GEAR TO SINK HOLE IN GROUND AND PROCESS OF FORMATION OF EXPANSION IN END OF HOLE WITH ITS USE Russian patent published in 2002 - IPC

FIELD: construction equipment, sinking of vertical holes in ground for cast-in-place piles, anchors and for water intake purposes. SUBSTANCE: proposed gear includes reversible pneumatic punch and expander with cylindrical and at least single conical sections of external surface made of longitudinal sections individually mounted on pneumatic punch. Mentioned-above sections of expander are mounted on to pneumatic punch with use of joints for turn in longitudinal plane, their turning axes are positioned within bounds of conical section of its external surface. Technical objective of invention consists in guaranteed generation of accurate and repeated lateral dimensions of expansions in end of hole to stabilize bearing capacity of cast-in-place piles. With this in mind pioneer hole is sunk to projected depth of start of its expansion and sinking is continued with use of proposed gear. Diameter of expander in transportation position is approximately equal to diameter of pioneer hole. EFFECT: increased productivity of process of sinking and improved working conditions due to elimination of manual operations of attendance to gear. 8 cl, 9 dwg