DOWNHOLE DEVICE FOR FORMATION OF DIRECTED CREVASSES Russian patent published in 2008 - IPC E21C37/06 E21B43/26 

FIELD: mining.

SUBSTANCE: invention can be used for separation of blocks from massifs, for mining valuable crystal raw materials and building stones, breaking oversizes. The device comprises a tube, an elastic sealer mounted on the tube end and a system for injection of fluid into the tube. A plug is provided at one end of the tube and the second end is made in the shape of a collet and longitudinal slots are provided along the tube. An elastic sealing washer and a metal bush are fitted successively on the tube. The sealer is made as a sealing ring fitted in the circular groove provided on the lateral surface of the plug. A hydraulic cylinder installed so that its plunger can enter the tube from the collet side is used as a system for injection of fluid into the tube. A stepwise tapering is provided at the end of the hydraulic cylinder at the side, where the plunger comes out of the tube; a circular groove for cohesion with the tube collet is provided on the external surface of tapering.

EFFECT: increase of efficiency of the device due to reduction of labour consumption during operation of the same and reduction of power required for formation of a crevasse.

5 cl, 4 dwg