Patent Publication Number: US-2015075882-A1

Title: Wheelchair

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
     This application is a divisional application of U.S. patent application Ser. No. 13/168,262, filed Jun. 24, 2011, entitled “WHEELCHAIR,” which claims priority to, and any other benefit of U.S. Provisional Patent Application Ser. No. 61/358,066, filed on Jun. 24, 2010, entitled “WHEELCHAIR,” U.S. Provisional Patent Application Ser. No. 61/412,031, filed on Nov. 10, 2010, entitled “WHEELCHAIR,” U.S. Provisional Patent Application Ser. No. 61/412,043, filed on Nov. 10, 2010, entitled “WHEELCHAIR SEAT ASSEMBLY,” and U.S. Provisional Patent Application Ser. No. 61/412,041, filed on Nov. 10, 2010, entitled “ELECTRIC MOTOR AND BRAKE ASSEMBLY,” all of which are hereby incorporated by reference in their entirety. 
     U.S. patent application Ser. No. 13/168,262, filed Jun. 24, 2011, entitled “WHEELCHAIR,” is a continuation in part of U.S. Design Patent Application Serial No. 29/364,464, filed on Jun. 24, 2010, now U.S. Pat. No. D642,500, issued on Aug. 2, 2011, entitled “FRAME,” which is hereby incorporated by reference in its entirety. 
     U.S. patent application Ser. No. 13/168,262, filed Jun. 24, 2011, entitled “WHEELCHAIR,” is a continuation in part of U.S. Design Patent Application Serial No. 29/364,463, filed on Jun. 24, 2010, now U.S. Design Patent No. D642,499, issued on Aug. 2, 2011, entitled “WHEELCHAIR,” which is hereby incorporated by reference in its entirety. 
     U.S. patent application Ser. No. 13/168,262, filed Jun. 24, 2011, entitled “WHEELCHAIR,” is a continuation in part of U.S. Design Patent Application Serial No. 29/378,840, filed Nov. 10, 2010, now U.S. Design Patent No. D654,408, issued on Feb. 21, 2012, entitled “WHEELCHAIR FRAME,” which is hereby incorporated by reference in its entirety. 
     U.S. patent application Ser. No. 13/168,262, filed Jun. 24, 2011, entitled “WHEELCHAIR,” is a continuation in part of U.S. Design Patent Application Serial No. 29/378,841, filed on Nov. 10, 2010, now U.S. Design Patent No. D656,070, issued on Mar. 20, 2012, entitled “WHEELCHAIR SHROUD,” which is hereby incorporated by reference in its entirety. 
     U.S. patent application Ser. No. 13/168,262, filed Jun. 24, 2011, entitled “WHEELCHAIR,” is a continuation in part of U.S. Design Patent Application Serial No. 29/378,834, filed on Nov. 10, 2010, now abandoned, entitled “WHEELCHAIR SEATING SYSTEM”, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND  
     Wheelchairs and similar conveyances are an important means of transportation for a significant portion of society. Whether manual or powered, wheelchairs provide an important degree of independence for those they assist. Powered wheelchairs often have a seat coupled to a chassis. The chassis of the wheelchair may take a variety of forms. 
     SUMMARY  
     In one embodiment, the present application is directed to a conveyance such as a wheelchair that includes a seat assembly coupled to a chassis. The chassis includes a frame having a rear wheel support member, one or more front wheel support members extending in a forward direction from the rear wheel support member, and a seat support member. The rear wheel support member comprises a central portion and left and right portions extending downward from the central portion. The conveyance also includes one or more drive wheels for propulsion of the conveyance, a set of front wheels for supporting the conveyance, and a shrouding system for at least partially covering the frame and other components of the conveyance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which, together with a general description of the invention given above, and the detailed description given below, serve to example the principles of this invention. 
         FIG. 1A  is a partially exploded perspective view of one embodiment of a conveyance. 
         FIG. 1B  is a perspective view of one embodiment of the chassis of  FIG. 1A . 
         FIG. 1C  is a bottom plan view of one embodiment of the chassis of  FIG. 1A . 
         FIG. 2  is an exploded perspective view of one embodiment of the chassis of  FIG. 1A . 
         FIG. 3  is a perspective view of one embodiment of the frame of  FIG. 2 . 
         FIGS. 4A-4E  are perspective, top plan, side elevational, front elevational, and rear elevational views, respectively, of one embodiment of a frame. 
         FIGS. 5A and 5B  are perspective and rear elevational views of one embodiment of a frame having a battery support. 
         FIGS. 6A-6C  are perspective, front elevational, and rear elevational views of one embodiment of a battery support. 
         FIGS. 7 and 8  are side elevational and top plan views of one embodiment of a conveyance having an occupant seated therein. 
         FIG. 9  is a perspective view of another embodiment of a chassis. 
         FIGS. 10A-10C  are perspective, exploded perspective, and exploded side elevational views of one embodiment of a seat attachment assembly. 
         FIGS. 11A-11C  are perspective and cross-sectional views of one embodiment of a seat latch assembly. 
         FIG. 12  is a perspective view of one embodiment of a junction block. 
         FIG. 13A  is a perspective view of another embodiment of a chassis. 
         FIG. 13B  is a bottom plan view of one embodiment of the chassis of  FIG. 13A . 
         FIG. 14  is an exploded perspective view of one embodiment of the chassis of  FIG. 13A . 
         FIG. 15A  is a perspective view of one embodiment of the frame of  FIG. 14 . 
         FIGS. 15B and 15C  are perspective and cross-sectional views of one embodiment of a foot plate. 
         FIGS. 16A-16E  are perspective, top plan, side elevational, front elevational, and rear elevational views, respectively, of one embodiment of the frame of  FIG. 14 . 
         FIGS. 17A and 17B  are perspective and rear elevational views of one embodiment of a frame having a battery support. 
         FIGS. 18A-18C  are perspective, front elevational, and rear elevational views of one embodiment of a battery support. 
         FIG. 19A  is a perspective view of one embodiment of a drive wheel assembly. 
         FIG. 19B  is a side elevational view of one embodiment of a chassis shown with a drive wheel assembly removed. 
         FIG. 19C  is a rear elevational view of one embodiment of a chassis shown with a drive wheel assembly exploded from one side. 
         FIGS. 20A-20C  are perspective and rear views of one embodiment of a battery housing and frame. 
         FIGS. 21A and 21B  are perspective views of one embodiment of a top cover. 
         FIG. 21C  is a perspective view of one embodiment of a handle. 
         FIG. 22  is a rear perspective view of one embodiment of a frame having wires associated therewith. 
         FIGS. 23A and 23B  illustrate exemplary drive wheel assembly mounting configurations. 
         FIGS. 24A-24C  are perspective, top plan, and side elevational views, respectively, of another embodiment of a frame. 
         FIGS. 25A and 25B  are perspective views of another embodiment of a battery support. 
         FIG. 26  is a perspective view of an embodiment of a shrouding system. 
         FIGS. 27A and 27B  are perspective and top plan views, respectively, of one embodiment of a top shroud. 
         FIGS. 28A-28E  are cross-sectional views of one embodiment of the top shroud shown in  FIG. 27A . 
         FIGS. 29A and 29B  are perspective and top plan views, respectively, of one embodiment of a lower shroud. 
         FIGS. 30A-30D  are cross-sectional views of one embodiment of the lower shroud shown in  FIG. 29A . 
         FIGS. 31A-31C  are perspective, side elevational, and cross-sectional views, respectively, of one embodiment of a front shroud. 
         FIGS. 32A-32D  are perspective, side elevational, top plan, and front elevational views, respectively, of another embodiment of a frame. 
     
    
    
     DESCRIPTION OF EMBODIMENTS  
     As described herein, when one or more components are described as being connected, joined, affixed, coupled, attached, or otherwise interconnected, such interconnection may be direct as between the components or may be indirect such as through the use of one or more intermediary components. Also as described herein, reference to a “member,” “component,” or “portion” shall not be limited to a single structural member, component, or element but can include an assembly of components, members or elements. Furthermore, while the drawings are to relative scale, it is within the disclosure of thus specification to vary the relative size of components to one another. 
     In one embodiment, the present application is directed to a conveyance such as a wheelchair that includes a seat assembly and a chassis. The chassis comprises a frame that includes portions for connecting to or supporting any one or more of the following: front casters; a seat assembly; drive wheel assemblies; an energy source (e.g., batteries); rear anti-tip wheels; and a foot plate. Optional shrouding may also be supported on the frame or chassis. The frame structurally distributes the weight of the seat assembly (and optionally the weight of the energy source) to the supporting drive wheels and casters. Further, the drive wheels, caster supports, one or more anti-tip supports, and seat support of the wheelchair are all attached to a drive wheel support member of the frame. 
     In another embodiment, the present application is directed to a shrouding system for a conveyance such as a wheelchair. The shrouding system may include one or more components configured to cover the frame and other components of the conveyance. For example, the shrouding system may include a rear shroud, a top shroud, a front shroud, a left shroud, and a right shroud. The left shroud and the right shroud may form a lower shroud of the shrouding system. The rear shroud, top shroud, and front shroud may be configured to collectively cover a top and front of the frame and other components of the conveyance. Further, the lower shroud may be configured to cover the left and right sides, bottom, and rear of the frame and other components of the conveyance. The shrouding system may also includes openings to permit attachment of wheels, casters, and/or a seat assembly of the conveyance and may include raised and recessed portions and transitions there between acting to catch and focus light providing color tone (e.g., light to dark or vice-versa) to components made from a single color. 
     In another embodiment, the present application is directed to a frame for a conveyance such as a wheelchair. The frame includes a rear wheel support member, a left front wheel support member, and a right front wheel support member. The frame may also include a seat support member, a left rear mounting plate, a right rear mounting plate, and one or more cross members extending between the left and right front wheel support members. The left and right front wheel support members extend forward and downward from the rear wheel support member and then curve upward and outward to a distal end. The rear wheel support member curves upward when viewed from the front or rear and includes a substantially straight central portion at its apex. Left and right curved portions extend downward and away from the central portion of the rear wheel support in a rearward direction. 
     In yet another embodiment, the present application is directed to a wire routing system for a conveyance such as a wheelchair. A frame of the conveyance is configured such that the leads or wires emanating from a terminal or junction block are at least partially hidden and unexposed. The frame includes openings in a rear wheel support member for at least partially hiding one or more leads from the terminal to one or more drive wheels. The frame also includes access openings in the shroud and frame components for at least partially hiding one or more leads from the terminal to a joystick. A such, the frame with its entry and exit access opening or ports provides for one or more protected cable or wire runs or passageways within the wheelchair. 
     Illustrated in  FIG. 1A  is a partially exploded perspective view of one embodiment of a conveyance such as a wheelchair  100 . Wheelchair  100  includes a seat assembly  102  and a chassis  112 . As shown, seat assembly  102  is removable from chassis  112 . Seat assembly  102  includes a back portion  104 , a seat portion  106 , and two armrest assemblies  108  and  110 . Back portion  104  and seat portion  106  are constructed in such a manner so as to allow the angle there between to be adjusted and to also allow for folding of these components together to facilitate disassembly and transportation of wheelchair  100 . A joystick  124  is also provided to allow a user to control the drive system of wheelchair  100 . 
     Illustrated in  FIGS. 1B and 1C  are perspective and bottom plan views of chassis  112 . Chassis  112  includes drive wheels  114  and  116  connected thereto for propulsion of wheelchair  100 . Drive wheels  114  and  116  may be driven by a plurality of types of drive assemblies including, for example, electric motor and gear combinations or gearless brushless motors such as wheel hub motors. Casters  118  and  120  are also connected to chassis  112  for providing forward support of wheelchair  100 . A foot plate  122  having an opening  130  is connected to the front portion of chassis  112  to support the feet of a user. Foot plate  122  is pivotally attached to a foot plate mounting member  262  ( FIGS. 2 and 3 ) by use of a fastener through appropriately aligned apertures in the foot plate and the foot plate mounting member. In other embodiments, footrests such as left and right swing away footrests may be used. 
