Abstract:
Embodiments of the invention comprise a self-supporting platform style lift system operating from a transport position to a lifting position for assisting in egress and ingress from a vehicle. In a lifting position, a platform member extends from a rotating frame capable of axial rotation about a vehicle frame. A ground frame, lifting frame, and platform frame system allow the platform member to be raised and lowered to the vehicle. The point at which the platform frame and lifting frame make contact with the ground provides support for applied loads on the platform member, thereby reducing stress and strain on the frame of a vehicle. In a transport position, the platform member extends parallel with the face of the vehicle.

Description:
BACKGROUND 
       [0001]    The invention relates to lift systems. Specifically, embodiments of the invention relate to lift systems designed to provide persons with disabilities access to a vehicle. 
         [0002]    Lift systems may be used by persons in wheelchairs, either manual or powered; persons who are unable to climb steps; or operators of mobility scooters. It is desirable to lift both the wheelchair and the occupant of the wheelchair to a vehicle, particularly a travel trailer type recreational vehicle (RV). Conventional handicapped lift systems must be fixedly mounted to the frame of a vehicle. Such systems depend on the structural strength of the vehicle. Such systems may also require permanent modification to a vehicle. Further, such systems may also interfere with functionality. Therefore, a need exists for a lift system which is capable of lifting a wheelchair and the occupant of the wheelchair to a vehicle, which provides a support means independent of the structural strength or suspension to the vehicle. 
       SUMMARY 
       [0003]    Embodiments of the invention are directed to solving the need for a lift system which is capable of lifting a wheelchair and the occupant of the wheelchair to a vehicle, and provides a support means independent of the structural strength or suspension to the vehicle. Exemplary embodiments of the invention set forth herein pertain to RVs, however embodiments may also be directed towards other vehicles. 
         [0004]    Embodiments of the invention comprise a self-supporting platform style lift system attached to a frame on one side an RV, near the door. The self-supporting platform style lift system operates from a transport position to a lifting position. When in transport, a platform extends parallel with the face of the RV. The platform is designed to maintain a reduced profile, for portability in transportation. In a lifting position, the platform extends from the RV, providing an elongate support surface. The platform is supported by one or more movable support members. The support members extend from the RV, and provide a means of structural support for the platform. The point at which the support members make contact with the ground provides support for applied loads on the platform, thereby reducing stress and strain on the frame of a vehicle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    These and other features, aspects and advantages of embodiments of the invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
           [0006]      FIG. 1  illustrates a perspective view of a self-supporting platform style lift system attached to an RV, where the platform member is raised, according to an embodiment of the invention; 
           [0007]      FIG. 2  illustrates a perspective view of a self-supporting platform style lift system attached to an RV, where the platform member is lowered, according to the embodiment of  FIG. 1 ; 
           [0008]      FIG. 3  illustrates a perspective view of a self-supporting platform style lift system, showing the relative motion of the platform member during lifting, according to the embodiment of  FIG. 1 ; 
           [0009]      FIG. 4  illustrates a perspective view of a self-supporting platform style lift system, where the platform member is raised, according to the embodiment of  FIG. 1 ; 
           [0010]      FIG. 5  illustrates a perspective view of a self-supporting platform style lift system, showing the relative motion of the platform member to the transport position, according to the embodiment of  FIG. 1 ; 
           [0011]      FIG. 6  illustrates a side view of a self-supporting platform style lift system attached to an RV, showing the relative positioning of the platform member in the transport position, according to the embodiment of  FIG. 1 ; 
           [0012]      FIG. 7  illustrates a top view of a rotating frame, according to the embodiment of  FIG. 1 ; 
           [0013]      FIG. 8  illustrates a side view of a self-supporting platform style lift system attached to an RV, showing the relative motion of the rotating frame when raising the rotating frame, according to the embodiment of  FIG. 1 ; 
           [0014]      FIG. 9  illustrates a side view of a self-supporting platform style lift system attached to an RV, according to the embodiment of  FIG. 1 ; 
           [0015]      FIG. 10  illustrates a perspective view of a self-supporting platform style lift system attached to an RV, where the platform member is raised, according to an alternate embodiment of the invention; 
           [0016]      FIG. 11  illustrates a perspective view of a self-supporting platform style lift system attached to an RV, where the platform member is lowered, according to the embodiment of  FIG. 10 ; 
           [0017]      FIG. 12  illustrates a side view of a self-supporting platform style lift system attached to an RV, showing the relative positioning of the platform member in the transport position, according to the embodiment of  FIG. 10 ; and 
           [0018]      FIG. 13  illustrates a top view of a rotating frame, according to the embodiment of  FIG. 10 . 
