| 摘要 |
<p>The hook-headed screw is for bracing a carrier claw with a support profile in an arched support system in a mine. The shaft for the hooked head has a threaded end. The shaft (11) incorporates a series of key surfaces above its threaded end (10). In each case one such surface (47) may be formed on a flank of the shaft. The screw is easily fitted and drawn tight, under arduous working conditions.</p> |
