摘要 |
The body of a raise boring head is produced from a truncated cone. A variety of efficient and economical methods such as spin-forming, casting, rolling, etc. may be used in producing the truncated cone body. A multiplicity of rolling cutters positioned in cutter saddles are mounted on the truncated cone body. The mounting surfaces for the cutter saddles are on a continuous plane. The continuous plane can be produced on the truncated cone body in one turning operation. The raise boring head is self-cleaning due to the natural tendency of the cuttings to slide toward the periphery of the truncated cone body surface. The overall gross weight of the raise boring head is reduced and the strength-to-weight ratio is increased. The structural rigidity of the raise boring head is improved even though many of the structural components used in prior art raise boring heads have been eliminated. |