FIELD OF THE INVENTION
The invention relates to transportation devices for disabled people or other invalids. In particular, the invention relates to an apparatus which is adjustable from a chair position to a position which permits the apparatus to transport the invalid to a location or enclosure having a raised surface.
BACKGROUND OF THE INVENTION
The problems associated with transporting disabled people or other invalids are well known. Such persons are often unable to move sufficiently to get out of a wheelchair and lift themselves onto a raised surface such as a vehicle floor. Consequently, invalids must often be transported onto such raised surfaces.
As discussed above, one common example of a transportation obstacle is the transportation of an invalid from a ground surface into a vehicle. In order for an invalid to be transported into a vehicle in a conventional wheelchair, the vehicle may have to be specially modified. Such modification is costly and must be performed for each new vehicle purchased by the invalid.
A number of adjustable chairs for transporting an invalid onto a raised surface, such as a vehicle floor, are known. One such chair is disclosed in U.S. Pat. No. 4,105,242. However, this prior art chair requires the presence of a third party attendant to adjust the chair and to move it onto the raised surface. While adjusting the chair, the attendant is required to bear at least part of the weight of the invalid.
Accordingly, there is a need for an improved invalid transportation apparatus which is capable of transporting an invalid onto a raised surface while reducing the need for third party assistance.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, a transportation apparatus for transporting an invalid onto a raised surface is provided. The transportation apparatus comprises a leg support pivotably connected to a seat portion. At least one middle leg and at least one rear leg depends downwardly from the seat portion. At least one middle wheel is connected to the middle leg and at least one rear wheel is connected to the rear leg. The middle wheel and rear wheel define a middle and rear rotation axes, respectively. At least one front wheel is operatively connected to the leg support. The middle leg is adapted to adjust the vertical position of the middle wheel, and the rear leg is adapted to adjust the vertical position of the rear wheel. The seat portion is adapted for movement in a substantially horizontal direction in relation to the rear rotation axis or the middle rotation axis.
According to a second aspect of the invention, a transportation apparatus for transporting an invalid onto a raised surface is provided. The transportation apparatus comprises a backrest and leg support pivotably connected to a seat portion. The seat portion is slidably connected to first and second spaced apart slide rails. Each slide rail comprises a plurality of telescoping members. At least one middle leg and at least one rear leg depends downwardly from the seat portion. At least one middle wheel is connected to the middle leg and at least one rear wheel is connected to the rear leg. The middle wheel and rear wheel define a middle and rear rotation axes, respectively. At least one front wheel is operatively connected to the leg support. The middle leg is adapted to adjust the vertical position of the middle wheel, and the rear leg is adapted to adjust the vertical position of the rear wheel. The plurality of telescoping members are adapted to slide the seat portion in a substantially horizontal direction in relation to the rear rotation axis or the middle rotation axis.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a top perspective view of an apparatus for transporting an invalid according to a preferred embodiment of the invention;
FIG. 2 is a bottom perspective view of the preferred embodiment;
FIG. 3 is a bottom perspective view of the preferred embodiment in the horizontal or stretcher position;
FIG. 4 is a partial cutaway perspective view of the preferred embodiment showing a rear leg and worm drive for the rear leg;
FIG. 5 is a partial perspective view of the preferred embodiment with the seat portion, backrest, and leg support removed;
FIG. 6 is a partial perspective view of the preferred embodiment showing a sliding rail;
FIGS. 7A-J are a series of elevation views of the preferred embodiment illustrating entrance of the apparatus on a raised surface; and
FIGS. 8A-F are a series of elevation views of the preferred embodiment illustrating exit of the apparatus from a raised surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 and 2 show an apparatus 10 for transporting an invalid according to an embodiment of the present invention. The apparatus includes a pivotable backrest 12 which is connected to a rear edge of a seat portion 14 by a hinge 16. A leg support 18 is pivotably connected to a front edge of the seat portion 14, as described in more detail below. Foldable arm rests 20a, 20b which connect to the backrest 12 and seat portion 14 may also be provided.
