Patent Publication Number: US-2022233375-A1

Title: Convertible mobility device

Description:
FIELD OF THE INVENTION 
     The present invention pertains to the field of mobility devices and in particular to devices that are convertible between multiple modes of use. 
     BACKGROUND 
     Assistive devices are needed by some people to help maintain their mobility. There a many rollator products that offer a walking user support while moving and some space to carry their belongings, while also functioning as a seat for a user to perch for short periods of time. There are also many transport chairs known in the art that allow a user to be seated while being pushed by a second person. However, while there are a few 2-in-1 products with both rollator and transport functionality, these products all suffer from many shortcomings. 
     WO 2016/137322 disclosed a rollator-trolley comprising a bracket shaped handle at a rear upper side of the assembly, wherein the bracket shaped handle is pivotally adjustable between a rollator position for use as a walking aid, in which the bracket shaped handle is substantially directed to a front side, and a trolley position for use in carrying goods, in which the bracket shaped handle is substantially directed towards a rear side. This device, however, is not suitable for use in transporting a user in a transport chair mode. 
     US 2017/0326019 disclosed a mobile walking and transport aid device for supporting particularly persons with impaired walking ability having lateral supports that can be swiveled about a horizontal axis from a first, backwardly tilted position into a at least one forwardly tilted position, the backwardly tilted position being suitable for pushing the walking and transport aid device and/or for supporting the user while walking and/or for the user to sit on the walking and transport aid device, and the at least one forwardly tilted position begin suitable for pulling the walking and transport aid device from the front. This device, however, is not suitable for use in transporting the person with impaired walking ability in a transport chair mode. 
     U.S. Pat. No. 7,628,411 B2 disclosed a walker device for assisting an individual with mobility which is temporarily convertible to a wheeled transportation chair. A backrest is selectively disposed in a front position for a rearward seating condition or in a rear position for a forward seating condition. This device, however, requires removal and replacement to convert between the rollator configuration and the wheeled transportation configuration. 
     EP 0759735 B1 disclosed a combination wheelchair and walker for handicapped or elderly persons walking with a difficulty, the chair having wheels and/or hand grips that may be mounted in first and second alternative positions, wherein in the first position the chair may be pushed by and support a walking or standing handicapped person, and in the second position the chair may be used for transporting a sitting handicapped person and the chair may be pushed by an assisting person. To facilitate conversion between the two modes, this device requires the tilting, rotating or folding of the chair seat. 
     US 2002/0050697 disclosed a wheeled walker convertible to a transport chair having a strap-type backrest that is pivotally attached to the upper end of the handlebars. The backrest can be placed in a forward position when the apparatus is used as a walker and the user wishes to rest in a rearward facing sitting position and in a rearward position when the apparatus is used as a transport chair and the user sits in a forward facing position and is propelled by a care-giver. The strap-type backrest of this device, however, has a limited ability to provide comfortable support to the user in both rollator and wheeled transportation configurations. In addition, the handles are fixed with a preference to the rollator mode, which means that the assisting user will be very close to the seated user, which can make it difficult to maneuver a seated person up a curb since the handles are not behind the rear wheel. 
     Therefore there is a need for a mobility device that offers both transport and rollator functionality with easy transition between the two modes without requiring the removal or installation of additional components or the use of tools to effect the conversion. 
     This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a convertible mobility device. In accordance with an aspect of the present invention, there is provided an assistive mobility device convertible between a rollator mode and a transport chair mode, the device comprising: two laterally spaced apart side frame structures, each side frame structure comprising: a rear handle support member having a top handle end and a bottom end, a front armrest member having a top armrest end and a bottom end, a wheel rail member connected to the handle support member, and a seat rail member extending substantially horizontally and connected to at least one of the handle support member and the front armrest member. The mobility device also comprises a seat bottom extending between the two side frame structures and attached to a respective seat rail; a cross brace assembly extending between the two side frame structures; a seat back member extending between and attached to each of the side frame structures, the seat back member being convertible between a first rollator mode and a second transport chair mode; a handle assembly located at the top handle end of each handle support member, two rear wheels, each of the rear wheels being mounted at the rearward end of a respective side frame structure; and two front wheels, each of the front wheels being mounted at the front end of a respective side frame structure. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1A  illustrates a perspective view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 1B  illustrates a perspective view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 2A  illustrates a perspective view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 2B  illustrates a perspective view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 3  illustrates a perspective view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 4  illustrates a perspective view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 5A  illustrates a side view of a mobility device in accordance with one embodiment of the invention, in which the handle support member that is closest to the viewer has been removed to show the rear of the seat. 
         FIG. 5B  illustrates a top view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 6A  illustrates a side view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 6B  illustrates a top view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 7  illustrates a bottom perspective view of a seat back hinge mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 8A  illustrates a partial perspective view of a handle support member with the handle extension shaft in transport chair mode, in accordance with one embodiment of the invention. 
         FIG. 8B  illustrates a partial perspective view of a handle support member with the handle extension shaft between rollator and transport chair mode, in accordance with one embodiment of the invention. 
         FIG. 8C  illustrates a partial perspective view of a handle support member with the handle extension shaft in rollator mode, in accordance with one embodiment of the invention. 
         FIG. 9  illustrates a perspective view of the top and bottom joint components of a handle rotation mechanism, for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 10A  illustrates a top exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 10B  illustrates a bottom exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIGS. 11A-C  illustrate cross sectional views of the top and bottom joint of a handle rotation mechanism in transport chair mode, between transport chair and rollator modes, and in rollator mode, respectively. 
         FIG. 12  illustrates a cross sectional view of the handle assembly portion of a braking mechanism in accordance with one embodiment of the invention. 
