Methods and apparatus for assembling a wheel chair

A wheelchair back assembly mounts to a pair of spaced apart laterally-aligned support posts of a wheelchair back frame. The back assembly includes a relatively rigid shell member, and a mounting system for coupling the shell member to the wheelchair back frame. The mounting system includes at least a first mounting bracket assembly, a second mounting bracket assembly, and a lateral member that is configured to be coupled to the first and second mounting bracket assemblies. The first mounting bracket assembly is configured to couple to a first of the wheelchair back frame support posts, and the second mounting bracket assembly is configured to couple to the second of the wheelchair back frame support posts. The lateral member is selectively operable to uncouple the shell member from the wheelchair back frame.

BACKGROUND OF THE INVENTION

This invention relates generally to wheelchairs, and more particularly, to back assemblies used with wheelchairs.

At least some known wheelchairs include an upholstery sling back that may be removed and/or folded for storage. However, because such wheelchair backs are generally not adjustable, such sling backs may not be comfortable to an individual confined in a wheelchair, and as such, may actually increase the health risks to such individuals. More specifically, the posture of individuals who are confined to wheelchairs may be a significant factor in the health problems associated with the individual. For example, over time, the posture of an individual confined to a wheelchair may increase the individual's risk for progressive spinal deformations, reduced mobility, fatigue, impaired respiration or swallowing, and/or tissue breakdown.

To facilitate reducing the risks of posture-related health problems and to increase the comfort to such individuals, at least some known wheelchairs have replaced the conventional back assemblies with back assemblies that are adjustable. More specifically, at least some known systems have attempted to provide a back assembly that is not only adjustable while a user is seated in the wheelchair, but is also attachable to, and/or detachable from, the wheelchair, while the user is seated in the wheelchair. For example, U.S. Pat. No. 5,556,168 to Jay et al. describes a wheelchair back system that is removably coupled to a wheelchair frame and includes height adjustability, tilt adjustability, and lateral support adjustability. Moreover, because the back system described in U.S. Pat. No. 5,556,168 is detachable from, and/or attachable to, the wheelchair in a single-handed operation that does not require the disengagement of, and/or installation of, other latching hardware from the back system, the back system overcame many of the installation/removal problems associated with other known removable wheelchair back systems.

However, depending on the type of wheelchair used, and/or the dexterity and overall condition of the wheelchair user, attaching or detaching the back system described in U.S. Pat. No. 5,556,168 may still be difficult. For example, the back system includes a pair of hook assemblies which each include a plurality of moving parts which may provide pinch points to the user, and/or locations in which a user's clothing may become entangled. Moreover, if either hook assembly becomes jammed, the back system may require an extensive disassembly to repair the hook assembly.

BRIEF SUMMARY OF THE INVENTION

In one aspect, a wheelchair back assembly for mounting to a pair of spaced apart laterally-aligned support posts of a wheelchair back frame is provided. The back assembly includes a relatively rigid shell member, and a mounting system for coupling the shell member to the wheelchair back frame. The mounting system includes at least a first mounting bracket assembly, a second mounting bracket assembly, and a lateral member that is configured to be coupled to the first and second mounting bracket assemblies. The first mounting bracket assembly is configured to couple to a first of the wheelchair back frame support posts, and the second mounting bracket assembly is configured to couple to the second of the wheelchair back frame support posts. The lateral member is selectively operable to uncouple the shell member from the wheelchair back frame.

In another aspect, a wheelchair is provided. The wheelchair includes a back frame and a back assembly. The back frame includes a pair of spaced-apart support posts. The support posts are substantially laterally-aligned. The back assembly includes a relatively rigid shell member coupled between the pair of support posts, and a mounting system for coupling the shell member to the back frame. The mounting system includes a first mounting bracket assembly, a second mounting bracket assembly, and a lateral member that is coupled therebetween. The lateral member is configured to couple to each of the support posts and is selectively operable to uncouple the shell member from the back frame.

In a further aspect, a method for assembling a back assembly for a wheelchair is provided. The method comprises coupling a first mounting bracket assembly to a first support post of a wheelchair back frame, and coupling a second mounting bracket assembly to a second support post of the wheelchair back frame. The method also comprises coupling a lateral member to a relatively rigid shell member, and coupling the lateral member to the first and second mounting bracket assemblies such that the lateral member is selectively operable to uncouple the shell from the wheelchair back frame.

