Patent GB-697217-A (GB)
Title: Improvements in or relating to apparatus for and method of forming paste mold glassware
IPC: C03B40/027
Filed: 1952-02-26
Abstract: 697,217. Making hollow glassware. EMHART MANUFACTURING CO. Feb. 26, 1952 [March 5, 1951], No. 5060/52. Class 56. In a machine for making paste mould glassware, a hollow parison is formed at one station and transferred to a second station whereat it is blown to the final form whilst being rotated in the paste mould, the latter being formed so as to support the parison to allow the transferring means to be removed and means being provided to grip the parison and rotate it in the mould whilst introducing the blowing air. The invention is applicable to " press and blow " or " blow and blow " machines such as those described in Specifications 668,983, 560,672, 532,778 and 257,637. Fig. 1 shows a general arrangement of a " press and blow " machine modified for paste mould operation according to the invention, the various operations of the machine being controlled by a standard timer in the usual way. The parison 12 is formed in a two part mould 4 and two-part neck ring 5 by a plunger 10 which passes a charge of glass from a supply chute 9 into the mould. Each half of the neck ring is attached to an arm 16 which is secured to a turnover shaft 18 driven by a rack 20 which engages a wheel 17. After the parison has been formed, the mould 4 opens and the parison, held in the neck ring is turned over and supported. so that it can be engaged by the two halves of a paste mould 21, the inwardly projecting flanges of which support the parison by means of a flange 15 formed thereon so that the neck ring can be opened and the shaft 18 reversed to return the neck ring to the parison forming station. A combined blower head and gripper mechanism 27 described below is then lowered towards the mould 21 by a piston rod 23 and the parison is gripped by jaws which lift it slightly and commence to spin it in the mould. At this point the mould is opened for a short period and sprayed with water through nozzles 117 and 118a as indicated in Fig. 6, the parison elongating due to its reheating and the admission of a small amount of blowing air. The mould is again closed, the top of the parison is sealed by a weighted cap and blowing air is admitted to expand it to its final form. The mould is opened and the article taken out either by the gripping mechanism which is raised by piston rod 23 or by separate take-out tongs. The blower head and gripper mechanism is shown in detail in Fig. 2. It consists of a bearing housing 30 secured by an arm 28 and clamp 29 to the piston rod 23, a tubular shaft 31 being rotatable in the housing in bearings 32 and 33. Within shaft 31 is a second tubular shaft 34 and within that shaft, an inner tubular shaft 36, the three shafts being keyed so that whilst they must rotate together, the inner shaft 36 can move up and down inside shaft 34 and the latter can move up inside shaft 31 against the action of a coiled spring 48 which bears on a flange 45 formed at the lower end of shaft 34. On the underside of the flange 45 are pivoted four gripper jaws 41, the jaws carrying rounded arms 39 which engage in a grooved member 38 mounted on the inner shaft 36 so that axial movement of that shaft with respect to shaft 34 causes the jaws to open or close. The closing movement is produced at the appropriate moment by the admission of air under a piston 80, the rod 79 of which carries a fork 82 which lifts the shaft 36 by engagement with a grooved member 83 carried on its upper end so causing the jaws to close. The jaws are opened by the return action of the spring 48. The inner shaft 36 also serves as a blow spindle, being connected by a tube 100 through a valve 101, which is controlled by the machine timer, to the compressed air supply. To seal the parison during blowing, the lower end of the shaft 36 carries a sealing cap 92, the weight of which is adjusted to allow it to lift to relieve any excessive air pressure which may occur inside the parison. The shafts are rotated by a belt 53 which engages a pulley 52 on the shaft 31, the belt being driven by a pulley 54 on a shaft 55 which is driven through a clutch member 60 and chain 64 by a shaft 66. The clutch member 60 ensures that the shafts are not rotated until the blower head is lowered onto the mould. As a further safeguard, rotation of the grippers is prevented until they are closed on to the parison by a pawl 74 which holds the pulley 52 stationary until it is lifted clear by the upward movement of rod 79, this movement also causing the closing of the grippers as described above.