CUTTING BIT FOR MINING MACHINE Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: this is used in heading machines at driving main and auxiliary underground workings, and also in stoping operations in chambers. Cutting bit for mining machine has hollow body, face part, spiral blades, holders, and rock-crushing tools. Face part is fixed on body end. Blades are secured on outer side surface of body and are uniformly displaced relative to each other over body perimeter. Height of each blade is successively reduced in direction towards face part. Holders are arranged on face part and on each blade, and each holder carries rock-crushing tool. Cutting bit has front and rear parts. Rock-crushing tools are installed on front part cutting bit at crushing pitch reduced in direction towards face part. On rear part, rock-crushing tools are installed at permanent crushing pitch. Length of front part of cutting bit over its longitudinal axis is at least 0.53 and not over 0.73 of bit rear part length over same axis. Rock-crushing tools are arranged so that one of them is in each crushing line. EFFECT: high efficiency. 28 cl, 6 dwg