FIELD: drilling, in particular, design of drill boxes of mine drills. SUBSTANCE: drill box has drive including rotary motion source and connected device with chuck unit for rotation and holding of detachable tool for mining operations with shank made in the form of rod. Chuck unit includes spindle, collet grip and collet. Spindle is made in the form of cylindrical bushing with male thread on its end. Collet grip is made in the form of ring-shaped body with threaded hole to join spindle. Collet is located inside bushing and installed for axial motion inside bushing. EFFECT: higher efficiency. 11 cl, 3 dwg
