| 摘要 |
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. |
