GB858833A - Double-billet extrusion presses - Google Patents

Abstract

858,833. Extruding. SCHLOEMANN A.G. May 2, 1957 [May 19, 1956], No. 14002/57. Class 83 (4). In the simultaneous extrusion of a pair of billets by means of a pair of rams 6, equal pressures are initially exerted on the two billets and subsequently the positions of the two rams are synchronized for equalizing the size of billets in the two containers 2. The two rams 6 are actuated by pistons 7 working in cylinders 8 whose pressure spaces may be connected together directly by pipes 9 through a valve 10. The pressure spaces are also connected through pipes 27a, 27b to a synchronizing slide valve 14 whose valve element 22 is coupled by a rod 21 and links 19, 17 with a mechanism 15, 16 responsive to the positions of the two rams, and also with an indicator 24, 26. The exhaust from valve 14 is connected through a throttle valve 31 having a hand lever 32. Initially the valve 10 is opened by an electromagnet 11 energized by switch 35 which is closed by lever 32 when throttle-valve 31 is closed. Pressure liquid is then admitted from an accumulator to the pressure spaces 8a through pipe 36, control device 37, pipes 40a, 40b and adjustable valves 41. After the billets, which may be of aluminium, have been compressed against the residue of the preceding billets to become welded thereto, high-pressure liquid to effect the extrusion is then supplied to the cylinder spaces 8a through pipes 12 and non-return valves 13, and if the indicator 24 shows a difference in ram positions, the valve 31 is gradually opened whereby the synchronizing valve slowly equalizes the piston positions and hence the container contents. When the valve 31 is fully open extrusion proceeds through die 5 under the control of the synchronizing valve. The highpressure liquid may be supplied by separate sets of identical pumps as described in Specification 802,615.