DEVICE FOR FORMATION A BOREHOLE IN A SOIL BY EXPANDING Russian patent published in 1996 - IPC

FIELD: borehole drilling. SUBSTANCE: device for borehole origination in a soil by expanding has drive shaft, eccentric sleeves, roller bearing, conical rollers, seal members, and an arrangement for facilitating device withdrawal from the borehole originated. Each arrangement for facilitating device withdrawal is made in the form of cylindrical sleeve with a slot, two spacer sleeves with ring bores, and a projection on the drive shaft. Eccentric sleeve of each a shaft is made of two parts. Each seal member is of ring shape. The ring is spring loaded about appropriate roller and may interact with internal end surface of a flange of a proper part of the eccentric sleeve. Spacer sleeves of each roller are placed between portions of a proper eccentric sleeve and rigidly connected to a proper cylindrical sleeve. EFFECT: high productivity. 6 cl, 16 dwg