| 摘要 |
There is disclosed a removable core drill for use in geological prospecting and comprising a hollow cylindrical body (2), a drill bit (1) connected to the lower end of the cylindrical body (2), a latching device (9, 12) connected to the upper end of the cylindrical body (2), cutter elements (5) pivotally connected to the cylindrical body (2) and positioned intermediate the upper and lower ends thereof for inward and outward movement relative to the longitudinal axis of the cylindrical body (2) between retracted positions and operating positions, and a spreader device (8) which is movable longitudinally within the cylindrical body. The spreader device moves between an upper disengaged position and a lower position of engagement with the cutter elements, and causes outward movement and inward movement of the cutter elements as the spreader device moves respectively to and from the lower engaged position. The spreader device (8) is held in either of its upper and lower positions by engagement therewith of the latching device (9, 12). Slots (13) are formed in the wall of the cylindrical body (2) to permit the inward and outward movement of the cutter elements (5). <IMAGE> |
