Plunger mechanism for an I.S. machine

A plunger mechanism for an individual section glass container forming machine comprising

• an upper cylinder portion having a plurality of cylindrical chambers,
• a lower cylinder portion supporting said upper cylinder portion and having a corresponding plurality of cylindrical chambers with a selectively displaceable cylindrical piston disposed therein, each piston having a rod portion displaceable within a corresponding one of said upper cylinder chambers,
• said pistons each including an axially extending cooling air conduit,
• a base plate for supporting said lower cylinder portion, said base plate having an exhaust air passage,
• said upper cylinder portion including exhaust air exit ports at the bottom thereof for venting exhaust air from said upper cylinder portion and
• at least one tubular sleeve extending vertically from the top of said lower cylinder portion to said base plate for receiving exhaust air vented from said exhaust air exit ports and for conveying the received exhaust air to said base plate exhaust air passage,
• said tubular sleeve being spaced from said lower cylinder portion substantially from the top of said lower cylinder portion to the bottom thereof and said spacing communicating with the air surrounding said lower cylinder portion whereby the air surrounding the lower cylinder portion will insulate each of said tubular sleeves from said lower cylinder portion.