GB1483517A - Method of casting - Google Patents

Abstract

1483517 Casting apparatus GRAVICAST PATENTVERWERTUNGS GmbH 6 Nov 1974 48012/74 Heading B5A [Also in Division B3] A method of casting comprises holding a melt to be east in a storage chamber 2, allowing melt to flow from the storage chamber to a casting nozzle 6 which has an upwardly directed outlet opening 7, locating a mouth of a closure-free ingate of a casting mould 9 in engagement with the outlet opening so that the mould is filled with the melt, keeping the mould in engagement with the nozzle until the solidification front of the cast melt has entered into the outlet opening of the nozzle and until a plug 28 of solidified melt has been built up and then separating the mouth of the ingate from the casting nozzle by relative movement between the mould and nozzle away from a plane in which the mould and nozzle meet, the flow of melt from the storage chamber to the nozzle being controlled so that, between casting operations, the level of melt is kept in the region of the outlet opening of the nozzle. In apparatus for carrying out the method, the storage chamber 2 is connected by an opening 3, which is closable by stopper valve 5, to an equalization container 4, in turn, connected to the casting nozzle 6 having the upwardly directed outlet opening 7, the nozzle being surrounded by a heat-insulating layer 11 having a cover-plate 12 of ceramic material, and the assembly of storage chamber, equalization container and nozzle being mounted on a fixed frame 10. The mould 9 is mounted on one end of a swivel arm 13 movable about a pivot 14 on a carrier member 15 by an hydraulic piston-and-cylinder device 17. The carrier member is mounted on a turntable 21 supported by rollers 23 on a base member 22. The turntable is rotatable by a motor and gear drive 26 which drives a pinion 25 engaging a gear 24 on the turntable to move the mould between positions 27, 31 and an intermediate position in which the ingate of the mould engages the outlet opening 7 of the nozzle. In operation, a mould is attached to the arm 13 in the position 27, the arm is lifted and is then swung to a position above the outlet opening 7. The hydraulic device is actuated to effect lowering of the arm so that the ingate of the mould engages the outlet opening. The stopper valve is raised so that the melt flows through the nozzle into the mould. The mould is retained in engagement with the nozzle until the solidifying front of the melt in the mould has entered the nozzle to form the plug 28, the stopper valve 5 being closed then or when filling of the mould is complete. The arm is then raised to disengage the mould from the nozzle and swung to the position 31 for opening the mould to release the cast product. A new mould may be mounted on the arm at position 31 or the arm moved to position 27 for mounting a new mould. A brush 32 may be moved across the outlet opening for cleaning the upper surface of the nozzle and the surrounding area. In another embodiment, the mould is engaged with the nozzle by raising the nozzle and, if desired, the total casting plant.