GB404308A - An improved process for the mechanical manufacture of glass bottles with precisely dimensioned neck opening - Google Patents

Abstract

404,308. Glass manufacture. MAREK, J., 58, Rakoczi Ut, and KOVACS, E., 20, Keleti Karoly Utca, both in Budapest. April 29, 1932, No. 12421. Convention date, March 14. [Class 56.] A neck-forming mandrel, for use in forming glass bottles with neck openings of uniform diameter, is made with thin walls of a material of low specific heat and high thermal expansion, and has a number of perforations of small diameter distributed over its end surface. The mandrel 4 is hollow, and it is inserted in the glass charge 8 for a depth m corresponding to the length of that portion of the bottle neck the diameter of which is to be of accurate dimensions. Also, since the mandrel remains in the glass until the neck portion has set, it is thin-walled and is made of a material of low specific heat, high conductivity, and high thermal expansion, such as the alloy described in Specification 403,938, in order that the shrinkage of the glass shall not form hairlike cracks on the inner wall of the bottle neck. Within the mandrel there is a seating 12 for a ball valve 11, and apertures 13 for the admission of air below the valve. The upper end of the mandrel is concave towards the exterior and is perforated with small holes 14. In use, the mandrel co-operates with a parison mould 7, a ring mould 5 which is formed with suction passages 6, and a head which provides a suction and blowing chamber 9 around the mandrel. When a charge of glass 8 enters the mould 7, suction applied through the chamber 9 and the passages 6 settles the glass in the ring mould around the mandrel. During the suction period, the ball 11 rests on its seating and glass is not sucked through the perforations 14. Compressed air is then supplied to the chamber 9, and the pressure unseats the ball 11 and allows the air to pass through the perforations 14. The mandrel remains in the neck until the blowing of the parison is completed, though it may be withdrawn if the glass of the neck has set sufficiently to prevent it from changing its shape during the blowing. A construction for use with suction gathering machines is also described in the Specification.