EXPLOSION-PROOF CUTTING BIT FOR DRILLING EXTRACTION MACHINE Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: invention is intended for use in actuating elements of drilling extraction machines to ensure explosion safety of the latter thanks to prevention of friction spark formation. Proposed cutting bit has body, cutting tool holders and rolling cutter bits anchored in extreme holders. Distance between pins of rolling cutter bit should not exceed 50.0 mm and length of protruding part of rolling cutter bit is not less than length of protruding part of cutting tool. Usage of rolling cutter bit in cutting bit allows risk of ignition of methane to be diminished as rock is cut by rolling cutter bits that will form no friction sparking thanks to their rolling. EFFECT: improved explosion safety cutting bit. 2 dwg