In yet another aspect, a back assembly for a wheelchair including a pair of laterally-aligned support posts is provided. The back assembly includes a shell member having an upper portion and a lower portion, and a mounting system for coupling the shell member between the support posts. The mounting system includes a first mounting bracket assembly, a second mounting bracket assembly, a coupling assembly, and a lateral member. The first mounting bracket assembly is configured to couple the shell upper portion to a first of the support posts, and the second mounting bracket assembly is configured to couple the shell upper portion to a second of the support posts. The coupler assembly is configured to couple between the first mounting bracket assembly and the shell member, and between the second mounting bracket assembly and the shell member. The lateral member extends across the shell member upper portion and is selectively operable to uncouple the shell member from the coupler assembly.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a perspective view of an exemplary folding wheelchair10. Wheelchair10is known in the art and includes a pair of side frames12connected by a folding strut arrangement14as well as a folding lock arrangement16including a front hinged brace18and a rear hinged brace20.

In the exemplary embodiment, each side frame12includes a lower frame unit30, a seat rail32, a front support unit34, a back support unit36, a back frame rail or support post38, a side connecting link40, and an armrest support unit42. Armrest support unit42includes a generally horizontally-aligned member44and a generally vertically-aligned member46that is pivotally coupled between member44and an intersection50formed by the coupling of front support unit34, seat rail32, and side connecting link40. Each armrest support unit member44is coupled between member46and back frame support post38.

Support posts38each have a diameter D and are spaced apart a distance W and each extends generally perpendicularly upwardly from lower frame unit30to a pair of support post handles52. Accordingly, posts38are substantially parallel to each other, and as such, are generally laterally-aligned. In the exemplary embodiment, posts38are also coupled together by a pair of strut members54and56which are pivotally secured together approximately mid-way along their lengths. More specifically, the upper ends58and60of respective members54and56are rotationally, and pivotally, coupled to support posts38, and are rotationally and pivotally mounted to back support units36.

FIG. 2is a perspective rear view of exemplary back assembly70that may be used with a wheelchair, such as wheelchair10(shown inFIG. 1).FIG. 3is an enlarged perspective view of a portion of a mounting system72used with back assembly70and including a lateral member100and a coupling assembly74, andFIG. 4is an exploded view of mounting system72.FIG. 5is a side perspective view of coupling assembly74.FIGS. 6 and 7are respectively an enlarged exploded view of an upper mounting bracket assembly80and a partially exploded enlarged view of a lower mounting bracket assembly82used with back assembly70.FIG. 8is a cross-sectional view of mounting system72coupled to upper mounting bracket assembly80.

Wheelchair back assembly mounting system72is used to mount a relatively rigid shell member84to wheelchair back frame posts38. More specifically, and as described herein, mounting system72provides a universal mounting system which enables shell member84to be coupled to a plurality of different wheelchairs10having different widths W and/or different support post diameters D (shown inFIG. 1). Moreover, mounting system72also enables shell member84to be coupled to posts38(shown inFIG. 1) which have a different curvature or tilt than those illustrated inFIG. 1. As such, mounting system72facilitates enabling wheelchair back assembly70to be retrofitted on existing wheelchairs, and/or installed as original equipment on new wheelchairs.

Shell member84is hard, relatively rigid matrix which is sized to extend laterally between wheelchair posts38to provide mechanical support to a back cushion (not shown) coupled thereto. Shell member84is contoured to facilitate providing lumbar support and lateral support to a seated user. More specifically, in the exemplary embodiment, the contour of shell member84also enables shell member84to generally conform to the slight backward bend of wheelchair posts38. In an alternative embodiment, shell member84has a different contour and/or exterior shape defined by an outer perimeter of shell member84. More specifically, the shell outer perimeter is defined by an upper edge90, a lower edge92, and a pair of opposite side edges94that extend between the upper and lower edges90and92, respectively.

In the exemplary embodiment, mounting system72includes a pair of upper mounting bracket assemblies80, a pair of lower mounting bracket assemblies82, and lateral support member100. Upper mounting bracket assemblies80facilitate removably coupling an upper portion96of shell member84to wheelchair back frame posts38, and lower mounting bracket assemblies82facilitate removably coupling a lower portion97of shell member84to posts38.

