| 摘要 |
1,239,051. Telescopic lattice girders. L. ALZIARI. 17 July, 1968 [19 July, 1967], No. 34059/68. Heading E1S. A telescopic lattice girder comprises a main section 1 with an inverted channel-sectioned upper boom, side lattices 4 and a lower boom comprising spaced stringers 3, and an end section 8 with an inverted channel-sectioned upper boom, lattices 10, and an inverted T- sectioned lower boom, the section 8 being maintained in any desired position by means of a bolt 7, passing through a flexible plate 5 welded to the stringers 3, and facing the section 8 against the upper boom of the main section 1. The only cross-bracing in the main section 1 beyond the plate 5 comprises two ties T welded to the plate 5 intermediate the stringers 3 at one end and to the upper boom at the other. |
