| 摘要 |
<p>A Trenching Method and Apparatus A trench, particularly a drainage trench for grassed sports fields and the like, is formed by a two stage method in which the upper half of the trench is excavated by removing soil with a rotary cutting tool, and the lower half of the trench is ploughed to its finished depth without removing soil. Immediately behind the plough there is a delivery chute extending the full depth and width of the trench and has an inclined exit aperture, which delivers material to fill the trench from above-ground hoppers. The chute may be partitioned to form separate upper and lower exit apertures connected with separate hoppers to deliver, for example, gravel to the lower part of the trench and sand above it.</p> |
