FRACTURE FORMER Russian patent published in 2009 - IPC E21C37/00 E21B43/26 

FIELD: mining.

SUBSTANCE: invention refers to mining and can be implemented for generation of transverse germinating fractures in massif of rock for directed weakening by means of developing plane of fluid breaks and for facilitating optimal conditions for underground development of mineral deposits. The fracture former consists of a cartridge with lengthwise openings and of cutting elements installed in crisscross manner and intended to travel along crisscross opposite guiding inclines and to project their cutting edges from the lengthwise opening of the cartridge; the fracture former also includes a return spring. The said inclines are made on internal surface of the cartridge. The cutting elements are assembled on a piston located inside the cartridge and designed to rotate axially; check supporting valve is installed inside the cavity of the cartridge. The return spring is mounted between the piston and the cartridge.

EFFECT: increased reliability of operation due to control over loads to cutting elements during cutting; also increased efficiency of operation owing to possibility to cut initiating fracture on any section of blasting hole.

2 dwg