GB759135A - Improvements in or relating to extrusion presses - Google Patents

Abstract

759,135. Extruding. GENDERS, R., FIELDING & PLATT, Ltd., and ROWLES, R. V. May 28, 1953 [Feb. 15, 1952], No. 4147/52. Class 83 (4). An extrusion press constructed to operate selectively under direct or inverted flow conditions or under combined or mixed direct and inverted flow conditions, has a billet container H whose bore is of larger cross-sectional area at the billet insertion end than at the other end. The bore is stepped to provide a large diameter portion B and a small diameter portion X. For direct extrusion, Fig. 1 (not shown), the container is held stationary. by a latch E, Fig. 2, whilst the billet A is extruded by the ram C, having a dummy block P, through a die G carried by a stationary hollow ram D. For indirect extrusion the latch is released and the container then moves forwardly with the ram C and passes over the ram D, Fig. 3 (not shown). In a combined process described, a heated billet, which may be machined or a rough casting, is inserted in the bore B and, whilst the container is held stationary by the catch E, is pressed by the ram C into the bore X until it reaches the extrusion die G. The catch is then released and the container moves with the ram C, whereby the die enters the bore X and the billet metal therein is extruded through the die. For mixed extrusion the movement of the container after its release is controlled by auxiliary rams F, Fig. 4, whereby the billet is extruded partly by the direct action of the ram C and partly by movement of the container The press may be used for extruding solid bars or tubes, in which case a mandrel is fitted in the ram C. The shoulder between the two portions B and X of the container bore may alternatively be tapered or curved. The press is suitable for extruding steel and nickel alloys. Specification 660,257 is referred to.