Method and apparatus for delivering cased glass stream

Apparatus for forming a cased glass stream having an inner core of glass surrounded by an outer glass casing, includes (i) means for delivering core glass from a first source through a first orifice 22, (ii) means forming a second orifice 28 vertically below the first orifice with a chamber 30 surrounding the second orifice and communicating with the second orifice through a gap between the first and second orifices and (iii) means for delivering casing glass from a second source to the chamber such that glass flows by gravity through the orifices to form the cased glass stream. The first and second orifices are carried by an orifice housing assembly 44 with means for moving the assembly into seating engagement against the means for delivering core and casting glass so as to form an area seating engagement. The orifice housing assembly further includes a fluid manifold 50 mounted on the housing assembly and having inlet means for connection to a source of cooling fluid and outlet means 58 directed toward the area 59,60 of seating engagement between the assembly and the means for delivering core and casing glass for cooling the area and thereby reducing leakage of glass between the housing assembly and the means for delivering core and casing glass. Also claimed is an orifice housing assembly for an apparatus for forming a cased glass stream. Also claimed is a method of cooling the area of seating engagement between the orifice housing and the means for delivering streams of core and casing glass.