GB731723A - New or improved process and apparatus for the extrusion of elongated articles havingprofiled heads - Google Patents

Abstract

731,723. Extruding. KREIDLER, A. Dec. 30, 1952 [Dec. 31, 1951], No. 32925/52. Class 83(4). A metal body having a profiled head 8 and an elongated shank 9 is produced in an extrusion press by forcing a billet through an extrusion nozzle 4 into a removable die 5, 5<SP>1</SP> which forms the head, and after removing the die, extruding the shank through the nozzle. The extrusion press, Fig. 3, has its punch 3 operated by a hydraulic motor whose cylinder 11 has supply and exhaust pipes 10, 12 respectively for pressure liquid, controlled by valves 13, 14 respectively. These valves are operated by a common spindle 15 connected through a pinion 21 and rack 20 with a servomotor piston 18 biased by a spring 19 and subjected to the extrusion pressure in the supply pipe 10. The removable die comprises two parts 5, 5<SP>1</SP> slidable on a table 6 into closed and open positions by hydraulic motors 23, 23<SP>1</SP> respectively, controlled by a reversing slide-valve 24. The pressure in the supply pipe 10 during the filling of the die 5, 5<SP>1</SP> is insufficient to move the piston 18 against its spring. When the die is filled, however, this pressure rises and moves the piston 18 and rack 19 to the left thereby closing the valves 13, 14 to stop the press, and moving the slide 25 of the reversing valve 24 which causes the motors 23, 23<SP>1</SP> to open the die. This causes a reduction of pressure in the pipe 10 whereby the spring 19 returns the piston 18 and opens the valves 13, 14; the extrusion process then recommences. The die is closed by moving a handle 26. The opening movement of the die 5, 5<SP>1</SP> may alternatively be controlled by mechanical, electrical or pneumatic means responsive to the extrusion pressure.