       
    
    
     DESCRIPTION 
       [0019]    Overview 
         [0020]    The following detailed description illustrates the preferred embodiment of the invention by way of example. This description will clearly enable one skilled in the art to make and use the invention, and will set forth the best mode of doing so. The embodiments listed herein are not intended to limit the scope of the invention. Several alternative embodiments are set forth, and it is contemplated that other permutations, arrangements, adaptations, uses, and variations of the invention are possible. 
         [0021]    Detailed Description of the Elements 
         [0022]      FIGS. 1-9  show a self-supporting platform style lift system of an embodiment of the invention. According to the embodiment, the self-supporting platform style lift system  10  is attached to an RV frame  81 , on one side an RV  80 , near the entrance  82  of the RV  80 . The self-supporting platform style lift system  10  comprises: a platform member  11 ; a ground frame  21   a ,  21   b ; a lifting frame  30 ; a platform support frame system  41 ,  43 ; a rotating frame  50 ; a platform member lifting arrangement  61 - 64 ; and a ground frame lifting arrangement  71 - 74 . The self-supporting platform style lift system  10  is movable between a transport position and a lifting position. 
         [0023]    A platform member  11  is a longitudinally extending support surface forming the resting surface during lifting, having a front end  11   a  and a back end  11   b.  The platform member  11  is substantially planar, and constructed of a resilient material. The occupant of a wheelchair may position or load the wheelchair upon the platform member  11  for elevation to the entrance  82  of the RV  80 . The platform member  11  has a platform frame  12 , providing structural support for the platform member  11 . The platform frame  12  has a frame aperture  91   a , existing on both sides of the platform frame  12 . A support stop element  16 , allows a bridge from the ground to the platform member  11 . The support stop element  16  is an extending planar surface comprised of a rear surface  16   a  and a front surface  16   b . The rear surface  16   a  and front surface  16   b  meet near the center of support stop element  16 , forming a dihedral angle. The support stop element  16  is pivotably fastened to the edge of the platform member  11 . The support stop element  16  is allowed to axially rotate. A locking arm may lock the support stop element  16  into position, providing a wheel stop during lifting. A platform ramp may be used to allow a bridge from the platform member  11  to the entrance  82  of the RV  80 . The platform ramp may be an extending planar surface, pivotably mounted to the edge of the platform member  11 . Platform railing members  15   a,    15   b  may be attached to the platform member upon deployment. 
         [0024]    A ground frame is comprised of individual support members  21   a ,  21   b . The individual support members  21   a ,  21   b , are longitudinally extending support beams, constructed of resilient material. Each individual support member  21   a ,  21   b  extends perpendicular with said rotating frame  50 , as illustrated in  FIG. 2 ,  3 . The individual support members  21   a ,  21   b  are spaced a width apart, such as to permit occupant to enter an RV  80 . In the exemplary embodiment, the width is greater than the horizontal surface of the stairs  83  of the RV  80 . Each individual support member  21   a ,  21   b  may be attached to the RV frame  81  via ground frame attachment brackets or other equivalent means. 
         [0025]    A lifting frame  30  is lift support element, rotatably fastened at one end to said rotating frame  50 , and at another end to said platform member  11 . The lifting frame  30  is capable of axial rotation relative to a lift pivot  31 . In the exemplary embodiment, the lifting frame  30  is a substantially planar elongate support member, affixed to the lift pivot  31 . The lift pivot  31  is rigid elongate cylinder. The lift pivot  31  attaches to the side of the lifting frame  30  closest to the RV  80 , and extends a lower portion of each individual support member  21   a ,  21   b . During lifting, the lifting frame  30  rotates axially upward about the lift pivot  31 , applying an upward moment force on the lower surface of the platform member  11 . The relative motion of the platform member  11  is illustrated in  FIG. 3 . During deployment, the lifting frame  30  rotates axially downward about the pivot  31 , allowing the platform  11  to descend. The platform  11  is connected to the lifting frame  30  by a pair of connection bolts (although other means of connection are contemplated). Such connection allows the platform  11  to axially rotate with respect to the lifting frame  30  during lifting. 
         [0026]      FIG. 3  shows a platform support frame system  41 ,  43 . The platform support frame system comprises a lower support member  41 , and a pivot member  43 . A lower support member  41  is a substantially planar, rigid, support body, which rotatably fastens at one to the lifting frame  30 , and rotatably fastens at another end to the pivot member  43 . A pivot member  43  comprises a pair of longitudinally extending beams, which rotatably fasten at one to the lower support member  41 , and rotatably fastens at another end to the platform frame  12 . Each longitudinally extending beam attaches on one side by a pair of beam connection bolts (or other fixable means). The pivot member  43  has a pivot aperture  91   b , attached to both sides of the pivot member  43 . Both the lower support member  41 , and pivot member  43  is capable of free axial rotation with respect to the platform member  11 , and lift pivot  31 . 