     Illustrated in  FIG. 2  is an exploded perspective view of chassis  112 . Chassis  112  includes several components for supporting and driving wheelchair  100  and its occupant. Chassis  112  includes a frame  202  disposed substantially about a centerline C L  of wheelchair  100  ( FIGS. 1C and 4B ; centerline C L  represents the centerline of both chassis  112  and wheelchair  100 ). As shown, frame  202  includes central member  280 , two caster support members  204  and  206 , two axle support members  208  and  210 , one or more anti-tip support members  214  and  215 , and a seat support member  216 . 
     Caster support members  204  and  206  emanate forward from central member  280  and provide for mounting of casters  118  and  120 . As shown, casters  118  and  120  each comprise a single fork to support the caster wheel on one side. Axle support members  208  and  210  emanate outwardly and in a slightly rearward direction from central member  280  and provide for mounting of drive wheels  114  and  116 . Axle support members  208  and  210  may be extensions or portions of central member  280 . In this particular embodiment, drive wheels  114  and  116  are of a wheel hub motor design having the drive motors incorporated into the hub of the wheels. Hub motors permit the use of smaller batteries and eliminate the need for a gearbox such that the drive assembly of the wheelchair requires less space in chassis  112 . However, as described above, other types of drive assemblies may be used. 
     One or more anti-tip support members  214  and  215  emanate rearward from central member  280  and provide for mounting of one or more anti-tip wheels or casters  222  and  224 . Seat support member  216  is disposed proximate central member  280  and provides for mounting of seat assembly  102  to chassis  112 . Seat support member  216  is configured to receive a seat support  264  therein for adjusting and fixing the floor-to-seat height of the wheelchair. Although not shown in  FIG. 2 , seat assembly  102  may be attached, either directly or indirectly, to seat support  264  in a wide variety of different manners. For example, seat support  264  may have a plate affixed thereto for connection to seat assembly  102 . One exemplary embodiment of a seat attachment assembly is shown in  FIGS. 10A-10C  and described below. Any manner of connecting the seat assembly to the chassis  112  may be employed. 
     In one embodiment, chassis  112  includes a battery support tray  212  disposed between caster support members  204  and  206  of frame  202 . In this particular embodiment, battery support tray  212  is configured to receive a removable housing  240  designed to hold one or more batteries  218  and  220 , which are the energy source of wheelchair  100 . In another embodiment (not shown), battery support tray  212  is configured to hold one or more batteries  218  and  220  without the use of housing  240 . One or more electrical connectors  260  for connecting one or more batteries  218  and  220  to the electrical system of the wheelchair may also be coupled to frame  202  or battery support tray  212 . Further, battery support tray  212  or removable housing  240  may include a resettable fuse for one or more batteries  218  and  220 . 
     A junction block may also be coupled to frame  202  to permit electrical connection of various components of the wheelchair. The junction block can take a wide variety of different forms. Illustrated in  FIG. 12  is a perspective view of junction block  258  of chassis  112 . In the illustrated embodiment, junction block  258  is an overmolded board with four leads, or wires, extending therefrom for connection to various wheelchair components. More specifically, leads  1206  and  1210  extend from junction block  258  and connect to drive wheels  114  and  116 , lead  1208  extends from the junction block and connects to one or more batteries  218  and  220  via one or more electrical connectors  260 , and lead  1212  extends from the junction block and connects to joystick  124 . In other embodiments, the junction block may include terminals, or connections, for coupling leads from various components of the wheelchair. For example, the junction block may include four terminals for connecting two leads from drive wheels  114  and  116 , one lead from one or more batteries  218  and  220 , and one lead from joystick  124 . 
     The leads or wires emanating from junction block  258  may be hidden. For example, leads  1206  and  1210  ( FIG. 12 ) may be routed through an opening  480  ( FIG. 4E ) in the bottom portion of central member  280 , through the central member and axle support members  208  and  210  ( FIGS. 2 and 4E ), and out the distal end of the axle support members to connect to drive wheels  114  and  116  ( FIG. 2 ). Leads  1206  and  1210  are not shown in  FIGS. 2 and 4E  to simplify the drawings. Lead  1208  ( FIG. 12 ) may extend from junction block  258  and connect to electrical connector  260  ( FIG. 2 ) attached to connector mounting bracket  408  ( FIG. 5B ). Further, lead  1212  ( FIG. 12 ) may extend from junction block  258  and out the top of a rear shroud  252  ( FIG. 2 ) of chassis  112  for connection to a lead from joystick  124  ( FIG. 1A ) when seat assembly  102  is mounted to the chassis. 
     Although not shown in  FIG. 2 , junction block  258  may be coupled to a member of frame  202  by various methods, such as with a bracket, fastener, weldment, adhesive, etc. As shown in  FIG. 12 , junction block  258  includes an arcuate portion  1204  such that the junction block can fit around a member of frame  202  (e.g., support member  404  shown in  FIGS. 4B and 4C ). Apertures  1202  permit attachment of a fastener and/or bracket such that junction block  258  may be coupled to one or more members of frame  202 . 
     Chassis  112  also includes shrouding coupled to frame  202 . As shown in  FIGS. 1A and 1B , the shrouding of chassis  112  at least partially encompasses frame  202 . Referring to  FIG. 2 , chassis  112  includes a front shroud  250 , rear shroud  252 , two side shrouds  246  and  248 , and two drive wheel fenders  254  and  256  coupled to frame  202 . Also, a top shroud or cover  242  is removably attached to battery housing  240 . In combination, the various shroud components form an elliptical or egg shaped shrouding that at least partially covers the top, front, sides, and rear of frame  202 . However, other embodiments of shrouds may also be employed or even no shroud. Further, the shrouding of chassis  112  may include more or less shroud components. As shown in  FIGS. 1A-1C , the visible frame components that extend outside of the shroud components are tubular in form 
     Top cover  242  includes a handle  244  and is configured to be attached to battery housing  240  such that the top cover and the housing can be removed from the wheelchair as a single unit, e.g., to service and/or charge one or more batteries  218  and  220 . In another embodiment (not shown), top cover  242  is attached to battery housing  240  such that the top cover may be removed from, or manipulated relative to, the housing to expose one or more batteries  218  and  220  contained within the housing. A latch type mechanism may also be used to lock battery housing  240  and top cover  242  in place relative to frame  202 . For example, handle  244  may include a button or latch type mechanism that, when manipulated, will unlock battery housing  240  and/or top cover  242  from frame  202  (e.g., seat support member  216 ). 
     As illustrated in  FIG. 1C , the bottom of battery support tray  212  extends below the bottom of side shrouds  246  and  248 . As such, battery support tray  212  acts a skid plate to protect side shrouds  246  and  248  from damage due to various objects (e.g., curbs, ramps, bumps, rocks, etc.) that may contact the bottom of the chassis  112  during transport. 
       FIG. 3  is a perspective view of frame  202  illustrating the connection between seat support  264  and the frame. Seat support member  216  of frame  202  includes a receiving portion  324  having one or more apertures therein. Receiving portion  324  telescopically receives seat support  264  therein for adjusting and fixing the floor-to-seat height of the wheelchair. The floor to seat height of the wheelchair is adjusted and fixed through the use of a plurality of apertures  320  in seat support  264 , which are aligned with the apertures in receiving portion  324 . A suitable fastener is then used through the appropriately aligned apertures to fix or maintain the relative position of seat support  264  and receiving portion  324 . The fastener may be of an easily removable type not requiring the use of tools. 
       FIG. 3  also illustrates the connection between foot plate mounting member  262  of foot plate  122  and frame  202 . A foot plate support member  330  of frame  202  includes a receiving portion  302  having one or more apertures therein. Receiving portion  302  telescopically receives foot plate mounting member  262  therein for adjusting and fixing the foot plate of the wheelchair. Foot plate  122  ( FIG. 2 ) is adjusted and fixed through the use of one or more apertures  306  in foot plate mounting member  262 , which are aligned with the one or more apertures in receiving portion  302 . A suitable fastener is then used through the appropriately aligned apertures to fix or maintain the relative position of foot plate mounting member  262  and receiving portion  302 . The fastener may be of an easily removable type not requiring the use of tools. 
     Further, as illustrated in  FIGS. 2 and 3 , the chassis  112  is configured such that battery support tray  212  is disposed forward of seat support member  216 . As shown, battery support tray  212  is disposed between caster support members  204  and  206  and forward of seat support member  216  such that one or more batteries  218  and  220  may be removed or installed towards the front of the wheelchair. 
       FIGS. 4A-4E  illustrate various views of frame  202 . Although frame  202  is described herein as having multiple members or components, the frame may be fabricated as a single component or formed from any number of components integrally fabricated, joined, or fixed together. For example, in one embodiment, frame  202  is fabricated from multiple components made of metal and/or composite material that, when joined or fixed together, form the frame of the conveyance. In another embodiment, frame  202  is a single fabricated component made of metal and/or composite material. Also, various members or components of frame  202  may be a larger size or diameter than other members or components of the frame. For example, in one embodiment, central member  280  may be a larger size or diameter than caster support members  204  and  206 , axle support members  208  and  210 , and anti-tip support members  214  and  215 . In other embodiments, these members can be all of the same size or different sizes so long as the proper load-bearing requirements are met. Further, frame  202  is shown with arcuate members or components forming the frame. In other embodiments, straight members or components may be arranged at various angles to form the shape of the frame. 
     As shown in  FIGS. 4A-4E , frame  202  includes central member  280 , caster support members  204  and  206 , axle support members  208  and  210 , anti-tip support members  214  and  215 , and seat support member  216 . Caster support members  204  and  206 , axle support members  208  and  210 , and anti-tip support members  214  and  215  extend from central member  280  in various directions. Thus, in this particular embodiment, frame  202  resembles a spider-like arrangement in that its members emanate from an intermediate or central portion of the frame. Further, frame  202  may be described as an “H” shaped box frame in that axle support members  208  and  210  and central member  280  form one side of the “H” and the front portions of caster support members  204  and  206  form the other side of the “H”. The box shape of frame  202  includes the area between caster support members  204  and  206 , a cross member  406 , and central member  280 . 
       FIG. 4B  illustrates a top plan view of frame  202 . As shown in  FIG. 4B , frame  202  is disposed substantially about centerline C L , which represents the centerline of chassis  112  and wheelchair  100  ( FIG. 1C ). In particular, central member  280 , caster support members  204  and  206 , axle support members  208  and  210 , and anti-tip support members  214  and  215  are all symmetrically disposed about centerline C L . As such, in this embodiment, each of these members possess a geometry on one side of the centerline C L  that is a mirror image of the geometry on the other side of the centerline C L . 
       FIGS. 4A-4E  illustrate the geometry of axle support members  208  and  210  in this embodiment. Axle support members  208  and  210  emanate from central member  280  and extend downwardly and away therefrom. In this particular embodiment, axle support members  208  and  210  extend in a rearward direction of the chassis. These members also collectively form a “U” or “V” shape extending away from central member  280 . Central member  280  and axle support members  208  and  210  collectively form a drive wheel support member of frame  202 . 
     Furthermore, each axle support member includes a flange  440  and  442  disposed proximate the distal portion of the axle support member and having one or more apertures therein for mounting drive wheels  114  and  116 . Various shapes and sizes of apertures may be used depending at least on the size and type of drive assembly. 
     Other geometric configurations for axle support members  208  and  210  include members having only upwardly or downwardly arcuate portions or only linear portions extending from central member  280  and members having various combinations of arcuate portions and linear portions extending from central member  280 . Other geometries are also possible. While axle support members  208  and  210  are shown emanating from central member  280  in a manner providing a rear wheel drive configuration for wheelchair  100 , axle support members  208  and  210  can be disposed more forward of their current positions so as to provide a mid-wheel drive configuration or even a front wheel drive configuration. 
