DEVICE FOR SCREW-LIKE PILE BOTTOM SCREWING DOWN Russian patent published in 2004 - IPC

FIELD: construction of pile foundations for civil and industrial structures. SUBSTANCE: device has screw-like bottom, removable metal tube, which is slidably arranged in inner gripping sleeve and connected through ratchet gear to outer sleeve. Outer sleeve has two symmetric shoulders. Each shoulder is pivotally connected to two reciprocating hydraulic jacks pivotally arranged on device body. Body is hung on vehicle. Screw-like ferroconcrete pile bottom is reinforced with helical reinforcing members and has multithreaded vines fixed to rod thereof. Pile bottom rod has sharpened end for pulp supply. Rod upper end has socket with square or polyhedral cross section for cup receiving. Cross section of lower removable metal tube end is equal to that of screw-like pile bottom. Lower removable metal tube end is located into cup and rests against cup bottom. Socked depth is 1,5...2 Δ, screw-like bottom height is h = 3...4 Δ, pile bottom rod is d = 1,5...2 Δ, and maximum pile bottom diameter is D = 2,25...4 Δ, where Δ is dimension of cup side wall. EFFECT: increased labor productivity by mechanical aid applying; increased bearing strength. 6 dwg