METHOD FOR AUTOMATION OF CHISEL FEED AND DEVICE FOR REALISATION OF THIS METHOD Russian patent published in 2012 - IPC E21B19/08 E21B44/06 

FIELD: mining.

SUBSTANCE: device for automation of chisel feed comprises a casing connected in its upper part with an adapter bushing, which in its turn is connected to a valve unit having through holes, in the lower part the casing is detachably connected to a stem adapter bushing, which is fixed with a nut, and between the casing and the stem adapter bushing there is a circular cavity, where a diaphragm is installed, besides, the circular cavity is connected with a groove in the casing by a hole, above which there is a check valve arranged in the groove. The method for automation of chisel feed includes using a drilling circulation system to determine the axial load at the chisel. Above the chisel a device is installed for realisation of the method for automation of chisel feed, the axial load at the chisel during flush drilling is determined using the pressure drop in the circulation system with variation of the axial load in the lower part of the drilling string, namely, if there isn't an axial load at the chisel, through holes open in the valve unit of the device for realisation of the method for automation of chisel feed, and in case there is an axial load at the chisel, through holes partially close in the valve unit as a result of upward displacement of the stem adapter bushing, besides, pressure in the circulation system is fixed with a pressure gauge on the drilling string.

EFFECT: development and use of pressure drops in the circulation system, facilitation of drilling string operation accounting to maintain the specified bottomhole conditions.

3 cl, 4 dwg