| 摘要 |
1,188,833. Casing tube. G. REHM, and R. BUHRER. 20 July, 1967 [21 July, 1966; 12 May, 1967], No. 33430/67. Heading F2P. A casing tube for embedding in a concrete structure and receiving prestressing elements and mortar is provided with a first profiling comprising a rib, bulb or fold inclined at an angle to the tube axis and a second profiling disposed at an angle to the first and to the tube axis. The first profiling may comprise a helical, inwardly directed rib 13 and the second indentation 12 which taper towards their ends 14. The tube may be of square section (Fig. 5, not shown) and the first profiling (24) is then discontinuous. The depressions of the second profiling may taper only in the radial direction (Fig. 2a, not shown). |