       FIGS. 4A-4E  also illustrate the geometry of caster support members  204  and  206 . In this embodiment, each caster support member extends in an arcuate manner and in the forward direction of the chassis. More specifically, each caster support member extends downward and away from central member  280  and centerline C L , curves to become substantially parallel to the centerline, continues to extend downward while remaining substantially parallel to the centerline, then curves upward and away from the centerline to a distal end for attachment of casters  118  and  120 . Thus, each caster support member emanates forward and away from central member  280  to form an “S” shape. Other geometric configurations for caster support members  204  and  206  include members having only upwardly or downwardly arcuate portions or only linear portions extending from central member  280  and members having various combinations of arcuate portions and linear portions extending from central member  280 . Other geometries are also possible. 
     In the embodiment illustrated in  FIGS. 4A-4E , cross member  406  extends between the front portion of caster support members  204  and  206 . Attached to cross member  406  is foot plate support member  330  having receiving portion  302  that telescopically receives foot plate mounting member  262  therein. As shown, cross member  406  is arcuate and forms a generally “U” shape with foot plate support member  330  attached proximate the bottom of the “U”. However, other geometric configurations of cross member  406  are possible, such as a straight member or a member forming a generally “V” shape. 
       FIGS. 4A-4E  also illustrate the geometry of anti-tip support members  214  and  215 . In this embodiment, anti-tip support members  214  and  215  emanate from central member  280  and extend downward and away therefrom. Apertures are located in the distal ends of anti-tip support members  214  and  215  for attachment of anti-tip wheels or casters  222  and  224 . As shown, the distal end of anti-tip support members  214  and  215  projects beyond the rearward most portion of frame  202 . However, this need not be the case. Collectively, anti-tip support members  214  and  215  form a generally inverted “V” or “U” shape having arcuate segments, though linear and a combination of arcuate and linear segments may also be used in the construction of the shapes. 
       FIGS. 4A-4E  illustrate seat support member  216  of frame  202 . In this embodiment, seat support member  216  is attached to central member  280  by a first support member  404  and to caster support members  204  and  206  by a second support member  420  and a third support member  422 , respectively. The support members  404 ,  420 , and  422  hold the seat support member  216  in an upright and vertical position such that receiving portion  324  may telescopically receive seat support  264  therein. However, more or less support members may be used to hold seat support member  216  in position, In some embodiments, seat support member  216  may be angled relative to the floor and not substantially vertical. Further, in the embodiment illustrated in  FIGS. 4A-4E , a flange  410  is attached to the distal end of seat support member  216 . Attached to flange  410  is a connector mounting bracket  408  and a battery tray mounting bracket  412 . These mounting brackets are described below relative to battery support tray  212 . 
     In the embodiment illustrated in  FIGS. 4A-4E , a rear handle  402  extends rearward from seat support member  216  to provide a gripping point for the user to lift chassis  112 , which is further discussed below in relation to  FIG. 9 . Rear handle  402  may also be used to support rear shroud  252  ( FIG. 2 ). As shown, rear handle  402  includes arcuate and linear portions, forming an “O” shape with the ends of the member attaching to seat support member  216 . However, other geometric configurations of rear handle  402  are possible, such as one or more straight members, arcuate members, or plates extending from seat support member  216 . Rear handle  402  may also extend from other members or components of frame  202 , e.g., extending upward and/or rearward from central member  280 , one or more anti-tip support members  214  and  215 , and/or axle support members  208  and  210 . 
       FIGS. 5A and 5B  illustrate battery support tray  212  attached to frame  202 . In this embodiment, battery support tray  212  is disposed between caster support members  204  and  206 , seat support member  216 , and cross member  406 . Tabs  504  and  506  of battery support tray  212  are configured to rest on caster support members  204  and  206 , respectively, to support two side walls of the tray. Further, tabs  508  and  510  of battery support tray  212  are configured to rest on cross member  406  to support the front wall of the tray. In other embodiments, more or less tabs may be used to support battery support tray  212 . Further, the tabs may be attached to frame  202 , such as with weldments, adhesives, and/or fasteners. 
     As shown in  FIG. 5B , one or more locating pins or fasteners  520  are used to locate battery support tray  212  relative to frame  202  and/or attach the battery support tray to battery tray mounting bracket  412 . However, battery support tray  212  can be, but does not necessarily have to be, attached to one or more of the aforementioned portions of frame  202 . Other configurations of supporting and attaching battery support tray  212  to frame  202  are possible. Attachment may be by any suitable means, including weldments, adhesives, and/or fasteners. For example, in one embodiment, battery support tray  212  is welded to caster support members  204  and  206 , seat support member  216 , cross member  406 , and battery tray mounting bracket  412 . Welding battery support tray  212  to frame  202  increases the rigidity of the frame and helps to distribute the weight associated with seat assembly  102  ( FIG. 1A ) and the energy source (one or more batteries  218  and  220 ;  FIG. 2 ) to the drive wheels and casters. 
       FIGS. 5A and 5B  also illustrate a seat support member opening  512  and a connector opening  514  of battery support tray  212 . As shown, seat support member opening  512  is a vertical slot extending downward from an upper edge of the rear wall of battery support tray  212 . Seat support member opening  512  provides clearance for battery support tray  212  to be disposed within frame  202 . Further, battery support tray  212  may be welded to seat support member  216  along one or more edges of seat support member opening  512 . However, other geometric configurations of battery support tray  212  are possible, such as removing all or a portion of the rear wall or fabricating the rear wall to fit around seat support member  216 . 
     As shown in  FIG. 5B , connector opening  514  provides clearance for one or more electrical connectors attached to connector mounting bracket  408 . in some embodiments, connector mounting bracket  408  may be configured to “cushion” the electrical connection and reduce the amount of stress on the connection. For example, a spring and/or elastomeric material may be used to allow the connector mounting bracket  408  to flex relative to frame  202 , for example during connection or disconnection of the electrical component or during use of the wheelchair. 
     As shown in  FIGS. 5A and 5B , frame  202  structurally distributes the weight associated with seat assembly  102  ( FIG. 1A ) and the energy source (one or more batteries  218  and  220  supported by battery support tray  212 ; FIG.  2 ) to the drive wheels and casters through axle support members  208  and  210  and caster support members  204  and  206 , respectively. 
       FIGS. 6A-6C  illustrate the geometry of battery support tray  212  in this embodiment. As shown, battery support tray  212  includes a planar bottom, a front wall, a rear wall, and two side walls. The front wall of battery support tray  212  includes tabs  508  and  510  and a foot plate opening  602  to provide clearance for the foot plate support member and foot plate mounting member. The rear wall of battery support tray  212  includes one or more apertures  604  for receipt of one or more locating pins or fasteners  520  ( FIG. 5B ), seat support member opening  512 , and connector opening  514 . The side walls of battery support tray  212  include tabs  504  and  506 . 
     Referring now to  FIGS. 7 and 8 , side elevational and top plan views of wheelchair  100  are shown having an occupant  700  seated therein. The position of occupant  700  can be adjusted by, for example, lateral and/or angular movement of back portion  104  relative to seat portion  106 , or lateral movement of the seat portion relative to chassis  112 . In one embodiment, the position of occupant  700  is configured such that the occupant&#39;s center of perception  704  is substantially aligned with a vertical plane  702  extending between or through the axles of drive wheels  114  and  116 . In other embodiments, the occupant&#39;s center of perception  704  can be placed proximate to vertical plane  702 , either slightly forward or rearward thereof. 
     Referring now to  FIG. 9 , a perspective view of chassis  112  is shown having foot plate  122  rotated upward. Foot plate  122  may be attached to foot plate mounting member  262  by various suitable means that permit the foot plate to pivot relative to the foot plate mounting member, such as with a fastener or hinge. Further, foot plate  122  may include various means to fix the foot plate in an upright or other position, such as with a friction pivot, latch, or pin. Opening  130  of foot plate  122  provides a handle for a user to grasp and lift the front portion of chassis  112 . With foot plate  122  in the upright position, opening  130  is conveniently located for the user to grasp and is at the substantially same height as rear handle  402 . A user may lift chassis  112  by grasping opening  130  with one hand and rear handle  402  with the other hand, for example to lift the chassis for transport in an automobile. Further, the rear shroud of chassis  112  may be configured for the user to grasp rear handle  402 . As shown, rear shroud  952  does not extend to the distal portion of rear handle  402  to provide room for a user to grasp the rear handle. However, many other configurations are possible, such as a rear shroud with an opening for the user&#39;s hand. 
     Referring now to  FIGS. 10A-10C , a perspective view, exploded perspective view, and exploded side elevational view of a seat attachment assembly  1000  is shown. Seat attachment assembly  1000  includes an attachment plate  1004  ( FIGS. 10B and 10C ), a seat plate  1002 , and seat support  264 . Attachment plate  1004  is configured to be attached to an end of seat support  264 . Attachment plate  1004  may be attached to seat support  264  by various means, such as with a weldment, adhesive, or fastener. In some embodiments, attachment plate  1004  may be integrally fabricated with seat support  264 . Further, seat plate  1002  is configured to be attached to, or integrally fabricated with, seat assembly  102 . 
     Attachment plate  1004  includes two sets of bosses  1008  and  1010  extending outward from attachment plate  1004 , each set having bosses extending from opposite sides of the plate. As shown in  FIG. 10B , each set of bosses  1008  and  1010  includes two ends of a pin extending between two flanges of attachment plate  1004 . However, other configurations are possible, e.g., fasteners extending from each side of the plate, bosses integrally fabricated with the plate, etc. 
     Seat plate  1002  includes two sets of slots or openings  1006  and  1012  disposed on either side of the seat plate. Slots  1006  extend vertically upward from the bottom of two flanges of seat plate  1002 . As shown, slots  1006  are configured to mate with bosses  1008  of attachment plate  1004 . Slots  1012  extend upward at an angle from the bottom of the two flanges of seat plate  1002 . As shown, slots  1012  are configured to mate with bosses  1010  of attachment plate  1004 . 
     Seat plate  1002  is configured to be removably coupled to attachment plate  1004 . The connection between seat plate  1002  and attachment plate  1004  permits repeated attachment and removal of seat assembly  102  with chassis  112 . For example, a first end of seat plate  1002  having slots  1006  may be rotated upward to permit alignment of slots  1012  with bosses  1010  of attachment plate  1004 . In this position, slots  1012  may be slid over bosses  1010 . The first end of seat plate  1002  may then be rotated downward such that slots  1006  are slid over bosses  1008  of attachment plate  1004 . In this configuration, seat plate  1002  is attached to attachment plate  1004 . 
     Seat attachment assembly  1000  may also include a seat latch assembly to prohibit movement of seat plate  1002  relative to attachment plate  1004 . The latch assembly may be releasable to permit repeated attachment and removal of seat plate  1002  with attachment plate  1004 , and thus repeated attachment and removal of seat assembly  102  with chassis  112 . Many configurations of the seat latch assembly are possible. For example, a seat latch assembly  1100  for seat attachment assembly  1000  is shown in  FIGS. 11A-11C . Seat latch assembly  1100  includes a housing  1102 , latch member  1104 , shaft  1106 , and biasing mechanism  1120 . 
       FIGS. 11A and 11B  are bottom perspective views of seat attachment assembly  1000  (seat support  264  is removed) having seat latch assembly  1100  attached to the bottom of seat plate  1002 . In  FIG. 11A , latch member  1104  of seat latch assembly  1100  is in a retracted or unlocked position and does not engage attachment plate  1004 . In  FIG. 11B , latch member  1104  is in an extended or locked position and does engage attachment plate  1004  to prohibit movement of seat plate  1002  relative to the attachment plate. 
       FIG. 11C  is a side elevational cross-sectional view of latch assembly  1100  with latch member  1104  in the extended or locked position. As shown, biasing mechanism  1120  biases latch member  1104  into the extended position such that the notched tip of the latch member engages the edge of attachment plate  1004 . In this position, seat plate  1002  is prohibited from rotating upward relative to attachment plate  1004 . Seat plate  1002  may be released and permitted to rotate upward relative to attachment plate  1004  by forcing latch member  1104  away from the attachment plate and into the retracted or unlocked position. This may be accomplished by pulling back on shaft  1106  and compressing biasing mechanism  1120 . As shown, biasing mechanism  1120  is a spring. However, other biasing mechanisms may be used with latch assembly  1100 , such as an elastomeric material or compressible fluid. In some embodiments, no biasing mechanism is used, e.g., the latch member may be fixed in the extended and/or retracted position with the use of pin or other fastener. 
