| 摘要 |
PURPOSE:To facilitate exchange work of a cutter bit, to lighten a burden applied on a worker, to improve safety and working performance of digging work and to exchange the cutter bit at proper time in accordance with an abrasion state of the cutter bit. CONSTITUTION:A fixed cutter bit 15 is fixed on a cutter head 12 which is free to drive to rotate, and a cutter bit 31 for exchange is installed free to appear and disappear adjacent to this fixed cutter bit 15. When the fixed cutter bit is abrased and its diggingcapacity is lowered, the cutter bit 31 is projected forward in the digging direction rather than the fixed cutter bit 15 by an actuation control mechanism 32, and digging work is carried out by this cutter bit 31 for exchange. |
