Abstract
The purpose of this study is to develop a power assist machine that can assist the user's arm to reduce burden on farm workers. The assist machine consists of a linkage mechanism in order to use a single actuator. In this paper, we used a screw feed mechanism and a worm gear mechanism as a deceleration mechanism having a self-lock function. As a result, it is possible to keep the work posture of the upper limbs without controlling an actuator. The effectiveness of the proposed two kinds of power assist machines is verified by the result of the experiments.
