Retractable expander

The utility model discloses a retractable expander, including pitman shaft, direction sloping block, arc, the direction sloping block is radial distribution on the outer wall of pitman shaft, the bottom fixed connection of every direction sloping block on the pitman shaft, the top of direction sloping block from this direction sloping block front end terminad gradually tilt up form an inclined plane, the length of direction sloping block is greater than the length of arc, the arc slides along direction sloping block length direction at the top of direction sloping block. This application is through setting up direction sloping block and arc, and the arc slides to a high position along direction sloping block length direction from the low level at the top of direction sloping block, and atthe in -process that slides, the arc is constantly to high shift, constantly outside expansion simultaneously to can outwards expand sunken pipeline, accomplish the repair. 本实用新型公开了种可伸缩式扩管器，包括连杆轴、导向斜块、弧形板；导向斜块呈辐射状分布在连杆轴的外壁上，每