         FIG. 13A  illustrates a partial cutaway view of a braking mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 13B  illustrates a perspective view of a braking mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 14  illustrates a bottom perspective view of a mobility device in accordance with one embodiment of the invention. 
         FIG. 15  illustrates a bottom view of a seat bottom and cross brace, including mounting elements, for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 16  illustrates a rear partial view of a seat bottom and cross brace of a mobility device in accordance with one embodiment of the invention. 
         FIG. 17A  illustrates a partial perspective view of a footrest member on a mobility device, in a storage position, in accordance with one embodiment of the invention. 
         FIG. 17B  illustrates a partial perspective view of a footrest member on a mobility device, in a use position, in accordance with one embodiment of the invention. 
         FIG. 18  illustrates a perspective view of the top and bottom joint components of a handle rotation mechanism, for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 19A  illustrates a top exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 19B  illustrates a bottom exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIGS. 20A-C  illustrate cross sectional views of the top and bottom joint of a handle rotation mechanism in transport chair mode, between transport chair and rollator modes, and in rollator mode, respectively. 
         FIGS. 21A-C  illustrate cross sectional views of a handle assembly portion of a braking mechanism in accordance with one embodiment of the invention. 
         FIGS. 22A-E  illustrate perspective views of a pivoting handle assembly portion in accordance with one embodiment of the invention. 
         FIGS. 23A-E  illustrate perspective views of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIGS. 24A-B  illustrate cross sectional views of the locking mechanism of  FIGS. 23A-E . 
         FIG. 25A  illustrates a top exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 25B  illustrates a bottom exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 26  illustrates a perspective view of the top and bottom joint components of a handle rotation mechanism, for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 27A  illustrates a top exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 27B  illustrates a bottom exploded view of the top and bottom joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIGS. 28A-C  illustrate perspective views of the top joint components of a handle rotation mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 29A-B  illustrate cross-sectional views of the pivot joint components of a handle rotation mechanism within the receiving tubes for use with a mobility device in accordance with one embodiment of the invention. 
         FIGS. 30 and 31  illustrate a seat back member for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 32  illustrates a bottom perspective view of a seat back hinge mechanism for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 33  illustrates a seat back member for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 34  illustrates a perspective view of a mobility device in accordance with one embodiment of the invention, incorporating the seat back member depicted in  FIGS. 30, 31 and 33 . 
         FIG. 35A  illustrates a perspective view of a pivot arm for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 35B  illustrates a perspective view of a pivot arm and pivot sleeve and footrest member for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 36A  illustrates a front perspective view of a pivot sleeve for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 36B  illustrates a rear perspective view of a pivot sleeve for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 37A  illustrates a partial perspective view of a footrest member in a use position on a mobility device, in accordance with one embodiment of the invention. 
         FIG. 37B  illustrates a partial perspective view of a footrest member in transition between use and storage positions on a mobility device, in accordance with one embodiment of the invention. 
         FIG. 37C  illustrates a partial perspective view of a footrest member in a storage position on a mobility device, in accordance with one embodiment of the invention. 
         FIG. 38  illustrates a seat back member for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 39  illustrates a partial perspective view of a hinge region of the seat back member depicted in  FIG. 38 . 
         FIG. 40A  illustrates a partial perspective view of a hinge region of a seat back member, including hinge bracket, for use with a mobility device in accordance with one embodiment of the invention. 
         FIG. 40B  illustrates a partial perspective view of a hinge region of a seat back member for use with a mobility device in accordance with one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The term “rollator” is used to describe a walking frame equipped with wheels for users with mobility problems, preferably with a seating capability. 
     The expression “rollator mode” refers to the configuration of the device suitable for providing support to a user while walking, while also functioning as a seat for a user to sit or perch for short periods of time. 
     The expressions “transport chair mode” and “transport mode” each refer to the configuration of the device suitable for the user to be seated while being pushed by another person. 
     The expressions “mode change” and “modal change” each refer to the conversion between transport chair mode and rollator mode, or vice versa. 
     The expressions “deployed state” and “use state” each refer to the configuration of the device when unfolded and suitable for use in either rollator or transport chair mode. 
     The expressions “collapsed state” and “storage state” each refer to the configuration of the device when folded, for example, if the device needs to be stored or put into a trunk, or if a user needs to get through a narrow doorway. 
     The expression “state change” refers to the conversion of the device from the deployed (or use) state, to the collapsed (or storage) state. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. 
     The present invention therefore provides a mobility device that offers both transport and rollator functionalities with easy transition between the two modes. The assistive mobility device of the present invention is provided with all components required to effect this modal change into the alternate modes without requiring the removal or installation of additional components or the use of tools to effect the conversion. 
     The present invention therefore provides an assistive mobility device that is easily and readily convertible between a rollator mode and a transport chair mode. 
     In a preferred embodiment, the mobility device is also convertible between a deployed state suitable for use, and a collapsed, or folded, state for storage. 
     An exemplary mobility device in transport mode is depicted in its deployed state  100   a  in  FIG. 1A , and in its storage state  100   b  in  FIG. 1B . 
     An exemplary mobility device in rollator mode is depicted in its deployed state  100   c  in  FIG. 2A , and in its storage state  100   d  in  FIG. 2B . 
     In accordance with the present invention, the mobility device comprises two laterally spaced apart side frame structures, each side frame structure being formed from a rear handle support member, a front armrest member, a wheel rail member connected to the handle support member, and a horizontal seat rail member upon which the seat bottom is located, connected to at least one of the handle support member and the front armrest member. 
     The mobility device also includes a seat back member that is convertible between a first rollator mode and a second transport chair mode, the seat back member extending between and attached to each of the side frame structures. In one embodiment the seat back is connected to the front armrest member. In one embodiment, the seat back is connected to the handle support member. 