Referring to FIGS. 1 and 3 (which shows the apparatus 10 in a horizontal or stretcher position), the seat portion 14 includes a frame 17. Preferably, a pair of middle legs 30a,b and a pair of rear legs 32a,b depend downwardly from the frame. Middle wheels 34a,b are connected to lower ends of middle legs 30a,b, respectively. Rear wheels 36a,b are connected to lower ends of rear legs 32a,b, respectively. The middle wheels 34a,b define a rotation axis A, and the rear wheels 36a,b define a rotation axis B. Rotation axes A and B are shown in FIG. 1. Preferably, the rear wheels, 36a,b are conventional swiveling wheels.
Referring now to FIG. 3, a pair of front legs 38a,b are also preferably provided on the leg support 18. Front wheels 40a,b are connected to lower ends of front legs 38a,b. Preferably, front wheels 40a,b are able to roll only in a forward direction (i.e. the front wheels are prevented from rolling backward) by any suitable means, such as anti-reverse bearings (not shown). It will be understood by those skilled in the art that the apparatus 10 may be constructed without front legs 38a,b. In an alternative embodiment, the front wheels 40a,b may be mounted directly to the underside of leg support 18.
Continuing to refer to FIG. 3, leg worm drives 42a-f are provided to extend (i.e. lower) and retract (i.e. raise) middle legs 30a,b, rear legs 32a,b, and front legs 38a,b, respectively. The leg worm drives 42a-d which move the middle legs 30a,b and rear legs 32a,b are mounted to the sides of the frame 17. The leg worm drives 42d,f which drive the front legs are mounted to the underside of the leg support 18.
FIG. 4 shows leg worm drive 42c and rear leg 32a in detail. Leg worm drive 42c includes a worm housing 50 which receives a threaded worm rod 52. A conventional electric motor 54 which drives the worm rod 52 is mounted at one end of the worm housing 50. An internally threaded worm follower 56 engages the worm rod 52. The rotation of the worm rod 52 by electric motor 54 causes the worm follower 56 to move outwardly or inwardly along the worm rod 52 (depending on the direction of the rotation of the worm rod). Preferably, all of the leg worm drives 42a-f are substantially identical to leg worm drive 42c. Consequently, the remaining leg worm drives are not illustrated in detail.
Continuing to refer to FIG. 4, rear leg 32a is suspended from worm drive 42c. Rear leg 32a includes a primary member 60 which is hinged to the worm follower 56 at its upper end in any suitable fashion, such as by pin hinge 62. At its bottom end, the primary member 60 is connected to rear wheel 36a (shown in FIG. 3) also by pin hinge 62. A secondary member 64 is hinged by pin hinge 62 to a proximate end 63 of the worm housing 50 at one end and to a point along the length of primary member 60 at the other end. A support member 66 is hinged to a lower end of the secondary member 64 and extends generally parallel with primary member 60. The lower end of support member 66 is connected to rear wheel 36a (shown in FIG. 3). The movement of the worm follower 56 toward the proximate end 63 of the worm drive 42c causes the hinged assembly of primary member 60 and secondary member 64 to extend downwardly away from the worm drive. The movement of the worm follower 56 toward the distal end 68 causes the hinged assembly of primary member 60 and secondary member 64 to retract upwardly toward the worm drive. The extension and retraction of the primary member 60 of the rear leg 32a in turn raises and lowers the rear wheel 36a. The support member 66 acts to maintain the orientation of the rear wheel 36a in relation to the ground or floor surface.
Preferably, the rear leg 32b is identical to rear leg 32a and will not be further described. The remaining legs (middle legs 30a,b and front legs 38a,b) are preferably similar to rear leg 32a, with the difference being that the remaining legs are constructed without support member 66. It will be understood by those skilled in the art that the legs 30a,b, 32a,b, and 38a,b may be constructed in any other suitable fashion which permits such legs to be extended and retracted. For example, the legs may be constructed from telescoping members.
Referring again to FIG. 3, electric motors 70a,b are mounted on the middle legs 30a,b, respectively, in order to drive middle wheels 34a,b. The electric motors driving the middle wheels 34a,b permit the apparatus 10 to be self-propelled. In other words, the invalid can operate the apparatus without assistance from an attendant.
