Patent GB-415634-A (GB)
Title: Improvements in or relating to method and apparatus for the manufacture of hollow glassware
IPC: C03B9/16
Filed: 1933-12-22
Abstract: 415,634. Glass manufacture. HARTFORD-EMPIRE CO., 333, Homestead Avenue, Hartford, Connecticut, U.S.A.-(Assignees of Rowe, G. E. ; 72, Somerset Street, Wethersfield, Connecticut, U.S.A.) Dec. 22, 1933, No. 36190. Convention date, March 18. [Class 56.] Relates to the production of hollow glass articles with walls of even thickness by the method described in Specification 368,302 in which a plunger is thrust into the open end of an inverted parison mould, as soon as possible after the mould has received a charge of glass, to form an axial cavity in the parison. According to the present invention, air under pressure is applied to the glass, in addition to the pressure applied by the plunger, in order to settle the glass in the ring mould. Apparatus for carrying out the method comprises a combined blow-head and plungersupporting head, shown in sectional elevation in Fig. 2, consisting of a longitudinally extensible shell composed of telescopic tubular sections 1, 2 which are normally kept extended by a spring 23, the shell being adjustably supported by a vertically movable arm 6. The glass-displacing plunger 9 is mounted within the section 2 and is retained in position by a tubular core 16. The plunger may be hollow from its upper end to near its tip, and an air-supply pipe 19 may be fitted within the axial cavity. Air from the pipe 19 will pass into the lower end of the cavity and thence upwards to an annular chamber 21 in the plunger, whence it passes out through orifices or passages 22 into the space surrounding the plunger. A further supply of air under pressure may pass from an additional pipe line 25, Fig. 8, to an annular chamber 28 which, in turn, communicates with the space surrounding the plunger. The arm 6 is clamped to a vertical shaft 32 which forms the piston rod of a pneumatic cylinder 34. When the piston is raised, the plunger is swung to one side by a cam slot 41 in a plate 37 which engages a roller 38 secured to the rod 32. The plunger may be cooled when in its raised position by a spray of air and a suitable liquid. The cylinder 34 also moves the plunger downwards into the parison mould 42, means being provided for adjusting the rate at which the plunger descends into the mould. The device may be embodied in a machine of the double-table intermittently-rotated type in which each parison mould is associated with a divided ring mould 62, Figs. 2 and 8, and the parison mould is carried by an inverting head 63. A neck pin or mandrel 64 can be raised into the ring mould by a pneumatic cylinder 65 at the mould-charging position, and the pin may be cooled by circulating fluid through its interior. Suction may also be applied, through a pipe 68 and passages 67, to the space surrounding the pin, to assist in settling the glass in the ring mould. In operation, a charge of glass from a feeder is guided into the mould by a funnel 18 which is lowered and seated on top of the mould by suitable mechanism, such as a pneumatic cylinder 69. As soon as the charge of glass has entered the mould, the cylinder 34 lowers the rod 32 until the blow-head 1, 2 is seated on the funnel 18. Further movement of the rod 32 compresses the spring 23 and forces the plunger 9 down into the mould 42, thus causing the glass to rise around the plunger and distribute itself along the wall of the mould. At the same time, air is supplied through the pipe 19 to the space within the section 1 where it may be supplemented by air pressure supplied by the pipe 25. The air not only cools the plunger, but also compacts the glass in the mould around the neck pin. The application of the air pressure may commence as soon as the section 1 rests on the funnel, and the pressure applied by the pipe 25 may be cut off as soon as the glass begins to compact. After the plunger has been raised, the mould 42 is inverted, a bottom plate is applied, and pressure is applied to expand the glass and remove the axial cavity formed by the plunger. The parison is transferred to the finishing mould table and blowing is completed in one or more stages.