     Other configurations of seat latch assemblies are possible. For example, a removable pin or plate structure may be used to hold bosses  1008  of attachment plate  1004  within slots  1006  of seat plate  1002  to prohibit upward rotation of the seat plate relative to the attachment plate. Further, seat plate  1002  may be coupled to attachment plate  1004 , e.g., with a removable clip or other fastener, to prohibit movement of the seat plate relative to the attachment plate. 
     Illustrated in  FIGS. 13A and 13B  are perspective and bottom plan views of an exemplary chassis  1312  of a wheelchair. Chassis  1312  includes drive wheels  1314  and  1316  connected thereto for propulsion of the wheelchair. Drive wheels  1314  and  1316  may be driven by a plurality of types of drive assemblies including, for example, electric motor and gear combinations or gearless brushless motors such as wheel hub motors. Casters  1318  and  1320  are also connected to chassis  1312  for providing forward support of the wheelchair. A foot plate  1322  having an opening  1330  is connected to the front portion of chassis  1312  to support the feet of a user. Foot plate  1322  is pivotally attached to a foot plate mounting member  1462  ( FIGS. 14 and 15 ) by use of a fastener through appropriately aligned apertures in the foot plate and the foot plate mounting member. 
     Illustrated in  FIG. 14  is an exploded perspective view of chassis  1312 . Chassis  1312  includes several components for supporting and driving the wheelchair and its occupant. Chassis  1312  includes a frame  1402  disposed substantially about a centerline C L  of the wheelchair ( FIGS. 13B and 16B ; centerline C L  represents the centerline of both chassis  1312  and the wheelchair). As shown, frame  1402  includes central member  1480 , two caster support members  1404  and  1406 , two axle support members  1408  and  1410 , one or more anti-tip support members  1414  and  1415 , a seat support member  1416 , and a rear handle support member  1470 . In other embodiments, one or more of these members may be omitted. 
     Caster support members  1404  and  1406  emanate forward from axle support members  1408  and  1410 , respectively, and provide for mounting of casters  1318  and  1320 . As shown, casters  1318  and  1320  each comprise a double fork to support the caster wheel on both sides. Axle support members  1408  and  1410  emanate outwardly and in a slightly rearward direction from central member  1480  and provide for mounting of drive wheels  1314  and  1316 . In this particular embodiment, drive wheels  1314  and  1316  are of a wheel hub motor design having the drive motors incorporated into the hub of the wheels. However, as described above, other types of drive assemblies may be used. 
     One or more anti-tip support members  1414  and  1415  emanate rearward from axle support members  1410  and  1408 , respectively, and provide for mounting of one or more anti-tip wheels or casters  1422  and  1424 . Seat support member  1416  is disposed proximate central member  1480  and provides for mounting of a seat assembly to chassis  1312 . Seat support member  1416  is configured to receive a seat support therein for adjusting and fixing the floor-to-seat height of the wheelchair. 
     Rear handle support member  1470  emanates rearward from central member  1480  and axle support members  1408  and  1410 . As shown, rear handle support member  1470  is a plate configured to support a rear shroud  1452  having a handle. Rear handle support member  1470  comprises an opening to permit the user to grasp the handle of rear shroud  1452 . As shown, rear handle support member  1470  and rear shroud  1452  combine to form a rear handle of the wheelchair. However, in other embodiments, only one member may be used to form a rear handle of the wheelchair. 
     Chassis  1312  includes a battery support tray  1412  disposed between caster support members  1404  and  1406  of frame  1402 . In this particular embodiment, battery support tray  1412  is configured to receive a removable battery housing  1440  designed to hold one or more batteries  1418  and  1420 , which are the energy source of the wheelchair. A junction block  1458  may be coupled to frame  1402  to permit electrical connection of various components of the wheelchair, Further, removable housing  1440  may include a resettable fuse or breaker  1490  for one or more batteries  1418  and  1420 . 
     Electrical connectors  1460 A and  1460 B for connecting one or more batteries  1418  and  1420  to the electrical system of the wheelchair may be coupled to chassis  1312 , such as to frame  1402 , battery support tray  1412 , or removable housing  1440 . For example, as shown in  FIGS. 20B and 20C , electrical connector  1460 A is attached to removable housing  1440  and mating electrical connector  1460 B is attached to a connector mounting bracket  1608  of frame  1402 . Electrical connectors  1460 A and  1460 B may be positioned such that they are substantially aligned for connection or disconnection when removable housing  1440  is inserted into and removed from battery support tray  1412 .  FIGS. 20A and 20B  illustrate the insertion and removal of removable housing  1440  relative to battery support tray  1412 . As shown in  FIG. 20B , removable housing  1440  includes a recessed area  2020  that provides clearance for the connection or disconnection of electrical connectors  1460 A and  1460 B. Further, a connector opening  1714  of battery support tray  1412  provides clearance for at least electrical connector  1460 B attached to connector mounting bracket  1608 .  FIG. 20C  illustrates removable housing  1440  inserted into battery support tray  1412  and electrical connectors  1460 A and  1460 B connected together such that batteries  1418  and  1420  are connected to the electrical system of the wheelchair. 
     Chassis  1312  also includes shrouding coupled to frame  1402 . As shown in  FIGS. 13A and 13B , the shrouding of chassis  1312  at least partially encompasses frame  1402 . Referring to  FIG. 14 , chassis  1312  includes a front shroud  1450 , rear shroud  1452 , two side shrouds  1446  and  1448 , and two drive wheel fenders  1454  and  1456  coupled to frame  1402 . Also, a top shroud or cover  1442  is removably attached to battery housing  1440 . However, other embodiments of shrouds may be employed or even no shroud. The shrouding of chassis  1312  may also include more or less shroud components. For example, in one embodiment, each side shroud  1446  and  1448  comprises more than one shroud component, a first component including the side and rear vertical portions of the side shroud and a second component including the rear horizontal portion of the side shroud positioned below rear handle support member  1470 . 
     As illustrated in  FIG. 13B , the bottom of battery support tray  1412  extends below the bottom of side shrouds  1446  and  1448 . As such, battery support tray  1412  acts a skid plate to protect side shrouds  1446  and  1448  from damage due to various objects (e.g., curbs, ramps, bumps, rocks, etc.) that may contact the bottom of the chassis  1312  during transport. 
     As shown in  FIGS. 13A and 14 , each drive wheel fender  1454  and  1456  comprises an opening (see opening  1482  for drive wheel fender  1456  in  FIG. 14 ) that provides access to a brake release lever  1486  and  1484  of drive wheel  1314  and  1316 , respectively. Attached to an end of each brake release lever  1486  and  1484  is a handle  1478  and  1476  that is partially exposed through the opening in drive wheel fender  1454  and  1456 . The user may move handle  1478  and  1476  of brake release lever  1486  and  1484  forward and backward to selectively engage and disengage the brakes of drive wheels  1314  and  1316 . Drive wheels  1314  and  1316  and/or brake release levers  1486  and  1484  may be configured or arranged such that the user can move the handles in the same direction (e.g., both forward or both backward) to selectively engage and disengage the brakes of the drive wheels. In other embodiments, the brake release levers, handles, and/or openings in the drive wheel fenders may be a variety of different shapes and sizes. 
     Top cover  1442  includes a handle  1444  and is configured to be attached to battery housing  1440  such that the top cover and the housing can be removed from the wheelchair as a single unit, e.g., to service and/or charge one or more batteries  1418  and  1420 . A locking assembly  1472  is attached to handle  1444  to selectively lock and unlock top cover  1442  and removable housing  1440  in place relative to frame  1402 . As shown, locking assembly  1472  is spring biased toward a locked position such that when manipulated, the locking assembly will unlock top cover  1442  from seat support member  1416  of frame  1402  (See  FIGS. 21A-21C ). In another embodiment, the top cover may be removed, leaving the battery compartment in place. 
       FIGS. 15A-15C  illustrate the connection between foot plate mounting member  1462  of foot plate  1322  and frame  1402 . As shown, foot plate mounting member  1462  comprises a horizontal portion  1508  and a vertical portion  1510 . A foot plate support member  1530  of frame  1402  includes a receiving portion  1502  having one or more apertures  1504  therein. Receiving portion  1502  telescopically receives horizontal portion  1508  of foot plate mounting member  1462  therein for adjusting and fixing the horizontal position of foot plate  1322  relative to frame  1402  of the wheelchair. Foot plate  1322  is adjusted and fixed through the use of one or more apertures  1506  in foot plate mounting member  1462 , which are aligned with one or more apertures  1504  in receiving portion  1502 . A suitable fastener is then used through the appropriately aligned apertures to fix or maintain foot plate mounting member  1462  in position relative to receiving portion  1502 . The fastener may be of an easily removable type not requiring the use of tools. 
     As illustrated in  FIG. 15B , the vertical position of foot plate  1322  relative to foot plate mounting member  1462  may be adjusted and fixed through the use of one or more apertures in the foot plate, which are aligned with one or more apertures  1512  in vertical portion  1510  of the foot plate mounting member. A suitable fastener is then used through the appropriately aligned apertures to fix or maintain foot plate  1322  in position relative to foot plate mounting member  1462 . The fastener may be of an easily removable type not requiring the use of tools. 
     Further, the connection between foot plate  1322  and foot plate mounting member  1462  permits the foot plate to rotate or pivot relative to the foot plate mounting member, e.g., from a lowered position (shown in  FIGS. 15B-15C ) to an upright or other position. Opening  1330  of foot plate  1322  provides a handle for a user to grasp and lift the front portion of chassis  1312 . With foot plate  1322  in the upright position, opening  1330  is conveniently located for the user to grasp, for example to lift chassis  1312  for transport in an automobile. Foot plate  1322  and/or foot plate mounting member  1462  may include various means to fix the foot plate in the lowered, upright or other position, such as with a friction pivot, latch, or pin. 
       FIG. 15C  is a cross-sectional view taken along line  15 C- 15 C in  FIG. 15B . As shown, foot plate  1322  includes a stop  1514  that engages vertical portion  1510  of foot plate mounting member  1462  in the lowered position. Stop  1514  may be adjustable such that the position of foot plate  1322  relative to foot plate mounting member  1462  can be altered based on the preferences of the user. For example, stop  1514  may be extended or retracted relative to foot plate  1322  such that the footplate is positioned slightly upward or downward, respectively, when the footplate is in the lowered position. Stop  1514  may be a variety of shapes and sizes. Further, various methods may be employed to adjust stop  1514  relative to foot plate  1322 . For example, stop  1514  may be adjusted relative to foot plate  1322  through the use of a threaded fastener or a pin aligned with one or more apertures in the foot plate. 
     Further, as illustrated in  FIGS. 14 and 15A , the chassis  1312  is configured such that battery support tray  1412  is disposed forward of seat support member  1416 . As shown, battery support tray  1412  is disposed between caster support members  1404  and  1406  and forward of seat support member  1416  such that one or more batteries  1418  and  1420  may be removed or installed towards the front of the wheelchair. 
       FIGS. 16A-16E  illustrate various views of frame  1402 . As shown, frame  1402  includes central member  1480 , caster support members  1404  and  1406 , axle support members  1408  and  1410 , anti-tip support members  1414  and  1415 , seat support member  1416 , and rear handle support member  1470 . One or more of these members can be omitted in other embodiments. 
       FIG. 16B  illustrates a top plan view of frame  1402 . As shown in  FIG. 16B , frame  1402  is disposed substantially about centerline C L , which represents the centerline of chassis  1312  and the wheelchair ( FIG. 13B ). In particular, central member  1480 , caster support members  1404  and  1406 , axle support members  1408  and  1410 , anti-tip support members  1414  and  1415 , and rear handle support member  1470  are all symmetrically disposed about centerline C L . As such, in this embodiment, each of these members possess a geometry on one side of the centerline C L  that is a mirror image of the geometry on the other side of the centerline C L . 