Referring again to FIG. 2, a backrest tilting arm 80 is connected to a rear surface of the backrest 12. The other end of the backrest tilting arm 80 is connected to a backrest worm drive 42g. The backrest worm drive 42g is substantially identical to the leg worm drive 42c and will not be further described. The backrest tilting arm 80 preferably comprises a first member 82 (secured to backrest 12) hinged to a second member 84 by pin hinge 62. The other end of the second member 84 is connected to the worm follower 56 (shown in FIG. 4) of backrest worm drive 42g also by pin hinge 62. Accordingly, backrest worm drive 42g moves the backrest tilting arm 80, which in turn tilts the backrest 12.
Referring again to FIG. 3, a leg support tilting arm 90 is provided to raise and lower the leg support 18. One end of leg support tilting arm 90 is connected to the underside of leg support 18 by pin hinge 62. The other end of leg support tilting arm 90 is connected to worm follower 56 (shown in FIG. 4) of a leg support worm drive 42h. The leg support worm drive 42h is substantially identical to the leg worm drive 42c and will not be further described. The leg support worm drive 42h moves the leg support tilting arm 90 to raise and lower the leg support 18.
Referring to FIG. 5, the frame 17 preferably comprises two telescoping slide rails 100a, 100b running along opposing sides of the seat portion 14 (not shown in FIG. 5 for clarity). A seat worm drive 42i is provided to slide the seat portion 14 on slide rails 100a, 100b. The worm housing 50 of seat worm drive 42i is secured to slide rail 100b by bracket 102. The worm follower 56 of seat worm drive 42i is secured to the underside the seat portion 14 by connector 104.
Referring now to FIG. 6, each slide rail 100a, 100b preferably comprises three telescoping members to permit the seat portion 14 (shown in FIG. 1) to translate by a distance of preferably at least 100% of its length. In particular, a middle 110 rail is received within a channel 111 of an outer rail 112. An inner rail 114 slides within another channel 116 of the middle rail 110. Bearings 118 may be provided to facilitate the sliding movement. The sliding rails 100a, 100b permit the seat worm drive 42i to slide the seat portion 14 forward and backward in relation to the rotation axis A, B of the middle wheels 34a,b and rear wheels 36a,b. The seat worm drive 42h is substantially identical to the leg worm drive 42c and will not be further described.
A battery (not shown) and any suitable control system (not shown), such as a conventional electronic control system may be provided to operate electric motors 70a, 70b and the worm drives 42a-i. The battery or batteries may be mounted under the seat portion 14 or behind the backrest 12. The electronic control system may be linked to an actuator module (not shown) operated by the invalid. The actuator module may be mounted on the armrests 20. The actuator module may include one or more joysticks or levers to control the various movements (described above) of the apparatus 10.
It will be understood by those skilled in the art that use of the worm drives 42a-i is not essential. Any other suitable mechanism (such as hydraulics, servo motors, or the like) may be used to move the legs 30, 32, 38, backrest 12, leg support 18, and seat portion 14.
The operation of the preferred embodiment of the present invention will now be described with reference to FIGS. 7A-J and 8A-F. The operation will be described in connection with the apparatus 10 entering and exiting a vehicle. However, it will be understood by those skilled in the art that the apparatus 10 may exit or enter any other raised surface (either enclosed or not) in the same manner.
The operation of the apparatus 10 in connection with entering the vehicle will be described first with reference to FIGS. 7A-J.
The apparatus 10 is typically in the position shown in FIG. 7A for wheelchair operation. When the invalid wishes to transport herself onto a vehicle or other raised surface, the invalid first drives the apparatus 10 forward in proximity of the raised surface 150.
Referring to FIG. 7B, the invalid raises the leg support 18 into a substantially horizontal position and drives the apparatus forward until the middle wheels 34a, 34b are adjacent to the edge 152 of the raised surface 150.
Referring to FIG. 7C, front legs 38a, 38b then extend to lower front wheels 40a,b onto the raised surface 150. If required due to height restrictions (such as a vehicle roof), the backrest 12 may be lowered (not shown in lowered position) to a height sufficient to clear vehicle roof or to a horizontal stretcher position at this stage.
