Abstract: A wheelchair frame includes a pair of side frame assemblies, a connector connecting the two side frame assemblies, a seat, caster wheel mountings, drive wheel mountings, and a leg rest mounting. Each of the side frame assemblies have an upper frame member and a lower frame member. The upper frame member is pivotally connected at its forward end to the forward portion of the lower frame member and supported at its rearward end by a suspension support member (i.e., shock absorber) connected to the rearward end of the lower frame member. The seat is attached between the upper frame members of each side frame assembly. With this configuration, the upper frame members and the seat are free to pivot about the pivotal connection between the upper frame member and the lower frame member. In operation, the upper frame members and seat "float" up and down on the shock absorber to provide cushioning to the user.

Abstract: A foldable wheelchair has a folding mechanism connecting two side frame assemblies to each other. The side frame assemblies each support a castor frame piece, pivoting shafts of the folding mechanism, drive wheel axles and a seat back tube. The side frame assemblies are made of two halves that are secured together and may be fabricated from compression or injection molded composite plastics. The seat angle is adjusted by pivoting the side frame assemblies around a pivot point located in an upward and forward region of the side frame assembly.

Abstract: A modular wheelchair that is fully adjustable for a wide range of users in a wide range of uses includes a wheelchair chassis, a wheel assembly and a seat assembly. Drive wheels of the wheel assembly may be adjusted to have a different camber angle without changing the wheel base or the height of the wheelchair chassis. The modular wheelchair may also include a leg rest assembly that is adjustable to provide easy access to the wheelchair. The seat assembly and the leg rest assembly are each foldable so that the wheel chair may be easily stored.