Abstract:
An improved lifting and transportation device including an attachment means adapted to engage a wheeled device to be transported; and one or more driving wheels adapted to engage the ground to propel said lifting and a transportation device, whereby, said lifting and transportation device is steerable by the independent engagement of said driving wheels; and a controller adapted to control the motion of said driving wheels and control the operation of said attachment means. The attachment means may be an attachment assembly with laterally opposed attachment brackets adapted to engage said wheeled device, whereby, a vertical actuator is used to adjust the vertical height of said attachment assembly and a horizontal actuator is used to adjust the horizontal separation of said laterally opposed attachment brackets

Description:
FIELD OF THE INVENTION 
     The present invention relates to an improved lifting and transportation device. In particular, a detachable transportation device for use with manually operated wheelchairs. 
     BACKGROUND OF THE INVENTION 
     Wheelchairs are typically manually operated or power driven, depending on the requirements of the user. Power driven wheelchairs are driven by ground engaging wheels, with an electric motor and gearbox arrangement supplying the wheels with the necessary motion to propel the wheelchair in the desired direction. This arrangement is both bulky and heavy. Typically, a power driven wheelchair will contain more than one electric motor, gearbox and battery and have a frame adapted to support the additional weight. The additional components are required to move the wheelchair in the desired direction and supply enough torque to move the load, consisting of the wheelchair frame, drive system and user. 
     Manually operated wheelchairs therefore possess certain advantages over power driven wheelchairs. Manual wheelchairs are significantly lighter, allowing for a lighter construction, and have the ability to be dismantled for ease of storage and portability. Manually operated wheelchairs can therefore be transported more easily in vehicles and do not require the need for trailers or specific wheelchair carrying devices. There are also advantages with the simplicity of design of manually operated wheelchairs, as there is obviously less equipment to malfunction. In the event of a power operated wheelchair malfunctioning, it generally cannot be easily operated manually due to its weight. It is therefore desirable for a person to have both a powered and manually operated wheelchair at their disposal, adding further costs to the user. 
     Buildings and public infrastructure, such as railway terminals, bus stops, and footpaths, now have ramps for disabled and wheelchair access. However, some of these ramps are too steep for a user to traverse with a manually operated wheelchair and they require the assistance of an additional person. The additional person is therefore required to exert significant effort, which may result in injury to that person and/or the wheelchair user. In locations where a person, such as a staff member, is subjected to the repetitive stresses of assisting a manually operated wheelchair user up an incline repeatedly, the chance of injury is greatly increased. 
     It is therefore an object of the present invention to overcome the aforementioned problems and to provide the public with a useful alternative. 
     SUMMARY OF THE INVENTION 
     Therefore in one form of the invention there is an improved lifting and transportation device proposed comprising:
     an attachment means adapted to engage a wheeled device to be transported; and   a pair of driving wheels adapted to engage the ground to propel said lifting and transportation device, whereby, said lifting and transportation device is steerable by the independent engagement of said driving wheels; and   a controller adapted to control the motion of said driving wheels and control the operation of said attachment means.   

     Preferably said transportation and lifting device includes at least one rotatable castor wheel. 
     Preferably each said driving wheel is rotated by a corresponding electric motor and gearbox. 
     Preferably said transportation and lifting device includes at least one battery to supply power to said electric motors and said attachment means. 
     Preferably said attachment means includes an attachment assembly with laterally opposed attachment brackets adapted to engage said wheeled device, whereby, a vertical actuator is used to adjust the vertical height of said attachment assembly and a horizontal actuator is used to adjust the horizontal separation of said laterally opposed attachment brackets. 
     Preferably said vertical actuator can be adapted to lift said wheeled device vertically, whist said attachment brackets are engaging the wheeled device. 
     Preferably said wheeled device is typically a wheelchair and said attachment brackets are adapted to be attached to vertical struts of said wheelchair frame. 
     Preferably said attachment brackets are pivotable, maintaining a perpendicular attachment between said attachment brackets and said vertical struts of the wheelchair. 
