GB560365A - Improvements in or relating to a method of and means for carrying out the heat treatment of glass articles - Google Patents

Abstract

560,365. Glass manufacture; burners. GREETHAM, E. Dec. 11, 1942, No. 17660. [Class 56] [Also in Group XI] A method of heat treating a glass article consists in subjecting the desired part of the article to a number of gas flames arranged around it, and automatically increasing the size and intensity of the flames in a predetermined manner so as to raise the temperature in desired stages up to the required final temperature. The method may be used for sealing electric lamp bulbs, radio valves, or vacuum flasks, and may be carried out with a substantially annular burner having a number of closelyspaced jets disposed around its inner peripheral surface. A number of such burners 2, Fig. 1, may be spaced equally around a rotating table 1, the glass articles being gripped by holders 4 which are raised and lowered by a cam, as the table rotates, to bring the article into and remove it from the ring of flame from the burner jets. The supply of gas to the burners may be controlled and varied in a predetermined cycle by a valve actuated by any suitable mechanism. Preferably the valve comprises a stationary disc 17 and another disc 18 which is fixed to and rotated with the table 1. The discs have ground faces in contact with one another, and ports are formed in these faces. Gas at different pressures supplied to the ports 21-23, Fig. 4, in the disc 17, and ports I-XII in the disc 18 each of which is connected to a burner 2. Thus as the disc 18 revolves, the ports I-XII sweep over the ports 21-23 and each burner is supplied with gas at increasing pressures. Small " buffer " ports 24-26 are also provided in the disc 17 between the main ports and are provided with gas at intermediate pressures in order to keep the burners alight during the change from one gas pressure to the next. In a modification, the burner unit or head may be stationary, and the operator may stand on a platform that is rotated to carry him past the burner units.