| 摘要 |
<p>Driving blades are pressed forward by a set of presses supported on the support frame of a cutting shield used for opening up tunnels, open trenches or other cavities in the ground. The support frame has dirt skimmers mounted on it, reaching into the bottom blades. The bottom blades are pref. hollow, esp. box, profile units, with profile apertures for engagement by the dirt skimmers, extending at least over a length as great as the thrust of the presses. Skimmers may be wedge or cutter-chaped, and extend to the bottom of the bottom blades. Collection and retention of loose earth material in the floor area is prevented.</p> |
