Control for an I.S. machine

A control for use with a glass forming machine which includes a blank station for forming a parison from a gob of molten glass having at least one mechanism, a blow station for forming a parison into a bottle having at least one mechanism, a feeder system for shearing a gob from a runner of molten glass so that it can be delivered to the blank station including at least one mechanism, a mechanism for transferring a parison from the blank station to the blow station and a takeout mechanism for removing a bottle from the blank station,

• wherein the machine has a set cycle time,
• wherein each of the mechanisms is cycled within the time of one machine cycle,
• wherein each displacement of each of said mechanisms has a determinable duration,
• wherein interferences exist between the motion paths of the gob, the parison, the bottle and individual mechanisms,
• wherein the displacement of at least one of the mechanisms is divided up into at least two submotions which locates an interference with the gob, the parison, the bottle or another mechanism,
• wherein process air is supplied for at least one process for a finite duration by turning a supply valve “on” and then “off” during the time of one machine cycle,
• wherein the thermal forming of the parison and bottle involve a predetermined number of thermal forming processes having finite durations,
• wherein displacements begin and valves are turned “on” and “off” in a desired sequence, and
• wherein an unwrapped bottle forming process wherein a gob of molten glass is formed from a runner of molten glass, the gob is then formed into a parison in the blank station, the parison is then formed into a bottle in the blow station, and the bottle is then removed from the blow station, takes more than one machine cycle to complete, comprising
• a computerized model of a mathematical representation of a network constraint diagram of the unwrapped bottle forming process for determining, with inputs including the following:
• 1. the event time in an unwrapped bottle forming process for each displacement to begin and for each valve to be turned “on” and “off”;
• 2. the machine cycle time;
• 3. the motion durations of each of the mechanisms, and
• 4. the submotion durations,
• the duration of each of the thermal forming processes.