| 摘要 |
<p>A mine roof bolt expansion anchor utilizes a plurality of transversely bent elongated leaves (21) which are compressed within a bail (17) by the rotation of the roof bolt (12). The compression results in movement of the leaves toward a flattened position whereby the outer edges (25) of the leaves engage the bore hole walls to anchor the bolt. Downwardly extending flanges (22) on each end of the leaves increase the bearing surface which engages the bore hole wall, while spacers (24) near the center of the leaves act as a spine to evenly distribute the compression to all the leaves so that they all engage the bore hole wall simultaneously and with the same pressure.</p> |
