WELL DRILLING DEVICE (VARIANTS) Russian patent published in 2007 - IPC E02F5/18 E21B7/26 

FIELD: trenchless well drilling, particularly for underground service line laying.

SUBSTANCE: device comprises shaft 1 with removable forward stroke 3 and reverse stroke 4 modules, as well as threaded conical head 2. Reverse stroke module is made as conical auger. Forward stroke module 3 includes a number of eccentric wheels serially turned with respect to rotational axis. Each wheel consists of hubs rigidly connected to driving shaft and rims rotary installed on the hubs. Rim sides are inclined to driving shaft 1 and define angle φ₁ in-between, wherein the angle obey the following inequality: arctg(p/π·d_i)≤ φ₁≤ arctg(p/2(d_i+2ε_i)), where p is pitch of conical head 2 thread, d_i and ε_i are diameter and eccentricity of i wheel correspondingly. In accordance to the second variant rim sides are parallel to driving shaft axis and provided with thread made in working rim surfaces. The thread has pitch equal to that of conical head thread.

EFFECT: increased drilling efficiency, decreased power inputs and increased device capability due to reduced area of device contact with ground and elimination of device slippage.

4 cl, 3 dwg