       FIGS. 16A-16E  illustrate the geometry of axle support members  1408  and  1410  in this embodiment. Axle support members  1408  and  1410  emanate from central member  1480  and extend downwardly and away therefrom. In this particular embodiment, axle support members  1408  and  1410  extend in a rearward direction of the chassis. These members also collectively form a “U” or “V” shape extending away from central member  1480 . Central member  1480  and axle support members  1408  and  1410  collectively form a drive wheel support member of frame  1402 . 
     A distal portion of each axle support member  1408  and  1410  may be configured such that anti-tip support members  1414  and  1415  can be coupled to the distal portion of the axle support members. As shown, the distal portion of axle support members  1408  and  1410  are cut to form a face substantially parallel to centerline C L  of frame  1402  for attachment of anti-tip support members  1414  and  1415 . Anti-tip support members  1414  and  1415  extend rearward from axle support members  1408  and  1410  and are substantially parallel to centerline C L  of frame  1402 . Anti-tip support members  1414  and  1415  may be coupled to axle support members  1408  and  1410  by various means, such as, for example, with weldments, fasteners, and/or adhesives. 
     The distal portion of each axle support member  1408  and  1410  may also include attachment members for mounting drive wheels  1314  and  1316  (see  FIGS. 13A-14 ) to the axle support members. Referring to  FIGS. 14-16E , drive wheel attachment members  1624  and  1626  are cylindrical in shape and coupled to the distal portion of axle support members  1408  and  1410 , substantially perpendicular to centerline C L  of frame  1402  and positioned between the axle support members and anti-tip support members  1414  and  1415 . Each drive wheel attachment member  1624  and  1626  includes an opening for mounting drive wheels  1314  and  1316 . Drive wheel attachment members  1624  and  1626  and the openings therein may be various shapes and sizes depending at least on the size and type of drive assembly. Drive wheel attachment members  1624  and  1626  may be coupled to axle support members  1408  and  1410  by various means, such as, for example, with weldments, fasteners, and/or adhesives. 
     Furthermore, an opening in the distal portion of each axle support member  1408  and  1410  may align with an opening  1680  in anti-tip support members  1414  and  1415  to provide access for leads or wires connecting drive wheels  1314  and  1316  to junction block  1458 . For example, the leads or wires from drive wheels  1314  and  1316  may be routed through opening  1680 , axle support members  1408  and  1410 , and central member  1480  and then out an opening  1690  ( FIG. 16E ) in the central member to junction block  1458 . 
     The embodiments of the frame of the conveyance or wheelchair disclosed in this application may be configured as a wire routing system. For example, as illustrated in  FIG. 22 , frame  1402  may be configured as a wire routing system such that the leads or wires emanating from junction block  1458  are at least partially hidden and unexposed. Hiding the leads or wires within the frame and/or underneath the shrouding reduces the risk that the leads or wire will be damaged during use. 
       FIG. 22  is a rear perspective view of frame  1402  illustrating the routing of the leads or wires emanating from junction block  1458 . The wire routing system may include a terminal block or terminal strip in place of junction block  1458 . As illustrated in  FIG. 22 , leads  2214  and  2216  are routed from junction block  1458  through opening  1690  of central member  1480 , through the central member and axle support members  1408  and  1410 , and out openings  1680  in anti-tip support members  1414  and  1415  to connect to drive wheels  1314  and  1316 . Lead  2260  extends from junction block  1458  and connects to electrical connector  1460 B attached to connector mounting bracket  1608 . Further, lead  2202  is routed from junction block  1458 , out an opening  2204  between seat support member  1416  and rear handle support member  1470 , and between rear shroud  1452  ( FIG. 14 ) and the seat support member for connection to a lead from the joystick when the seat assembly of the wheelchair is mounted to chassis  1312  ( FIG. 13A ). The wires or leads may include various strain relief elements to relieve strain on the wires or leads routed throughout the wheelchair. 
     Many other configurations of a wire routing system are possible. For example, any or all of the portions of the frame may be configured for routing wire. Wire may be routed through the front support members, cross members, rear support member, or anti tip members or mounting plates of the frame. Further, the terminal or junction block may be located and positioned in a variety of ways to facilitate routing of the wires or leads. 
       FIGS. 16A-16E  also illustrate the geometry of caster support members  1404  and  1406 . In this embodiment, each caster support member  1404  and  1406  extends from axle support member  1408  and  1410 , respectively, in a forward and downward direction substantially parallel to centerline C L  of frame  1402 . Each caster support member  1404  and  1406  then curves upward and away from centerline C L  to a distal end for attachment of casters  1318  and  1320 . Thus, each caster support member  1404  and  1406  emanates forward and away from axle support members  1408  and  1410  to form an “L” shape. 
     In the embodiment illustrated in  FIGS. 16A-16E , cross members  1606  and  1620  extend downward from a front portion of caster support members  1404  and  1406 , respectively, and substantially perpendicular to centerline C L  of frame  1402 . Cross members  1606  and  1620  are attached to foot plate support member  1530 . As shown, cross members  1606  and  1620  are straight and form a generally “V” shape with foot plate support member  1530  attached proximate the bottom of the “V”. 
       FIGS. 16A-16E  also illustrate the geometry of anti-tip support members  1414  and  1415 . In this embodiment, anti-tip support members  1414  and  1415  are plates that emanate rearward from axle support members  1408  and  1410  substantially parallel to centerline C L  of frame  1402 . As shown, the distal end of anti-tip support members  1414  and  1415  projects beyond the rearward most portion of frame  1402 . Apertures are located in the distal ends of anti-tip support members  1414  and  1415  for attachment of anti-tip wheels or casters  1422  and  1424 . 
     Each anti-tip support member  1414  and  1415  includes an opening  1682  for mounting drive wheels  1314  and  1316 . As described in more detail below, opening  1682  includes a first portion substantially aligned with the opening in drive wheel attachment member  1624  and  1626  for receipt of a mounting shaft of the drive wheel. Further, opening  1682  includes a second and third portion for receipt of keys or locator pins of the drive wheel. Opening  1680  in anti-tip support members  1414  and  1415  provides access for leads or wires connecting drive wheels  1314  and  1316  to junction block  1458 . 
       FIGS. 16A-16E  illustrate seat support member  1416  of frame  1402 . In this embodiment, seat support member  1416  is coupled to central member  1480 . As shown, central member  1480  includes a cut out portion that permits the central member to at least partially surround seat support member  1416 . Seat support member  1416  may be coupled to central member  1480  by various means, such as, for example, with weldments, fasteners, and/or adhesives. Central member  1480  holds seat support member  1416  in an upright and vertical position such that it may telescopically receive a seat support therein. Further, in the embodiment illustrated in  FIGS. 16A-16E , a flange  1610  is attached to the distal end of seat support member  1416 . Attached to flange  1610  is a connector mounting bracket  1608  and a battery tray mounting bracket  1612 . These mounting brackets are described below relative to battery support tray  1412 . 
     In the embodiment illustrated in  FIGS. 16A-16E , a rear handle support member  1470  extends rearward from central member  1480  and axle support members  1408  and  1410  to provide a gripping point for the user to lift chassis  1312 . Rear handle support member  1470  may be coupled to central member  1480  and axle support members  1408  and  1410  by various means, such as, for example, with weldments, fasteners, and/or adhesives. As shown, rear handle support member  1470  is a plate configured to support rear shroud  1452  having a handle. Rear handle support member  1470  comprises an opening to permit the user to grasp the handle of rear shroud  1452 . In this embodiment, rear handle support member  1470  and rear shroud  1452  combine to form a rear handle of the wheelchair. However, in other embodiments, only one member may be used to form a rear handle of the wheelchair. 
       FIGS. 17A and 17B  illustrate battery support tray  1412  attached to frame  1402 . In this embodiment, battery support tray  1412  is disposed between caster support members  1404  and  1406 , seat support member  1416 , and cross members  1606  and  1620 . Tabs  1704  and  1706  of battery support tray  1412  are configured to rest on caster support members  1404  and  1406 , respectively, to support two side walls of the tray. Further, tabs  1708  and  1710  of battery support tray  1412  are configured to rest on cross members  1606  and  1620 , respectively, to support the front wall of the tray. The tabs may be attached to frame  1402 , such as with weldments, adhesives, and/or fasteners. 
     As shown in  FIG. 17B , one or more locating pins or fasteners  1720  are used to locate battery support tray  1412  relative to frame  1402  and/or attach the battery support tray to battery tray mounting bracket  1612 . Attachment may be by any suitable means, including weldments, adhesives, and/or fasteners. 
       FIGS. 17A and 17B  also illustrate a seat support member opening  1712  and a connector opening  1714  of battery support tray  1412 . As shown, seat support member opening  1712  is a vertical slot extending downward from an upper edge of the rear wall of battery support tray  1412 . Seat support member opening  1712  provides clearance for battery support tray  1412  to be disposed within frame  1402 . Further, battery support tray  1412  may be welded to seat support member  1416  along one or more edges of seat support member opening  1712 . As shown in  FIGS. 17B ,  20 B, and  20 C, connector opening  1714  provides clearance for electrical connector  1460 B attached to connector mounting bracket  1608 . 
       FIGS. 18A-18C  illustrate the geometry of battery support tray  1412  in this embodiment. As shown, battery support tray  1412  includes a planar bottom, a front wall, a rear wall, and two side walls. The front wall of battery support tray  1412  includes tabs  1708  and  1710  and a foot plate opening  1802  to provide clearance for the foot plate support member and foot plate mounting member. The rear wall of battery support tray  1412  includes one or more apertures  1804  for receipt of one or more locating pins or fasteners  1720  ( FIG. 17B ), seat support member opening  1712 , and connector opening  1714 . The side walls of battery support tray  1412  include tabs  1704  and  1706 . 
     The drive wheel assemblies of the wheelchair may be mounted to the frame in a variety of ways, such as with fasteners, weldments, or adhesives. The drive wheel assemblies may be removable and include one or more locating features, such as a pin, key, or aperture, configured to mate with a corresponding locating feature of the frame. The locating features may facilitate alignment and orientation of the drive wheel assembly relative to the frame. The locating features may also prohibit rotation of the drive wheel assembly relative to the frame. Further, the locating features of the drive wheel assembly and/or the frame may differ on each side of wheelchair such as to ensure the correct drive wheel assembly is mounted on the correct side of the frame. 
       FIGS. 23A and 23B  illustrate exemplary drive wheel assembly mounting configurations.  FIG. 23A  illustrates drive wheel assemblies  2302 A through  2316 A and corresponding frame portions  2302 B through  2316 B. As illustrated, each drive wheel assembly  2302 A through  2316 A has a center circular mounting shaft and one or more pins configured to mate with one or more corresponding apertures in each frame portion  2302 B through  2316 B. More specifically, drive wheel assemblies  2302 A (square pin),  2304 A (single round pin),  2306 A (three pins),  2308 A (two vertically aligned pins),  2310 A (four pins),  2312 A (two horizontally aligned pins),  2314 A (two horizontally aligned pins), and  2316 A (two vertically aligned pins) are configured to mate with frame portions  2302 B (square aperture),  2304 B (single round aperture),  2306 B (three apertures),  2308 B (two vertically aligned apertures),  2310 B (four apertures),  2312 B (two horizontally aligned apertures),  23148  (horizontal slot), and  2316 B (vertical slot), respectively. 
       FIG. 23B  illustrates drive wheel assemblies  2350 A through  2364 A and corresponding frame portions  2350 B through  2364 B. As illustrated, drive wheel assemblies  2350 A through  2364 A and frame portions  2350 B through  2364 B are grouped as four right/left mounting combinations (groups A-D) for a wheelchair. The locating features of frame portions  23508  and  2352 B of group A and frame portions  2354 B and  2356 B of group B are asymmetrical such that the mirrored right and left frame portions are not identical. To compensate for the asymmetrical locating features on frame portions  2350 B through  2356 B (shown as apertures), the top pin of drive wheel assemblies  2350 A through  2356 A is movable between two locations depending on whether the drive wheel assembly is to be mounted on the left or right frame portion. Thus, the drive wheel assembly may be configured to be mounted on the left or right asymmetrical frame portion by moving the top locator pin. 
