Wheelchair back system

Claim 2

A wheelchair back system adapted to be mounted on the vertical posts of a wheelchair, said back system comprising: a shell, a mounting system and a cushion; said mounting system comprising a pair of vertical channels attached to said shell, said channels having an upper end and a lower end, said channels adapted to partially encircle vertical wheelchair posts and contact said posts at said upper end and said lower end; bracket means affixed to a vertical post of a wheelchair; strap means affixed to said channels adapted to engage said bracket to hold said shell adjacent to said wheelchair post and to affix said shell in a selected vertical position on said wheelchair post; and said cushion affixed to the front side of said shell.

Claim 3

A wheelchair back system as described in claim 1, wherein said cushion includes a vertical channel adapted to receive a pad, said pad comprising a plurality of horizontally divided chambers, said chambers being filled with a flowable fluid.

Claim 4

A wheelchair back system as described in claim 2, wherein said chambers are filled with a viscous liquid material which flows under pressure, but which maintains its shape and position in the absence of applied pressure.

Claim 5

A wheelchair back system as described in claim 2, wherein said cushion comprises a cover which surrounds said cushion and which extends to the rear of said cushion, whereby said cover extension is located between said shell and said cushion when said cushion is attached to said shell.

Claim 6

A wheelchair back system as described in claim 1, wherein said cushion includes a lumbar support affixed to said cushion, said lumbar support adapted to be affixed to said cushion at a selected height, independent of the height of said back.

Claim 7

A wheelchair back system as described in claim 1, wherein said cushion includes bolsters which are affixed to the front lateral portions of said cushion, said bolsters being affixed to said cushion at a selected position and adapted to provide lateral support to a person sitting in the wheelchair.

Claim 8

The wheelchair back system as described in claim 1 wherein said strap means includes an elongated slot and said mounting system includes a twist lock mounted on the back of said shell, said twist lock being aligned with said slot and adapted to maintain said strap means in close engagement with said shell.

Claim 9

A wheelchair back system as described in claim 7 wherein said twist lock includes a cam surface adapted to urge said strap means toward said shell as said twist lock is rotated from the unlocked position to the locked position.

Claim 10

A wheelchair back system which includes a mounting system by which said back system is removably affixed to a wheelchair having a pair of vertical posts, said mounting system including a pair of vertical channels open to the rear, attached to said back system, said channels being about two inches wide, said channels adapted to encircle the front side of the vertical posts of a wheelchair, and said mounting system including strap means to encircle the rear side of the vertical posts and to removably affix said channels to said vertical posts said strap means further including an elongated slot and said mounting system further including a twist lock mounted on the back of said shell, said twist lock being aligned with said slot and adapted to maintain said strap means in close engagement with said shell.

Claim 11

A wheelchair back system which includes a mounting system by which said back system is removably affixed to a wheelchair having a pair of vertical posts, said mounting system including a pair of vertical channels open to the rear, attached to said back system, said channels being about two inches wide, said channels adapted to encircle the front side of the vertical posts of a wheelchair, and said mounting system including strap means to encircle the rear side of the vertical posts and to removably affix said channels to said vertical posts said strap means further including an elongated slot and said mounting system further including a twist lock mounted on the back of said shell, said twist lock being aligned with said slot and adapted to maintain said strap means in close engagement with said shell.

Claim 12

A wheelchair back system as described in claim 9 wherein said mounting system includes bracket means affixed to the back side of said vertical post, said bracket adapted to engage said strap means to removably position said back system at a selected height on said vertical post.

Claim 13

A wheelchair back system as described in claim 10 wherein said bracket includes a lower shelf adapted to support said strap.

Claim 14

A wheelchair back system as described in claim 9 wherein said twist lock includes a cam surface adapted to urge said strap means toward said shell as said twist lock is rotated from the unlocked position to the locked position.