DEVICE FOR FORMING BOREHOLES IN SOIL BY EXPANDING Russian patent published in 1996 - IPC

FIELD: mining. SUBSTANCE: device for forming boreholes in soil by expanding includes drive shaft with eccentric sleeves and rotatable conical rollers installed on the eccentric sleeves. Disks connected rigidly to the eccentric sleeves are placed between ends of adjacent rollers. Symmetry axis of a disk is shifted about lengthwise axis of the device by a value of "e" eccentricity of the appropriate eccentric sleeve. Sealing members made in the form of spring loaded ring with concave spherical surface interacting to spherical surface of an appropriate disk are placed between end surfaces of each roller and disk. Roller supports are made in the form of self setting radial/spherical frictionless bearings. Sphere center of R₁ radius coincides with center of spherical surfaces of R₂ radius of the spring loaded ring and disk. EFFECT: high productivity. 4 cl, 16 dwg