     Preferably said transportation and lifting device is adapted to be positioned within said wheelchair frame, whilst engaged to said wheelchair, so that said driving wheels are located parallel to the wheelchair&#39;s rear wheels. 
     Preferably said controller is detachably mounted on a controller arm. 
     Preferably said controller arm is extendable and detachably mounted to said transportation and lifting device. 
     Preferably said laterally opposed attachment brackets can be replaced with a clamping mechanism adapted to engage a horizontal strut of the wheeled device frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings: 
         FIG. 1  illustrates a perspective view of a transportation device; and 
         FIG. 2  illustrates a side view of a transportation device; and 
         FIG. 3  illustrates a top view of a transportation device before engaging a wheelchair; and 
         FIG. 4  illustrates a top view of a transportation device in an engaged state; and 
         FIG. 5  illustrates a top view of a transportation device attached to a wheelchair; and 
         FIG. 6  illustrates a side view of a transportation device and a wheelchair awaiting engagement to traverse a ramp; and 
         FIG. 7  illustrates a side view of a transportation device engaging a wheelchair before traversing a ramp; and 
         FIG. 8  illustrates a side view of a transportation device and a wheelchair traversing a ramp. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. 
       FIG. 1  shows a perspective view of a transportation device  10  comprising a frame  12 , adapted to support both the transportation device driving mechanism and an attachment mechanism for the attachment of the device to a wheelchair. The transportation device  10  can be used to transport any manner of wheeled devices requiring a detachable drive system to assist users during manual operation. Typically, the device is to be used on manually operated wheelchairs as a detachable drive system. 
     The device  10  is driven by a pair of ground engaging wheels  14  and  16 , with each wheel having its own motor and gearbox arrangement (not shown in this figure). Also attached to the frame  12 , is the attachment mechanism comprising of a vertically moveable assembly  18 . The assembly  18  is raised or lowered using an actuator, by the user, to accommodate different purpose and different dimensioned wheelchairs. In order for the device  10  to be compatible with a large variety of wheelchairs, the attachment mechanism, comprising of two attachment arms  20  and two attachment brackets  22 , must be adapted to move in and out depending on the width of the wheelchair frame. This is achieved using a horizontal actuator  24 , which can horizontally separate two laterally opposed horizontal arms  25  according to the width required. The device  10  is also narrower than the majority of wheelchairs, so as to fit within the majority of wheelchair frames. 
     The device frame also supports a battery case  26  containing two 12 volt batteries  28 , installed to provide power to the two driving wheels  14  and  16 . It is envisaged that an alternative power arrangement could be used. The battery case  26  has a detachable lid  27  attached to protect the batteries  18 . An extendable controller stand  30 , attached to the frame  12 , supports a detachable controller unit  32 . The controller unit  32  can be operated from its position atop of the extendable stand  30  by a user operating the device to move both the wheelchair and the person within. However, should the wheelchair user not require additional assistance, the control unit  32  can be detached and operated by the wheelchair user. The device  10  then functions as a detachable transportation device and should the person require this facility regularly, different sized wheels and gearing could be employed to ensure a smoother ride. 
     The controller unit has a mode button  33 , allowing multiple uses of the joystick  34  both to direct movement of the wheelchair and the attachment mechanism. The joystick can be used to activate the horizontal actuator  24  and move the horizontal arms  25  in or out depending on the width of the wheelchair. Due to a pivot arrangement, moving the horizontal arms inwards will force the attachment brackets  22  outwards towards the wheelchair frame, similarly, moving the horizontal arms outwards will retract the attachment brackets  22 . There is also a toggle switch  36 , located on the control unit  32 , used to raise or lower a vertical actuator to move the attachment frame  18  and subsequently the attachment brackets  22  vertically to the desired position on a wheelchair. Once the device  10  is attached to the wheelchair in the desire position, the joy stick  34  can be used to direct power to the driving wheels  14  and  16  and direct the wheelchair. Having each wheel moving independently allows for the tighter turning circle and greater manoeuvrability of the wheelchair. 