     In one embodiment, the side frame structure further comprises an upper rail member extending between the front armrest member and the handle support member near their respective upper ends to further stiffen the side frame. 
     The mobility device is conveyed on four wheels, including two rear wheels mounted at the rearward end and two front wheels mounted at the front end of respective side frame structures. In a preferred embodiment, the rear wheels are larger than the front wheels. 
     In one embodiment, each of the front wheels is mounted at the bottom end of a respective front armrest member. In a preferred embodiment, each of the front wheels is pivotably mounted to the front armrest member. 
     In one embodiment, each of the rear wheels is mounted at the rearward end of a respective wheel rail member. 
     An exemplary mobility device in transporter mode is shown in  FIG. 5A  (side view) and  FIG. 5B  (top view). All elements of the side frame structure, including handle support member  2 , front armrest member  4 , wheel rail member  6 , and seat rail member  8 , are shown. Also shown is seat bottom member  7 , front wheels  46  and rear wheels  66 . Handle assembly  3  and seat back member  1  are shown in the transport mode configurations. Foot rest member  11  is shown in the deployed position. 
     An exemplary mobility device in rollator mode is shown in  FIG. 6A  (side view) and  FIG. 6B  (top view). All elements of the side frame structure, including handle support member  2 , front armrest member  4 , wheel rail member  6 , and seat rail member  8 , are shown. Also shown is seat bottom member  7 , front wheels  46  and rear wheels  66 . Handle assembly  3  and seat back member  1  are shown in the rollator mode configurations. Foot rest member  11  is shown in the storage position. 
     Seat Back 
     In a preferred embodiment, the seat back member is formed of a flexible material to facilitate the transition between modes, while also providing comfort in use by conforming to the user&#39;s back while also providing some side support while in the sitting position. Thus, in this embodiment, the central portion of the seat back and its two sides are integrated in a single piece of flexible material. 
     The seat back member can be cut out from a sheet of flexible material with the post processing addition of features such as window cut outs, calendared flex area, and holes for mounting to the hinge mechanism. Alternatively, the seat back can be formed with all such features present by injection molding or casting a suitable polymer that can allow for reliable performance within the range of extreme seasonal temperatures, while also allowing for the demanding flexing requirement for mode transition. Suitable polymer types include, but are not limited to, high-density polyethylene (HDPE), low-density polyethylene (LDPE), thermoplastic polyurethane (TPU), Nylon, or other polymers suitable to the requirements. Thermoset polyurethane can be cast and can allow for favorable changes in wall thickness suitable to the different functional areas of the seat back. 
     In one embodiment, the seat back member is provided with a cushioned outer surface formed by overmolding a low density compressive material over the main flexible seat back member, to offer improved comfort to the user when in contact with the seat back. Other soft or cushioning material fabrics, coverings and/or foams, able to withstand the mode transition, may also be used. In one embodiment, the overmolded or cushioning material is provided on both sides of the seat back. In another embodiment, the overmolded or cushioning material is provided on one side of the seat back. In such an embodiment, the overmolded or cushioning material is preferably provided on the side that is in contact with the user when in transport chair mode. In one embodiment, the overmolded or cushioning material is provided as a continuous layer on the seat back. In another embodiment, the overmolded or cushioning material is provided as a discontinuous layer, to provide localized islands or pillows of cushioning on the seat back. 
     In accordance with the present invention, the seat back member does not require removal or the use of tools to facilitate the transition between a first rollator mode to a second transport chair mode. 
     In one embodiment, the seat back member is mounted to each of the front armrest members through a hinging mechanism. In this embodiment, one hinge is located at the end of each of the seat back&#39;s sides, each hinge allowing for about 180 degrees of motion in order to transition the seat back from the rollator mode to the transport chair mode. The use of the hinging mechanism allows the seat back member to transition between modes without requiring removal during the transition process. 
     In one embodiment, the seat back is removably attached to allow for a reduced height to the device that may be desirable during shipping. In one embodiment, the seat back connection and disconnection process requires the use of tools. In a preferred embodiment, the seat back connection and disconnection process employs releasable connection mechanisms that require no tools. 
     In the embodiment depicted in  FIG. 7 , hinge mechanism  45  is mounted on front armrest member  4 . In this embodiment, the two hinges are provided in approximate vertical orientation to facilitate the transition of the seat back member between rollator and transport modes. Also shown is armrest  48 . 
     In one embodiment, the hinge comprises a metal bracket and the portion of the hinge extending to the right of the image can further include any suitable mechanism to connect to the seat back. In one embodiment, the hinge is configured to support the seat back at the connection point as well as fastening features. In one embodiment, the seat back can be formed with integral hinge features for connecting to the hinge bracket part mounted to the armrest upright. 
       FIGS. 30, 31 and 33  depict one embodiment of a seat back member  12  for use in the present invention, including hinge  245  and hinge bracket  246 . In this embodiment, hinge bracket  246  is associated with and integral to hinge  245  (which is attached to armrest member  4  via hinge tab  243 ), and is configured to provide a more robust connection to the seat back member, while also stiffening the area of the seat back adjacent to the hinge bracket. Use of the hinge bracket provides protection against damage to the seat back that can occur due to repeated impacts sustained during normal use. 
     Hinge  245  and hinge bracket  246  can each be formed from any suitable material that can withstand the forces applied during manipulation of the seat back between rollator and transport modes, as well as in general use. Such materials can be, but are not limited to, metal (steel, aluminum, or stainless) or polymers (including engineering grade, impact modified, filled, glass filled, UV stabilized, or other appropriate additives). 
