A method for improving the backward extrusion rate of brass billets and the like, and an apparatus for the implementation thereof

摘要

To improve the rate of backward extrusion of brass billets and the like, a horizontal extrusion press is provided with two parallel tubular headers (25,26) to which respective extrusion dies (29,30) are affixed permanently and which are mounted on slides (27,28) adapted to be driven in a guided fashion perpendicularly to the extrusion axis (X-X) of the press; one header (25) is set at an operative position for extrusion aligned to the extrusion axis (X-X), and the other header (26) set at an inoperative position laterally of the axis (X-X), and a billet is extruded with said one header (25) to form a residual brass jacket (36) around the header; on completion of the extrusion step, the positions of the headers (25,26) are reversed, and said one header (25) is cleared of the residual brass jacket (36) in the inoperative position, while another billet is simultaneously extruded with said other header (26).