| 摘要 |
<p>The invention concerns a tool (7) for drawing samples or extracting the content of a pit (4) which is suspended to a cable (8) passing through a narrow opening (3) of a slab (2) covering the pit. A spider (13) hanging to guide cables (11) converging thereon enables it to move the lifting cable (8) beneath the slab (2) along different movements imparted by the winches (10). Thus, the tool can be displaced up to the desired spot with great accuracy and without having to go down into the pit (4).</p> |
