Patent GB-1493807-A (GB)
Title: Blow moulding machine
IPC: B29C49/00
Filed: 1974-11-13
Abstract: 1493807 Continuous blow moulding machine MONSANTO CO 13 Nov 1974 [14 Nov 1973] 49113/74 Heading B5A A machine for continuously stretch-blow moulding comprises a continuous motion transfer means (e.g. conveyer chain 12, Fig. 1) carrying pins 121 for stretching and blowing parisons which are mounted thereon during passage around a loading turret 10 and which remain thereon during passage around a moulding turret 14 carrying moulding stations 13 into which respective pins 121 are located by the transfer means 12 during the stretching, blowing and cooling operations. The moulded articles (e.g. bottles 397) are ejected during passage of the pins round an ejecting device 17. The pins 121, Fig. 45, are mounted at intervals along the transfer chain 2 by attachment to chain links 84 of outer sleeves 80 through which the pins are slidable. Air for blowing a parison is supplied through a fitting 406 and passes between the sleeve 80 and the pin 121 through passage 399. Air for ejecting a moulded bottle 397 is fed through an inlet post 420 in the sleeve 80 and through holes 422 into a passage 423 in the pin, whence it passes through a non-return valve 424 and passages 425 into the parison. A block 122 on the bottom of the pin 121 engages a cam track 120, Fig. 1, to lower the pin before loading with a parison. A safety device 165, Fig. 5, detects pins which have not been lowered as they pass round an adjustable tensioning sprocket 138. Heated parisons are dropped into tapering shoots 40 through an opening 77 (Fig. 3, not shown) in the top 59 of a fixed shroud 58, Fig. 5. An inner shroud 74 fixed to the turret also reduces heat losses. A pin 121 is located below each shoot 40 from which it receives a parison before travelling to an input wheel 91, Fig. 1, which feeds it into a moulding station 13. The mould which is initially open, Fig. 54, is partly closed so that the threaded neck of the parison is engaged by a neck ring 96. The pin 121 is extended to stretch the parison into contact with the mould and plug 194 which may be lowered into the mould, Fig. 55. The plug and pin are raised together until the mould sides 192 can be closed around the plug 194 for blowing the parison. The mould sides 192 and the neck ring portions 196 are pivoted about a shaft 230, Fig. 14, and are moved by arms pivoted on a shaft 241 and connected to the sides 192 by pivoted links. The neck portions 196 are urged inwardly relative to the sides 192 by springs 327 (Fig. 35, not shown) so that they engage the parison first. A latch bar 344 is operated to hold the mould halves together and other latches hold the plug 194 and pin 121 in position. Cooling water is supplied to each moulding station via manifolds and conduits 201 to 205, Fig. 4, on top of the turret 14, and air for blowing the bottles is supplied from manifolds 411 below the moulds to the fittings 406 in the neck ring supports 320, Fig. 45. The movements of the parts of the mould and the latches, and also the admission of blowing and ejecting air are controlled by respective cam followers attached to parts of the mould, &c. engaging fixed cam tracks around the turret (Figs. 21, 22, not shown). After cooling the moulds are opened so that the pins carrying the moulded bottles can be transferred to a turret 506 of the ejection device 17, Figs. 1 and 4 which has fittings for engaging and supplying air to the inlet parts 420 of the pins to eject the bottles. Three transfer shoots are positioned on the turret over respective pins to pass the ejected bottles to a stationary receiving shoot 517.