Apparat og dets anvendelse til levering af en overfangsglasstrøm

Apparatus (10) for forming a cased glass stream having an inner core glass surrounded by an outer casing glass includes a first orifice (22) for receiving core glass from a first source (12), and a second orifice (28) vertically spaced beneath and aligned with the first orifice. A chamber (30) surrounds the second orifice and communicates with the second orifice through a metering gap (42) between the first and second orifices. Casing glass is delivered from a second source (40) to one side (44) of the chamber such that glass flows by gravity from both the first and second sources through the orifices to form the cased glass stream. In accordance with one aspect of the present invention, the metering gap (42) is of non-uniform dimension around the chamber, providing greater resistance to glass flow through the metering gap on a side thereof adjacent to the side of the chamber that receives casing glass from the second source and less resistance to glass flow through the metering gap on the side thereof remote from the side of the chamber that receives the casing glass.