DUMMY SHAFT HAVING VARIABLE EXTERNAL DIAMETER

摘要

PURPOSE: A dummy shaft with variable external diameter is provided to be publicly used in various shaft coupling objects which have different diameter of a combined shaft. CONSTITUTION: A dummy shaft(100) with variable external diameter comprises a center shaft(110), a block, a shaft pad(130) and a control unit. The center shaft comprises a screw thread processing unit on a circumferential surface. A first slope is formed in the front and the rear of the center shaft. The shaft pad comprises a second slope sliding according to the first slope of the block. The control unit is coupled with the front and the rear of the center shaft. The control unit slides the shaft pad and changes the external diameter of the shaft pad.