Document Type and Number:
Japanese Patent JPS4857401
Kind Code:
A
Abstract:
A fixed shaft is mounted on the cutterhead to extend across the rotary axis of the cutterhead. A plurality of independently freely rotating disc cutter wheels are mounted on said shaft at different radial spacings from the cutterhead axis. The cutterhead carries additional disc cutters spaced radially outwardly from the center cutter assembly. All disc cutters include circumferential cutting edges which cut concentric kerfs in the rock at the tunnel face and sloping breaker surfaces on opposite sides of the cutting edge for crushing and dislodging the rock between the kerfs. The centermost disc cutter of the center cutter assembly includes a radially inwardly facing breaker surface which crushes and dislodges the material within the kerf cut by said centermost disc cutter.
Application Number:
JP10982972A
Publication Date:
August 11, 1973
Filing Date:
November 01, 1972
Export Citation:
International Classes:
E21B10/12; E21B10/22; E21D9/10; (IPC1-7): E21C13/00
Domestic Patent References:
| JP35001635A |