     Hinge bracket  246  can be attached to the seat back material by any suitable mechanism, including but not limited to, adhesive, rivets, overmolding of the seat back onto the hinge bracket, melt/weld assembly, snap rivets, threaded mechanical fastener hardware, and the like. 
       FIGS. 38 and 39  depict one embodiment of seat back member  12   c  which has been formed with an overmolded outer surface. In this embodiment, hinge bracket  246  is sandwiched between layers of soft overmolded material. This embodiment provides the benefit of increased user comfort through contact with the soft overmold material during use. 
       FIGS. 40A-B  depict one embodiment of seat back member  12   d  which has also been formed with an overmolded outer surface, but which has been provided with hinge allowance  248  in the overmold material, sized to accommodate hinge bracket  246 . This embodiment allows for easy disassembly of the seat back member, for example, to replace the hinge member. 
       FIGS. 38, 39 and 40A -B also depict seat back members covered with overmolded materials formed with a plurality of crease zones  242  formed as vertical grooves in the overmold material. The use of crease zones provides a seat back member having increased flexibility for ease of transition between modes by providing ‘allowances’ for the flexing of the seat during the transition. 
     In one embodiment, each of the crease zones is located equidistant from each other. In one embodiment, the distance between adjacent crease zones is not equal. In one such embodiment, the distance between crease zone decreases as the sides of the seat back is approached. In one embodiment, the creases are provided as areas of discontinuity in the overmolded materials. 
       FIG. 33  depicts a seat back member  12   b  provided with integrally molded force distribution features  212 . In one embodiment, seat back member  12   b  may be provided with an overmolded outer surface that covers the force distribution features, partially or fully. 
     It is within the scope of the present invention that the seat back member can be attached to any upright member of the side frame structure, either directly or through the use of suitable mounting brackets, for example, a mounting bracket that extends from the handle receiving tube. 
     In one embodiment, two different seat back depths are provided through the non-centered location of the seat back hinge relative the seat bottom. This is depicted in  FIGS. 5B and 6B , which show a deeper seat depth in the transport configuration relative to the seat depth of the rollator configuration, which provides additional stability and security for the seated passenger in a mobility device in the transport configuration. 
     The seat back member can have any suitable shape or size, including a full height seat back that provides full back support for the user. 
     In a preferred embodiment, the seat back is configured to have a backwardly sloped recline to provide a desired backrest angle for comfortable seating in both modes. In one embodiment, the hinges are mounted in a slightly off-vertical orientation, thus allowing the seat back to be in a slightly more reclined position in the transport mode relative to the rollator mode. This difference in seat back slope is apparent in  FIG. 5A  (transport mode) and  FIG. 6A  (rollator mode). 
     The seat back member is optionally provided with one or more cut through openings to allow a user to “see through” the seat back when in rollator mode, thus ensuring visibility of items located in the path of the rolling device. 
     In some embodiments, the seat back has features that can be used to collapse the seat back, for example longitudinal flex lines, and associated retention features to retain the seat back in the collapsed state, thereby reducing its height/surface area to improve the user&#39;s view or the approaching terrain. 
     In another embodiment, the seat back is made from three main components in addition to the described hinge mechanism, including two lateral side walls that are hingeably or flexibly connected to a seat back wherein these elements can still be pushed through to transition between modes. 
     In one embodiment, the seat back can be provided with the polymer in direct contact with the user. In one embodiment, the seat back can be provided within a fabric sleeve or with a padded cover. In one embodiment, the seat back can be provided with padded surfaces on both of its sides. In such an embodiment, a differential amount of padding can be applied such that there is additional padding appropriate to the transport mode side of the seat back. In one embodiment, the padding is laminated to the substrate. In one embodiment, the padding is formed of padded elements that are then connected to the polymer. 
     In one embodiment, the seat back is made from a clear or translucent material to assist with the user&#39;s ability to see through the seat back. 
     In one embodiment, the seat back of the mobility device can be transitioned between modes using a push-through process in which the user grips the seat back and pulls or pushes it through to the other side to transition between modes. The spring force of the flexible material results in an “over-center” mechanical layout where the seat is stable in either end condition (i.e., in rollator mode or transport chair mode), but is unstable during the transitional mid-positions, thus providing the user with the feeling that the seat is mechanically assisting the transition. 
     In one embodiment, an action point may be included on the seat back to guide the user in transitioning the seat back from a first rollator mode to a second transport chair mode. For example, an action point can be provided as a handle feature to assist the user in gripping the seat back, or a grip point to indicate to the user the location of the optimal grasp point. In one embodiment, the action point is not centrally located since it may be easier for some users to move one side of the seat through at a time rather than from the center, as pulling the seat back from a point that is off center allows the seat back to pass through in an ‘S’ shape, with one side following the other. 
     Handle Assembly 
     In accordance with the present invention, the mobility device comprises a handle assembly located at the top handle end of each handle support member, to be gripped by the user of the device during use. 
     In accordance with the present invention, the handle assembly can be converted between a rollator configuration and a transport configuration. The handle assembly in the rollator configuration is directed toward the front of the device, and forward of the rear wheels, to facilitate control of the device by the person using the device as a walking support, such that a user applied force onto the handles does not encourage the device to tip backwards about the rear wheels with the handle in the forward positon. The handle assembly in the transport configuration is directed toward the rear of the device to facilitate control of the device by the person pushing the mobility device. 
     In one embodiment, the handle support member comprises a handle receiving tube, and a rotatable and extendible handle extension shaft inserted into the handle receiving tube. In such an embodiment, the handle assembly is preferably mounted on the handle extension shaft. 
