DEVICE FOR ROCK BREAKAGE BY BREAKING-OFF FROM ROCK MASS Russian patent published in 1997 - IPC

FIELD: mining; rock breakage. SUBSTANCE: the offered device has hydraulic cylinder with stop piston and rod with end stop on the free end, thrust piston and tubular rod with cone expansion on free end coaxially installed on stop rod, opening collet embracing cone expansion of tubular rod and connected with hydraulic cylinder piston, hydraulic pump with pressure line, return line, supplying lines communicated with hollows of hydraulic cylinder, hydraulic distributor communicating pressure and return lines with supplying lines. Device also has mechanism for turning the stop rod during its withdrawal into hydraulic cylinder and additional hydraulic pump with pressure and return lines and two supplying lines communicated with hollows of hydraulic cylinder above stop piston and between the pistons, distributor of alternating communication of additional supplying lines with additional main lines. Hydraulic drive of distributor is communicated with additional pressure line. Installed on additional supplying lines is normally opened valve with spring-loaded control valve and control cavity communicated with the main pressure line. End stop is made in form of drill crown bit. EFFECT: higher efficiency. 2 dwg