DEVICE FOR FORMATION OF WORKING IN SOIL Russian patent published in 1994 - IPC

FIELD: devices for formation of workings in soil. SUBSTANCE: device has working chamber, drive drum, flexible hose, working fluid supply source, gaseous agent supply source, and additional flexible hose. Flexible hose is wound on drive drum. Free end of flexible hose is turned inside out and secured to working chamber outlet. Working fluid and gaseous agent supply sources are communicated with inner space of working chamber. Additional flexible hose is coaxially located inside main flexible hose and displaced relative to the latter towards working chamber. Free end of additional hose is turned inside out and secured to working chamber outlet. Main and additional hose have through holes over their length. Holes in main hose are located so that they are periodically closed by additional hose during their mutual displacement. EFFECT: higher efficiency. 6 dwg