| 摘要 |
PURPOSE:To easily carry out the removing operation of a paved portion without generating noise by lowering a vertically moving member installed on a strut by means of an actuator and pressingly driving a core cutter against the paved portion of the lid frame for a manhole to cut same in a cylindrical shape. CONSTITUTION:A fixed board 11 on which a strut 10 is erected is fixed to the top of a manhole lid 8 by means of magnets 9 and, by adjusting adjusting screw rods 16, each core cutter 19 is positioned on the upper portion of a paved portion 7. Then, by lowering a vertically moving member 12 along the strut 10 by means of hydraulic cylinders 14, 14, the rotary knife of each core cutter 19 is pressed against the paved portion 7 and driving motors 18 are driven to give a high-torque rotation to each core cutter 19 via each reduction gear 17 to carry out cutting 7a into a cylindrical shape. Then, by rotating the vertically moving member 12 each time by a certain angle on the strut 10, cutting 7a is equally carried out to remove the whole paved portion 7 from the top of a flange portion 3. Thereby, the removing operation of a paved portion can be carried out very easily while hardly generating noise. |
