform13is pivotally connected to the vehicle1by a pair of spaced armatures14and15(also referred to herein as first and second vertical arms) which are identical and each pivotally mounted to the anchoring plate3through armature brackets16. Each of the armatures defines with bracket16a deformable parallelogram. Each armature is formed of two parallel links17and18and of a vertical link19. The parallel links17and18are pivotally secured at one extremity to the armature bracket16and to the vertical link19at the other extremity. The lower parallel links18on both armatures14and15are connected to the transverse shaft6by means of an articulated linkage20(FIGS. 1 and 5) to displace the platform13under the action of hydraulic cylinder11.

Because of the use of a transverse shaft6, only one hydraulic cylinder is needed to operate the lift assembly; it is an advantage of the invention to use one cylinder because of the reduction in cost and size of the assembly. However, it will be understood that more than one hydraulic cylinder can be used to operate the lift assembly.

The platform13comprises a flat and rigid surface made of first and second separate sections21and22(FIG. 6) having a combined area sufficient to support a wheel chair A (FIGS. 1 and 5). In a preferred embodiment, the platform sections21and22are each formed of a frame44which supports a rigid mesh45. In another embodiment, the platform sections can be a solid plate or the like. The platform13includes a transverse member43mounted in rotative relationship by pivot pins31in between the lower extremities of the vertical links19(FIG. 6), and two parallel longitudinally extending members41and42extending transversely from the extremities of the member43.

The platform13is normally in a plane parallel to the ground when the lift assembly is in use. This is also referred to herein as the fully extended configuration. The fully extended configuration comprises both the ground level position (when the lift assembly is in a position such that a person in a wheelchair can roll from the ground onto the platform13or vice versa, as shown inFIG. 5) and the floor level position (when the lift assembly is in a position such that a person in a wheelchair can roll from the vehicle floor C onto the platform13or vice versa, as shown inFIG. 1). For storage, the platform13is raised to a vertical position (often referred to herein as the pre-stowed position) and then collapsed along a horizontal path into a stowed position to reduce the storage size and then shifted within the vehicle1to allow closing of the vehicle door B (seeFIG. 3).

In conventional lifts, the door opening is blocked by the raised platform while in the present invention the platform comprises first and second sections21and22pivotally connected in the middle by a hinge or hinges60or the like.

The platform13is moveable in between a vertical plane and a horizontal plane by means of a pair of articulated linkages24each having two links25,26(seeFIGS. 1 and 5) pivotally secured together and installed in between the vertical links19and the parallel members41and42on each side of the lift assembly.

The upper members25are ended by a curved section27. When the platform13, during its upward movement, has reached its floor level position, the curved sections27abut on a short rod28located on the underside of the lower parallel links18causing the rotation of the members25around the axis29and the displacement of the lower links26which pull on the platform13to pivot the platform13upwardly.

Barriers are installed around the platform13as a security measure to prevent the user from falling (seeFIGS. 1,5,6and7).

Lateral barriers36upwardly extend from and are fixed to the parallel members41and42; and front barriers32are pivotally secured to the front edge of the frames44and each comprises a protection plate33, a pair of guiding plates49pivotally secured at49′ on either sides of the frame44and supporting the plate33. A rod34having its extremities slidably secured in slots53of the guide plates49, forms a loop pivotally supported by the frame44. A striking plate35is fixed to the center of the loop formed by rod34.

Each protection plate33is biased to an upward position by means of a tension spring54which is secured at its ends to the frame44and to a small pin55transversely mounted on the rod34.

When protection plate33is in an upward position, striking plate35protrudes from the underside of frame44as shown in dotted lines inFIG. 8. When the platform13is lowered to ground level, striking plate35abuts the ground and pivots protection plate33to a lowered ground engaging position, shown in full lines inFIGS. 7 and 8, to permit passage of the wheel chair A.

A bridge plate or ramp39is used to bridge the gap between the platform13and the vehicle floor C when the platform13is horizontal and level with the vehicle floor. The bridge plate39is preferably pivotally attached to the anchoring plate3(attached to vehicle floor). It does not travel up and down with the platform13. It always stays at vehicle floor level. When the platform13is stowed, the bridge plate39pivots vertically, and folds into three sections to wrap around the platform13.