       FIG. 2  shows a side view of the device  10  with the motor and gearbox arrangement  38  for the ground engaging wheel  14  visible. The motor and gearbox arrangement for the wheel  16  is not shown in this figure as it is located directly behind the motor  38 . Also shown in this figure is the rear castor wheel  40 . In this embodiment only one rotatable rear wheel is used for extra mobility, however, it is possible for the device to have more than one non driving wheel. The rear wheel  40  is attached to the transportation device frame  12  centrally. Also attached to the frame is the battery case  26  and the extendable stand  30  attached thereto. It can be seen that the stand  30  can be detached from the case  26  for ease of transportation. 
     The adjustment assembly  18  is vertically moved by the vertical actuator  42 . This allows the attachment brackets  22  to be attached to a wheel chair frame in a position free of any cross bracing or any other obstacles. From this figure, it is also clear that the brackets  22  rotate in the direction of the arrow  43 , allowing for the brackets to retain the wheelchair in a position parallel to the ground, regardless of the slope of the ground. This is especially important in traversing ramps and other steep slopes. 
       FIG. 3  and  FIG. 4  show a top view of the device  10  and the attachment device in both its unattached and the attached states respectively. In the unattached state, brackets  22  are closest together in a position defined by the width of the device  10 . This allows the device  10  to transport any width of wheelchair with a frame greater than the width of the device. In this position, the horizontal actuator  24  has the horizontal arms  25  in their most outwards position.  FIG. 4  shows the horizontal actuator  24  bringing in the horizontal arms  25  and in turn bringing out the attachment brackets  22 , due to the pivot located on the attachment airs  20 . The attachment brackets  22  continue to be forced wider, by the horizontal actuator  24 , until they exert a predetermined lateral force on the wheelchair being attached. This force is sufficient to retain the wheelchair but not sufficient to distort the wheelchair frame. The brackets  22  are shaped so to engage with the vertical up stands of the wheelchair frame. 
       FIG. 5  shows a transportation device  10  attached to a wheelchair  44 . The attachment brackets  22  are forced outwards exerting a lateral pressure on the vertical struts  46  of a wheelchair  44 . The ground engaging wheels  14  and  16  of the device  10  are located in a position in line with the wheelchair&#39;s rear wheels  48 . This allows for smoother wheelchair travel, with it behaving as it would were it operated manually. Thus, the addition of the device  10  does not restrict any of the wheelchair&#39;s functionality and mobility. The user also experiences a familiar riding experience and can easily learn and adapt to use the control unit  32 . The device  10 , when attached to the wheelchair  44 , uses its drive wheels  14  and  16  to propel the wheelchair in a given direction with the wheelchair&#39;s wheels  48  still engaging the ground. Thus, the wheelchairs own wheels  48  are used to distribute weight to the ground and provide a more comfortable ride. The vertical actuator  42  could be used to raise the wheels of the wheelchair  44  whilst being transported. However, this function is envisaged to be used with other wheeled devices requiring transportation. 
       FIG. 6  shows a wheelchair  44 , placed in a position to have the device  10  attached. The device  10  is used in the situation where the wheelchair user, either with or without the help of an assistant, cannot traverse the upcoming ramp  50 .  FIG. 7  shows the transportation device  10  being attached to the wheelchair  44  and  FIG. 8  shows the wheel  44  and device  10  traversing the ramp  50 . Not shown in these figures is; the wheelchair user, and an assistant, operating the device  10 . 
     The device may also have an alternative attaching mechanism to be adapted to uses other than transporting wheelchairs. A clamp arrangement could be used, instead of the horizontally expanding attachment brackets  22 , to clamp onto the horizontal frame strut of any wheeled device requiring transportation. For example, the device could be used in the situation where a user is unable to negotiate a trolley up an incline and requires assistance. The device  10  could be adapted to assist the movement of such a trolley with a suitable attachment clamp. In order to traverse a greater variety of slopes and surfaces, the wheels of such a trolley can be raised or lowered using the vertical actuator  42 . 
     Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus. 
     In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprising” is used in the sense of “including”, i.e. the features specified may be associated with further features in various embodiments of the invention.