GB783833A - Improvements in and relating to methods for recharging continuous extrusion presses - Google Patents

Abstract

783,833. Extruding. SCHLOEMANN AKT.- GES. Dec. 30, 1955 [Feb. 23, 1955], No. 37397/65. Class 83 (4). In the extrusion of metal by forcing it through a die from opposite sides of the die axis, the metal is replaced from each side in alternate sequence whilst extrusion continues from the other side at reduced pressure. In a continuous extrusion process a pair of billets a, b, Fig. 2, are extruded simultaneously through a die by a pair of press stems 10 and recharging of a container is effected by reducing the pressure in both containers until a low extrusion speed is obtained, withdrawing one of the stems, Fig. 4 (not shown), from said container whilst the low speed extrusion is continued from the other container, inserting a new billet into the said container, and then continuing extrusion at full pressure from both containers. For commencing the extrusion process a half-size billet a is used initially in one container whereby the two billets will subsequently be expanded alternately. The friction of the extrusion residue prevents back flow of metal during re-charging. The press described is for sheathing cables with lead or aluminium and has a die 6, Fig. 1, secured in a die holder 5 by a plug 7, and a mandrel 8 supported in a mandrel holder 3 preferably formed integral with the die holder and screwed into a part 15 which is rigidly secured in the container 2 by a threaded plug 16. The die holder is prevented from rotating by a rib 1b. A number of webs 4 interconnect the die and mandrel holders and the extrusion metal flows between these webs to a common extrusion chamber 11. The mandrel holder may be separate from the die holder with the webs 4 omitted. The billet container is supported between a pair of container holders 2a, 2b with a through bore d. The extrusion orifice may alternatively be disposed on the centre line of the bore d. An example is given of the extrusion pressures used.