| 摘要 |
1425791 Anchoring bolts ACIERIES REUNIES DE BURBACH-EICH-DUDELANGE SA 2 April 1974 [2 April 1973] 14668/74 Heading F2H To reinforce the material of, e.g. a mine roof, a bore formed in the material is partly filled with the reactive components of a bonding agent, a bolt 1 roughened at its leading end 2 and threaded at its rear end 4, with a nut 5 held captive on the threaded portion 4 by a discontinuity 6 in the thread, is inserted in the bore and, to stir and mix the bonding agent components, is rotated in a direction tending to unscrew the nut from the bolt by rotation of the nut so that the nut backs on to the thread discontinuity 6, allowing the bonding agent to harden, rotating the nut 5 in the opposite direction until it bears on the surface of the material being reinforced, and continuing rotation of the nut to prestress the bolt and the surrounding material. As shown, a second nut 7 on the part of the threaded portion 4 to the rear of the discontinuity 6 enables a load to be attached to the bolt. The roughened portion 2 is a coarse screw thread of the same hand as the thread 4. A washer or bearing plate 8 is provided ahead of the nut 5. Preferably the bonding agent components are separately packaged in rupturable cartridges or bags which are pierced by teeth 3 or a point at the tip of the bolt. If the second nut 7 is not required, the discontinuity may be formed at the rear end of of the bolt by hammering. |
