Ergonomically designed seat assembly for a portable wheelchair

An ergonomically designed seat assembly comprising:

• a seat frame;
• a backrest subassembly connected to said seat frame, said backrest subassembly comprising a backrest frame, at least one resilient pivotal member connected to said backrest frame, and a backrest connected to said at least one resilient pivotal member such that said backrest is capable of resilient pivotal flexing about a transverse horizontal axis, and wherein said backrest subassembly is connected to a back support member which is slidably mounted within a hole in said seat frame such that the depth of said backrest relative to said seat is adjustable, and wherein said back support member comprises at least two portions in a telescoping relationship such that the height of said backrest relative to said seat is adjustable;
• a seat pivotally connected to said seat frame such that said seat is capable of pivotal tilting about a transverse horizontal axis relative to said seat frame and independent of said backrest subassembly;
• at least one resilient member disposed between said seat frame and said seat so as to allow resilient relative pivotal tilting therebetween;
• two leg rests pivotally connected to said seat frame such that said leg rests are capable of pivoting about a transverse horizontal axis relative to said seat frame, said leg rests having a locking mechanism whereby said leg rests may be held in place at various angles relative to said seat frame.

A portable wheelchair comprising:

• a collapsible wheelchair chassis;
• a seat frame detachably connected to said wheelchair chassis;
• a seat pivotally connected to said seat frame such that said seat is capable of pivotal tilting about a transverse horizontal axis relative to said seat frame and independent of said backrest subassembly;
• at least one resilient member disposed between said seat frame and said seat so as to allow resilient relative pivotal tilting therebetween;
• and,
• a backrest subassembly adjustably connected to said seat frame and detachably connected to said wheelchair chassis, said backrest subassembly comprising a backrest frame, at least one resilient pivotal member connected to said backrest frame, and a backrest connected to said at least one resilient pivotal member such that said backrest is capable of resilient pivotal flexing about a transverse horizontal axis.