MANUFACTURING DEVICE FOR GLASS BULB FOR EMISSION TUBE

PURPOSE:To enable glass bulbs with high quality and high dimensional accuracy to be manufactured in a short time, without any need of the skillfulness, irrespective of the diameter of the glass bulbs, by providing a means of stopping the radiating action of a laser-light radiating device in preference to control of a program controller when the outer diameter detected by an outer-diameter detector indicates a given value. CONSTITUTION:It is clear that the outer diameter and the shape of a spherical expanded part are determined for each combination of the diameter and the thickness of a worked glass tube (P), according to the radiation time of laser light, the periods of the forward movements and the backward movements of shucks 4a and 4b, and the increasing state of the internal pressure. Therefore, by sputtering a cam timer 23 and timers 25, 27 and 28 according to a manual prepared on the basis of the results of experiments, glass bulbs with a designated size can be manufactured in large numbers in a short time. In addition, since laser light is used as a heating source, high-quality glass bulbs which are not contaminated with any hydrogen or the like can be manufactured.