GB792133A - Improvements in or relating to a process and apparatus for casting a plurality of moulds - Google Patents

Abstract

792,133. Casting-machines. BUHRER, E. June 23, 1955 [June 23, 1954], No. 18211/55. Class 83 (1). In a casting process for casting in a mould having at least two sprues, a common pouring- basin is connected with the sprue-openings by channels, and a predetermined quantity of molten-metal required for casting is placed in the casting-ladle which is completely discharged in filling said mould. A mould, Fig. 5, comprises channels leading to sprue-openings 10-13 from a pouring-basin 2 provided with a grill 3, Fig. 2, or screen, and at least one ribinsert 4 which reduces turbulence. The moulds 26, Figs. 7, 9 and 11, are carried on a conveyer 25, and parallel thereto are rails 21, 22, carrying a track 23. Rotatably-supported in bearings 28 on the truck is a casing 29 including a motor 30 which drives gears within the casing engaging with racks 37, 38, movable in guides 39, 40, and supporting at their lower end a framework 41 which supports, through pivoted-linkwork 42, 43, 48, 49, a casting-ladle 54. The linkwork may be moved between the positions shown in Figs. 7 and 11 by a pneumatic-cylinder 59 whose piston-rod 57 is connected by a link 58 to the framework 41. Pivotally-connected to the ladle are rods 68, 69, connected at their other ends to .levers 64, 65 and to the lever 43. A cylinder 72 pivotally-connected at one end to the truck 23 and at the other to the guides 39, 40 may push the guides into the position shown in Fig. 11. A lever 79 actuates a lever 83 which engages a chain 85 driven at the same speed as the conveyer 25, to thereby cause the truck to move parallel to the moulds, and also actuate an air-valve controlling the air-supply to the cylinder 59. A molten-metal storagetank 87 has an opening closed by a spring- pressed stopper 90, which may be lifted by the introduction of pressure-air to the cylinder 96. A piston-rod 101 of a cylinder 99 carries a scale 102 which, upon admission of pressureair to the cylinder, is lifted to take the weight of the ladle 54, Fig. 11. The operation of the apparatus is described as applied to the filling of successive batches of six different moulds, each batch consisting of four different mouldheights which are standardized. With the parts in the position shown in Fig. 11, but with the scale lowered, the operation is initiated by actuation of a foot-operated switch 106 to raise the scale 102 to take the weight of the ladle, and to lift the stopper 90 to allow moltenmetal to flow into the ladle. The weighing- apparatus opens the circuit when the correct weight of metal is in the ladle, and the scale 102 is lowered to replace the ladle in trunnions 50, and the stopper 90 is lowered. The removal of the ladle from the scale closes a limit-switch and a circuit to the motor 30, which lowers the racks 37, 38 carrying the frame 41 and ladle. A preselected limit-switch at the appropriate height for the mould being filled is opened by a cam on the frame and stops the motor. Lever 79 is then shifted in the direction of the arrow 139, and the lever 83 engages the chain 85 so that the truck moves parallel to, and at the same speed as, the conveyer. The movement of the lever also feeds pressure-air to the cylinder 72 and to the cylinder 59, thus shifting the ladle to the position shown in full-lines in Fig. 7. When the ladle has reached its extreme emptying-position, the lever 42 closes a switch, which causes the motor 30 to raise the racks 37, 38 and the ladle to resume the elevated-position shown in Fig. 11. At the same time the lever 79 is returned and the cylinders 59, 72 opened to exhaust, the casting-ladle rotating to the position shown dotted in Fig. 7, and the guides 39, 40 swung back to the position shown in Fig. 11. The return of the lever 79 also releases lever 83 from the chain, and the truck may be manually returned to the position with the ladle beneath the stopper-opening 88. The arrangement may be such that one ladle is pouring while another is being filled. In a modification the cycle is completely automatic, the sequence being controlled by a motordriven drum. In a further modification, Fig. 12, the ladle is carried on a lever 216 suspended from a cylinder 210 contained in a cylinder 202. With the pressure-air-feed connected to exhaust, the cylinder 210 &c. and the ladle, are pushed upwardly by a spring 207. Pressure-air fed to the underside of piston 205 causes the ladle to be lowered. The ladle is counterweighted by an adjustable-weight 221.