Referring now to FIG. 7D, the slide rails 100a,b extend to slide seat portion 14 forward relative to the rotational axis A (shown only in FIG. 1) of middle wheels 34a,b until the center of gravity of the invalid is preferably located forward of the rotational axis A. The force of the mass of the invalid acting through the center of gravity is indicated on FIG. 7D by arrow CG.
Referring to FIG. 7E, the middle wheels 34a,b are then raised to a height above the raised surface 150.
Referring to FIG. 7F, the slide rails 100a,b (not shown in FIG. 7F) retract causing the middle wheels 34a,b and rear wheels 36a,b to roll forward, such that middle wheels 34a,b are above the raised surface 150. At the same time, the seat portion slides backward relative to rotational axis A (shown only in FIG. 1). All of this occurs due to the fact that the front wheels 40a,b are prevented from rolling backwards by the anti-reverse bearings.
Referring to FIG. 7G, middle legs 30a,b then lower the middle wheels 34a,b such that they are in contact with the raised surface 150.
Referring to FIG. 7H, the seat portion 14 again slides forward relative to the rotational axis A of middle wheels 34a,b such that the center of gravity CG of the invalid is forward of the rotational axis A.
Referring to FIG. 7I, the rear legs 32a,b retract rear wheels 36a,b to a height above the raised surface. The apparatus 10 drives forward to a position where the rear wheels 36a,b are above the raised surface.
Referring to FIG. 7J, the rear wheels 36a,b are then lowered until they are in contact with the raised surface. The slide rails 100a,b are retracted such that the middle wheels 34a,b and rear wheels 36a,b again roll forward on the raised surface. The seat portion 14 moves backward relative to rotation axis A to position the center of gravity CG of the invalid between the middle and rear wheels. In addition, depending on the height of the vehicle roof, the backrest 12 may be adjusted for comfort of the invalid.
The operation of the apparatus 10 in connection with exiting the vehicle will now be described with reference to FIGS. 8A-F.
Referring to FIG. 8A, the apparatus 10 is driven forward until the front wheels 40a,b overhang the edge 152 of the raised surface 150. The front wheels 40a,b are then lowered until they are in contact with the ground surface 160.
Referring to FIG. 8B, the seat portion 14 then slides forward on slide rails 100a,b until the center of gravity CG of the invalid is forward of rotation axis A of middle wheels 34a,b. This causes the front wheels 40a,b to move forward, further away from the edge 152 of the raised surface 150.
Referring to FIG. 8C, the slide rails 100a,b retract causing the middle wheels 34a,b and rear wheels 36a,b to roll forward due to the anti-reverse bearing on the front wheels 40a,b. As a result, the middle wheels 34a,b overhang the edge 152 of the raised surface 150. The center of gravity CG of the invalid is positioned between the rotation axes A and B (shown only in FIG. 1) of the middle and rear wheels, respectively.
Referring to FIG. 8D, the middle wheels 34a,b are then lowered until they are in contact with the ground surface 160. The slide rails 100a,b again extend to slide the seat portion 14 forward such that the center of gravity CG of the invalid is forward of rotation axis A.
Referring to FIG. 8E, the apparatus 10 then drives forward until the rear wheels 36a,b clear the edge 152 of the raised surface 150. The rear wheels are lowered until they are in contact with the ground surface 160.
Referring to FIG. 8F, the slide rails 100a,b again retract causing the middle wheels 34a,b and rear wheels 36a,b to roll forward on the ground surface and causing the seat portion 14 to slide backward in relation to rotational axis A.
The front wheels 40a,b are then retracted and the leg support 18 is lowered to place the apparatus 10 in a wheelchair position shown in FIG. 1.
The present invention provides the advantage of permitting the invalid to transport herself in the apparatus 10 to and from raised surfaces of varying heights without the need of an attendant (either to push a wheelchair or to bear any weight of the invalid while moving the chair to or from a raised surface).
While the present invention as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and thus, is representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims.
Patent Grant
7841611