     In a preferred embodiment, the handle support member is adjustable in length by extending the handle extension shaft in the handle receiving tube. In such an embodiment, the handle support member is provided with a height adjust and locking assembly to maintain the handle extension shaft at the desired height within the handle receiving tube. In one embodiment, this locking function is provided using a height adjust lock lever. 
       FIG. 3  depicts the mobility device in a transport mode with handle extension shaft  24  fully extended and with both handle assemblies  3   a,b  in the transport configuration. 
       FIG. 4  depicts the mobility device in a transport mode with the handle extension shaft  24  fully extended and with one handle assembly in the transport configuration  3   a  and the other in rollator configuration  3   b  (for illustration purposes only). 
     One embodiment of a handle rotation mechanism is depicted in  FIG. 9 . In accordance with this embodiment, the handle rotation mechanism is a pivot joint  5  comprising top pivot joint  51  and bottom pivot joint  52 , wherein the top joint is rotatable relative to the bottom joint and the bottom joint remains in a fixed position within the handle receiving tube. Also shown is bottom joint retainer  53 , which prevents the pivot joint from being pulled out of the handle receiving tube. The top pivot joint  51  is provided with flex member  57  with integral button  54  to lock/retain the top joint in the respective tube. 
       FIGS. 10A and 10B  depict exploded views of the top and bottom joints, showing the cooperative elements that limit the motion of the top and bottom joints relative to each other in moving between rollator and transport modes. 
     This embodiment employs the frictional interaction of elements on the top pivot joint with elements on the bottom joint to control movement from a first rest zone on the bottom joint defining a first mode to a second rest zone on the bottom joint defining a second mode. 
     As depicted in  FIGS. 10A and 10B , striking protrusion  58  on top pivot joint  51  is configured to frictionally engage with cam lobes  55   a,b  located on bottom pivot joint  52  to prevent free rotation of the top pivot joint between modes. Also provided on bottom pivot joint  52  are stop features  56   a,b  that limit the top joint to 180 degree rotation. When top joint  51  is rotated to either of the first and second modes, the user can reinsert handle support  24  into the receiving tube  23 . 
       FIGS. 11A-C  further depict a cross sectional view of the pivot joint assembly in transport mode ( FIG. 11A ), between transport chair and rollator modes ( FIG. 11B ), and in rollator mode ( FIG. 11C ). 
       FIGS. 18, 19A -B, and  20 A-C depict an alternative embodiment of a pivot joint suitable for use in the present invention. 
     In accordance with this embodiment, the handle rotation mechanism is a pivot joint  15  comprising top pivot joint  151  and bottom pivot joint  152 , wherein the top joint is rotatable relative to the bottom joint and the bottom joint remains in a fixed position within the handle receiving tube. Also shown is bottom joint retainer  153 , which prevents the pivot joint from being pulled out of the handle receiving tube. The joint retainer  153  can collapse into the bottom pivot joint  152  when the handle shaft is in the lowest position and with less room taken because of its collapsed state, more length/height extension in the handle shaft can be provided. The top pivot joint  151  is provided with flex member  157  with integral button  154  to lock/retain the top joint in the respective tube. 
     As depicted in  FIGS. 19A and 19B , top joint is provided with protrusion element  158  that extends into receiving channel  159  on bottom joint  152 . Receiving channel  159  is shaped to limit top joint rotation through 180 degrees, between a first mode and a second mode. Top joint  151  pulls away from bottom joint  152  as a result of the ramped shapes of detent tabs  163  and detent grooves  164  that drive a vertical motion from the user applied rotational motion, to provide enough separation between joints to enable rotation of the top joint about rotation bolt  162 . Compression spring  160 , held in place by nut  161 , is provided to bias top joint  151  into contact with bottom joint  152 , while also allowing for separation between the two joints. When top joint  151  is rotated to either of the first and second modes, the user can reinsert handle support  24  into the receiving tube  23 . Also shown are detent tabs  163 , which situate within respective detent grooves  164  when the top joint is in either of the first and second modes. The compression spring  160  captured within the nut and bolt, holds top joint  151  and bottom joint  152  together, but the ramping function overcomes the spring, and this provides resistance to rotation and then an assistive feel to ramping down and into the new mode position. With it held into the new mode, the joint  151  and  152  are aligned to allow for easy re-insertion into receiving tube  23 . It is within the scope of the present invention to use other spring types. It is also conceived that other approaches to the joint detent  163  and joint groove  164  features (i.e., a plate detent features and another with grooves), could be used other than the integrally molded features shown in  FIGS. 19A and 19B . 
       FIGS. 20A-C  further depict a cross sectional view of the pivot joint assembly of  FIGS. 19A and 19B  in transport mode ( FIG. 20A ), between transport chair and rollator modes ( FIG. 20B ), and in rollator mode ( FIG. 20C ). 
     In use, the handle rotation mechanism is deployed by disengaging the height adjust lock lever, pulling the handle extension shaft out of the handle receiving tube until the pivot joint is exposed, rotating the handle extension shaft so that the handle assembly is position in the alternate modal orientation, dropping the handle extension shaft down to the desired height, and re-engaging the height adjust lock lever to secure the handle into the desired modal orientation. 
     Placing the pivot joint at the bottom of the handle extension shaft provides the handle support member with improved rigidity since the modal pivot is deep within the receiving tube in both rollator and transport modes, rather than at the handle location, which ensures that it is not subject to twisting or bending forces during use. 
     In a preferred embodiment, the handle extension shaft is rotatable through 180 degrees relative to the receiving tube thus providing for the conversion of the handle assembly between the rollator configuration and the transport configuration. Rotation of the extension shaft is facilitated by a handle rotation mechanism comprising a pivot joint associated with the extension shaft. 
