IMPACT-EFFECT DEVICE Russian patent published in 2009 - IPC E21C37/00 E02D7/10 

FIELD: mining.

SUBSTANCE: proposed device is designed for impact destruction of thick rocks and other materials, pile driving, soil compacting etc. and comprises a casing to house piston-striker, hydro pneumatic accumulator, two-position pressure control slide valve, two cylindrical two-position valves with control pistons. The control piston of every valve represents a two-stage cylindrical rod, the smaller stage end of which faces the valve to form, along with the casing, the first circular chamber constricted by the said smaller stage end and stem and permanently communicated with the pressure line, the second circular chamber constricted by the larger stage end and smaller stage side surface permanently communicated with the drain line and the piston control chamber, alternately communicated with pressure and drain lines, constricted by the casing and the larger stage free end face. The larger stage sidewall features a circular groove arranged so that the isolated chamber, constricted by the said groove and casing, communicates with the second chamber only in case the valve is closed, that is, it is in contact with the casing bore ledge. The hydraulic control slide valve represents a cylindrical plunger moving the casing with one its smooth end, its diametre being equal to that of the plunger, in permanently located in the end face chamber communicated with the rear coaxial groove of the working stroke chamber. The opposite end represents three-stage cylindrical rod with its diametre increasing towards the plunger and its smaller stage is permanently in the said end face chamber communicated with the front coaxial groove of the working stroke chamber. Two other stages make, along with the casing, circular chambers with diametre smaller than and equal to the plunger permanently communicated with the drain and pressure lines.

EFFECT: higher reliability and simple design.

3 cl, 1 dw