DEVICE FOR ROOF-BOLT BOREHOLE DRILLING BY FLUID-CIRCULATION METHOD Russian patent published in 2007 - IPC E21B4/02 F15B11/20 

FIELD: coal-mining industry, particularly cutting machines for hydromines.

SUBSTANCE: device comprises oil 1 and water 6 loops including oil 2 and water 9 pumps correspondingly, control members and pressure hydrolines 8. Oil loop 1 comprises hydraulic cylinder 5 and discharge hydroline 4. Water loop has hydraulic drive 7 mechanically connected to hydraulic cylinder 5. Device has water pressure sensor 10 communicated with pressure hydroline 8 of water loop and with two-way spring-loaded slide 11 having sealed chamber 14 arranged from spring 13 side. Pressure branch 17 of the slide is connected with pressure hydroline 3 of oil loop. Sealed chamber 14 of the slide is communicated with discharge hydroline 4 through connected in parallel throttle flap 16 and check valve 15. Slide end opposite to sealed chamber 14 is mechanically connected with water pressure sensor 10 included in water loop 6.

EFFECT: prevention of hydrodrive overturning as moment of cutting resistance increases during drilling operation and increased borehole drilling reliability.

2 dwg