[Problems] The structure is simplified, to reduce the cost and weight. A rotatably provided about an axis perpendicular to the rotating body 14 on the base 12, the left recess 20 and the right recess 22 of the upper opening provided on the upper surface of the rotating body 14, is provided on the base 12 and reciprocally rotates the rotary body 14 at a predetermined rotation angle by an electric motor 30 that is.BACKGROUND 1【課題】構造を簡素化し、コストダウンと軽量化を図ること。【解決手段】基台12上に回転体14を垂直な軸線周りに回転可能に設け、回転体14の上面には上方開口の左足用凹部20および右足用凹部22を設け、基台12に設けられた電動モータ30によって回転体14を所定の回転角をもって往復回転駆動する。【選択図】図1
