| 摘要 |
This appts. is used in constructing chimneys and steel towers(I). The jib crane is periodically adjusted upwards while the chimney and the steel tower are being constructed. When the construction of (I) is finished, the jib crane descends through the inner space (32) of (I). A horizontal stay (4) is established beyond the rotating body (1), including the jib (2).
|
