| 摘要 |
<p>780,439. Blow-moulding hollow articles. GLENN PROPRIETARY, Ltd., L. & I. Nov. 18, 1954 [Dec. 2, 1953], No. 33457/54. Class 87(2). A machine for moulding hollow articles from thermoplastic materials comprises a heated stationary extrusion cylinder 3 terminating in one or more tube-forming nozzles N each having a hollow mandrel 15 through which compressed air is passed to blow the extruded tube against the interior of a mould ; a hydraulicallyreciprocated platen 8 ; and a two-part hydraulically-opened-and-closed mould 9, 9a. As shown, two articles are made simultaneously. When two tubes have been extruded from nozzles N the platen rises, the mould parts 9, 9a thereon being initially in the open position. As the platen rises the mould parts close on the extruded tubes, fitting neatly around the nozzle parts 16 and pinching the tubes at the bottom of the moulds. As the moulds close they operate air valves 30 to admit compressed air through conduit 4b, annular groove 4c and hollow mandrels 15 into the tubes to expand them against the moulds. After a timed dwell in the up position, to enable the water-cooled moulds to set the article, the platen descends and the moulds open. Automatic operation. Depression of a switch 27 energises solenoid valve 24 which operates control valve 21 to lower extrusion ram 1a to extrude tubes from nozzles N. At the end of its stroke the ram depresses limit switch 28 to (a) de-energize valve 24, (b) energize solenoid valve 25 which operates control valve 22 to raise the platen and (c) sets a timer 29. As the platen rises it operates a pilot valve 23 to cause hydraulic rams 6a, 7a to move inwardly to close the mould parts together on the extruded tube. The articles are blown, the timer times out and the parts return to their original position. A guard may be provided, closing of which initiates the cycle. As the ram ascends it operates a valve 31 which actuates an air cylinder 33 to move a feed slide 34 to deliver fresh material from a hopper 19 to a shoot 20 which feeds the cylinder 3. Feed-adjusting screws 17 ensure constant lengths of tubes. A filter 13, 14 is provided.</p> |