Lateral support member100is formed symmetrically about a center axis of symmetry102and is formed integrally with a pair of ends104and106, and a body108extending therebetween. In one embodiment, lateral support member100is formed integrally with shell member84. Body108has a width WBmeasured between an inner surface112and an outer surface113of body108. In an alternative embodiment, lateral support member100is formed non-symmetrically. Inner surface112is contoured such that width WBis variable across body108between ends104and106. More specifically, in the exemplary embodiment, body inner surface112has a contour that substantially matches a contour of shell member84. Accordingly, and as described in more detail below, body inner surface112enables body108to substantially mate against a rear exterior surface114of shell member upper portion96when lateral support member100is coupled to shell member84.

In the exemplary embodiment, lateral support member100is coupled against shell member84by a series of threaded fasteners (not shown) which extend through a plurality of openings (not shown) formed in shell member84and into corresponding openings (not shown) formed in, and extending into body108from body inner surface112. In an alternative embodiment, support member100is coupled to body108using any coupling means that enables support member100to function as described herein.

Body108is also formed integrally with a handle portion120which, as described in more detail below, enables a user to selectively uncouple, or couple, shell member84from wheelchair back frame posts38using only one hand. More specifically, the combination of mounting system72and lateral member hand portion120enables even a user with limited hand functionality to install and/or remove shell member84to wheelchair back frame posts38in a single-handed operation.

Handle portion120is mechanically coupled to a pair of retaining pins130that are biased to extend radially outwardly through an opening132formed in each end104and106. In the exemplary embodiment, pins130are biased through a spring-mechanism and are retractable when pressure is exerted to handle portion120. More specifically, and as described in more detail below, when an upward force is induced to an activator portion134of handle portion120, pins130are retracted, such that each pin130is drawn through opening132and into body108.

Each end104and106of lateral member100is formed with a coupling portion140and an interlock portion142. In the exemplary embodiment, coupling portion140is a male rail portion used within a tongue and groove coupling arrangement, and thus has a dovetail-shaped cross-sectional profile. In alternative embodiments, coupling portion140has a cross-sectional profile that is not dovetail-shaped. In another alternative embodiment, coupling portion140is formed as a female coupling portion within a tongue and groove coupling arrangement. More specifically, in the exemplary embodiment, coupling portion140extends widthwise from inner surface112for a length L to interlock portion142. In an alternative embodiment, coupling portion140extends at least partially lengthwise between upper and lower sides144and146, respectively, of support member100. In a further alternative embodiment, coupling portion140extends only partially widthwise across each end104and106and as such does not extend from inner surface112. Length L is shorter than body width WBmeasured adjacent each end104and106. Moreover, in the exemplary embodiment, coupling portion140is substantially centered between upper and lower sides144and146, respectively, of support member100.

Because coupling portion length L is shorter than body width WB, a coupling portion rear surface150is defined. More specifically, in the exemplary embodiment, surface150extends generally perpendicularly between an outer surface152of coupling portion140and a radially inner surface154of interlock portion142. In the exemplary embodiment, an alignment pin opening156extends substantially concentrically through surface150. Alignment pin opening156is sized to receive an alignment pin158therein, as described in more detail below.

Opening132extends through coupling portion140and is sized to receive a retracting pin130therethrough. More specifically, in the exemplary embodiment, opening132is substantially concentrically aligned within coupling portion140between upper and lower surfaces144and146, respectively.

Interlock portion142extends from coupling portion surface150to lateral support member outer surface113. In the exemplary embodiment, interlock portion142is recessed with respect an outer surface157of each end104and106. Moreover, in the exemplary embodiment, interlock portion142has a generally rectangular recessed profile defined by surface154. More specifically, and as described in more detail below, interlock portion142is sized to receive at least a portion of coupling assembly couplers160therein in an interlocked coupling arrangement. In an alternative embodiment, coupling portion140extends only partially widthwise across each end104and106and in such an embodiment, each end104and106can be formed with an interlock portions142at each end of coupling portion140.