     In one embodiment, the pivot joint is located at the base of the extension shaft, and optionally includes features to resist complete pullout. By locating the pivot joint at the base of the extension shaft, exposure of the extension shaft to stresses and strains during the adjustment process can be minimized. 
     In addition to being in different relative rotational positions for each of the rollator and transport modes, the handle assemblies can also be beneficially raised or lowered to different heights for each mode according to the requirements of the respective users. 
     In a preferred embodiment, the height adjust lock lever is the only mechanism that requires manipulation to adjust both handle height and handle orientation mode, thus providing a simplified system for converting the mobility device between rollator and transport modes. This minimizes the introduction of excessive “play” between components that can result from the inclusion of additional mechanisms (hinges, pivots, etc.) to allow the modal change. 
     In the embodiment depicted in  FIGS. 8A-C , handle support member  2  is shown at full extension in transport mode ( FIG. 8A ), between transport chair and rollator modes ( FIG. 8B ), and in rollator mode ( FIG. 8C ). Shown is handle extension shaft  24  with indexing detents  27  for locking, receiving tube  23  for receiving handle extension shaft  24 , locking assembly  25  attached to receiving tube  23 , and pivot joint assembly  5  attached to bottom of handle extension shaft  24 . 
       FIGS. 22A-E  depict a pivoting handle assembly portion in accordance with one embodiment of the invention. In this embodiment, handle assembly  3  employs locking lever  36  that, when released, allows rotation of handle assembly  3  between transport chair and rollator modes.  FIG. 22A  depicts handle assembly  3  in transport mode with locking lever  36  in locked position,  FIG. 22B  depicts handle assembly  3  in transport mode with locking lever  36  in released position,  FIG. 22C  depicts handle assembly  3  in between transport and rollator modes with locking lever  36  in released position,  FIG. 22D  depicts handle assembly  3  in rollator mode with locking lever  36  in released position, and  FIG. 22E  depicts handle assembly  3  in rollator mode with locking lever  36  in locked position. 
     An alternative embodiment of a pivot joint suitable for use in the present invention is depicted in  FIGS. 23A-E ,  24 A-B, and  25 A-B. This embodiment employs locking lever  136  that, when released, allows conversion of the handle assembly between transport chair and rollator modes. Pivot joint  35  comprises top pivot joint  351  and bottom pivot joint  352 , wherein the top joint is rotatable relative to the bottom joint and the bottom joint remains in a fixed position relative to the handle receiving tube (not shown). Pivot joint  35  is also provided with mounting assembly  353 , on which the handle assembly (not shown) can be mounted. 
       FIG. 23A  depicts pivot joint  35  in transport mode with locking lever  136  in locked position,  FIG. 23B  depicts pivot joint  35  in transport mode with locking lever  136  in released position,  FIG. 23C  depicts pivot joint  35  in between transport and rollator modes with locking lever  136  in released position,  FIG. 23D  depicts pivot joint  35  in rollator mode with locking lever  136  in released position, and  FIG. 23E  depicts pivot joint  35  in rollator mode with locking lever  136  in locked position. 
       FIG. 24A  is a cross-sectional view of pivot joint  35 , showing locking lever  136  in the locked position, which stops rotation of top joint  351  around rotation shaft  362  through engagement of slot  369  located on the locking lever with keying rib  358  located on rotation shaft  362 .  FIG. 24B  depicts locking lever  136  in the released position, resulting in the disengagement of slot  369  located on the locking lever  136  from keying rib  358  located on rotation shaft  362 , thus allowing rotation of top joint  351  relative to bottom joint  352 . 
       FIGS. 25A and 25B  show further detail of pivot joint  35 , in particular the respective lock zones  364   a,b  located on bottom joint  352  which engage with detent  365  located on top joint  351  when in chair or rollator mode. 
       FIGS. 26, 27A -B,  28 A-C and  29 A-B depict an alternative embodiment of a pivot joint suitable for use in the present invention. 
     In accordance with this embodiment, the handle rotation mechanism is a pivot joint  225  comprising top pivot joint  251  and bottom pivot joint  252 , wherein the top joint is rotatable relative to the bottom joint and the bottom joint remains in a fixed position within the handle receiving tube. Also shown is annular flange bead  253 , which prevents the pivot joint from being pulled out of handle receiving tube  23 . 
     As depicted in  FIGS. 27A and 27B , top joint is provided with protrusion element  258  that extends into receiving channel  259  on bottom joint  252 . Receiving channel  259  is shaped to limit top joint rotation through 180 degrees, between a first mode and a second mode. Top joint  251  pulls away from bottom joint  252  as a result of the ramped shapes of detent tabs  263  and detent grooves  264  that drive a vertical motion from the user applied rotational motion, to provide enough separation between joints to enable rotation of the top joint about rotation bolt (not shown). In a similar manner to that illustrated in the embodiment depicted in  FIGS. 18, and 19A -B, compression spring (not shown), held in place by nut (not shown), is provided to bias top joint  251  into contact with bottom joint  252 , while also allowing for separation between the two joints. When top joint  251  is rotated to either of the first and second modes, the user can reinsert handle support  24  into the receiving tube  23 . The compression spring captured within the nut and bolt holds top joint  251  and bottom joint  252  together, but the ramping function overcomes the spring, and this provides resistance to rotation and then an assistive feel to ramping down and into the new mode position. With it held into the new mode, the joint  251  and  252  are aligned to allow for easy re-insertion into receiving tube  23 . It is within the scope of the present invention to use other spring types. It is also conceived that other approaches to the joint detent  263  and joint groove  264  features (i.e., a plate detent features and another with grooves), could be used other than the integrally molded features shown in  FIGS. 27A and 27B . 
