Birmingham Bolt Company

Jim Walter Resources, Inc.

Frederick Carr

Claude C White

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.

Combination expansion shell and resin secured mine roof anchor assembly

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.

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.

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.

Growing community of inventors

Tuscaloosa, AL, United States of America

Frederick Carr