Apparatus for producing glass parison by the press-and-blow process

An apparatus to be used in the production of a glass parison by a press-and-blow process in which a press mould and an annular gap surrounding said mould are to be filled with a change of glass melt, said apparatus comprising:

• a plunger ring having a chamber therein;
• a plunger movable in said plunger ring chamber for axial displacement relative to the press mould, said plunger when moved into said press mould defining therewith a shaping cavity;
• and
• neck retaining ring means mounted to enclose a parison and tightly abut against said press mould in a sealing manner during pressing;
• said plunger ring including a first surface portion on an axially outwardly facing end thereof and said retaining ring means including a first surface portion on an axially inwardly facing end thereof, when said plunger is in a molding position in said pressing mould said first surface portion of said plunger ring is spaced from said first surface portion of said retaining means to cooperatively define therewith said annular gap such that said annular gap surrounds the plunger and communicates with said press mould to receive glass melt forced from said mould by said plunger;
• said plunger ring including a second surface portion laterally spaced adjacent its associated first surface portion and said retaining ring means including a second surface portion laterally spaced adjacent its associated first surface portion, said second surface portion of said plunger ring being spaced from said second surface portion of said retaining ring means and at least one of said second surface portions extending at an angle relative to its associated first surface portion so that when said plunger is in a moulding position in said press mould, said second surface portions are cooperatively arranged to define an enlarged, annular compensating chamber located radially outwardly of said annular gap and communicating therewith to compensate for the presence of an amount of charge which is in excess of that filling said shaping cavity and said annular gap, by receiving such excess.