PURPOSE: To enable a glass tube with the strength increased due to its configuration into U-shape to be produced irrespective of its curvature, by heating and softening two glass tubes each of which has its one end closed, thereafter pressurizing the insides of the tubes, forming opening parts in order to connect them to each other, putting them into a molding tool, and molding them into the predetermined shape.
CONSTITUTION: The facing parts (parts to be connected) in the vicinity of the closed parts of two glass tubes 1 are locally heated with a gas burner 6, after that, when they are softened, air is fed into respective glass tubes 1 through air- feeding inlets 33. When the parts to be connected to each other project outward and the tips of the projecting parts are perforated by the pressure of air, a holder 22 is moved in order to connect the glass tubes 1 to each other. The vicinity of the connected part 1a is heated with the gas burner 6, the softened part is covered with a molding split die 55, and air is fed thereinto from the air- feeding inlets 33 in order to pressure-mold the inside of the glass tubes. By doing this, the wall-thickness of the curved part of glass can be controlled without difficulty, and consequently, a U-shaped fluorescent lamp having the sufficient strength can be easily produced.
TAKEDA TAKAO
YAMAMOTO HIROJI
NAKANO SHIZUO
ITOU HIROSHI
IMAI JIYUN
| JPS55133730A | 1980-10-17 |
| US2561859A | 1951-07-24 |