         [0027]    A rotating frame  50  is a resilient longitudinally extending support frame capable of being mounted to the RV frame  81 . The rotating frame  50  is capable of axial rotation at one end of the rotating frame  50  with respect to the RV frame  81 . A pair of beam support members  51   a,    51   b , may extend across the rotating frame  50  for additional support. One end of the rotating frame  50  (the end opposing the entrance  82 ) is attached to the RV frame  81  via frame mounting brackets  90 . The other end of the rotating frame  50  is attached to the individual support members  21   a ,  21   b.    
         [0028]    A platform member lifting arrangement  61 - 64  allows the platform member  11  to be raised or lowered between the ground and the entrance  82  of the RV  80 . The platform member lifting arrangement  61 - 64  uses a lifting motor  61 , lifting actuator  62 , lifting cable  63 , a pair of lifting pulleys  64   a,    64   b,  and a pair of rotating frame pulleys  64   c,    64   d.  A lifting motor  61  is a 12 volt electrical motor, fixedly attached to the rotating frame  50 , and connected to the RV&#39;s 12 volt electrical system. The lifting motor  61  drives the lifting actuator  62 , which is fixedly attached to the rotating frame  50 . The lifting actuator  62  is connected to a lifting cable  63 . The lifting cable  63  is an elongate tensile material, applying a lifting force to the platform member  11 . The pair of lifting pulleys  64   a,    64   b  are located on the upper surface of individual support members  21   a ,  21   b . The pair of rotating frame pulleys  64   c,    64   d  are located on the rotating frame  50 . A length of lifting cable  63  extends in one direction: from the lifting actuator  62 , around the rotating frame pulleys  64   c,    64   d;  into the internal portion of an individual support member  21   b ; over a lifting pulley  64   a;  underneath the lifting frame  30 , and attaches to the platform frame  12 . A length of the lifting cable  63  extends in the opposite direction: from the lifting actuator  62  into the internal portion of an individual support member  21   a ; over a lifting pulley  64   a;  underneath the lifting frame  30 , and attaches to the platform frame  12 . A pair of tension springs (not shown) extend from the lifting frame  30 , to the platform member  11 . 
         [0029]    A ground frame lifting arrangement  71 - 74  allows raising and lowering of the rotating frame  50 , with respect to the RV frame  81 . The ground frame lifting arrangement  71 - 74  comprises a deployment motor  71 , a deployment actuator  72 , a deployment cable  73 , and a deployment pulley  74 . A deployment motor  71  is a 12 volt electrical motor, fixedly attached to the rotating frame  50 , and connected to the RV&#39;s 12 volt electrical system. The deployment motor  71  drives the deployment actuator  72 , which is fixedly attached to the rotating frame  50 . The deployment actuator  72  is connected to a deployment cable  73 . The deployment cable  73  is an elongate tensile material, fixedly attached to the lower surface of the RV frame  81 . A length of deployment cable  73  extends over the deployment pulley  74 . The deployment pulley  74  is mounted on the beam support member  51   b.    
         [0030]    One or more electrical switches  75  may be placed on the surfaces of the RV  80  or self-supporting platform style lift system  10 . According to the current embodiment, an electrical switch  75  is placed on a platform railing member  15   a;  and on the inside of the RV  80  (not shown). The electrical switch  75  allows for the operator to actively deploy or activate the self-supporting platform style lift system  10 . 
         [0031]    The self-supporting platform style lift system  10  is movable between a transport position to a lifting position. In the transport position, the rotating frame  50  is raised such it is substantially parallel with the RV frame  81 . The platform member  11 , ground frame  21   a ,  21   b , lifting frame  30 , platform support frame system  41 ,  43 , rotating frame  50 , platform member lifting arrangement  61 - 64  and ground frame lifting arrangement  71 - 74  are raised such that they are substantially parallel with the side surface of the RV  86 , and perpendicular with the ground. When in transport position, the self-supporting platform style lift system  10  extends approximately 3 inches beyond the side of the RV  86  (less space than required for the factory installed awning) and is supported with frame brackets  90 , and not the lifting cable  63 . The self-supporting platform style lift system  10  engages the side of the RV  86  such that it does not interfere with the operating or storage of the awning. One or more support pins  92  may be inserted into the platform aperture  91   a , and pivot aperture  91   b , securable fastening the platform member  11  during transport. 
         [0032]    How the Invention is Used 
         [0033]    Deployment of the self-supporting platform style lift system  10  involves first lowering the rotating frame  50 ; and next raising/lowering the platform member  11 . Engaging the deployment motor  71  allows the rotating frame  50  to downwardly axially rotate about the frame mounting brackets  90 —which lowers the rotating frame  50 . The rotating frame  50  is lowered such that the lower surface of the individual support members  21   a ,  21   b  make contact with the ground. A small piece of material such as wood may be placed between the individual support members  21   a ,  21   b  to reach desired height. 
