| 摘要 |
<p>The invention relates to a device (1) mountable on a dozer blade (10), for skimming a substrate to a required depth, comprising an open box or collector for skimmed material, and a cutting edge (3) of a rear wall (6) which is used to effect skimming. The depth of skim is adjustable by height adjusting means which are described in the specification. A slow sand filter may be cleaned using a device according to the invention.</p> |
