| 释义 |
WordReference Random House Unabridged Dictionary of American English © 2024four′fold pur′chase, - Naval Termsa tackle that is composed of a rope passed through two fourfold blocks in such a way as to provide mechanical power in the ratio of 1 to 5 or 1 to 4, depending on whether hauling is done on the running or the standing block and without considering friction. Cf. tackle (def. 2).
|