The invention "a racking machine" uses a screw rod and a guide rod to make a sliding seat move laterally, and an impact rod is connected with an elastic racket to make a longitudinal movement, forming a racking function； and the angle or position of the racket can be adjusted by adjusting the position of the guide rod or the height or angle of the mounting frame. Further combining with a controller can achieve the function of automatic back clapping.本創作「一種拍背機」，係以螺桿及導桿使一滑座能橫向運動，並配合一衝擊桿連結一彈性拍背器做縱向運動，形成一拍背功能；並且調整導桿之位置或安放架之高度或角度，即可調整拍背之角度或位置。進一步結合一控制器可以達成自動拍背之功能。
