GB508021A - Improvements relating to the manufacture of hollow glassware - Google Patents

Abstract

508,021. Making hollow glassware. BRIDGES, E. G. Dec. 22, 1937, No. 35507. Convention date, Nov. 30. [Class 56] Relates to the manufacture of hollow glassware by a machine of the double table type described in Specifications 160,366, 365,245, and 386,012. The invention consists in subjecting each parison, after it has been formed and while confined in the parison mould, to air pressure after the normal cotmterblow in order to set the glass. The mould is opened earlier than usual to allow the parison to reheat, and after the parison is transferred to the finishing mould the final blowing is continued at several successive positions where the moulds are stopped. The parison mould table 11 and the finishing mould table 13 may have an equal number of moulds on each, or more finishing moulds may be used, and the tables may be rotated step by step by a pneumatic motor 40, or by a Geneva gear of the kind described in Specification 508,056, so that the moulds are presented to a number of operating stations. At station A, a parison mould 10 is inverted and is charged with molten glass through its open end, the mouth portion being closed by a mandrel 15 raised and lowered by a pneumatic motor 16. After charging, the open end of the' mould is covered by a blowhead 17 through which air is blown to compact the glass. The mould then moves to station B where the glass is counterblown to form a parison. The mould moves next to station C where the parison is again subjected to air pressure to cool and set the glass. Reinversion of the mould takes place while moving to station D, and at this station the mould is opened to allow the chilled skin of the parison to reheat. This reheating takes place preferably at three successive stations D, E, F during a time equal to the parison - forming period, but it may be accelerated by applying the flame of a gas burner. In order to straighten the parison and to prevent @indue elongation during reheating, a paddle or former 30 having an inclined upper surface is brought into contact with the lower end of the parison at station D. Transfer of the parison to a finishing mould 12 takes place between stations D and E, and blowing of the parison to its final form commenced at station G and continues at stations H and I for a period preferably equal to or greater than the parison-forming and reheating periods. The finished bottle may be removed by a take-out device such as that described in Specification 365,245. In a modified construction, the parison mould is reinverted between stations A and B, and the parison is counterblown while it is neck upwards. This construction allows a longer time for the parison to reheat..