Abstract: An expansion anchor received within a predrilled bore for mounting a platelike panel to a portion of stratum in which the bore is drilled and including a bolt having a head on a lower end thereof, an upper portion, distal the head, defining a set of right hand threads thereon and a lower portion, intermediate the upper portion and the head, defining a set of left hand threads thereon. A destructible thrust nut having at least one groove therein is threadably connected to the lower portion and moves upwardly thereon when the rod is rotated in a clockwise direction. A cutting member, having an annular base supported by the thrust nut for sliding movement along the bolt and a plurality of cutting fingers connected to the base in divergent relation to the bolt, is urged upwardly by the thrust nut when the rod is rotated in the predetermined direction.

Abstract: A portable tool for bending elongated mine roof bolts in situ including a stationary support portion for holding a part of a roof bolt, a movable support portion for holding another part of the roof bolt, a power cylinder and piston for moving the movable support portion in an arc to effect bending one end of the bolt, to permit insertion thereof into a mine roof opening. The power cylinder and piston being activated to return the movable support portion to its initial position, thereby straightening the bolt to permit full insertion of the bolt into the mine roof opening.

Abstract: A mine roof truss including opposed angularly disposed roof bolts, a horizontal truss member extending between the roof bolts, and couplings connecting the roof bolts to the truss member. Each coupling comprises a housing having walls forming a cavity into which the head of the roof bolt and an end of the truss member are inserted and secured. The end of the truss member is provided with a T-shaped head which is inserted through a slot in the housing wall leading to the cavity, following which the truss member is rotated relative to the housing to lock the truss member to the coupling. The roof bolt head and truss member are pivotally connected with the coupling to permit adjustments thereof when installed on an uneven roof surface.

Abstract: A combination expansion shell and resin secured mine roof anchor assembly comprising an elongated bolt which carries rebar and an expansion shell. The assembly is inserted into a mine roof opening, in the back end of which is positioned a resin and catalyst cartridge. The cartridge is ruptured by the assembly allowing the resin and catalyst to gravitate downwardly, where they are mixed together by the rebar upon rotation of the bolt. The bolt is rotated a predetermined number of revolutions to obtain proper mixing of the resin and catalyst preparatory to setting, after which the continued rotation of the bolt in the same direction effects movement of the expansion shell into gripping engagement with the mine roof.

Abstract: A combination expansion shell and resin secured anchor assembly for installation in a mine roof opening including an elongated bolt having rebar attached to the upper end thereof and an expansion shell below the rebar. The assembly is inserted into a mine roof opening in the back end of which is positioned a resin and catalyst cartridge, the cartridge being ruptered by the rebar, allowing the resin and catalyst to gravitate downwardly between the opening wall and rebar, where they are mixed upon rotation of the bolt and rebar. The bolt is rotated a predetermined number of revolutions to obtain optimum mixing of the resin and catalyst, after which continued rotation of the bolt in the same direction causes outward movement of the expansion shell into gripping engagement with the mine roof.

Abstract: A combination expansion shell and resin secured anchor assembly for installation in a mine roof opening including an elongated bolt having rebar attached to the upper end thereof and an expansion shell below the rebar. The assembly is inserted into a mine roof opening in the back end of which is positioned a resin and catalyst cartridge, the cartridge being ruptured by the rebar, allowing the resin and catalyst to gravitate downwardly between the opening wall and rebar, where they are mixed upon rotation of the bolt and rebar. The bolt is rotated a predetermined number of revolutions to obtain optimum mixing of the resin and catalyst, after which continued rotation of the bolt in the same direction causes outward movement of the expansion shell into gripping engagement with the mine roof.

Abstract: A combination expansion shell and resin secured anchor assembly for installation in a mine roof opening including an elongated bolt having rebar attached to the upper end thereof and an expansion shell below the rebar. The assembly is inserted into a mine roof opening in the back end of which is positioned a resin and catalyst cartridge, the cartridge being ruptured by the rebar, allowing the resin and catalyst to gravitate downwardly between the opening wall and rebar, where they are mixed upon rotation of the bolt and rebar. The bolt is rotated a predetermined number of revolutions to obtain optimum mixing of the resin and catalyst, after which continued rotation of the bolt in the same direction causes outward movement of the expansion shell into ripping engagement with the mine roof.

Abstract: A mine roof anchor assembly comprising an elongated bolt, one end of which is threadedly engaged with an expansion anchor. The expansion anchor includes a cone nut threaded on the bolt which moves axially through a shell for expanding the latter into gripping engagement with the mine roof. A bail member of inverted L-shape is connected to, and extends upwardly from, the expansion shell, a portion of the bail member overlying the cone nut to limit the relative longitudinal movement of the bolt when it is rotated in the cone nut. That portion of the bail member overlying the bolt is deflected by the latter to urge teeth mounted on the bail member portion into impinging engagement with the mine roof.

Abstract: A mine roof bolt assembly including a shank having anchoring means at one end for securing the shank in the back of the bore, the opposite end of the shank being threaded. A bolt head having a central bore, includes a first threaded bore portion threadedly engaged with the threaded end of the shank. A stop plug is threaded into a second threaded bore portion in the bolt head and abuts an end of the shank to initially limit penetration of the shank into the bore of the head. The bolt head is rotated by rotational means having a predetermined torque limit, moving the head longitudinally with respect to the shank, exerting a force on the stop plug which strips the threads from the second threaded bore portion, thereby permitting uninterrupted passage of the shank through the bore. A roof plate positioned on the shank between the bolt head and roof is then forced upwardly by the head into supporting engagement with the mine roof, and the predetermined torque of the rotational means is established.

Abstract: This is a support assembly for underground mine and tunnel roofs. The assembly includes a tubular member comprising two opposed semi-cylindrical portions, the opposed longitudinal edges on one side of the member being connected together. Portions of the edges on the opposite side of the member are provided with one or more complemental mating angular recesses, which together form a tapered opening in the tubular wall for receiving wedge members. A ram successively engages the wedge members to force the same through the tapered opening, to effect expansion of the tubular member into bonding engagement with the roof.

Abstract: A support plate for a mine roof including a substantially flat body engageable with the mine roof, the body having an enlarged central opening through which are passed one end of a roof bolt on which is threaded an expansion shell which is inserted into a mine roof opening. Ribs extend longitudinally of the flat body on both sides of the central opening for additional strength. The ribs are spaced a predetermined distance apart on opposite sides of the central opening. Centering members are provided on the body portion intermediate the ribs on opposite sides of the central opening, the centering members and ribs serving to center the washer and bolt portion of the bolt assembly.