| 摘要 |
PURPOSE:To prevent the fullness of earth in a chamber by controlling pressure of sludge or air to control an amount of earth taken in from a cutter slit, and keeping only fallen earth in the bottom of the chamber from the slit during the stopping of an excavator. CONSTITUTION:A turnable cutter head 1 is provided to the front of a pipe-like body 2 in a swingable manner, and the front end of the head 1 is blocked with a circular face plate 2 opening only a cutter slit 3 for taking in earth 16. At that time, the slit 3 is only one and is placed within range of less than 120 deg. of the central angle on the face plate 2, and scrapers 4 or bits 6 are provided to the central shaft or both sides of the slit 3. After that, in the case of ground excavation, pressure feed of sludge or air to the inside of a chamber 9 backward of the face plate 2 is made, and pressure is heightened to control earth 16 taken in from the slit 3. Pressure is lowered to increase earth 16 taken in from the slit 3. According to the constitution, an amount taken in is easily controlled, and the fullness of earth 16 in the chamber 9 is prevented during the stopping of an excavator, and it can be driven forward smoothly. |
