BALL CASE CONTROLING BALL'S POSITION

摘要

A ball case controlling the location of ball is provided to increase the durability of ball and reliability of the apparatus by including a plurality of binding protrusions which restricts to move of ball. A ball case controlling the location of ball comprises the rotation lamp delivering the torque; and a plurality of binding protrusions(244) which restricts to move of the direction to the forward direction of the advance lamp. The ball case includes the control protrusion(242) in the outer circumference and the guiding slot(246) which restricts to move of ball according to the direction induced with the guiding groove.