PNEUMATIC IMPACT-ACTION DEVICE FOR DEVELOPMENT OF WELL IN SOIL Russian patent published in 2010 - IPC E21B1/30 E02F5/18 

FIELD: mining.

SUBSTANCE: device includes hollow housing with longitudinal throttle channel, stepless hammer arranged in the housing and having central through channel dividing the housing cavity into operating and no-load stroke chambers, central tube interacting with central through channel of hammer, threaded sleeve with constant open inlet channel and hose for supply of compressed air from network; cover with peripheral channel, radial bypass channel and through central hole for passage of the tube; pre-chamber of network air, which is formed between threaded sleeve and cover and interconnected via peripheral channel and longitudinal throttle channel to idle stroke chamber; shank and threaded sleeve, which are provided with through channels for passage of central tube installed in central hole of cover with an annular gap forming an annular throttle inlet channel of working stroke chamber. In central tube there installed coaxially with annular gap is additional tube with radial outlet channel and with fixation along its edges relative to central tube; at that, radial outlet channel in additional tube is made at acute angle to its axis with the top on the threaded sleeve side, and is offset along screw line relative to radial outlet channel of central tubes towards threaded sleeve. Additional tube protects central tube against possible deformations which appear on the side of ropes, chains, etc. of rigid elements, which are passed through the device, as well as soil particles, and which lead to jamming of the hammer and shutdown of the device operation.

EFFECT: improving protection of central tube against deformation.

1 dwg