Patent GB-1394716-A (GB)
Title: Casting apparatus
IPC: B22D39/00
Filed: 1972-09-21
Abstract: 1394716 Casting machines UNION CARBIDE CORP 21 Sept 1972 [22 Sept 1971] 43727/72 Heading B3F [Also in Division F4] Apparatus for casting metal objects of uniform shape and weight comprises a plurality of moulds 47, a reservoir 39 for molten metal, means for conveying the moulds sequentially through a feed zone below the reservoir, at least one orifice in the bottom of the reservoir, a vertically movable stopper rod 65 for obstructing the orifice and mechanical means for synchronizing the action of the conveying means with the movement of the stopper rod 65 so that molten metal is discharged from the reservoir into a mould when the latter is located in the feed zone. The moulds 47 are moved through the feed zone by means of a pair of endless chain link belts 42 passing around sprocket wheels (45) and (46). They are mounted on bars 43 attached to opposite individual links of the belts, said bars comprising an insulating layer (89) and a metallic support layer (91), and may be vibrated by a vibrator 86. A vibrator bar 88 extends longitudinally for a distance sufficient to vibrate the moulds while at least the top layer of molten metal solidifies. The moulds may be split moulds which automatically open when they reach the front end of the apparatus to discharge the casting. They may be made from graphite or porcelain and in the embodiment shown have five cavities each. The reservoir 39 is provided with an overflow 54 and is continuously supplied with molten metal from a further reservoir (36) located below the conveyer by a pump (41). Excess metal flows out through the overflow and back to the said further reservoir so as to maintain a constant level of metal in the reservoir 39. The orifices in the bottom of the reservoir 39 are formed in plugs 70 made of a Mo/W alloy and provided with a bushing (69) having a hole (68) therein for guiding the rod 65. The bushing also has a plurality of holes (71), through which the metal flows to the orifice (64), Fig. 20 (not shown). At its upper end the rod 65 passes through a loosely fitting hole 72 in a rocker arm 73. The rod 65 is lifted when the rocker arm 73 moves upwardly and engages a collar 74 attached to the rod at a position above the rocker arm. The rocker arm 73 pivots about a bar 76 and is pivotally attached at 77 to an adjusting arm 78 which rests freely on the top of a lifting bar 79 attached to a pair of support arms 81. The support arms 81 are moved up and down by means of a push rod 84 which is vertically oscillated by an eccentric 96 and is connected to the support arms 81 via an arm 112 and a rotatably mounted bar 82. The amount of metal discharged from the reservoir 39 is controlled by adjustment of the position of the collar 74 and by means of a screw 85 mounted in the adjusting arm 78 and bearing against the rocker arm 73. The latter provides a very fine adjustment for the molten metal feed. Synchronization of the movement of the stopper rods 65 with the movement of the moulds is effected by driving the eccentric 96 from the rear sprocket wheel (46) via a chain drive and further sprocket wheels, Fig. 12 (not shown).