Patent ID: 6146055
Filing Date: 2000-11-14
Classification: E21D

Abstract:
A mine roof bolt anchor, insertable in a pre-drilled hole in a mine roof, for expansion within said hole by rotation of an associated mine roof bolt, comprising, in combination:a. a shell circumscribing said mine roof bolt and having a plurality of segments extending longitudinally of said bolt, said segments having a radially inward face defining a camming surface and terminating in a radially outwardly protruding rib at an upper end thereof, said shell including an internal flange forming a lower reduced diameter portion;b. a camming nut threadedly engaged on said mine roof bolt and having a radially outwardly flaring surface for engagement with said camming surface, said flaring surface having an abrupt variation in its slope proximal an upper end thereof;c. a compression washer positioned within said shell on said flange for securing said mine roof bolt therethrough; and,d. means engagable with a wall of said hole upon rotation of said mine roof bolt for arresting the rotation of said shell relative thereto, such that further rotation of said mine roof bolt urges said camming nut linearly along the axis of said mine roof bolt displacing said segments radially such that said rib is forced into said wall and said segments are urged against said wall over a large surface area of said shell to compress said wall in the region beneath said rib.