Abstract:
The present invention provides a modular lateral transfer assembly (MLTA) adaptable to a wheelchair for easily transferring a wheelchair bound person, and a modular wheel assembly (MWA) adaptable to a wheelchair for easily transferring a wheelchair bound person laterally. The present invention also provides a wheelchair integrating the MLTA and MWA either individually or in combination.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to wheelchairs, and more particularly to methods and apparatuses that can be integrated into a wheelchair so that a wheelchair bound person can be easily transferred. 
     BACKGROUND OF THE INVENTION 
     Transferring from a wheelchair to another place, such as car, bed, bath, toilet, furniture, or other places, is a problem for both wheelchair riders and their helpers. Present wheelchair riders can rely on separate transfer apparatus such as lifters and transfer boards to aid the transfer. The lifters are not only costly but also lack of portability, whereas the transfer boards are economical but require extreme care and skills in using. Some riders choose to perform these transfers independently using their upper limbs, while others request assistance from helpers. Depending on a rider&#39;s condition, the recommended transferring technique can involve use of transferring aids such as a lifter, belt, transfer board, easy slide, turntable, and draw sheet-slow process. The problem in performing these transfers manually, without the aid of apparatus, is that the transfers may lead to repetitive strain injuries as a result of prolong actions that place strain on a body. Other causes of physical injuries to both helpers and wheelchair riders may include a traumatic accident, or a series of small accidents because of incorrect transferring procedures or techniques. 
     Therefore, there is an existing need for methods and apparatuses that can help the transfer of a wheelchair bound person. 
     SUMMARY OF THE INVENTION 
     One embodiment of the present invention provides a modular lateral transfer assembly (MLTA) adaptable to a wheelchair for easily transferring a wheelchair bound person. The MLTA comprises a pivotal shaft being secured onto a frame of the wheelchair, thereby providing physical support for the MLTA, a main slide board for providing a transfer plane, one or more sleeve units disposed underneath of the main slide board for securing the board onto the pivotal shaft, and a location hole assembly disposed at one end of the main slide board; thereby when the main slide board via the location hole assembly is secured to the frame of the wheelchair, the wheelchair bound person is transferred via the transfer plane. 
     In another embodiment of the MLTA, the main slide board has a plurality of through holes for lightening the board. 
     In another embodiment of the MLTA, it further comprises a secondary slide board, wherein the main slide board has one end for receiving the secondary slide board so that when the secondary slide board is pulled out, it forms an elongated transfer plane. 
     In another embodiment of the MLTA, each sleeve unit has a channel allowing the sleeve unit to rotatably accommodate the frame and a threaded hole for accommodating a fastener for securing the sleeve unit onto the main slide board. 
     In another embodiment of the MLTA, the location hole assembly has an oversized cavity for receiving a quick-release locking means disposed onto the opposite side of the frame, so that the main slide board is ready for transfer. 
     In another embodiment of the MLTA, the main slide board comprises one or more casing disposed onto its top surface for receiving one or more rollers, easing the transfer process. 
     In another embodiment of the MLTA, the main slide board comprises a plurality of casings disposed onto its top surface for receiving a plurality of rolling balls, easing the transfer process. 
     In another embodiment of the MLTA, the main slide board has a one-piece configuration. In another embodiment of the MLTA the main slide board has a two-piece configuration. 
     Another embodiment of the present invention provides a modular wheel assembly (MWA) adaptable to a wheelchair for easily transferring a wheelchair bound person laterally. The MWA comprises a linear guide assembly being disposed onto a frame of the wheelchair, a slidable wheel assembly coupled with the linear guide assembly, where the slidable wheel assembly slides along the linear guide assembly from a front position and a rear position, and a quick-release locator working together with the linear guide assembly to secure and lock the slidable wheel assembly at a desired position, whereby when the slidable wheel assembly is moved away from the front to the rear, a lateral transfer is allowed. 
     In another embodiment of the MWA, the slidable wheel assembly comprises a wheel, a wheel axle for supporting the wheel, a cover plate, a wheel lock/brake mounted on the cover plate for locking the wheel when it is not in motion, a quick-release locator mounted on the cover plate for securing the slidable wheel assembly at a desired position, and a hand rim for allowing hand pushes. 
     In another embodiment of the MWA, the linear guide assembly comprises a backplate, a pair of linear guide rods, a pair of linear guide holding blocks securely coupled onto the backplate for holding the two ends of the linear guide rods, a linear slide unit slidably disposed on the linear guide rods so that the linear slide unit moves between the linear guide holding blocks, wherein the linear slide unit is coupled with the slidable wheel assembly so that it moves the slidable wheel assembly, and a bracket securely coupled with the backplate for attaching the linear guide assembly to the frame. 
