| 摘要 |
561,996. Composite structural metal bars. MILLS SCAFFOLD CO., Ltd., and WELLS, G. W. Aug. 18, 1942, No. 11574. [Class 20 (ii)] A composite structural member formed from pressed sheetmetal sections 3, has the flanges 3b of the member formed of double thickness by returning these parts of the sections on themselves as described in Specification 561,505, and have the abutting faces of the sections 3a, 4a dished at or between the positions where gusset plates are fitted for joining the structural members together as described in Specification 561,739, so that, after assembling, recesses are formed to receive the ends of the gusset plates 5, which are bolted to the members as described in Specification 559,593, [Group XXII]. The double thicknesses of the flanges are secured together by pressing flanged holes 11 in the double thickness of metal and then rolling over or clinching the edges down on to the metal, as described in Specification 561,506. The webs are joined together and to the gusset plates by bolts 7 and annular washers 8 with recessed faces, the holes in the webs being larger than the bolts so that the bearing takes place annularly around the bolt holes, as shown in Fig. 4. |
