GB803332A - Method of and means for the production of metal castings - Google Patents

Abstract

803,332. Foundry-plant. WALLWORK & CO., Ltd., H., and WALLWORK, C. M. G. March 7, 1957 [March 9, 1956], No. 7403/56. Class 83 (1). Sand-moulds are produced with complementary pattern-impressions in their vertical end-faces, a succession of said moulds is formed into a horizontal line, with complementary endfaces of adjacent moulds in contact to form mould-cavities, and the line is then moved in the direction of its length past a fixed pouring- station. The apparatus comprises a moulding- station 1, two parallel mould-guiding tracks 2, pouring-ladles 3, a rumbling-barrel 4 and a shotblasting-machine 5. Sand from a hopper 6 and sodium silicate from a hopper 8 are mixed at 7 and pass to a hopper 10, and thence to a blowing head 11 at the moulding-station 1. Beneath the blowing-head is mounted a slider 13 having two openings 36 forming moulding-boxes, and which is reciprocable by an hydraulic-ram 32 between two positions, in one of which one of the boxes is in line with the blowing-head and the other box is in line with a track 2, and in the other position the first box is in line with the other track 2 and the other box is in line with the blowing-head. Pattern-plates 41 carried on opposed rams 14 compress the sand blown into the box beneath the head 11, and CO gas is then admitted through the rams and patterns to harden the mould, and the rams 14 are then retracted. Each ram 14 comprises an internal cylinder 45, Fig. 11, to which pressure-fluid is first supplied to move the pattern up to the box, and a cylinder 43 to which pressure-fluid is applied to apply moulding-pressure. The slider is moved so that the other box is in line with the blowing-head, and the moulded-box is in line with a track 2, on to which the mould is ejected from the slider by a ram 15. When the slider is returned to its original position the mould formed in the other box is similarly ejected on to the other track 2. Thus as the process proceeds, each track has built up on it a continuous length of moulds, intermittently moved forward by action of the corresponding ram 15 and supported by the walls of each track 2. Clamps 17, Fig. 1, actuated by pneumatic-cylinders in timed-relation to the action of the corresponding ram 15, clamp the moulds against movement, except that effected by the ram 15. Tilting of the ladle 3 associated with each track is effected by a ram 19 in synchronism with the ram 15 and clamps 17, so that pouring is effected while the moulds are stationary and clamped. Hoppers 20 distribute new sand on the tops of the poured-moulds so that it is dried-out by the heat of the castings. The tracks 2 lead into the common rumbling-barrel 4 which breaks up the moulds. The fine sand therefrom passes to a conveyer 23 and magnetic-separator 26, thence by pneumatic conveyer 27 to the hopper 6; coarser particles pass through a shoot 24 to waste and the castings, runners, &c., pass through the shot-blast 5 to a conveyer 25. When changing patterns, new pattern-plates arrive below the rams 14 in their retracted position, on roller-conveyers 62, and are lifted therefrom by supports 63 which raise the patterns until they push the old pattern-plate vertically upwards from the rams and take their place. The displaced pattern-plates are gripped by jaws 70 carried in arms 68 rotatable in a vertical plane by rams 69, which drop them on to roller-conveyers. The pattern-plates are held to the rams 14 by clamps and locating-pins, which are actuated by pneumatic-cylinders and rendered inoperative during pattern-changing. The invention may be applied to other forms of moulding, such as shell moulding, and the moulds may be carried in light boxes which fit into the openings in the slider 13. When shellmoulding, the pattern-plates are heated, sandresin mix is blown between them, excess mix withdrawn and the shells fed into the track 2, separated by a backing such as shot or loose sand. The moulds may be vibrated during consolidation and casting