GB484006A - An improved press for the extrusion of lead and other metals - Google Patents

Abstract

484,006. Squirting. CALLENDER'S CABLE & CONSTRUCTION CO., Ltd., and GRIEVE, G. T. W. Oct. 30, 1936, No. 29547. [Class 83 (iv)] An extrusion press comprises a container from which metal is extruded, a main ram whch exerts a steady pressure on the metal, and an auxiliary ram which pumps molten metal into the container, all coaxially arranged. Molten metal is forced into the upper end of a container 2, Fig. 1, and is solidified in its downward passage to the die block 5 by a water chamber 66. The metal is under the constant pressure of a ram 15 which performs relatively small movements with respect to the container 2, and metal is fed into the container by a ram 13 which draws in metal from a chamber 9 through orifices 58 and discharges it through a ball valve 10. The chamber 9 is supplied by a pipe 56. Water under pressure is admitted to a space 30 to exert the constant pressure on the ram 15, and beneath a surface 34 normally to raise the ram 13. Pressure fluid is admitted to a space 44 by a valve 42 to produce downward movement of the ram 13, the valve being controlled by a motor 46 and cam 51, the speed of the motor being varied by a hand operated controller 118. In the event of abnormal upward movement of the ram 15, the operation of the auxiliary ram 13 is temporarily stopped by movement of the piston 48 clear of the cam 51 by means of a rod 93 when its upper end contacts a fixed stop 95. The metal in the upper part of the container and in the chamber 9 is kept molten by burners 63 within a furnace 62, the gases passing also through a flue pipe 64 surrounding the pipe 56. In a modification, a short container 2, Fig. 2, is employed, the main ram 15 being hollow and entering the lower end of the container. A further modified arrangement wherein the main and auxiliary rams engage in opposite ends of a short container is described. In a further modification wherein the rams are concentrically arranged, the main ram is fixed to the head of the press, and the integral container and feeding vessel make a small downward movement when metal is pumped into the upper end of the container by the auxiliary ram.