     Still referring to  FIG. 23B , the locating features of frame portions  2358 B and  2360 B of group C and frame portions  2362 B and  2364 B of group D are symmetrical such that the mirrored right and left frame portions are identical. Further, the locating features of drive wheel assemblies  2358 A and  2360 A of group C and drive wheel assemblies  2362 A and  2364 A of group D are not identical. However, the locating features of the frame portions are configured to compensate for the differences in the locating features of the drive wheel assemblies. Thus, either drive wheel assembly in group C may be mounted to either frame portion in group C and either drive wheel assembly in group D may be mounted to either frame portion in group D. 
     Many other drive wheel assembly mounting configurations are possible in addition to those illustrated in  FIGS. 23A and 23B . For example, the frame portion may include one or more pins configured to mate with one or more corresponding apertures in the drive wheel assembly. Further, each drive wheel assembly and/or frame portion may have more or less mounting shafts, pins, and/or apertures of various shapes, sizes, and/or orientations. 
     An exemplary method of mounting a drive wheel assembly to an axle support member of chassis  1312  is illustrated with  FIGS. 19A-19C . A rear perspective view of drive wheel  1314  is shown in  FIG. 19A . As shown, a bolt having a mounting shaft  1902  is used to mount drive wheel  1314  to axle support member  1410 . Drive wheel  1314  comprises three locator pin openings, two upper openings and one lower opening. Two locator pins  1904  and  1906  are received in locater pin openings, locator pin  1906  in an upper opening and locator pin  1904  in the lower opening. The other upper locator pin opening  1908  is shown without a locator pin. As discussed below, locator pin  1906  may be moved to locator pin opening  1908  to mount the drive wheel assembly to axle support member  1408  on the other side of chassis  1312 . 
       FIG. 19B  is a side elevational view of chassis  1312  with drive wheel  1314  removed. As shown, anti-tip support member  1414  includes opening  1682  for mounting drive wheel  1314 . However, the opening does not necessarily need to be in anti-tip support member  1414  and may be in one or more other members of chassis  1312 . Opening  1682  includes a first portion  1914  substantially aligned with the opening in drive wheel attachment member  1626  for receipt of mounting shaft  1902 . Further, opening  1682  includes a second portion  1910  and a third portion  1912  for receipt of locator pins  1906  and  1904 , respectively, of drive wheel  1314 . 
       FIG. 19C  is a rear elevational view of chassis  1312  with drive wheel  1314  partially removed. To mount drive wheel  1314  to axle support member  1410 , the drive wheel is positioned such that mounting shaft  1902  is substantially aligned with first portion  1914  of opening  1682  and the opening in drive wheel attachment member  1626 . Further, drive wheel  1314  is orientated such that locator pins  1906  and  1904  are substantially aligned with second portion  1910  and third portion  1912 , respectively, of opening  1682 . Mounting shaft  1902  is then inserted through first portion  1914  of opening  1682  and the opening in drive wheel attachment member  1626  by moving drive wheel  1314  in a direction D. Nut  1916  is then threaded onto a threaded portion of mounting shaft  1902  to secure drive wheel  1314  to axle support member  1410 . 
     An exemplary method of mounting drive wheel  1316  to axle support member  1408  is similar as described above, except the upper locator pin of drive wheel  1316  is moved to the other upper locator pin opening (described as locator pin opening  1908  of drive wheel  1314 ). Because anti-tip support members  1414  and  1415  are symmetrically disposed about centerline C L , each member possess a geometry on one side of the centerline C L  that is a mirror image of the geometry on the other side of the centerline C L . Thus, the portion of the opening in the anti-tip member that receives the upper locator pin is mirrored, requiring the upper locator pins of drive wheels  1314  and  1316  to be in different upper locator pin openings. Therefore, a drive wheel assembly can be configured to be mounted on the right or left side of the wheelchair by moving the upper locator pin. 
       FIGS. 20A-20B  illustrate the insertion and removal of removable housing  1440  and top cover  1442  relative to battery support tray  1412  of frame  1402 . As shown, battery support tray  1412  is configured to receive removable housing  1440 . Removable housing  1440  includes a resettable fuse support portion  2004  formed in one wall of the housing to support resettable fuse or breaker  1490  ( FIG. 14 ) for one or more batteries  1418  and  1420 . The bottom of resettable fuse support portion  2004  includes an opening (not shown) in which a reset switch  2002  of resettable fuse  1490  ( FIG. 14 ) protrudes. 
       FIGS. 21A-21C  illustrate top cover  1442 , handle  1444 , and locking assembly  1472  of chassis  1312 . Locking assembly  1472  is attached to handle  1444  to selectively lock and unlock top cover  1442  and removable housing  1440  in place relative to frame  1402 . As shown, locking assembly  1472  comprises a body member mounted to a bracket  2108  with a fastener  2110  that permits the body member to pivot relative to the bracket. The body member comprises a trigger portion  2106  and a latching portion  2102 . Trigger portion  2106  is configured to extend through an opening  2122  in top cover  1442  such that it can be manipulated by the user when grasping handle  1444 . Latching portion  2102  is configured to extend through an opening  2120  ( FIG. 14 ) in removable housing  1440  and selectively engage striker  1622  ( FIG. 16A ) of seat support member  1416 . 
     Locking assembly  1472  also comprises a biasing mechanism  2104 . As shown, biasing mechanism  2104  is a spring positioned between the body member of locking assembly  1472  and a bottom side of handle  1444 . Biasing mechanism  2104  is configured to bias locking assembly  1472  toward a locked position in which latching portion  2102  is engaged with striker  1622  and top cover  1442  is prohibited from moving relative to frame  1402 . When trigger portion  2106  is moved toward handle  1444 , latching portion  2102  disengages striker  1622  and top cover  1442  is permitted to move relative to frame  1402 . Although a spring is illustrated, any biasing mechanism may be used that permits latching portion  2102  to selectively engage and disengage striker  1622 , such as an elastomeric material or compressible fluid. 
       FIGS. 24A-24C  illustrate various views of a frame  2402  according to an embodiment of the present application. Similar to frame  1402  described above, frame  2402  includes a central member  2480 , caster support members  2404  and  2406 , axle support members  2408  and  2410 , anti-tip support members  2414  and  2415 , a seat support member  2416 , and a rear handle support member  2470 . 
       FIG. 24B  illustrates a top plan view of frame  2402 . As shown in  FIG. 24B , frame  2402  is disposed substantially about centerline C L , which represents the centerline of the chassis and the wheelchair. In particular, central member  2480 , caster support members  2404  and  2406 , axle support members  2408  and  2410 , anti-tip support members  2414  and  2415 , and rear handle support member  2470  are all symmetrically disposed about centerline C L . As such, in this embodiment, each of these members possess a geometry on one side of the centerline C L  that is a mirror image of the geometry on the other side of the centerline C L . 
       FIGS. 24A-24C  illustrate the geometry of axle support members  2408  and  2410  in this embodiment. Axle support members  2408  and  2410  emanate from central member  2480  and extend downwardly and away therefrom. In this particular embodiment, axle support members  2408  and  2410  extend in a rearward direction of the chassis. These members also collectively form a “U” or “V” shape extending away from central member  2480 . Central member  2480  and axle support members  2408  and  2410  collectively form a drive wheel support member of frame  2402 . 
     A distal portion of each axle support member  2408  and  2410  may be configured such that anti-tip support members  2414  and  2415  can be coupled to the distal portion of the axle support members. As shown, the distal portion of axle support members  2408  and  2410  are cut to form a face substantially parallel to centerline C L  of frame  2402  for attachment of anti-tip support members  2414  and  2415 . Anti-tip support members  2414  and  2415  extend rearward from axle support members  2408  and  2410  and are substantially parallel to centerline C L  of frame  2402 . Anti-tip support members  2414  and  2415  may be coupled to axle support members  2408  and  2410  by various means, such as, for example, with weldments, fasteners, and/or adhesives. 
     The distal portion of each axle support member  2408  and  2410  may also include attachment members for mounting drive wheels to the axle support members. As illustrated in  FIGS. 24A-24C , drive wheel attachment members  2424  and  2426  are cylindrical in shape and coupled to the distal portion of axle support members  2408  and  2410 , substantially perpendicular to centerline C L  of frame  2402  and positioned between the axle support members and anti-tip support members  2414  and  2415 . Each drive wheel attachment member  2424  and  2426  includes an opening for mounting drive wheels. Drive wheel attachment members  2424  and  2426  and the openings therein may be various shapes and sizes depending at least on the size and type of drive assembly. Drive wheel attachment members  2424  and  2426  may be coupled to axle support members  2408  and  2410  by various means, such as, for example, with weldments, fasteners, and/or adhesives. 
     Furthermore, an opening in the distal portion of each axle support member  2408  and  2410  may align with an opening  2450  in anti-tip support members  2414  and  2415  to provide access for leads or wires connecting the drive wheels to a terminal or junction block. For example, the leads or wires from the drive wheels may be routed through opening  2450 , axle support members  2408  and  2410 , and central member  2480  and then out an opening in the central member to the terminal or junction block. 
       FIGS. 24A-24C  also illustrate the geometry of caster support members  2404  and  2406 . In this embodiment, each caster support member  2404  and  2406  extends from axle support member  2408  and  2410 , respectively, in a forward and downward direction substantially parallel to centerline C L  of frame  2402 . Each caster support member  2404  and  2406  then curves upward and away from centerline C L  to a distal end for attachment of the casters. Thus, each caster support member  2404  and  2406  emanates forward and away from axle support members  2408  and  2410  to form an “L” shape. 
     In the embodiment illustrated in  FIGS. 24A-24C , cross members  2420  and  2422  extend downward from a front portion of caster support members  2404  and  2406 , respectively, and substantially perpendicular to centerline C L  of frame  2402 . Cross members  2420  and  2422  are attached to foot plate support member  2430 , As shown, cross members  2420  and  2422  are straight and form a generally “V” shape with foot plate support member  2430  attached proximate the bottom of the “V”. 
       FIGS. 24A-24C  also illustrate the geometry of anti-tip support members  2414  and  2415 . In this embodiment, anti-tip support members  2414  and  2415  are plates that emanate rearward from axle support members  2408  and  2410  substantially parallel to centerline C L  of frame  2402 . As shown, the distal end of anti-tip support members  2414  and  2415  projects beyond the rearward most portion of frame  2402 . Apertures are located in the distal ends of anti-tip support members  2414  and  2415  for attachment of anti-tip wheels or casters. 
     Opening  2450  in each anti-tip support member  2414  and  2415  includes portions for mounting the drive wheels and coupling anti-tip support members to the axle support members  2408  and  2410 . As illustrated in  FIG. 24C , opening  2450  includes a first portion  2482  substantially aligned with the opening in drive wheel attachment member  2424  and  2426  for receipt of a mounting shaft of the drive wheel. Further, opening  2450  includes a second portion  2484  and a third portion  2486  for receipt of keys or locator pins of the drive wheel. Opening  2450  also includes a fourth portion  2488  that provides access for leads or wires connecting the drive wheels to the terminal or junction block. The shape of fourth portion  2488  is also configured to follow the contour of the face formed by cutting the distal portion of axle support members  2408  and  2410 . In this regard, the shape of the fourth portion  2488  facilitates coupling anti-tip support members  2414  and  2415  to axle support members  2408  and  2410 , such as, for example, with weldments, fasteners, and/or adhesives. 
       FIGS. 24A-24C  illustrate seat support member  2416  of frame  2402 . In this embodiment, seat support member  2416  is coupled to central member  2480 . As shown, central member  2480  includes a cut out portion that permits the central member to at least partially surround seat support member  2416 . Seat support member  2416  may be coupled to central member  2480  by various means, such as, for example, with weldments, fasteners, and/or adhesives. Central member  2480  holds seat support member  2416  in an upright and vertical position such that it may telescopically receive a seat support therein. As shown in  FIG. 24C , the longitudinal axis  2490  of seat support member  2416  is angled slightly rearward relative to a vertical axis  2492  of frame  2402  to facilitate insertion of the seat support and stabilization of the seat. Angle A between longitudinal axis  2490  and vertical axis  2492  is generally acute and preferably in the range of 0 to 10 degrees, but may have an even larger range depending on the design. In one embodiment, angle A is 5 degrees. 
