| 摘要 |
In incandescent lamps having a pinched seal surrounding an exhaust tube, it is customary to heat the exhaust tube in situ in the surrounding glass envelope and then to pinch the softened envelope on to the tube. This involves complex heating arrangements. According to the method of invention the envelope (1) and exhaust tube (2) are heated separately by respective burner assemblies (7, 8) and are moved into their relative positions, and the pinch formed, when each has reached the required temperature. This provides a simpler and more rapid manufacturing operation. <IMAGE> |
