DEVICE FOR HYDRAULIC ROCK FRACTURING IN WELL Russian patent published in 2008 - IPC E21C39/00 

FIELD: mining, particularly mining geophysics, namely equipment to determine stressed in rock massif.

SUBSTANCE: device comprises cylindrical body with sealing members installed at body ends. The sealing members have compression mechanism made as piston and cylinder unit with orifice in cylinder installed on cylindrical body between sealing members. Two channels are made in cylindrical body. One channel is communicated with working chamber of piston and cylinder unit. Another one is connected with orifice made in piston and cylinder unit cylinder. Two check valves are coaxially installed in cylindrical body from end side thereof. One check valve has stem located from the first valve side and projecting from cylindrical body. Said stem is supported by control arm eccentric. Connected to another valve side is tapered pusher, which may cooperate with another check valve.

EFFECT: simplified structure and assemblage, increased operational reliability due to decreased number of supply pipelines.

2 dwg