| 摘要 |
PURPOSE: To simplify an operating mechanism by placing a copy cutter which is projected toward the outer peripheral surface of a cutter head by the operation of a single-acting cylinder and is retreated by the spring force of a compression coil. CONSTITUTION: High-pressure oil is supplied to the bottom side of a single-acting hydraulic cylinder 20 via hydraulic piping 21, and thereby a piston 20a is expanded to advance a support shaft 13 to cause a copy cutter 16 to project outwards from the outer peripheral surface 4a of a cutter head 4. As the cutter head 4 rotates, the natural ground around the cutter head 4 is drilled. To retreat the copy cutter 16 after the drilling is complete, the hydraulic tubing 21 of the single-acting hydraulic cylinder 20 is switched to the low pressure side and then the copy cutter 16 is retreated to an initial position along with the support shaft 13 by the spring force of a compression coil spring 15. The spring force of the compression coil spring 15 in this case is sufficient to retreat the copy cutter 16 to the initial position by overwhelming the weight of the spring and frictional forces even if the copy cutter device 10 is located beneath the cutter head 4. |
