GB890012A - A method and machine for forming a tubular workpiece - Google Patents

Abstract

890,012. Forging. APPEL PROCESS Ltd. July 28, 1958 [Dec. 6, 1957], No. 24162/58. Class 83 (4). In a method of forming a tubular workpiece by feeding it incrementally through an axially fixed die throat, wherein the dies act radially upon the work and in out-of-phase relation with the feed motion, a mandrel having successive portions of different diameters and with some portions shorter in length than the corresponding portions of the workpiece is used, the workpiece being alternately fed relative to the mandrel and together with the mandrel and the dies being moved inwards progressively and radially after each incremental advance of the workpiece until such repetition of the steps completes the required form of the work. A workpiece 10, Fig. 3, is formed with a series of different diameters and tapers defined by numerals 11-14, using a mandrel 20, Fig. 2, having portions 21, 23, 25 of a length considerably less than the corresponding lengths of portions 11, 13, 15 of the work. Machines of the type disclosed in Specifications 768,834 and 797,518 may be used to swage the work and to feed the work and mandrel together relative to the dies or alternatively to feed the work relative to the dies and mandrel. The mandrel may in fact be stationary, may move forward more slowly than the work or may even move in a reverse direction. In forming the workpiece 10 the end of portion 11 is aligned with the end of portion 21 of the mandrel and both work and mandrel are incrementally and intermittently advanced in out-of-phase relation with the action of the swaging dies for a distance of about 1¢ inch, due to elongation of the workpiece about 2 inches of the portion 11 will be formed. The mandrel then stops while the work is moved incrementally on 1 inch accompanied by ¢ inch elongation. The 4 inch long portion 11 is then completed by moving mandrel and work together incrementally for ¢ inch. Portion 12 of the work is then swaged incrementally moving mandrel and work together. The remaining portions of the work are then formed either in several steps as for the portion 11 or in one step as for the portion 12. Specification 829,122 and French Specifications 1,074,439 and 1,137,761 also are referred to.