         [0034]    The platform member  11 , ground frame  21   a ,  21   b , lifting frame  30 , platform support frame system  41 ,  43  are lowered into lifting position such that they are substantially perpendicular with the side surface of the RV  86 , and parallel with the ground. Engaging the lifting motor  61  allows the lifting actuator  62  to increase or decrease the tension in the lifting cable  63 . As tension is increased, the lifting cable  63  lifts the platform member  11  from the ground in a curvilinear arc towards the RV entrance, as shown in  FIG. 3 . As tension is decreased, the lifting cable  63  lowers the platform member  11  from the RV entrance to the ground. 
         [0035]    Upon lowering and securing the individual elements, the lift system may be operated solely by the occupant of a wheelchair. For transportation to the inside of the RV  80 , the occupant operates the wheelchair onto the upper surface of the platform member  11 . The occupant next engages the support stop element  16 . The occupant next raises the lift via a switch  75 . The occupant may then enter the RV by operating the wheelchair across the platform ramp and into the RV  80 . Conversely, transportation out of the RV  80  requires similar operation. 
         [0036]    Advantages of the Invention 
         [0037]    The lift system of embodiments of the invention may be easily installed on vehicles without significant modification to the vehicle or vehicle frame. Moreover, the lift system does not interfere with factory installed RV steps, and can be used while the steps are fully deployed. The lift system also functions on an RV&#39;s existent 12 volt power supply. 
         [0038]    Lift systems of embodiments of the invention do not depend solely on the structural strength or suspension of a vehicle during lifting. After deployment, lifting point load forces are supported by the ground and the elements of the lift system (as opposed to the vehicle frame). Embodiments of the invention may handle 500 lb loads (although embodiments of the invention can be made to handle more) without significant modification to a vehicle frame. The result of such a design reduces stress or strain on the structure of the vehicle. 
         [0039]    Alternatives 
         [0040]    Other embodiments are contemplated by embodiments of the invention. For example, the platform lifting member arrangement and ground frame lifting arrangement may employ a different type of lifting activation, such as: hydraulic lifts; pneumatic lifts; or other mechanically operated lifts capable of performing equivalent functions. Such lift systems may use one or more combinations of pulleys, or may use an equivalent mechanical structure. 
         [0041]    For example, in an alternate embodiment of the invention, a self-supporting platform style lift system  110  comprises: a platform member  111 ; a ground frame  121   a ,  121   b ; a lifting frame  130 ; a platform support frame system  141 ,  143 ; a rotating frame  150 ; and a ground frame lifting arrangement  171 - 174  as described as in the preferred embodiment. The self-supporting style lift system  110  also comprises a platform lifting member arrangement  161 - 163  which differs from that of the preferred embodiment, as illustrated in  FIGS. 10-13 . Specifically, the platform lifting member arrangement  161 - 163  of the alternate embodiment allows the platform member  111  to be raised or lowered between the ground and the entrance  182  of the RV  180  without the use of the pulleys or lifting cable (as described in the preferred embodiment in elements  63 - 64 ). The platform lifting member arrangement  161 - 163  of the alternate embodiment uses a lifting motor  161  driving a lifting actuator  162 . The lifting motor  161  and lifting actuation are rotatable fasted to the rotating frame  150 . A lifting cable  163  extends from the lifting actuator  162  to a coupling bracket  164  The coupling bracket  164  is directly connected to the lifting frame  130  (as opposed to the pulley and cable system as described in the preferred embodiment). As shown in  FIGS. 10-13 , the lifting motor  161  and lifting actuator  162  are capable of axial rotation about the rotating frame  150  during raising and lowering of the platform member  111 . Activation of the lifting motor  161  causes the lifting actuator  162  to exert a force on the lifting cable  164 , coupling bracket  164 , and lifting frame  130 , which in turn the allows the platform member  111  to be raised or lowered between the ground and the entrance  182  of the RV  180 . 
         [0042]    The frame, lifting frame, and platform support frame, may also encompass alternate configurations. For example, such surfaces have been described in detail as pairs of elongate extending members. However, such structures may also be comprised of a single solid structure, with equivalent mechanical structure. 
         [0043]    The number and placement of switches may vary between embodiments of the invention. For example, a switch may be added to any of the surfaces of the platform member, ground frame, lifting frame, and platform support frame. 
         [0044]    Differing combinations and permutations of the embodiments set forth are contemplated by the current invention. Additionally, all functional equivalents of materials used and means of attachment of elements are contemplated by the current invention. Therefore, the spirit and scope of the appended claims should not be limited to the descriptions of the preferred versions and alternate embodiments set forth herein. 
         [0045]    Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. §112, ¶6. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. §112, ¶6.