GB1395272A - Injection blow moulding machine - Google Patents

Abstract

1395272 Injection-blow-moulding WHEATON INDUSTRIES 4 Jan 1973 507/73 Heading B5A An injection blow-moulding machine comprises an injection, a blowing and an ejection station disposed in a common plane about a central axis, rotor means rotatable about this axis and having arms upon each of which a core rod is mounted perpendicularly to the arm. As shown in Figs. 1, 2, indexing means 12 is rotatable on shaft 52 and carries arms 10, 16, 24 carrying core rods 8, 18, 26 shown at the injection, blowing and stripping stations respectively. The injection mould 6 and blow mould 22 are mounted one half of each on a fixed platen 82 and the other half of each on movable platen 34, blow mould half 22b being mounted on platen 34 via spring washers 36 so that a greater closing pressure is applied to the injection mould. Platen 34 is opened and closed along shafts 50, 52 by rack 59 fixed to platen 82 and by pinion 56 which is connected by shaft 54 to pinion 58 of half the diameter of pinion 56, pinion 58 driving indexing means 12 by rack 60 half the distance of platen 34 in the direction of mould opening/closing. A sprocket wheel 74 is mounted on shaft 52 and connected by a chain to sprocket wheel 76 engageable via fluid operated clutch 78 to shaft 40 carrying gear 44 which engages stripper rack 38 via gear 42. In operation, material is injected from cylinder 2 through nozzle 4 into injection mould 6 around core 8 on arm 10. Simultaneously, blowing air passes through inlet means 20 and core 18 to expand a previously formed parison thereon into blowmould 22. Also simultaneously, a previously blown bottle on core 26 is stripped therefrom by yoke 86, clutch 78 being disengaged to prevent indexing. Core 26 may then be supplied with temperature conditioning gas, heating or cooling, in readiness for the next injection cycle. After a timed period, platen 34 is opened, also opening the moulds and moving outwardly by half that distance the indexing mechanism 12 carrying cores 8, 18, 26. Press opening also actuates clutch 78, returns stripper yoke 86 and rack 38 which via gears 42, 44, clutch 78, and sprockets 76, 74 indexes mechanism 12. Limit switch 146, actuated by rack 38, then actuates press closure for a further cycle. Each stage of a cycle is actuated by limit switches, timers, &c. operated by the previous stage, the control circuitry including a spring loaded sensor 70 engaging grooves 68 in indexing mechanism 12 and preventing press closure if mechanism 12 is incorrectly indexed, and a further limit switch (LS-5, not shown) in the discharge shoot to check correct discharge of bottles after stripping. The arms 10, 16, 24 are correctly positioned at the injection station by guides 14 (15) and the mould parts may be correctly positioned by adjustable wedge parts (126, Fig. 7, not shown).