DEVICE FOR FREE-FALL BORING Russian patent published in 2009 - IPC E21B1/12 E21B11/02 

FIELD: mining.

SUBSTANCE: invention relates to well-drilling field, and particularly to devices for free-fall boring. Device contains arm, over block of which it is overthrown instrumental rope, bearing at one end boring bar with drilling assembly, and by other end is connected to winch, and additional drop point, installed over boring bar with ability of free movement by instrumental rope. Drilling assembly is implemented in the form of sleeve and allows transverse axis, on which it is fixed mite-borne mechanism for overlapping of bottom by its part of inlet hole of drilling assembly, and by its top part contacting to wedgelike or tapered bottom part of boring bar, which in its top part allows receiving element - dish for interaction with additional drop point. Device allows also U-shaped spring, providing ultimate thrust jaw of mite-borne mechanism to the side of bottom edge of sleeve, maximum opening inlet opening of drilling assembly at its fall to bottom.

EFFECT: it provides productivity improvement of the device.

4 cl, 1 dwg