Patent ID: 7370876
Filing Date: 2008-05-13
Classification: A61G,B60G

Abstract:
1. A side frame assembly for a wheelchair suspension comprising: a mainframe; a front caster assembly including a front caster frame and a front caster, said front caster frame having two opposite ends connected respectively and pivotally to a front end of said mainframe and said front caster; a return spring disposed between said front caster frame and said mainframe so as to bias said front caster to a predetermined position relative to said mainframe; a drive wheel assembly disposed behind said front caster assembly and including a drive wheel frame, a drive wheel disposed pivotally on said drive wheel frame; and a driving unit operable to rotate said drive wheel; a linkage connected pivotally to said mainframe; said front caster frame and said drive wheel frame; and a rear caster assembly including a rear caster frame attached to a rear end of said mainframe, and rear caster disposed pivotally on said rear caster frame; wherein said front caster frame is connected pivotally to said mainframe at a first pivot point, said linkage including: a front link having a front end connected pivotally to said front caster frame at a second pivot point, and a rear connected pivotally to said front caster frame at a second pivot point, and a rear end connected pivotally to an end of said device wheel frame at a third pivot point; and an inclined rear link having a front end connected pivotally to said rear end of said front link at said third pivot point, and a rear end connected pivotally to said mainframe at a fourth pivot point.