Coupling assembly74includes a pair of opposed couplers160that are in a mirrored relationship. Each coupler160is configured to releasably couple to each end104and106of lateral support member100. In the exemplary embodiment, each coupler160includes a top side162and a bottom side164coupled together by an end wall166, an opposite inner end wall168, an inner surface170, and an outer surface172. Inner surface170is opposite outer surface172and may be contoured with a shape that substantially matches a contour of at least a portion of shell member84. Coupler inner end wall168is contoured to substantially match a contour of at least a portion of shell member84. Accordingly, and as described in more detail below, inner surface168enables coupler160to substantially mate against a portion of shell member rear exterior surface114when coupler160is coupled in position relative to back assembly70.

Each coupler160is formed with a coupling portion180and an interlock portion182. In the exemplary embodiment, coupling portion180is a female grooved portion used within a tongue and groove coupling arrangement, and thus has a recessed dovetail-shaped profile that is substantially similar to that of lateral member coupling portion140. Accordingly, coupling portion180is sized to slidably engage lateral ends104and106in releasable contact. In alternative embodiments, coupling portion180has a recessed profile that is not dovetail-shaped, but rather is shaped substantially similar to that of lateral member coupling portion140to enable lateral member ends104and106to be coupled to couplers160in slidable contact. In another alternative embodiment, coupling portion180is formed as a male coupling portion within a tongue and groove coupling arrangement. More specifically, in the exemplary embodiment, coupling portion180extends widthwise from inner surface168for a length LCto coupler interlock portion182. Depending on the contour of shell member84, length LCis as long as, if not longer than, lateral member coupling portion140. Accordingly, coupling portion180is sized to receive lateral member coupling portion140therein. Moreover, in the exemplary embodiment, coupling portion180is substantially centered between upper and lower sides162and164, respectively, of support member100.

In the exemplary embodiment, a retaining pin opening190extends through coupler160between outer surface166and inner surface170. More specifically, opening190is substantially centered within coupling portion180between upper and lower sides162and164, and each opening190is sized to receive a portion of a retaining pin130therein.

Coupler interlock portion182extends widthwise between coupling portion180and coupler outer surface166, and projects radially outwardly from coupler inner surface170. Coupler interlock portion182is shaped and sized to be received within lateral member recessed interlock portion142. More specifically, when couplers160are coupled to lateral support member100, lateral support member coupling portion140is slidably received within coupler coupling portion180, and coupler interlock portion182is received within lateral member interlock portion182to facilitate securing coupler160and lateral support member100in an interlocking coupling arrangement. Accordingly, when coupler160is fully secured and removably coupled to lateral support member100, coupler outer surface166, will be substantially co-planar with lateral support member outer surface113. Moreover, coupler upper and lower sides162and164, respectively, will also be substantially co-planar with respective lateral support member upper and lower sides144and146.

Alignment pin158extends outwardly from coupler interlock portion182into coupling portion180. More specifically, in the exemplary embodiment, alignment pin158extends substantially perpendicularly from a radial inner surface184of interlock portion182and is substantially co-axially aligned with respect to coupling portion180. Pin158is sized to be received within a respective alignment pin opening156, and, as described in more detail below, facilitates aligning and securing lateral support member100with respect to coupler160.

Coupler160also includes a plurality of fastener openings (not shown) extending at least partially through coupler160from coupler outer surface172towards coupler inner surface170. In the exemplary embodiment, coupler160is coupled to mounting bracket assembly80using a plurality of threaded fasteners (not shown) which extend into, and/or through, the fastener openings formed in coupler160. In an alternative embodiment, coupler160is coupled to bracket assembly80using any coupling means that enables coupler160to function as described herein.

In the exemplary embodiment, each upper mounting bracket assembly80is identical to each lower mounting bracket assembly82, and each includes a frame member200that couples to an alignment member202. Each frame member200includes a pair of fastening flanges204and an arcuate body206extending therebetween. Arcuate body206is contoured with a shape that enables an inner surface210of body206to substantially mate against an outer surface212(shown inFIG. 1) of a portion of a respective pole38when a respective bracket assembly80or82is securely coupled to pole38. In the exemplary embodiment, arcuate body206is formed with a radius of curvature that is sized to receive at least a portion of a respective pole38therein.

Each fastening flange204includes a plurality of openings214extending therethrough. Each opening214is sized to receive a fastener (not shown) therethrough for coupling frame member200to alignment member202. In the exemplary embodiment, fastening flanges204are substantially planar.

