| 摘要 |
<p>An attachment for a jib crane to enable it to be used for grading and carrying out other work on sloping banks has a more or less horizontal auxiliary jib mounted beneath the main jib of the crane, a carriage movable fore and aft along the auxiliary jib, a guide frame extending forwardly from the carriage, a tool carrier movable in either direction along the length of the guide frame, and a suspension tie connecting the guide frame to the jib of the crane. The tool carriage is provided with a scraper blade or other tool appropriate to an operation to be carried out, and is hauled, usually upwardly, along the guide frame by a cable operated by the winding gear of the crane.</p> |
