| 摘要 |
PURPOSE:To improve measuring precision, by a method wherein, through a lifting tool having an arm part energized by a spring and releasing a weight from grasping through the working of an electromagnet, a weight, engaged with a rod, is lifted up and released from grasping. CONSTITUTION:With a lifting tool 9 lowered through reverse running of an electric motor M, after a slope surface 45 of a coupling part 43 is brought into contact with the upper surface of a flange 3a of a weight 3 and an arm part 10 is forcibly opened against a spring 6, a grasping part 10a is engaged with the under surface of the flange 3a to grasp the weight 3. Thereafter, when, with the weight 3 lifted together with the lifting tool 9 through forward running of the electric motor M, a contact probe 27 makes contact with a contact piece 51, and a switch 54 is turned ON to energize an electromagnet 7. Thereafter, through magnetic repulsion action between the electromagnet 7 and a permanent magnet 41 of the arm part 10, the grasp part 10a is opened, and the weight 3 is dropped. Further, the weight 3 exertes an impact on a rod 4 through a drop pad 8 to insert a cone part 26 into a ground. |
