| 摘要 |
<p>A rock bolt is manufactured from a steel tube which has been deformed to have a deep depression so that it assumes a substantially reduced diameter. A sleeve is pressed onto the outer end thereof which is sealed through welding. An installation chuck carried on an installation rod comprises a socket for receiving the outer sleeve and when the rock bolt has been manually inserted in a borehole, for example by means of the chuck, high pressure liquid is conveyed through passages in the chuck to a hole which leads through the sleeve to an interior chamber of the tube so that the tube expands through plastic deformation, thereby anchoring the rock bolt in the borehole. The chuck is then relieved of pressure and removed from the anchored rock bolt.</p> |
