| 摘要 |
PURPOSE:To prevent the stress to be generated in the flanges of a metal frame at the time of resistance-welding from being transmitted to the low-melting point glass and the light- transmitting plate by a method wherein the upper wall with a penetrated hole formed therein is continuously provided on the upper ends of the sidewalls of the metal frame, the penetrated hole is used as the light-transmitting plate sealed with the low-melting point glass and parts of the sidewalls at the sites being separated from each other are each formed to have a wall thickness thinner than that of the sidewalls at other sites. CONSTITUTION:A light-transmitting plate 6 is sealed on an upper wall 4 of a metal frame 1 with a low-melting point glass 7 and covers a penetrated hole 5. The wall thickness of he whole region of each sidewall 2 is formed in a thin-walled thickness of nearly 1/2 of the wall thickness of the upper wall 4. Parts of the sidewalls 2 at other sites are each formed in a wall thickness of 70% or thereabouts of that of the upper wall 4 because the sidewalls are stretched at the time of draw processing. There is no possibility that the stress to occur along with the deformation to be generated in flanges 3 of the metal frame 1 when a stem is resistance welded to this window cap is transmitted to the low-melting point glass 7 and the light-transmitting plate 6 because the stress comes to be absorbed in these sidewalls 2 in such a way as to make the thin-walled sidewalls 2 deform. Accordingly, the generation of crack in the low-melting point glass 7 and the light-transmitting plate 6 is prevented. |
