BOREHOLE PUNCHER Russian patent published in 1994 - IPC

FIELD: mining industry. SUBSTANCE: device has a housing. It uses a suspension unit. Connected with the housing is the cutting unit. It is mounted for turning relative to the housing axis. The cutting unit is made in the form of a flat bed and cutter. The cutter is made in the form of a closed chain. It is placed on the bed for movement relative to the bed. The device has cutting unit driving and feeding mechanisms. It is provided with a housing fixation mechanism and a cutting unit hydraulic booster. The housing fixation mechanism is made in the form of a hydraulic cylinder and a grip. The hydraulic cylinder is rigidly connected with the housing. The grip is hinged to the housing and hydraulic cylinder piston. It is mounted for movement beyond the limits of the housing. The cutting unit hydraulic booster is made as a stepped hydraulic cylinder and differential piston. The differential piston is positioned in the stepped hydraulic cylinder; it is spring-loaded relative to the housing. Together with the housing it forms the super-piston, sub-piston and discharge spaces. The super-piston space is hydraulically connected with the housing space, the sub-piston space - with the cutting unit feeding and housing fixation mechanisms, and the discharge space-with the external space. EFFECT: enhanced reliability due to the increase of cutting unit stiffness. 5 dwg