Gas discharge lamp preparation process

Claim 1

A process for sealing a gas within an electronic tube such as a gas discharge lamp, comprising: providing within a gas tight chamber which includes heating means, a hollow axially extending vitreous body having a vitreous tube integral with said body extending along said axis to an orifice, said hollow vitreous body further including a pair of electrodes extending axially thereinto a respective one of which extends through said tube, is not sealed thereto and has a vitreous bead in the form of a sleeve about said respective electrode in said tube formulated of a solder type of glass, said bead having a softening temperature below a softening temperature of said tube, said bead allowing gas transfer through said first tube to the interior of said body and having the ability to wet, seal and thereby close off said tube on softening; evacuating said chamber and the interior of said body via said tube; pressurizing said chamber with a gas and thereby pressurizing the interior of said body via said tube with said gas; uniformly heating said entire chamber via said heating means and thereby uniformly heating said tube, said body and said bead with said tube and the interior of said body pressurized with said gas to a temperature intermediate the softening temperature of said bead and the softening temperature of said tube to soften said bead and wet, seal and thereby close off said tube therewith while sealing said bead to said respective electrode; cooling said sealed body, tube and electrodes.