| 摘要 |
An earth boring or shaft sinking apparatus in which a column is continuously rotatable about its axis, the column including a cutting wheel at one end rotatable about a wheel axis normal to the axis of the column, the cutting wheel including sprockets mounted about the wheel axis, the sprockets providing engagement for an endless bucket-carrying chain for direct conveyance of cuttings from the bottom of a hole to the top end of the column, which includes another set of sprockets for the endless bucket-carrying chain and discharges the cuttings into a feed bin. The cutting wheel is continuously rotated about the column longitudinal axis, as well as its wheel axis of rotation. In one example, a main, enlarged, cone-shaped cutting head is rotatable with the column for rotation about the column axis at a selected rate of speed, while the cutting wheel is additionally rotated about its wheel axis at a different selected speed, rotation of the cutting wheel and of the cutting head being continuous, the cutting wheel providing an advancing central bowl shaped recess adapted to serve as a lead or pilot hole to receive cuttings from the second enlarged main cutting head. Different arrangements of cutting wheels and endless bucket means are provided. |
