| 摘要 |
A series of adjoining concentric rings are cut from a metal plate. The same number of hubs, all the same shape, are also cut from plate material as are annular web plates to fit around hubs, but the outer diameters of the web plates are different from one another in order to fit in the different rings. Each web plate is welded to a hub and encircling ring to form a sheave that is then provided with a circumferential groove to provide a grooved rim for receiving a wire line. The sheaves can be mounted side by side on a common shaft, with the largest sheave at one end and the smallest at the opposite end. This arrangement is suitable for a crown block. |
