On the work surface acting in a cutting roller or cutting wheel with an unequal tooth pitch

摘要

247,477. Schmidt, A. Aug. 26, 1925. Addition to 173,752. Tunnelling by boring.-A machine as claimed in the parent Specification is provided with cutting tools comprising an axle and one or more toothed cutting wheels rotating with the axle, such tools being employed either for cutting the annular grooves or on the core-cutting arms. The inner cutter arms of the machine are connected by a ring carrying spaced tool holders 2 containing lubricant and each supporting two axles 3 integral with cutter wheels 4 provided with unsymmetrical and irregularly distributed teeth; the wheels are staggered and leave a central rib, and further pairs of cutter wheels are arranged side by side behind the holders 2 to remove this rib and widen the cut. The outer cutter arms of the machine are also connected by a ring carrying cutter wheel holders; some of these cutter wheels may be displaced through 90‹ and effect widening of the cut.