     Further, in the embodiment illustrated in  FIGS. 24A-24C , a bracket  2494  is attached to the distal end of seat support member  2416 . Attached to bracket  2494  is a connector mounting bracket  2474 , a battery tray mounting bracket  2476 , and a shroud mounting bracket  2478 . 
     In the embodiment illustrated in  FIGS. 24A-24C , a rear handle support member  2470  extends rearward from central member  2480  and axle support members  2408  and  2410  to provide a gripping point for the user to lift the chassis. Rear handle support member  2470  may be coupled to central member  2480  and axle support members  2408  and  2410  by various means, such as, for example, with weldments, fasteners, and/or adhesives. As shown, rear handle support member  2470  is a plate configured to support a rear shroud having a handle. Rear handle support member  2470  comprises an opening to permit the user to grasp the handle of the rear shroud. In this embodiment, rear handle support member  2470  and the rear shroud combine to form a rear handle of the wheelchair. However, in other embodiments, only one member may be used to form a rear handle of the wheelchair. 
       FIGS. 25A and 25B  illustrate battery support tray  2412 . Battery support tray  2412  includes a front wall  2502 , a rear wall  2504 , two side walls  2506  and  2508 , and a bottom  2510 . As shown, a unitary piece of material, such as, for example, a stamped piece of metal, is bent to form front wall  2502 , side walls  2506  and  2508 , and a lower portion  2504 A of rear wall  2504  extending upward from bottom  2510 . An upper portion  2504 B of rear wall  2504  is formed from a separate piece of material and is attached to lower portion  2504 A to form rear wall  2504 . Forming upper portion  2504 B of rear wall  2504  from a separate piece of material reduces the amount of material used to manufacture battery support tray  2412 . However, in other embodiments, the entire battery support tray is formed from a single piece of material. Upper portion  2504 B of rear wall  2504  may be attached to lower portion  2504 A by various means, such as with weldments, fasteners, and/or adhesives. Further, the walls and bottom of the battery support tray  2412  may be welded together to provide strength to the tray. 
     In the embodiment illustrated in  FIGS. 24A-24C , battery support tray  2412  is disposed between caster support members  2404  and  2406 , seat support member  2416 , and cross members  2420  and  2422  of frame  2402 . The walls of battery support tray  2412  include apertures  2512  configured for fasteners to attach the tray to the components of frame  2402 . However, battery support tray  2412  may be attached to frame  2402  by various means, such as with weldments and/or adhesives. 
     Battery support tray  2412  is configured to receive a removable battery housing designed to hold one or more batteries of the wheelchair. Tabs  2516  on the front wall  2502  and side walls  2506  and  2508  and tab  2520  on the rear wall  2504  of battery support tray  2412  are configured as guides to position the battery housing and hold the housing in place relative to the battery support tray. As illustrated in  FIGS. 25A and 25B , tabs  2516  and  2520  are bent such that they flex outward when the battery housing is placed in battery support tray  2412  to hold the housing in place and prohibit the housing from rattling in the tray. 
     Tab  2524  extends upwards from rear wall  2504  of battery support tray  2412 . Tab  2524  is configured as a striker or latch that engages a latching portion of a locking assembly designed to selectively lock and unlock the top cover and removable housing in place relative to frame  2402 , such as, for example, the latching portion  2102  of locking assembly  1472  illustrated in  FIGS. 21A-21C . Tab  2524  may be configured to extend through an opening in the removable housing to engage the latching portion of the locking assembly. 
     Tabs  2526  also extend upward from rear wall  2504  of battery support tray  2412 . Tabs  2526  are configured as guides for the removable battery housing when the housing is inserted into the battery support tray  2412 . As such, tabs  2526  prohibit the removable battery housing from catching on sharp edges of the battery support tray  2412  when the housing is inserted into the tray. Further, tabs  2522  extending from side walls  2506  and  2508  and tabs  2518  extending from front wall  2502  are configured as brackets for attaching various portions of shrouding to frame  2402 . As shown in  FIG. 25B , apertures  2528  are configured for fasteners to attach battery support tray  2412  to battery tray mounting bracket  2476 . However, attachment may be by any other suitable means, including weldments and/or adhesives. 
       FIGS. 25A and 25B  also illustrate a seat support member opening  2530  and a connector opening  2532  of battery support tray  2412 . As shown, seat support member opening  2530  is a vertical slot in rear wall  2504  of battery support tray  2412 . Seat support member opening  2530  provides clearance for battery support tray  2412  to be disposed within frame  2402 . Further, battery support tray  2412  may be welded to seat support member  2416  along one or more edges of seat support member opening  2530 . Connector opening  2532  provides clearance for an electrical connector attached to connector mounting bracket  2474 . A foot plate opening  2534  in front wall  2502  provides clearance for a foot plate support member and foot plate mounting member and an opening  2514  in bottom  2510  permits drainage of water or other liquids that may collect in battery support tray  2412 . Other openings in side walls  2506  and  2508  and rear wall  2504  help to reduce the weight of battery support tray  2412 . 
       FIG. 26  illustrates a shrouding system  2600  for a conveyance such as a wheelchair according to an embodiment of the present application. As illustrated in  FIG. 26 , the shrouding system  2600  includes a rear handle shroud  2610 , a top shroud  2620 , a front shroud  2630 , a left shroud, and a right shroud. Left shroud and right shroud form a lower shroud  2640  of shrouding system  2600 . Shrouding system  2600  may include more or less shroud components. Multiple shroud components may be combined to form a single shroud component, for example, left and right shrouds may be combined to form a single lower shroud. 
     Shrouding system  2600  is configured to cover the frame and other components of the conveyance. As illustrated in  FIG. 26 , rear handle shroud  2610 , top shroud  2620 , and front shroud  2630  are configured to collectively cover a top and front of the frame and other components of the conveyance. Further, lower shroud  2640  is configured to cover the left and right sides, bottom, and rear of the frame and other components of the conveyance. 
     Shrouding system  2600  also includes openings  2650 ,  2652 , and  2654  allowing frame components for the wheels, casters, and/or seat assembly of the conveyance to project from the shroud. Specifically, rear handle shroud  2610  and/or top shroud  2620  include opening  2654  allowing the frame component for attachment of a seat assembly of the conveyance to extend from the shroud. Lower shroud  2640  includes openings  2650  and  2652  allowing for frame components for attachment of the wheels and casters of the conveyance to extend from the shroud. Further, as illustrated in  FIG. 29A , lower shroud  2640  includes a bottom opening  2956  for a skid plate or battery tray of the conveyance. 
       FIGS. 27A and 27B  illustrate top shroud  2620  of shrouding system  2600 . Top shroud  2620  includes attachment portions  2710  for attachment of a handle to facilitate removal of the top shroud from the frame or other component of the conveyance such as, for example, the battery support. Further, a central portion of top shroud  2620  includes a depression  2712  that provides clearance for a user to grasp the handle. In one embodiment, the handle includes a locking assembly configured to lock or unlock top shroud  2620  relative to the frame or other component of the conveyance. Top shroud  2620  includes an opening for a latch of the locking assembly. Further, depression  2712  is configured to provide clearance for the locking assembly. Top shroud  2620  also includes a rounded notch, aperture, or opening towards is rear portion  2804  allowing seat support member  216  (shown in  FIG. 2 ) to project or extend from the shroud. Rear handle shroud  2610  includes a similar notch, aperture or opening corresponding located for the same purpose. 
       FIGS. 28A-28E  are various cross-sectional views of top shroud  2620  of shrouding system  2600 .  FIGS. 28A and 28B  are side cross-sectional views of top shroud  2620  taken along lines  28 A- 28 A and  28 B- 28 B, respectively, shown in  FIG. 27B . Line  28 A- 28 A is also the centerline of top shroud  2620 .  FIGS. 28C-28E  are front cross-sectional views of top shroud  2620  taken along lines  28 C- 28 C,  28 D- 28 D, and  28 E- 28 E, respectively, shown in  FIG. 27B . 
     As illustrated in  FIG. 28B , top shroud  2620  includes a top surface  2802  having a rear portion  2804  and a front portion  2806 . Top surface  2802  has a convex outer surface that curves outward and slopes downward from rear portion  2804  to front portion  2806 . As illustrated in  FIG. 28A , depression  2712  has a rear wall  2808  and a bottom  2810 . Rear wall  2808  extends downward from rear portion  2804  at an acute angle to vertical axis V and then curves to transition to bottom  2810 . Bottom  2810  extends from rear wall  2808  of depression  2712  and transitions to front portion  2806  of top surface  2802 . Bottom  2810  is substantially parallel to horizontal axis H, but may also include a gentle downward or upward slope toward front portion  2806 . A downward sloping bottom  2810  provides a complimentary configuration to downwardly sloping top surface  2802 . 
     Other configurations of rear wall  2808  and bottom  2810  of depression  2712  are possible. For example, rear wall  2808  may extend downward from rear portion  2804  substantially parallel to vertical axis V and may or may not be curved. Further, bottom  2810  may or may not be substantially parallel to horizontal axis H. For example, bottom  2810  may be angled relative to horizontal axis H and slope downward or upward from rear wall  2808  to front portion  2806 . 
       FIGS. 28C-28E  are front cross-sectional views of top shroud  2620  at three locations and illustrate the changing shape of the top shroud from the rear to the front of the conveyance. As illustrated in the Figures, top shroud  2620  includes a left portion  2812  and a right portion  2810  and depression  2712  has a left sidewall  2820  and a right sidewall  2818 . Top surface  2802  has a curved surface configuration and slopes upward from left portion  2812  and right portion  2810  to the central portion of top shroud  2620 . Top surface  2802  then curves downward to form a convex transition to left sidewall  2820  and right sidewall  2818  of depression  2712 . The convex transition from top surface  2802  to left sidewall  2820  and right sidewall  2818  forms a left ridge  2816  and right ridge  2814 , respectively. Left sidewall  2820  and right sidewall  2818  of depression  2712  extend downward from top surface  2802  at an acute angle to vertical axis V and then curve to transition to bottom  2810 . 
     Left sidewall  2820 , right sidewall  2818 , and bottom  2810  of depression  2712  form a concave surface of the depression. As illustrated in  FIGS. 28C-28E , the shape of the concave depression  2712  changes from the rear to the front of the conveyance. For example, the horizontal width of the depression  2712  increases and then decreases from the rear to the front of the conveyance (see also  FIG. 27B ). Further, the acute angle between left and right sidewalls  2820  and  2818  and vertical axis V decreases then increases from the rear to the front of the conveyance. Because top surface  2802  slopes downward from rear portion  2804  to front portion  2806 , the depth of depression  2712  decreases from the rear to the front of the conveyance. 
       FIGS. 29A and 29B  illustrate lower shroud  2640  of shrouding system  2600 . As illustrated, left and right side shrouds form lower shroud  2640 . Lower shroud  2640  includes a left and right sidewall  2902  and  2904 , a rear wall  2906 , and a bottom  2908 . Each side wall  2902  and  2904  includes a top, bottom, front, and rear portion. Each side wall  2902  and  2904  extends rearward from the front portion to the rear portion and then curves inward to transition to rear wall  2906 . Each side wall  2902  and  2904  also extends downward from the top portion to the bottom portion and then curves inward to transition to bottom  2908 . Bottom  2908  includes opening  2956  configured to at least partially expose a skidplate or battery tray of the conveyance. Each sidewall  2902  and  2904  includes openings  2650  and  2652  allowing frame components for attachment of wheels and casters of the conveyance to project therefrom. 
