GB703250A - Improvements in or relating to prefabricated units for use in building bridges, scaffolding and other structures - Google Patents

Abstract

703,250. Overhead travelling cranes. KWIKFORM, Ltd. June 11, 1951 [June 9, 1950], No. 14399/50. Class 78 (4) [Also in Group X] A prefabricated unit for building up a staith or the gantry of an overhead crane, comprises a rectangular tubular metal frame 10, Fig. 2, with the horizontal members 11, 12 projecting similarly at each end and a diagonal bracing member 14, the projecting ends being adapted to be secured by clamps 15 to and in alignment with the ends of further similar units and a clamping device 17, e.g. as described in Specification 642,386, [Group X], being permanently secured in each corner of the frame for connecting parallel sets of units by means of ledger tubes. The clamps 15 which are formed as described in Specification 703,251, [Group XXVIII], and the clamps 17 are such as to leave the upper and lower surfaces respectively of the connected members 11, 12 flush and unobstructed so that the arrangement permits of wheeled carriages, e.g. of a crane, to pass freely along the upper members 11 and of the assembled structure being launched across a space by passing over rollers or grooved wheels which engage the lower members 12. Alternatively the ledger tube clamping device may be formed as described in Specification 698,087, [Group X]. Two similarly connected sets of units may form a box girder serving as a gantry, Fig. 1, for supporting the movable carriage of a crane running on the upper members 11 and the box girder may in turn be supported by intervening wheels or rollers upon a pair of further box girders extending at right angles thereto so that the gantry carrying the crane is displaceable in a direction at right angles to its length. Specification 642,367, [Group X], is referred to in the Provisional Specification.