| 摘要 |
A reamer for enlarging a borehole, featuring at least two cutter assemblies 301-303, mounted radially, and each having a plurality of cutting bits 211-215 arranged thereon. The cutter assemblies are expanded into a cutting position by a series of angled ribs, which drive the cutters 301-303 outwards when loaded axially. The cutting bits on adjacent cutter assemblies are axially spaced intermediately of each other, such that the bits are arranged helically around the tool. The width of the cutting tool increases with distance away from the end of the tool. The cutting bits may be aligned with the helix and angled towards the cutting direction, which creates a controlled rate of advance for the tool. Each cutting assembly also includes a stabilising pad 305 where there are no cutters. |