     In another embodiment of the MWA, the backplate has a plurality of holes including home location holes, alternate home location holes and transfer location holes for stopping and securing the motion of the linear slide unit. 
     In another embodiment of the MWA the linear guide assembly further comprises a cover plate for covering the linear guide assembly. 
     In another embodiment of the MWA, the linear slide unit is preloaded with rolling elements for easy sliding. 
     In another embodiment of the MWA, the linear guide rods have a feature selected from the group consisting of spline, circular shaft, polygonal shaft, and track rail. 
     In another embodiment of the MWA, the linear guide rod holding block is configured to have a pair of holes for receiving the linear guide rods, a pair of holes for fastening the block onto the backplate, and a hole for receiving a fastener for locking the linear guide rods. 
     In another embodiment of the MWA, the bracket is configured to have a threaded hole and a through hole for cooperatively holding the backplate onto the frame, and a threaded hole for securing the bracket to the backplate. 
     Another embodiment of the present invention provides a wheelchair for easily transferring a wheelchair bound person. The wheelchair comprises a modular lateral transfer assembly (MLTA), where the MLTA comprises a pivotal shaft being secured onto a frame of the wheelchair, thereby providing physical support for the MLTA, a main slide board for providing a transfer plane, one or more sleeve units disposed underneath of the main slide board for securing the board onto the pivotal shaft, and a location hole assembly disposed at one end of the main slide board; thereby when the main slide board via the location hole assembly is secured to the frame of the wheelchair, the wheelchair bound person is transferred via the transfer plane, and a locking means for locking the main slide board when it is being used for transfer. 
     In another embodiment of the wheelchair, the quick-release locking means is a spring loaded plunger. 
     In another embodiment of the wheelchair, it further comprises a seat cover disposed on top of a sling seat and detachable from the sling seat. 
     Another embodiment of the present invention provides a wheelchair for easily transferring a wheelchair bound person. The wheelchair comprises a frame, and a modular wheel assembly (MWA), wherein the MWA comprises a linear guide assembly being disposed onto a frame of the wheelchair, a slidable wheel assembly coupled with the linear guide assembly, where the slidable wheel assembly slides along the linear guide assembly from a front position and a rear position, and a quick-release locator working together with the linear guide assembly to secure and lock the slidable wheel assembly at a desired position, whereby when the slidable wheel assembly is moved away from the front to the rear, a lateral transfer is allowed. 
     In another embodiment of the wheelchair, it further comprises a modular lateral transfer assembly (MLTA), where the MLTA comprises a pivotal shaft being secured onto a frame of the wheelchair, thereby providing physical support for the MLTA, a main slide board for providing a transfer plane, one or more sleeve units disposed underneath of the main slide board for securing the board onto the pivotal shaft, and a location hole assembly disposed at one end of the main slide board; thereby when the main slide board via the location hole assembly is secured to the frame of the wheelchair, the wheelchair bound person is transferred via the transfer plane. 
     In another embodiment of the wheelchair, it further comprises a locking means for quick-release locking the main slide board when it is being used for transfer. 
     In another embodiment of the wheelchair, the quick-release locking means is a spring loaded plunger. 
     In another embodiment of the wheelchair, it further comprises a seat cover disposed on top of a sling seat and detachable from the sling seat. 
     The objectives and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments according to the present invention will now be described with reference to the Figures, in which like reference numerals denote like elements. 
         FIG. 1  shows an isometric perspective view of a wheelchair in accordance with one embodiment of the present invention, where partial components of the wheelchair are shown. 
         FIG. 2  shows an isometric perspective view of a wheelchair in accordance with one embodiment of the present invention, where most components of the wheelchair are shown. 
         FIG. 3  shows an isometric perspective view of a wheelchair in accordance with one embodiment of the present invention, where the MLTA  100  is in a fully deployed horizontal position, and the MWA  200  is in the extended transfer position. 
         FIG. 4  shows an isometric perspective view of the detachable seat cover  12  in accordance with one embodiment of the present invention. 
         FIG. 5  shows an isometric perspective underside view of the MLTA  100  in accordance with one embodiment of the present invention, where the MLTA is in a tilted position. 
         FIG. 6  shows an isometric perspective underside view of the MLTA  100  in accordance with one embodiment of the present invention. 
         FIG. 7  shows an isometric perspective view of the MLTA  100  in accordance with one embodiment of the present invention, where a bushing  107  is included. 
