| 摘要 |
PURPOSE:To make it possible obtain a constant sealing shape even it the dimensions of glass tubes and stems include scattering errors, to miniaturize the device and also to simplify the processing by pushing into a glass tube a stem having a flare portion of larger outside diameter than an inside diameter of the glass tube, after heating and softening said flare portion. CONSTITUTION:The outside diameter D of a flare portion 5 of a stem 4 is formed previously to have a larger diameter than the inside diameter d of a glass tube 1. The stem 4 supported by a stem holder 10 is located under the glass tube 1 facing towards the glass tube 1 at a distance L aparting from it. The periphery of the flare portion 5 is heated by a burner 12 under this condition, then the peripheral part of the flare portion 5 is softened and causes drag 5' by its self weight, and the outside diameter D becomes a little smaller. Subsequently, when the stem 4 is raised together with the stem holder 10 and the burner 12 in one body, the stem 4 is inserted within the glass tube 1, the flare portion 5 in the softened state hits the opening end 2 of the glass tube 1, and is pushed therein, and the peripheral part of the flare portion 5 makes close contact with the inside surface of the glass tube 1. Moreover, when the glass tube 1 and the flare portion 5 are heated with the burner 12, both are melted together at the same time. |
