| 摘要 |
PURPOSE:To increase operating accuracy of a recorder by a method that a winding drum of wire rope suspending a heavy plumb-bob is connected to the rotation axis of a torque motor through a magnetic powder clutch, and the tension of the rope is always maintained constant. CONSTITUTION:Sand 6 is filled into a sand pile guide pipe 1, and a heavy plumb-bob 7 suspended by the wire rope 8 is put on the sand 6. Then, the pipe 1 is gradually pulled up from the ground 4, and when the sand 6 is discharged from the end of the pipe 1, a sand pile is formed. With the descent of the sand 6, the plumb-bob 7 descends, and the rope 8 is paid out from the winding drum 12, and the length of wire paid out is recorded in a recorder 14. As the drum 12 is connected to the rotation axis 18a of the torque motor 18 through the magnetic powder clutch 19, it gives constant tension to the rope 8 in the direction of an arrow 17, regardless of the speed of the wire paying out. Therefore, the rope 8 is not paid out more than required, so the sand surface descending condition in the pipe 1 can be accurately determined. |