         FIG. 8  shows an isometric perspective view of the sleeve unit  103  in accordance with one embodiment of the present invention. 
         FIG. 9  shows an isometric perspective view of the main slide board  101  and its locking mechanism in accordance with one embodiment of the present invention. 
         FIG. 10  shows an isometric perspective view of the location hole assembly  105  in accordance with one embodiment of the present invention. 
         FIG. 11  shows an isometric perspective view of the spring loaded plunger  30  in accordance with one embodiment of the present invention. 
         FIG. 12  shows an isometric perspective view of an optional roller assembly disposed onto the main slide board in accordance with one embodiment of the present invention. 
         FIG. 13  shows an isometric perspective view of an optional ball transfer units disposed onto the main slide board in accordance with one embodiment of the present invention. 
         FIG. 14  shows an isometric perspective view of the linear guide assembly  210  in accordance with one embodiment of the present invention. 
         FIG. 15  shows an isometric perspective view of the coverplate of the linear guide assembly  210  in accordance with one embodiment of the present invention. 
         FIG. 16  shows an isometric perspective view of the linear guide rod holding block  216  in accordance with one embodiment of the present invention. 
         FIG. 17  shows an isometric perspective view of a quick-release locator for being attached to the coverplate of the linear guide assembly in accordance with one embodiment of the present invention. 
         FIG. 18  shows an isometric perspective view of the bracket  218  in accordance with one embodiment of the present invention. 
         FIG. 19  shows an isometric perspective front view of the assembled modular wheel assembly  200  in accordance with one embodiment of the present invention. 
         FIG. 20  shows an isometric perspective view of the wheelchair with the MLTA  100  in accordance with one embodiment of the present invention. 
         FIG. 21  shows an isometric perspective view of the wheelchair with the MLTA  100  in accordance with one embodiment of the present invention. 
         FIG. 22  shows an exploded view of the wheelchair in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention may be understood more readily by reference to the following detailed description of certain embodiments of the invention. 
     Throughout this application, where publications are referenced, the disclosures of these publications are hereby incorporated by reference, in their entireties, into this application in order to more fully describe the state of art to which this invention pertains. 
     One embodiment of the present invention provides a transfer apparatus that is integrated with a wheelchair for allowing a wheelchair bound person to be transferred easily. In brief, the transfer apparatus comprises a modular wheel assembly (MWA) and a modular lateral-transfer assembly (MLTA). Depending on a user&#39;s choice, MWA and MLTA can be fitted on to a wheelchair for either a left- or a right-sided transfer. They can also be fitted on both sides of a wheelchair. In certain embodiments, MWA or MLTA can be incorporated separately to a wheelchair to meet a singular need. For example, only MWA will be incorporated in wheelchairs that use other transfer apparatus. The MWA can be linearly displaced to the rear freeing up sufficient space for a lateral transfer of a wheelchair rider. The MLTA can be deployed modularly to reach a targeted place or seat to provide a smooth and reliable transfer of the rider from the wheelchair. It is to be noted that the wheelchair with integrated MWA and MLTA does not need to be assembled de novo. Existing standard wheelchair users can remove one wheel with its associated components so that the remaining frame and wheel are ready for attachment of MWA and MLTA, a retrofitting option where the MWA and MLTA can be marketed and fitted separately. 
     Now referring to  FIG. 1 , there is provided an isometric perspective view of a wheelchair in accordance with one embodiment of the present invention, where partial components of the wheelchair are shown for the clarity. As shown in  FIG. 1 , the wheelchair  1  has a configuration for a left-sided transfer, comprising a frame  2  for providing supports for other components (e.g., wheels); a pair of push handles  3 ; a pair of armrests  4 ,  4 ′ where one of them  4 ′ is a swivel armrest that can be lifted; a pair of footplates  5 ; a backrest  6 ; an optional castor  7 ; a fixed wheel  8 ; an axle  9 ; a wheel lock/brake  10 ; and a sling seat  11 . The frame  2  is usually foldable for stowage. The push handles  3 , armrests  4 ,  4 ′, footplates  5 , axle  9 , and wheel lock/brake  10  are coupled to the frame  2  for support. The wheel  8  is coupled to the axle  9  and can be locked into a position by the wheel lock/brake  10 . The sling seat  11  is employed for supporting a wheelchair bound person. 