To facilitate reducing snag points, frame members200and alignment members202are sized approximately equal to each other based on the outer perimeters of each member200and202. Accordingly, when portions200and202are coupled together, no edges overhang from either member202or200. Alignment members202each include a plurality of orientation openings212formed therein which, as described in more detail below, facilitate selective orientation of shell member84with respect to wheelchair10. More specifically, in the exemplary embodiment, openings212extend at least partially through member202from an alignment face216of member202to an inner surface218of member202. Inner surface218is formed with an arcuate recessed portion220that is contoured with a shape that enables alignment member inner surface218to substantially mate against a portion of pole outer surface212when a respective bracket assembly80or82is securely coupled to pole38. In the exemplary embodiment, arcuate recessed portion220is formed with a radius of curvature that is sized to receive at least a portion of a respective pole38therein.

Coupling assembly74is coupled to upper mounting bracket assembly80through a positioning bracket230. More specifically, positioning bracket230, as described in more detail below, not only enables each coupler160to be secured to each respective mounting bracket80, but also enables each coupler to be variably positioned with respect to poles38. In the exemplary embodiment, positioning bracket230includes a pair substantially perpendicular legs232and234coupled together such that bracket230has a substantially L-shaped cross-sectional profile. Alternatively, bracket230has a non-L-shaped cross-sectional profile. Each leg232and234includes a pair of slotted openings236and238, respectively. In the exemplary embodiment, openings236or238are identically sized within each respective leg232and234. In an alternative embodiment, slotted openings236and/or238may be any shape or size that enables positioning bracket230to function as described herein. In a further alternative embodiment, positioning bracket230does not include slotted openings236and/or238but rather includes a plurality of spaced openings which enable positioning bracket230to function as described herein.

Bracket leg232includes an outer surface240and an opposite inner surface242. In the exemplary embodiment, leg232is substantially planar such that surfaces240and242are substantially parallel. Similarly, bracket leg234also includes an outer surface244and an inner surface246, and in the exemplary embodiment, leg234is substantially planar such that surfaces244and246are substantially parallel. In an alternative embodiment, either leg232and/or234is non-planar. It should be noted that the illustrations ofFIGS. 6 and 8are merely exemplary and as such, bracket230may be fabricated with any size, or leg dimensions that enable bracket230to function as described herein. For example, although leg234is shown as having a longer length than leg232, the lengths of legs234and232are variably selected depending on the dimensions of the wheelchair10, such as post spacing W, back assembly70is coupled to.

Shell member lower portion97is removably coupled to lower mounting bracket assembly82through a positioning bracket250. More specifically, positioning bracket250, as described in more detail below, not only enables shell member84to be removably coupled to each post38, but also facilitates orienting and/or variably positioning shell member lower portion97with respect to poles38. In the exemplary embodiment, positioning bracket250includes a pair substantially perpendicular legs252and254coupled together such that bracket250has a substantially L-shaped cross-sectional profile. Alternatively, bracket250has a non-L-shaped cross-sectional profile. Leg252includes a pair of slotted openings256which facilitate variably positioning shell member84with respect to poles38. In the exemplary embodiment, openings256are identically sized. In an alternative embodiment, slotted openings256may be any shape or size that enables positioning bracket250to function as described herein. In a further alternative embodiment, positioning bracket250does not include slotted openings256but rather includes a plurality of spaced openings which enable positioning bracket250to function as described herein.

Bracket leg252includes an outer surface260and an opposite inner surface262. In the exemplary embodiment, leg252is substantially planar such that surfaces260and262are substantially parallel. Similarly, bracket leg254also includes an outer surface264and an inner surface266, and in the exemplary embodiment, leg254is substantially planar such that surfaces264and266are substantially parallel. In an alternative embodiment, either leg252and/or254is non-planar. It should be noted that as illustrated, positioning bracket250is merely exemplary and as such, bracket250may be fabricated with any size, or leg dimensions that enable bracket250to function as described herein.

Bracket leg254is formed with an upper and a lower hinge bracket270and272. Each bracket is sized to receive a sleeve274therein to facilitate hingedly coupling shell member84to mounting bracket assembly82through positioning bracket250. More specifically, sleeve274is coupled to mounting bracket alignment member202by a fastener276inserted into any of the orientation openings212formed within member202. Accordingly, in the exemplary embodiment, each hinge bracket270and272is formed with an arcuate portion280that has a radius of curvature that is sized to enable sleeve274to be received therein in close tolerance, and such that bracket250is then rotatably coupled to mounting bracket assembly82, as is described in more detail below.

