We claim the design for wheelchair caster, as shown and described.
FIG. 1 is a perspective view of a wheelchair caster in accordance with a second variant of the present application;
FIG. 2 is a side elevation view of the wheelchair caster of FIG. 1, the right-side, left-side elevation views being mirror images thereof; and,
FIG. 3 is a front elevation view of the wheelchair caster of FIG. 1, the rear elevation view, top-plan view and bottom-plan view being mirror images thereof.
The broken line portions are included to show environmental unclaimed subject matter only and form no part of the claimed design.