MINE ROOF BOLTING Russian patent published in 2007 - IPC E21D21/00 

FIELD: mining, particularly mine roof supporting with bolting.

SUBSTANCE: roof bolting comprises composite bar including at least two sections 1, 2 formed of round rolled steel. End parts 3, 4 of bar sections 1, 2 have semicircular cross-sections and provided with transversal projections 5 extending at 90° angles to longitudinal bar axis from flat edges of said bar section cross-sections. The bar sections are mutually complementary and arranged in connection bush 7, which rests upon elastic annular collars 8 shaped as tores by lower ends thereof. The elastic annular collars are press-fitted on bar section 2 below bar section 1, 2 connection areas. Front end of section 1 has beveled part 10. Support plate 11 is connected to lower end of bar section 2 projecting in mine. The support plate 11 is fastened to bar section 2 through claw nut 12. Longitudinal bar axis extends through central parts of transversal projections 5 in area of bar section 1, 2 parts 3, 4 connection. Each bar section 1, 2 has the same number of projections 5 and the number may be determined from expression.

EFFECT: increased mine roof supporting efficiency, decreased time and force necessary for roof bolting driving and simplified bolting driving.

4 cl, 4 dwg