| 摘要 |
PCT No. PCT/EP91/00572 Sec. 371 Date Mar. 10, 1992 Sec. 102(e) Date Mar. 10, 1992 PCT Filed Mar. 25, 1991 PCT Pub. No. WO91/19074 PCT Pub. Date Dec. 12, 1991.A drill head (1) as part of a drill lance for an apparatus for drilling an underground tunnel, which drill head has a channel (10) extending along the center axis of the drill lance and is rotatable about the center axis, comprising at least one forwardly directed nozzle (2), the nozzle channel (21) of which communicates with the channel (10) and exits outside the center axis, the drill head (1) being characterized by at least one rearwardly directed nozzle (4) being provided, the nozzle channel (41) of which communicates with the channel (10).
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