Pneumatic plunger mechanism for a glassware forming machine

Abstract

Both blow-and-blow and press-and-blow plunger mechanisms for use in forming a parison from a gob of fluid glass in a individual section (IS) of a glassware forming machine are fully pneumatically controlled. Plunger and thimble pistons affirmatively position a thimble and a plunger in consistently repeatable positions during loading of the gob, counterblowing or pressing an initial opening in the parison, and transferring the formed parison. No springs or other mechanical components which are prone to cause inconsistencies or failures are employed. The plunger mechanism is preferably suspended from the frame of the IS by a plunger case assembly to avoid the problems associated with a support foot. The plunger case assembly allows the plunger mechanisms to be easily interchanged or replaced, to be adjusted to accommodate different types of operation and sizes and configurations of glass article produced, while still communicating pressurized air to the plunger mechanisms to achieve these effects.