| 摘要 |
<p>A powered wheelchair ramp (10) includes a drive mechanism (14) having a gear (21), a cam (22), and a lever arm (24) keyed to a common shaft (28) to prevent relative motion among these elements. An electric motor (31) drives the gear (21) through a clutch (33) and the lever arm (24) raises or lowers a folding ramp (10). Energy storage means (53, 91) engage the cam (22) through a follower (71) for storing energy as the ramp (10) is lowered and for releasing energy when the ramp (10) is raised. The energy storage means (53, 91) also damps the motion of the ramp (10). The energy storage means (53, 91) aids lifting the ramp (10). The clutch (33) is released for manual operation and can engage at any point for powered operation.</p> |
