Improvements of manipulation torque transfer mechanism and assist unit for one hand drive wheelchair with a triple ring

We develop a one hand drive wheelchair with original manipulation mechanism and power assist mechanism. In this investigation, first, we improve the transfer mechanism of this wheelchair. As a result, using an improved mechanism, the running resistance of the wheelchair decreased with about 1/2 to the previous one. The effects of this improvement are verified by long distance drive experiment using some one hand drive type wheelchairs. Secondly, we develop the assist unit, which has a new on/off mechanism constructed by link and sliding mechanism, in order to realize the sure assist torque transformation. During assist, improved unit surely keeps the distance of two rollers, which transfer assist torque to tires. Therefore, assist torques, provided by DC motor, are surely transfer to tires.