The first and second sections21and22remain co-planar when the platform13moves between the ground level position, floor level position and pre-stowed position. As discussed above, platform sections21and22are pivotally connected. This connection allows platform13to fold/collapse to allow the lift assembly to go from the pre-stowed position to the stowed position. In a preferred embodiment, transverse shaft6also includes a joint and is foldable. However, this is not a limitation on the present invention. It will be understood that any method for collapsing the first and second vertical arms14and15is within the scope of the present invention. For example, the second vertical arm15may be movable toward the first vertical arm14(or the first and second vertical arms may be movable toward one another) via rollers, a track, sliding, a foldable mechanism, telescoping members, etc. Furthermore, it is anticipated that this collapsing can be done manually or automatically, for example, hydraulically, electrically, pneumatically, etc. The platform13may include more than 2 foldable sections.

In a preferred embodiment, second vertical arm15is movable via rollers and a track. Anchoring plate3includes at least one track that corresponds to at least one roller on armature bracket16. In a preferred embodiment, a plurality of tracks and rollers are used. For example, the track assembly, rollers and movable tower from commonly owned, and concurrently filed U.S. patent application Ser. No. 11/374,360 titled Slidably Collapsible Two-Arm Wheelchair Lift, filed on Feb. 3, 2006, could be used. This allows vertical arm15to be pushed or pulled toward vertical arm14, thereby causing platform13to fold, as is shown inFIGS. 9 and 11.

As the vertical arm15is pushed or pulled toward vertical arm14, the longitudinal fold between platform sections21and22, including hinges60causes the platform13to begin to fold, as shown inFIG. 10. This drives the platform assembly to the stowed position, as shown inFIG. 12.

The stowing of the platform could be driven by a double acting hydraulic cylinder, a motor-chain drive, a motor and cable, a motor and toothed belt. With the exception of the hydraulic cylinder, these drive mechanisms work similar to a motorized driveway gate. Similarly, the system could use an electric clutch mechanism release the drive for manual operation.

As can be seen inFIG. 12, in the stowed position, first and second sections21and22are substantially parallel. As used herein substantially parallel does not mean exactly parallel. As can be seen inFIG. 12, the first and second sections21and22are much closer to being parallel than they are co-planar. Also as can be seen inFIG. 12, in the stowed position, the first and second vertical arms14and15are a second distance apart d2. D2is lesser than d1(seeFIG. 4).

When the lift assembly is moved out from its pre-stowed position, means are needed to help the frame section23rotate from an upstanding position to a horizontal position (or fully extended configuration).

These means are installed on the armature15(seeFIGS. 1 and 2) and comprise a tension spring37secured at one extremity to a support38extending from the curved section27of the upper link25and at the other extremity to a hook56secured to the lower section of the vertical member19.

The spring37forces the articulated linkage24to rotate the platform13downwardly.

In a preferred embodiment, a control box40is secured to an arm40′ (seeFIGS. 1 and 3), which is pivotally secured to one of the two vertical links19being moveable between operative and stored position. Box40carries control buttons electrically connected to an electrical circuit for the control of a hydraulic circuit (not shown), including a hydraulic pump and the hydraulic cylinder11. Control box40permits the user to operate the lift assembly alone.

As shown inFIG. 3, when the lift assembly is in the stowed position, it completely clears the conventional sliding door B of the vehicle.

Defined broadly, the present invention is a wheelchair lift assembly for use in conjunction with a vehicle having an opening that is movable between a fully extended configuration (including a ground level position and a floor level position), a pre-stowed position and a stowed position.

In a preferred embodiment, the wheelchair lift includes a power actuating system and a platform assembly having at least two plates (or sections) that are pivotable between a horizontal position (the fully extended configuration) where the plates lie in the same plane and a vertical position (the pre-stowed position) where the plates are substantially coplanar and a vertical position (the stowed position) where the plates are adjacent one another. The platform assembly is connected to the power actuating system by a linkage assembly (including the first and second vertical arms). The platform sections or plates are carried by the first and second vertical arms, respectively. In the-horizontal position (the fully extended configuration) and the first vertical position (the pre-stowed position) the arms are a first distance apart, and in the second vertical position (the stowed position) the arms are a second distance apart. The second distance is lesser than the first distance.

Of course the present invention is not intended to be restricted to any particular form or arrangement, or any specific embodiment disclosed herein, or any specific use, since the same may be modified in various particulars or relations without departing from the spirit or scope of the claimed invention hereinabove shown and described of which the apparatus shown is intended only for illustration and for disclosure of an operative embodiment and not to show all of the various forms or modifications in which the present invention might be embodied or operated.

The present invention has been described in considerable detail in order to comply with the patent laws by providing full public disclosure of at least one of its forms. However, such detailed description is not intended in any way to limit the broad features or principles of the present invention, or the scope of patent monopoly to be granted.