| 摘要 |
PURPOSE:To prevent the strength of an exhaust pipe from falling, by providing the exhaust pipe with an annular projection smoothly swelling from the pipe, and by using an adhesive to fix the exhaust pipe in an end plate closing the end of the glass bulb of a discharge lamp. CONSTITUTION:When an exhaust pipe 6 for evacuating the air out of the glass bulb 1 of a discharge lamp to produce a vacuum in the glass bulb is to be fitted in a ceramic-made end plate 2 gastightly fixed on the open end of the glass bulb, the exhaust pipe 6 is made of glass and provided with an annular projection 61 smoothly swelling from the pipe, and is inserted into the exhaust pipe hole 2a of the end plate 2. Frit glass 3 is put on the top of the projection 61. The frit glass is heated and then cooled to fix the exhaust pipe 6 in the end plate 2. Since the stress caused at the time of the fixation of the exhaust pipe 6 is dispersed by the projection 61 to eliminate any stress concentration, the strength of the exhaust pipe is not reduced. The exhaust pipe 6 is thus securely fixed. |
