| 摘要 |
PURPOSE:To prevent thickness variation crack at sealing section by encapsulating through a press chip where projections are provided on the press face of a press chip except the region in the vicinity of split face. CONSTITUTION:An outer tube bulb 1 is inserted into a mount 2 and set. Under this state, it is rotated around the mount 2 then thermally softened by means of a burner 3 to encapsulate by means of press chips 4, 4' advancing from left and right. A series of projections 5, 5' are fixed to said chips 4, 4'. Recessed sections 6, 6' are formed in the outer tube bulb 1 by means of said projections 5, 5'. Projections are not provided in the range of split face 45 deg. of press chips 4, 4'. Consequently burning can be reduced while variation of thickness of glass during molding can be reduced. |