During use, wheelchair back assembly70facilitates mounting shell member84to wheelchair back frame posts38, and more specifically, back assembly70includes a universal mounting system72which enables shell member84to be coupled to a plurality of different sized and/or shaped wheelchairs10having different post widths W and/or different support post diameters D. Moreover, mounting system72also enables shell member84to be coupled to wheelchair support posts38which have a different curvature or tilt than those illustrated inFIG. 1. Accordingly, wheelchair back assembly may be used to retrofit existing wheelchairs to replace existing back assemblies, and/or installed as original equipment on new wheelchairs.

When coupling back assembly70to a wheelchair10for the first time during a retrofit of an existing wheelchair10, or during assembly of a newly manufactured wheelchair10, initially lateral support member100is coupled to shell member84such that member100extends across the upper portion96of shell member84and between shell side edges94. More specifically, when coupled in position, lateral member inner surface112is coupled tightly against shell member rear exterior surface114, and handle portion120is positioned between shell upper edge90and lateral support member lower side146. Moreover, once coupled to shell member84, lateral support member100extends generally parallel to shell member upper edge90.

A pair of positioning brackets250are then fixedly secured to shell member84along shell side edges94. Depending on the design of wheelchair10, bracket250may be secured to shell member lower portion97such that either leg surface260or262is secured tightly against shell member exterior surface114. More specifically, each bracket250is secured to shell member84using a plurality of fasteners which extend through slotted openings256and at least partially through shell member84. Alternatively, brackets250may be coupled to shell member84using any coupling means that enables brackets250to function as described herein. Moreover, in the exemplary embodiment, bracket slotted openings256enable each bracket hinge bracket270or272to be selectively positioned with respect to shell member84and with respect to posts38.

Each mounting bracket assembly80and82is then securely coupled to each respective post38. More specifically, bracket assembly frame member200is coupled to each respective alignment member202using a plurality of fasteners. Alternatively, mounting bracket assemblies80and82are secured to posts38using any coupling means that enables bracket assemblies80and82to function as described herein. Accordingly, when members200are securely coupled to members202, each post38is secured between members200and202. The combination of the multi-piece nature of bracket assemblies80and82, and the radius of curvature of surfaces220and206enables bracket assemblies80and82to be used with support poles having a plurality of different diameters D.

A pair of positioning brackets230are then fixedly secured to upper mounting bracket assemblies80. Depending on the design of wheelchair10, each bracket230may be secured to shell member lower portion97such that the inner surface242or246, or the outer surface240or244is secured tightly against mounting bracket alignment face216. More specifically, each bracket230is secured to mounting bracket assembly80using a plurality of fasteners which extend through slotted openings236or238and at least partially through fastening flange openings214. Alternatively, brackets230may be coupled to mounting bracket assemblies80using any coupling means that enables brackets230to function as described herein. Moreover, in the exemplary embodiment, the combination that either positioning bracket leg232or234may be coupled against mounting bracket assembly80, and the bracket slotted openings236or238facilitate each positioning bracket230being variably positioned to selectively orient shell member upper portion96with respect to support poles38and with respect to wheelchair10.

Coupling assembly74is then coupled to upper mounting bracket assembly80such that each coupler160is fixedly secured to each positioning bracket230. More specifically, in the exemplary embodiment, each coupler160is coupled to each bracket230using a plurality of fasteners which are extended through the positioning bracket slotted openings236or238and at least partially into the fastener openings formed in coupler outer surface172.

Each fastener276is then inserted through a respective sleeve274and inserted into an applicable orientation opening212formed within lower bracket assembly member202. More specifically, the plurality of openings212enable shell member lower portion97to be variably positioned with respect to posts38and with respect to wheelchair10.

Shell member lower portion97is then hingedly coupled to posts38through positioning brackets250and from the front side of wheelchair10. More specifically, each positioning bracket230is positioned adjacent a respective lower bracket assembly member202such that each sleeve274is received within an the lower hinge bracket270and/or272on each positioning bracket250.

