GB1038477A - Method of making push rods - Google Patents

Abstract

1,038,477. Making push rods; extruding; forging. G.K.N. SCREWS & FASTENERS Ltd. June 23, 1965 [July 7, 1964], No. 27859/64. Heading B3A, B3H and B3P. A method of making a hollow metal push rod comprises the steps of forming a solid slug from stock, forming an axial hole through the slug, extruding the slug to form a tube, and forming each end into a port hemispherical shape. As described, the slug is cut from wire, Fig. 1 (not shown), and put in a die in which both ends are planished flat and central conical depressions are formed by a punch, Fig. 2 (not shown). The slug is then placed in a further die, Fig. 3 (not shown), where the conical depressions are enlarged by a punch into holes passing from both ends substantially through the slug leaving a thin wall of metal which is then removed by punching, Fig. 4 (not shown). The slug is next placed in a die 50, Fig. 5, having a restricted opening 56 through which the slug 5 is extruded by a ram 54 having a projecting mandrel 53 which passes through the slug. When the slug is extruded to the extent of the slug 5 as shown in the Figure, the ram is withdrawn and another slug placed on top of the one already in the die which can then be completely extruded as a tube 5a. After a further similar tube forming extrusion operation the tube is gripped in clamps whilst the ends are countersunk, Figs. 7 and 7A (not shown), and finally gripped in clamps whilst the ends are forged into a hemispherical shape, Figs. 8 and 9 (not shown). Dependant upon the angle of the countersink, the ends may have central holes 88, Fig. 9 (not shown), communicating from the exterior to the interior.