SEALED ARC TUBE WITH REFRACTORY METAL END CAPS

摘要

9 48,425 An arc tube for a high-pressure sodium (HPS) discharge lamp having an extended seal path to reduce leakage therethrough. The extended seal path is provided by a monolithic arc tube body having circular apertures in the ends thereof of a substantially smaller diameter than the diameter of the arc tube body and a skirted end cap having refractory metal tubulation extending centrally therethrough mounted on each end of the arc tube body. A glassy sealing frit is interposed between the entire interior surface of the end cap and that portion of the refractory metal tubulation extending through the circular aperture in the arc tube ends.