| 摘要 |
<p>PCT No. PCT/AU91/00315 Sec. 371 Date Jan. 26, 1993 Sec. 102(e) Date Jan. 26, 1993 PCT Filed Jul. 16, 1991 PCT Pub. No. WO92/01859 PCT Pub. Date Feb. 6, 1992.A rock bolt system comprises an inner part (1) disposed within an outer part (10). The inner part comprises an elongated tube having an axial depression (2) and an internal pressure fluid receiving chamber (4) which is closed at both of its ends. A fluid inlet communicates with the fluid receiving chamber. The outer part (10) comprises an elongated tube having a longitudinal slot (12), which slot extends at least part way along the length of the outer part tube. In use, the rock bolt system is placed in an oversized borehole (20) and pressurized fluid applied to the fluid receiving chamber. This causes the device to expand laterally and engage the walls of the borehole.</p> |
