Abstract: An expansion anchor for a mine roof support bolt having a one-piece shell, a tapered nut and a strap for maintaining the shell and nut in assembled relation. The shell includes a circular collar having four fingers extending therefrom in a generally cylindrical configuration with an open slot between each pair of adjacent fingers. A pair of solid elements formed integrally with the rest of the shell extend between pair of adjacent fingers to bridge the slots on opposite sides of the shell. The strap extends over the top of the nut, through the slots and has bent-over end portions which are engaged under the solid elements bridging the slots.

Abstract: An expansion bolt assembly of the type used in supporting mine roofs including an expansible shell having a tapered plug movable axially therein to force the outer surface of the shell into engagement with the interior of a drilled opening in the mine roof. The plug is moved by rotation in a threaded opening thereof of an axially fixed bolt, the plug being rotationally fixed with respect to the shell. The invention resides in the structure maintaining the bolt, plug and shell in assembled relationship during insertion into the drilled opening which comprises a circular metal stamping having a central opening through which the bolt is threaded and means for frictionally engaging the sides of the shell.