Method of preforming a booster casing element with its reinforcement

摘要

A method of forming a casing for a booster wherein the casing is preliminarily preformed with a peripheral sleeve portion and a flat base portion connected by a web. The preformed casing is placed in a frame and the peripheral sleeve portion held in substantially fixed position to maintain a required transverse dimension. A reinforcing member is positioned adjacent the flat base and an axial force applied to the reinforcing member to prestress the web to a final desired shape.