| 摘要 |
PROBLEM TO BE SOLVED: To visually confirm the oscillation of two excavating arms on the ground by transmitting the oscillations of the excavating arms through cams as upward/downward movement of one operation rod and observing this upward/downward movement on the ground.SOLUTION: The pile hole drill head 1 includes a coupling portion 18 to be coupled to a lower end portion of an excavating rod at the upper end of a head body 2 having the first excavating arm 14 and a second excavating arm 15; and a head operation body 3 continued thereto to confirm the positions of the excavating arms 14, 15. Extension excavation is performed by reversely rotating and largely oscillating the excavating arms 14, 15. The head operation body 3 is provided with cams 23-26. The oscillation of the excavating arm 14 is transmitted through the first cam 23 and the third cam 25, the oscillation of the excavating arm 15 is transmitted through the second am 24 and the third cam 25, and these oscillations are transmitted as upward/downward movement of one operation rod 27 through the third cam 25 and the fourth cam 26. |
