Method of forming a lightweight cylinder

摘要

A modular cylinder comprises a plurality of, in this case 24, modules each having a tongue to engage a groove of its neighbour and each either having a camming ramp to engage a camming ramp of its neighbour, or a filler rod inserted between adjacent modules at each interface. Where the camming means are provided, (n - 1) of the modules defining an almost complete cylinder and can then be strained in a radially outward direction to provide space for the final module which is placed in position by sliding longitudinally of the gap. Where the filler rods are used, all of the n modules may be loosely assembled in a first operation and the filler rods can be inserted in a second operation to pre-stress the cylinder. First filler rods of undersized type may be installed to hold the array of a module in loosely assembled configuration, and these may then be sequentially replaced by correctly sized larger filler rods.