A shock absorption mechanism for a wheelchair includes a caster fork including a first oblique surface and a second horizontally disposed surface, relative to a horizontal plane of travel of the wheelchair. A portion of the second surface includes a curved profile. A joint is mountable adjacent a first...http://www.google.co.uk/patents/US6892421?utm_source=gb-gplus-sharePatent US6892421 - Oblique angled suspension caster fork for wheelchairs