     Now referring to  FIG. 2 , there is provided an isometric perspective view of a wheelchair in accordance with one embodiment of the present invention, where most components of the wheelchair are shown. The components described above in reference to  FIG. 1  will not be described further. As shown in  FIG. 2 , the wheelchair  1  has a configuration for a left-sided transfer, comprising a modular lateral transfer assembly (MLTA)  100  described in detail hereinbelow; a modular wheel assembly (MWA)  200  including a linear guide assembly  210 , a quick-release locator  220  shown herein, and a slidable wheel assembly with a wheel  18 , a wheel axle  19 , a wheel lock/brake  20 , and a hand rim  21  for allowing hand pushes. The MLTA  100  is coupled with the frame  2  for providing the means to allow the wheelchair bound person to be laterally transferred from or into the wheelchair. The MLTA  100  is held in its upright position by a “C” channel  41  disposed onto the swivel armrest  4 ′. The MWA  200  is coupled to the frame  2  for allowing the slidable wheel assembly to slide between a front position and a rear position, so that the slidable wheel assembly of the MWA  200  can be moved away from the front to the rear when a lateral transfer is needed.  FIG. 2  shows that the swivel armrest is lifted upwards with the MLTA  100  in the stowed upright position, and the MWA is in the initial “home” position. 
     Now referring to  FIG. 3 , there is provided an isometric perspective view of a wheelchair in accordance with one embodiment of the present invention, where the MLTA  100  is in a fully deployed horizontal position, and the MWA is in the extended transfer position. As shown in  FIG. 3 , the wheelchair is ready for lateral transfer operation. The wheelchair further comprises an optional seat cover  12  that is disposed on top of the sling seat  11  and detachable from the sling seat  11 . In one configuration of the detachable seat cover  12  as shown in  FIG. 4 , it has a plane  12   a  for covering the sling seat  11 , a pair of gripping holes  12   b  located at two ends of the plane, and a plurality of easy hooks  12   c  positioned at four corners of the plane for securing the detachable seat cover onto the sling seat. 
     Now referring to  FIG. 5 , there is provided an isometric perspective underside view of the MLTA  100  in accordance with one embodiment of the present invention. As shown in  FIG. 5 , the MLTA is assembled into the wheelchair and in a tilted position with the sling seat being removed for visual clarity. The MLTA  100  comprises a main slide board  101 , a secondary slide board  102 , one or more sleeve units  103 , a pivotal shaft  104 , and a location hole assembly  105 . The main slide board  101  has one end for receiving the secondary slide board  102  so that the secondary slide board  102  can be pulled out in a telescopic way, thereby when lateral transfer is needed, the secondary slide board  102  can be pulled out from the main slide board  101  to form an elongated transfer plane. The sleeve units  103  are disposed underneath of the main slide board  101  for securing the boards onto the pivotal shaft  104  which in turn is secured onto the frame  2 . As shown in  FIG. 6 , another embodiment of the present invention provides a plurality of through holes  106  in the main slide board  101  for lightening the board. One end of the main slide board  101  has a cut corner configuration for making space for front castor wheel.  FIG. 7  shows an isometric perspective view of the MLTA  100  in accordance with one embodiment of the present invention, where a bushing  107  is included. The bushing  107  secures the main slide board  101  into a desired axial position onto the pivotal shaft  104  by using a standard screw. 
       FIG. 8  shows one configuration of the sleeve unit  103  in accordance with one embodiment of the present invention, where the sleeve unit  103  has a channel  103   a  allowing the sleeve unit  103  to rotatably accommodate the frame  2  and a threaded hole  103   b  for accommodating a fastener for securing the sleeve unit  103  onto the main slide board  101 . The rotational smoothness of the main slide board  101  can be enhanced by using of either suitable lubrication or rolling elements in between the interface of channel  103   a  and the shaft  104 . The main slide board is movable along the pivot shaft  104  for fine adjustment. Its relative position is lockable by the bushing  107 . 
     Now referring to  FIG. 9 , there is provided an isometric perspective view of the main slide board  101  and its quick-release locking mechanism in accordance with one embodiment of the present invention. The quick-release locking mechanism includes the location hole assembly  105  and a spring loaded plunger  30 . The location hole assembly  105  has an oversized hole  105   a  which can be circular and rectangular cavity for receiving the spring loaded plunger  30  disposed onto the opposite side of the frame  2 , so that the main slide board  101  is ready for transfer. This clearance derived from the diameter difference between the plunger  30   a  and the oversized hole  105   a , is needed to accommodate small initial height difference found between the targeted place and the fully deployed slide boards. In one embodiment as shown in  FIG. 10 , the location hole assembly  105  has a block configuration with a pair of threaded holes  105   b  formed at one end for securing the assembly onto the bottom surface of the main slide board  101 , and the oversized hole  105   a  formed at the other end. One embodiment of the spring loaded plunger is shown in  FIG. 11 , where the spring loaded plunger  30  has configured to include a cavity  30   d  for fitting the spring loaded plunger onto the frame  2 , a pair of holes  30   c  for fastening, a plunger  30   a  for inserting into the oversized hole  105   a , and a pull knob  30   b  for pulling the plunger  30   a . In addition,  FIG. 9  shows a recess clamp  31  for engaging and locking the sling seat  11  onto the frame  2 . 