Shell member84is then rotated backwards and away from a front edge of wheelchair10such that end104and106of lateral member100is slidably coupled to each respective coupler160. More specifically, as shell member84is rotated backwards, each lateral member coupling portion140is received in slidable contact within each respective coupler coupling portion180. As shell member84is rotated in a further direction backwards, each coupler interlock portion182is received within each respective lateral member interlock portion142. More specifically, as interlock portion182is received within interlock portion142, each alignment pin158is inserted in an interference fit within each respective lateral member opening156. Additionally, once interlock portion182is fully seated within interlock portion142, each retaining pin130is biased into, and received within, each respective coupler opening190. Accordingly, once pins130are received within openings190, lateral member100is removably coupled to each coupler160, and thus to wheelchair10, in an interlocked coupling arrangement. Moreover, the biasing of pins130prevents the inadvertent uncoupling of shell member from couplers160.

Accordingly, when desired, a seated user may easily uncouple shell member84from wheelchair10using only one hand. More specifically, as a minimum force is applied to lateral member handle portion120, retaining pins130are drawn into lateral support member100from openings190. After pins130have been retracted from openings190, shell member84may be rotated forward towards the front edge of wheelchair10, such that each end104and106of lateral support member100is slidably uncoupled from each coupler160. Continued rotation of shell member84uncouples shell member upper portion96from posts38, such that shell member lower portion97may be uncoupled from posts38by merely lifting shell member84until each sleeve274is no longer positioned within an applicable lower hinge bracket270and/or272. The remaining back assembly mounting system hardware remains coupled to wheelchair10, even if wheelchair10is folded for storage and/or transportation.

As such, the combination of brackets230and250, and mounting bracket assemblies80and82enable shell member84to be selectively adjusted relative to the wheelchair10. Specifically, bracket assemblies80and82accommodate height adjustments that may be required, such that shell member84may be raised or lowered along wheelchair posts38. Moreover, brackets230and250enable all, or a portion such as96or97of shell member84, to be tilted forward or rearward to accommodate the stabilization and therapeutic requirements of the seated user. Accordingly, wheelchair back assembly84is easily adjustable, and is easily attached or detached from wheelchair10in a single-hand operation.

The above-described wheelchair back assembly provides a user with a high degree of support and adjustablity, and thus accommodates a plurality of therapeutically significant adjustments and orientations. Specifically, the wheelchair back assembly includes a universal mounting system that is usable with a plurality of different sized and shaped wheelchairs. The mounting system is removably coupled to the wheelchair in a manner that enables a user to easily detach and reattach the shell member to the wheelchair, even a user having limited hand dexterity or function. An upper portion of the shell member is slidably coupled to the wheelchair posts in an interlocking coupling arrangement that prevents the inadvertent uncoupling of the shell member from the wheelchair. The lower portion of the shell member is pivotally coupled to the wheelchair posts in a hinged coupling arrangement. As a result, a removable wheelchair back assembly is provided which facilitates increasing the adjustability options available to a user in a cost-effective and reliable manner.

Exemplary embodiments of wheelchair back assemblies are described above in detail. Although the back assemblies are herein described and illustrated in association with seated users, it should be understood that the present invention may be used with a plurality of different wheelchairs. Moreover, it should also be noted that the components of each wheelchair back assembly are not limited to the specific embodiments described herein, but rather, aspects of each back assembly component and method of assembly may be utilized independently and separately from other methods described herein.

In addition, although in the described embodiment, the angular movement of the wheelchair shell member is in a generally vertical plane when the shell member is being attached to or detached from the wheelchair posts, in alternative embodiments, the wheelchair shell member could be moved in a generally horizontal rotational plane or at some other angular orientation as well. Furthermore, instead of the lower positioning brackets being the direct pivot point, alternate pivot points could be formed along the sides of the shell member, and/or fitted to a shape on the posts, in order to get the same type of rotational movement and hinged coupling.

In addition, although the wheelchair back assembly is described has having four mounting bracket assemblies, in alternative embodiments, the back assembly could have more or less than four mounting assemblies, depending on the desired application. Moreover, the lower mounting assemblies do not have to be hingedly coupled, but rather some other removable coupling means, such as the same coupling arrangement used with the upper mounting assemblies, could be used.