| 摘要 |
A cutting head 20, used to create continuous flight auger piles, having; a hollow cylindrical core 34, a helical flight 42 and a threading tooth 50. The tooth has an extended position where it protrudes beyond the periphery of the flight and a retracted position where it does not, an inner hollow tubular member 43 which can move inside the core along the longitudinal axis of the core. There is a control means (54, figure 7) for causing the tooth to be displaced in response to the translation of the inner tubular. The control means includes; a rack (56, figure 7) fixed to the inner tubular, a gear (58, figure 7) cooperating with the rack and mounted on the bottom end of the core, a lever (60, figure 8) connected to the gear, a connecting rod (62, figure 8) pivotally connected to the lever and the tooth, whereby translation of the rack causes displacement of the tooth. |