     Now referring to  FIGS. 12 and 13 , there are provided two examples of optional transfer means that can be disposed onto the top surface of the main slide board for easing the transfer process. The transfer means shown in  FIG. 12  comprises one or more rollers  106  that sit nicely on a metallic casing. The transfer means shown in  FIG. 13  comprises a plurality of rolling balls  106 ′ that sit snugly on metallic casings. 
     Now referring to  FIG. 14 , there is provided shows an isometric perspective view of the linear guide assembly  210  in accordance with one embodiment of the present invention. The linear guide assembly  210  comprises a backplate  211 , a pair of linear guide rods  215 , a pair of linear guide holding blocks  216 , a linear slide unit  217 , and a bracket  218 . The backplate  211  has a plurality of holes including home location holes  212 , alternate home location holes  213  and transfer location holes  214  for stopping and securing the motion of the linear slide unit  217 . The linear guide holding blocks  216  are securely coupled onto the backplate  211  for holding the linear guide rods  215 , where the linear slide unit  217  is slidably disposed on the linear guide rods  215  so that the linear slide unit  217  moves between the linear guide holding blocks  216 . The linear slide unit  217  is also coupled with the wheel axle  19  so that it moves the wheels  18  back/forward. The bracket  218  is securely coupled with the backplate  211  for attaching the linear guide assembly to the frame  2 . As shown in  FIG. 15 , the linear guide assembly  210  also comprises a cover plate  219  for covering the linear guides, where the cover plate  219  is configured to have a through hole  219   a  for mounting of the slidable wheel assembly, a through hole  219   b  for mounting the plunger/quick-release locator  220 , fastening holes  219   c  for securing the bracket that holds the wheel lock/brake  20 , and a fastening hole  219   d  for securing the cover plate to the linear slide unit  217 . The linear slide unit  217  can be preloaded with rolling elements such as rollers, balls or the likes. The linear guide rods  215  can have feature such as spline, circular shaft, polygonal shaft, track rail or the likes. The sliding contact surfaces can be suitably lubricated to facilitate smooth action. 
       FIG. 16  shows an isometric perspective view of the linear guide rod holding block  216  in accordance with one embodiment of the present invention. The linear guide rod holding block  216  is configured to have a pair of holes  216   a  for receiving the linear guide rods  215 , a pair of holes  216   b  for fastening the block onto the backplate  211 , and a hole  216   c  for receiving a fastener for locking the linear guide rod  215 . 
       FIG. 17  shows an isometric perspective view of a quick-release locator  220  for being attached to the cover plate  219  of the linear guide assembly in accordance with one embodiment of the present invention. In this case the quick-release locator  220  is a spring loaded plunger  2101 , configured to have a pull knob  2101   a , a housing for a spring  2101   b  and a plunger  2101   c.    
       FIG. 18  shows an isometric perspective view of the bracket  218  in accordance with one embodiment of the present invention. The bracket  218  is configured to have a threaded hole  218   a  and a through hole  218   c  for cooperatively holding the backplate onto the frame  2 , and a threaded hole  218   b  for securing the bracket to the backplate  211 . 
       FIG. 19  shows an isometric perspective front view of the assembled modular wheel assembly in accordance with one embodiment of the present invention. The modular wheel assembly  200  is in an extended position. 
       FIG. 20  shows an isometric perspective view of the wheelchair in accordance with one embodiment of the present invention. The wheelchair transfer apparatus is in a semi-deployed position with the sling seat removed for visual clarity. The modular lateral transfer assembly  100  has a main slide board  101  with a one-piece configuration.  FIG. 21  shows another main slide board  101  with a two-piece configuration. In both configurations, the use of the secondary slide board is contemplated. 
       FIG. 22  shows an exploded view of the wheelchair in accordance with one embodiment of the present invention. 
     While the present invention has been described with reference to particular embodiments, it will be understood that the embodiments are illustrative and that the invention scope is not so limited. Alternative embodiments of the present invention will become apparent to those having ordinary skill in the art to which the present invention pertains. Such alternate embodiments are considered to be encompassed within the spirit and scope of the present invention. Accordingly, the scope of the present invention is described by the appended claims and is supported by the foregoing description.