GB505403A - Improvements in or relating to the casting of easily oxidisable metals - Google Patents

Abstract

505,403. Casting-machines. WAGNER, K. F. May 27, 1938, No. 15844. Convention date, May 27, 1937. Addition to 475,541. [Class 83 (i)] Metal pouring.-In casting easily oxidizable metals, such as magnesium, as described in the parent Specification a charge of metal is received in an open-topped cylinder 9 which is submerged in the molten metal 2 in a crucible 1, freely supported by lugs 7, the cylinder and a plunger 13 are then raised by a head 23, Fig. 3, and rods 22 until the former seats in a passage 11. A plunger 10 is then raised in the cylinder by a rod 15 to transfer the molten metal to a transfer cylinder 14, which is then moved along a passage 12, Fig. 1, until it is in line with the plunger 19 for forcing the charge through a passage 18 into a mould, not shown. The residue is returned by a plunger 20 to the cylinder 14 which moves back to its original position where the residue is pushed through the passage 11 by the returning plunger 13 and strikes the conical end of the plunger 10 still in its upper position relative to the returning cylinder 9. The plunger 10 is then returned admitting a fresh charge of metal to the cylinder 9. A carrier 21 is clamped about the cylinder 9 and the ends of connecting rods 22 by bolts and cottars, as screws submerged in molten metal could not be unscrewed when required. The cover 25 rests on the crucible and carries one end of the member M in which the passages 11, 12 are formed, the whole being held by extensions 27, Fig. 3, of the member M and bolts 28 which are relatively cool. In order that the movement of the rods 22 may not be impeded by adhering metal they are carried freely through holes in the cover 25 and tubular caps 24 kept hot by gases escaping from the furnace. All the movements are effected by hydraulic pistons controlled in desired sequence, the cylinder 16, Fig. 1, for the transfer cylinder 14 being freely supported by a bracket 40, and connected to the member M by stays not shown, the furnace 3 is mounted on wheels to avoid irregularities caused by expansion due to heat. The transfer cylinder 14 may have edges 29, Fig. 4, to scrape adhering metal from the passage 12. Neutral gas may be admitted by a regulating valve 31, pipe 30, and groove 33 to the passage 12 and cylinder 14 and by a flexible pipe 36, bore 37, and non-return valve 35 to the passage 11.