APPARATUS FOR PRODUCING PREFORM FOR OPTICAL FIBER

摘要

PURPOSE:To continuously monitor the weight of a preform being prepared by a load cell without enlarging whirling of the preform. CONSTITUTION:Oxygen, hydrogen and a raw material gas fed into a reactor 4 are mixed and the mixture is subjected to flame hydrolysis reaction by a burner 14. Thereby, this preform 6 is prepared in a state in which the preform 6 is hung down from a starting rod 5 which is the lower end of a seed rod 1. The upper part of the seed rod 1 is supported by a rotating chuck 17 attached to an elevating frame 19. The rotating chuck 17 is constituted of a housing 23 attached to the elevating frame 19, a hollow shaft 25 rotatably supported to the housing 23, a center shaft 26 which is an extended shaft part of the seed rod 1 and a load cell 22 attached to this center shaft 26 and fixed to the inner face of top wall of the hollow shaft 25. The hollow shaft 25 is rotated by a motor 32 installed in the elevating frame 19.