WELL-SINKING DEVICE Russian patent published in 1997 - IPC

FIELD: construction, applicable for well-sinking without excavation of soil. SUBSTANCE: the device uses a motor-reduction gear whose shaft is coupled to the working member made in the form of a cantilever shaft with taper and cylindrical rolls successively installed on it, the rolls are shifted at an angle to the device shaft. An internal eccentric bush and two external bushes with ring knives are installed on the working member shaft in each space between the rolls. Flexible members of adjustable stiffness and brushes contacting with inner surface of the rolls are inserted in the grooves of the external bushes. Packing members are installed between the ring knives and between the bushes and rolls. The front and rear necks of the internal eccentric bushes have different values of eccentricities and angles of inclination relative to the device longitudinal axis equal respectively to the eccentricity and angle of inclination of the previous and subsequent rolls. The taper rolls have cylindrical tail pieces. The diameter of the ring knife and the length of the roll cylindrical tail piece are determined by mathematical formulas. EFFECT: constant sinking time. 2 cl, 3 dwg