     As illustrated in  FIG. 29B , each sidewall  2902  and  2904  of lower shroud  2640  comprises a convex outer surface that curves outward from the front portion to the rear portion of the sidewall. Further, each sidewall  2902  and  2904  includes a concave perimeter  2910  (see  FIG. 29A ) that curves inward and extends from the rear portion to the front portion of the sidewall. As shown in this embodiment, outward projecting nature of perimeter  2910  provides for a raised perimeter starting from the rear (e.g., mid to upper rear) and continuing to the front (e.g., mid to lower front). Perimeter  2910  may have a uniform or non-uniform width. As illustrated in  FIG. 29A , perimeter  2910  extends from the upper rear portion to the front portion of each sidewall  2902  and  2904 . Perimeter  2910  permits portions of lower shroud  2640  to appear differently than other portions, More specifically, perimeter  2910  is configured to reflect light such that portions of lower shroud  2640  appear to be a different color tone (i.e., toning) than other portions of the lower shroud even though the portions may be manufactured from the same color. 
       FIGS. 30A-30D  are front cross-sectional views of lower shroud  2640  at four locations and illustrate the changing shape of the lower shroud from the rear to the front of the conveyance.  FIGS. 30A-30D  are taken along lines  30 A- 30 A,  30 B- 30 B,  30 C- 30 C, and  30 D- 30 D, respectively, shown in  FIG. 29B . 
     As illustrated in  FIGS. 29A ,  30 A, and  30 D, each sidewall  2902  and  2904  transitions to convex portions  3010  and  3012  that surround openings  2650  and  2652  that permit attachment of the wheels and casters of the conveyance. The convex portions  3010  and  3012  follow the shape of openings  2650  and  2652 . The convex portions  3010  and  3012  may have a uniform or non-uniform width. 
     As illustrated in  FIGS. 30B and 30C , the depth of concave perimeter  2910  increases as the perimeter extends from the rear portion to the front portion of sidewalls  2902  and  2904 . As shown, the concavity of perimeter  2910  is more exaggerated and the depth of the perimeter is greater in  FIG. 30C  than in  FIG. 30B . Further, the width of concave perimeter  2910  decreases as the perimeter extends from the rear portion to the front portion of sidewalls  2902  and  2904 . As shown, the width of perimeter  2910  is smaller in  FIG. 30C  than in  FIG. 30B . 
     As illustrated in  FIGS. 30C and 30D , perimeter  2910  transitions to an inward region  3040  of sidewalls  2902  and  2904  at the lower front portion of the sidewalls. More specifically, the depth of perimeter  2910  decreases and the concavity of the perimeter flattens to form inward region  3040 . In other embodiments, concave perimeter  2910  may take the form of a raised perimeter having more orthogonal geometry including linear sections with apexes (one or more) there between. Also, a transition to inward region  3040  may or may not be present. 
       FIGS. 31A and 31B  illustrate front shroud  2630  of shrouding system  2600 . As shown, front shroud  2630  includes a top, bottom, left, and right portion. As illustrated in  FIG. 31B , front shroud  2630  includes a convex outer surface  3110  that curves outward and slopes downward from the top portion to the bottom portion.  FIG. 31C  is a top cross-sectional view of front shroud  2630  taken along line  31 C- 31 C shown in  FIG. 31A . As illustrated in  FIG. 31C , outer surface  3110  includes a convex region  3112  on the left portion and the right portion of front shroud  2630 . Each convex region  3112  extends from a side of front shroud  2630  and transitions into a central portion of the front shroud. In other embodiments, convex region  3112  may include orthogonal geometries having linear portions with apexes (one or more) there between. 
     Configures as such, shrouding system  2600  includes various curved and/or orthogonal surfaces configured to catch, reflect, and/or focus light in a manner so portions of shroud system  2600  appear to include different color tone (i.e., toning) than other portions even though the portions may be manufactured from the same color. For example, manufacture of shrouding system  2600  using a uniform white or pearl color results in both darker and lighter tones of white or pearl to be present through the use of features such as concave perimeter  2910 , convex region  3112 , and inward region  3040 . 
       FIGS. 32A-32D  illustrate a frame  3200  for a conveyance such as a wheelchair according to an embodiment of the present application. As illustrated, frame  3200  includes a rear wheel support member  3206 , a left front wheel support member  3202 , and a right front wheel support member  3204 . Frame  3200  also includes a seat support member  3216 , a left rear mounting plate  3212 , a right rear mounting plate  3214 , and one or more cross members  3208  and  3210  extending between left and right front wheel support members  3202  and  3204 . 
     As illustrated in  FIG. 32C , frame  3200  is disposed substantially about centerline C L , which represents the centerline of the frame and the conveyance. In particular, the rear wheel support, front wheel supports, seat support, rear mounting plates, and cross members are all symmetrically disposed about centerline C L . As such, in this embodiment, each of these members possess a geometry on one side of the centerline C L  that is a mirror image of the geometry on the other side of the centerline C L . 
     As illustrated in  FIGS. 32A-32D , each front wheel support member  3202  and  3204  includes a first portion  3220  and  3240  that extends forward and downward from rear wheel support member  3206 . First portion  3220  and  3240  of each front wheel support member  3202  and  3204  extends downward from rear wheel support member  3206  at an angle C D  relative to horizontal H. As illustrated in  FIG. 32B , angle C D  is generally acute and preferably in the range of 5 to 20 degrees, but may have an even larger range depending on the design. In one embodiment, angle C D  is 12.5 degrees. Further, as illustrated in  FIG. 32C , a centerline  3280  and  3282  of each first portion  3220  and  3240  of each front wheel support member  3202  and  3204  is substantially parallel to centerline C L  of frame  3200 . 
     Each front wheel support member  3202  and  3204  includes a curved transition from first portion  3220  and  3240  to a second portion  3222  and  3242 . Second portion  3222  and  3242  of each front wheel support member  3202  and  3204  extends outward and upward from first portion  3220  and  3240 . A centerline  3290  and  3292  of each second portion  3222  and  3242  of each front wheel support member  3202  and  3204  extends upward from first portion  3220  and  3240  at an angle C U  relative to horizontal H. As illustrated in  FIG. 32B , angle C U  is generally acute and preferably in the range of 5 to 15 degrees, but may have an even larger range depending on the design. In one embodiment, angle C U  is 11.5 degrees. Centerline  3290  and  3292  of each second portion  3222  and  3242  of each front wheel support member  3202  and  3204  extends outward from first portion  3220  and  3240  at an angle C O  relative to centerline  3280  and  3282  of the first portion. As illustrated in  FIG. 32C , angle C O  is generally acute and preferably in the range of 35 to 55 degrees, but may have an even larger range depending on the design. In one embodiment, angle C O  is 45.8 degrees. 
     As illustrated in  FIGS. 32A-32D , rear wheel support member  3206  includes a central portion  3260 , a left portion  3262 , and a right portion  3264 . Left portion and right portions  3262  and  3264  extend downward and outward from central portion  3260  in a rearward direction. Rear wheel support member  3206  includes curved transitions between central portion  3260  and left and right portions  3262  and  3264 . 
     Centerlines  3284  and  3286  of left and right portions  3262  and  3264  of rear wheel support member  3206  extend downward from central portion  3260  at an angle D D  relative to horizontal H. As illustrated in  FIG. 32B , angle D D  is generally acute and preferably in the range of 35 to 55 degrees, but may have an even larger range depending on the design. In one embodiment, angle D D  is 45 degrees. Further, centerlines  3284  and  3286  of left and right portions  3262  and  3264  of rear wheel support member  3206  extend outward from central portion  3260  at an angle D O  relative to a centerline  3288  of the central portion. As illustrated in  FIG. 32C , angle D O  is generally acute and preferably in the range of 15 to 35 degrees, but may have an even larger range depending on the design. In one embodiment, angle D O  is 25 degrees. 
     Left and right rear mounting plates  3212  and  3214  extend downward and rearward from left and right portions  3262  and  3264  of rear wheel support member  3206 . Centerlines  3296  of left and right rear mounting plates  3212  and  3214  extend downward at an angle A D  relative to horizontal H. As illustrated in  FIG. 32B , angle A D  is generally acute and preferably in the range of 15 to 35 degrees, but may have an even larger range depending on the design. In one embodiment, angle A D  is 27 degrees. Further, as illustrated in  FIG. 32C , each rear mounting plate  3212  and  3214  is substantially parallel to centerline C L  of frame  3200 . 
     As illustrated in  FIGS. 32A-32D , cross members  3208  and  3210  extend between front wheel support members  3202  and  3204 . As illustrated in  FIG. 32C , cross members  3208  and  3210  extend between second portions  3222  and  3242  of front wheel support members  3202  and  3204  at the curved transition between first portion  3220  and  3240  and the second portion. Cross members  3208  and  3210  extend downward and inward from front wheel support members  3202  and  3204  to a frame attachment member  3298 . Each cross member  3208  and  3210  extends downward at an angle M D  relative to horizontal H. As illustrated in  FIG. 32D , angle M D  is generally acute and preferably in the range of 20 to 45 degrees, but may have an even larger range depending on the design. In one embodiment, angle M D  is 35 degrees. Further, as illustrated in  FIG. 32C , each cross member  3208  and  3210  is substantially perpendicular to centerline C L  of frame  3200 . In some embodiments, cross members  3208  and  3210  are formed as a single member having, for example, a U or V shape when viewed from the front. 
     As illustrated in  FIGS. 32A-32D , seat support member  3216  is coupled to central portion  3260  of rear wheel support member  3206 . Seat support member  3216  is held in an upright orientation relative to frame  3200 . A centerline  3294  of seat support member  3216  is at an angle S to horizontal H. As illustrated in  FIG. 32B , angle S is generally obtuse and preferably in the range of 90 to 110 degrees, but may have an even larger range depending on the design. In one embodiment, angle S is 95 degrees. 
     It should be understood that the dimension and angle descriptions disclosed herein are subject to variance according to standard tolerances in the art. For example, the angle descriptions included herein can be to a tolerance of +/−½ degree or more. 
     While a rear wheel drive wheelchair is depicted in many of the drawings of this application, it is to be understood that any one or more of the features disclosed by this application can be used on a wide variety of different types of vehicles. For example, any one or more of the features disclosed in this application can be used on a front wheel drive wheelchair or a mid-wheel drive wheelchair. In a front wheel drive embodiment, the front casters may be located off the ground in their normal position or in contact with the ground in their normal position. In a mid or center wheel drive embodiment, the rear anti-tip wheels may be located off the ground in their normal position or in contact with the ground in their normal position. 
     The conveyance of the present application may in one embodiment include a transportable configuration. In this embodiment, the conveyance may be disassembled into subassemblies or components that are easily individually transportable in, for example, an automobile. The conveyance may be disassembled by removing the seat assembly from the chassis. Further, the drive wheels and batteries may be removed from the chassis. Still further, other components can be additionally or alternatively be removable from the chassis, including the foot plate and casters. 
     In this manner, these components can be easily stored for transportation and quick re-assembly without the use of tools. To facilitate disassembly and assembly, the conveyance can include any number of mechanisms including pluggable terminals for the batteries, and quick release or spring-loaded pins for the drive wheels and seat assembly. Also, the shrouding can include one or more covers capable of being opened and closed or removed and re-attached, such as to allow removal and insertion of the batteries. 
     Configured as such, a clean looking, simple, and lightweight chassis structure is provided for a conveyance. The chassis may be configured to be rear wheel drive, mid-wheel drive, or front wheel drive. The rear anti-tip wheels or casters may be positioned on the ground or off the ground. Similarly, the front casters may be positioned on the ground or off the ground. Furthermore, one or more suspension devices or assemblies may be added to the mounting of caster support members, axle support members, and/or anti-tip support members. The one or more suspension devices or assemblies can take the form of springs, spring/shock absorbers, pivoting assemblies, struts, pneumatic piston/cylinder assemblies, four-bar linkage assemblies, and combinations of the foregoing. 
     While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, devices and components, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure, however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention, the inventions instead being set forth in the appended claims. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated. 
     While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, the energy source or batteries can include an onboard charger unit, the casters can be coupled to pivot arms via shock absorbing fork assemblies, and the specific locations of the component connections and interplacements can be modified. Still further, while cylindrical or elliptical tubular components have been shown and described herein, other geometries can be used including polygonal (e.g., square, rectangular, triangular, hexagonal, etc.) can also be used. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures can be made from such details without departing from the spirit or scope of the applicant&#39;s general inventive concept.