     In the embodiment depicted in  FIGS. 26, 27A -B,  28 A-C and  29 A-B, top pivot joint  251  is provided as a two part component, including a main body  276  and an adjustable sliding wedge  277  movable relative to the main body and which is employed to retain the top pivot joint within the handle extension shaft  24  through adjustment of a threaded screw  275 . 
     Prior to installation in handle extension shaft  24 , top pivot joint  251  is provided with sliding wedge  277  in the “up” position as depicted in  FIG. 28C . Upon installation in handle extension shaft  24  ( FIG. 29A ), threaded screw  275  is adjusted to move sliding wedge  277  toward the “down” position depicted in  FIG. 28A  until the sliding wedge  277  is in tight contact with the inner wall of handle extension tube  24  ( FIG. 29B ). This ensures a tight fit within the extension tube, preventing inadvertent removal of top pivot joint  251  from the tube in use. 
     In an alternative embodiment, the handle rotation mechanism may be provided closer to the handle end of the handle extension shaft. In such an embodiment, the handle rotation can be carried out independently of the height adjustment process. 
     Braking System 
     In a preferred embodiment, the mobility device further comprises a braking system configured to allow the user to limit the movement of the mobility device. 
     In accordance with this embodiment, the braking system preferably comprises a braking mechanism associated with one or both of the rear wheels, a brake lever associated with the handle assembly, and a brake linkage system connecting the braking mechanism and the brake lever. 
     Accordingly, the handle assembly of the mobility device includes a brake lever which is connected via a brake linkage system to a braking mechanism, whereby the user&#39;s action on the brake lever actuates a braking mechanism that is associated with a corresponding wheel. 
     In one embodiment, the brake linkage system is a brake cable extending between the braking mechanism and the brake lever. In one embodiment, the brake linkage system further comprises a brake arm connected to the brake cable and associated with the braking mechanism. 
     In a preferred embodiment, the braking system is configured to function equally in both modal configurations. 
     In accordance with one embodiment, the brake linkage comprises a single cable connecting the brake lever to the brake mechanism associated with the corresponding wheel. 
     In one embodiment, the braking mechanism is a disc brake mechanism. In one embodiment, the braking mechanism is a drum brake mechanism. In one embodiment, the braking mechanism is configured to apply frictional force directly to the tread of the wheel. In one embodiment, the braking mechanism can be electric where braking forces drive a generator, allowing the option of capturing the generated electricity for use by assistive motorization. In another embodiment, any of the described braking mechanisms can be actuated using an electric motor or servomotor which provides the mechanical force for actuating the brake. In such an embodiment, the signal to trigger and release the brakes is provided by the user via one or both brake handles, or via a single brake handle input that can then actuate both brakes. In one embodiment, the signal to trigger and release the brakes is provided as a result of the processing of information gathered from sensors including, but not limited to, velocity sensors and/or proximity sensors. In one embodiment, the braking mechanisms are controlled using a low force use input device, or by voice control. 
     In one embodiment, the braking system is configured for instantaneous braking when the user pulls up on the brake lever, and for a “parking style” brake when the user pushes down on the brake lever. 
     In one embodiment, the brake cable system is provided internal to the frame structure, including a cable loop that passes through multiple frame structure members. In a preferred embodiment, the brake cable extending from the brake lever to the brake mechanism passes through the handle support member components, including the handle extension shaft, the receiving tube and the pivot joint. This configuration protects the brake cables from damage due to catching or snagging during use. 
     In the embodiment depicted in  FIGS. 12, 13A and 13B , the braking system comprises a single shielded cable  103  connecting the brake lever  102  to the brake mechanism (not shown). From the brake lever and its anchoring features, cable  103  travels through the interior of handle extension shaft  24  and handle receiving tube  25  of the handle support member  2 , then at the intersection of handle support member  2  and wheel rail member  6 , the cable is redirected to the wheel and brake mechanism. 
     In this embodiment, at the transition between vertical handle support member and the horizontal wheel rail member there is provided cable management component  105  that is insertable into the wheel rail member from its end such that it is in communication with the handle receiving tube. The cable management feature allows for management of the brake cable while also accommodating a loop of cable sufficient for the range of height adjustments, which can vary up to 8-12 inches in height at full extension. 
     In one embodiment, cable management component is a formed plastic cable loop manager that prevents the cable from reaching its bend radius limits. The cable management component also guides the flow of the internally stored brake cable required when the height of the handled is adjusted. In one embodiment, the cable management component terminates at the open end of the tube that it sits within. In another embodiment, the cable management component is only internal. 
     In one embodiment, the braking mechanism further comprises a foot activated brake control to provide the user with an additional stopping actuator option. In one embodiment, the foot activated brake control is associated with the cable management component. 
       FIGS. 21A-C  illustrate cross sectional views of a handle assembly portion of a braking mechanism in accordance with one embodiment of the invention of a compact linkage mechanism that transfers user&#39;s actuation motion to brake cable motion.  FIG. 21A  depicts brake lever  102  in a downward locked position, with actuation tab  106  located in the “locked brake” position of actuation guide  107 , which causes the brake mechanism to be maintained in a braking configuration without user action on brake lever  102 .  FIG. 21C  depicts brake lever  102  in an upward position, with actuation tab  106  located in the “brake” position of actuation guide  107 , which causes the brake mechanism to be maintained in a braking configuration only with user action on brake lever  102 .  FIG. 21B  depicts brake lever  102  in an intermediate position, with actuation tab  106  located in the “brake release” position of actuation guide  107 , which causes the brake mechanism to be maintained in the open configuration. 
     Seat Bottom 
     The mobility device of the present invention also comprises a seat bottom extending between the two side frame structures and attached to a respective seat rail. In a preferred embodiment, the seat bottom is convertible between an unfolded/deployed state and a folded/collapsed state, and comprises a first seat bottom member hingedly attached to a second seat member. In a preferred embodiment, each of the first and second seat members is also hingedly attached a frame mount element that is attached to a respective seat rail. 
