GB365592A - Method and machine for forming bottoms in glass tubes - Google Patents

Abstract

365,592. Glass manufacture. ZAPPERT, E., 55, Chancery Lane, London.- (Dichter, J. ; 4, M³nz Strasse, Berlin.) Oct. 15, 1930, No. 30813. [Class 56.] Forming articles from tubing.-Relates to the formation of bottoms on glass tubes by a machine of the kind in which sections of tubing, each having the length of two finished tubes, are heated in the middle, drawn apart, and the heated ends shaped as required. According to the invention, the operations of melting, drawing-apart, and finishing are performed at a number of stations, the heating of the tubes being effected at two or more stations. The machine comprises wheels or rollers a which support and rotate the glass tubes g and provide a number of working stations I .. VI. The tubes are fed on to the rollers, and are lifted from one station to another, by any suitable devices. Burners c, g are provided for heating [the tubes, and abutments b are provided for preventing the tubes from moving laterally. A tube is heated at stations I and II and arrives at station III with the heated zone of glass in a plastic condition. At this station, oblique rollers z rest on the tube and draw the ends apart in the known manner until they are stopped by the abutments b. A constriction is thus formed in the middle of the tube which is severed by the burner f at station IV. The two short tubes are then transferred to station V and the closed ends are flattened by laterally movable plates p. If rounded bottoms are required, as when making test tubes, a station VI is provided in which the abutments bare replaced by blowheads k. The tubes are pressed against the blowheads by oblique rollers z<1>, and the bottoms are blown to a rounded shape by compressed air supplied to the blowhead, through pipes r.