SCREW-IN ANCHOR Russian patent published in 1994 - IPC

FIELD: mine working support. SUBSTANCE: screw-in anchor comprises stem 1 with screw thread. Installed on stem shank 4 is supporting member 2 with nut 3. Driven-in end of stem 1 has spring plug 5 with pitch equalling that of thread of stem 1. Spring plug is installed so that its one end is free, and the other is engaged with stop 6 attached between turns 7 of anchor stem 1. Anchor is screwed in hole 8 after introduction of setting grout 9. During rotation-translational motion of anchor, setting grout moves into face of hole 8 and solidification takes place. After screwing the anchor in hole, three zones of its fastening with enclosing rocks over hole length are formed. EFFECT: higher load carrying capacity of screw anchor is attained. 2 dwg