     In accordance with the present invention, the mobility device can be easily converted between the deployed state and the storage state by folding along the three hinged connections. 
     In a preferred embodiment, the mobility device further comprises a locking mechanism to lock the seat bottom in a desired configuration. In one embodiment, the locking mechanism is configured to lock the seat in the deployed state. In one embodiment, the locking mechanism is configured to lock the seat bottom in the collapsed state. 
     In one embodiment, the mobility device further comprises a cross brace assembly extending between the two side frame structures to provide structural stability. In a preferred embodiment, the cross brace assembly comprises two cross members, each of the cross members extending between a frame mount on one of the side frame structures and the wheel rail member of the other of the side frame structures. In a preferred embodiment, each cross member comprises a collapsing link hingeably attached at a lower end of the cross member, wherein the collapsing link is configured to collapse/fold when the mobility device is in the collapsed state. In one embodiment, the collapsing link is a molded element. 
     In the embodiment depicted in  FIGS. 14, 15 and 16 , seat bottom  7  comprises first seat bottom member  7   a  hingedly attached to second seat member  7   b  by seat hinge  72 , wherein each of the first and second seat members is respectively attached by seat mount hinges  74   a,b  to frame mount elements  73   a,b , each frame mount element  73   a,b  being attached to a respective seat rail member  8 . Also shown is seat lock  75 , cross members  9   a,b  and collapsing links  19   a,b , provided as molded elements hingedly linked at one end to a respective cross member and at the other end to a respective side frame structure. In one embodiment, the central seat hinge  72  has a handle or strap attached to it that is accessible from above by the user. In such an embodiment, the handle rests within the space between the first and second seat members of each seat bottom such that the user does not feel the handle when seated. This handle or strap is used by the user to pull up on the seat as the lock is released, initiating the conversion from the deployed state to the storage state. 
     In one embodiment, the seat members are further provided with padded elements such as cushions. 
     Foot Rest 
     In a further embodiment, the mobility device comprises two footrest members mounted to the front of a respective side frame structure, wherein the footrest member is pivotable between a storage position ( FIG. 17A ) and a use position ( FIG. 17B ). 
     In one embodiment, the footrests are provided with a passive locking system where the footrest member is held in each of the use and storage positions by gravity. 
     In an alternate embodiment, the mobility device is provided with an active locking mechanism requiring a release action before transitioning the footrest member between storage and use positions. 
     In a preferred embodiment, the footrest member can be transitioned between the storage and use positions without requiring removal from the frame structure. For example, the footrest member can be transitioned between storage and use positions by lifting the pivot arm out of the storage position, rotating the footrest toward the use position, and dropping the footrest into the final use position. The reverse sequence can be carried out to transition from use to storage positions. 
       FIG. 17B  depicts one embodiment of a footrest member comprising pivot arm  111 , footrest extension arm  114 , foot surface  112 , and foot surface pivot mechanism  113 . 
     In the embodiment depicted in  FIGS. 17A-B , the user lifts up on pivot arm  111 , overcoming gravity to enable rotation of the footrest member out of the current state. The user continues to rotate until the farthest opposite extent is reached at which point the user lets pivot arm  111  drop with gravity into position for the other state. 
       FIGS. 35A-B  and  36 A-B depict one embodiment of a pivot arm  211  and sleeve  215 , suitable for use in retaining the footrest member in storage and use positions. As shown in  FIGS. 36A-B , sleeve  215  comprises an angled sleeve trough  216 , adapted to receive pivot arm post  218  and footrest extension arm  214  at both the use stopping point and the storage stopping point. In this embodiment, the footrest is lifted to initiate the rotational motion required to move the footrest between positions. Sleeve trough  216  extends in forward and rear directions to provide a secure resting surface for extension arm  214 , minimizing rotational play of the footrest member. 
       FIG. 37A  depicts a footrest member in the use position,  FIG. 37B  depicts a footrest member in transition between use and storage positions, and  FIG. 37C  depicts a footrest member in the storage position. 
     In the embodiment of  FIGS. 37A-C , footrest surface  212  is provided as a generally planar body having a grid-like configuration having openings formed therethrough to avoid build up of dirt and other materials on the surface of the footrest. It is within the scope of the present invention that the footrest may be made of any suitable material, including but not limited to, molded polymer, metal, wood and the like. 
     In the embodiment shown in  FIG. 35B , the footrest member is provided with pivot arm post  218  having pin  226  normal to its cylindrical surface. Pin  226  is adapted to slide through a channel located on the inner surface of sleeve  215 , wherein the channel is configured to guide the motion of pin  226  during rotation between storage and use positions. In use, pivot arm  211  is lifted vertically out of a first end position until pin  218  reaches a horizontal portion of the channel, at which point pivot arm  211  is rotated until pin  218  reaches the opposite extent of the horizontal portion. Pivot arm  211  is then dropped vertically until pin  218  reaches a second end position in the channel.  FIGS. 36A-B  depict first and second end points  236 ,  237  of the channel. 
     In another embodiment, between either extremity, the user can further lift up the pivot arm, and access a channel (at an angular position that may be indicated) to remove the footrest member. It is at this point that the footrest member can be reinserted. 
     In one embodiment, a strap tie down is provided to maintain the footrest in its storage position. 
     In alternate embodiments, in a configuration that is a rollator only or a transport chair only, it is conceived that each embodiment may also incorporate many of the innovations described herein. 
     It is obvious that the foregoing embodiments of the invention are examples and can be varied in many ways. Such present or future variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.