Patent GB-1008672-A (GB)
Title: A machine for moulding thermoplastic material
IPC: B29C44/58
Filed: 1964-06-12
Abstract: 1,008,672. Moulding thermoplastic material. NATIONAL CASH REGISTER CO. June 12, 1964 [June 19, 1963], No. 24545/64. Heading B5A. A machine for mass-producing regularly shaped bodies of expandible thermoplastic material comprises a plurality of open ended mould pots, an assembly of upper closure members, an assembly of lower closure and ejecting members, a feeding device positionable over the mould pots, a heating system for the mould pots. As shown in Fig. 11, each mould pot 24 is mounted in a carrier 23 and the mould cavity is defined by a vertically reciprocable core member 28 and a lower annular closure member 25, the cavity being closed, during moulding by an upper closure member 48. The material is fed to the mould cavity by a blowing and brushing device 42a as described later. The mould pots 24, Figs. 2A, 2B are mounted in a carrier 23 removably mounted in a table 19. The bottom closure members 25 are carried by a support plate 26 vertically movable by a ram 27. The hollow detachable core members 28 and the mould carrier are supplied with heated vapour, coolant and compressed air during a machine cycle, the cores 28 being carried by a support plate 29 vertically movable by a ram 30. The lower position of the plate 26 is adjustable so that the length of the mould cavity is variable. The upper closure members 48 are carried by a plate 47a detachably attached to a vertically movable ram 46a carried by a transverse head 20. Feeding and delivering.-A filling device 21, Fig. 12, is carried by the transverse head 20 and comprises a container 41 which on movement of the head during a machine cycle is located over the carrier 23 and from which the wetted pre-foamed material, e.g. polystyrene, is fed to the mould cavities by a rotary brush assembly connected to a source of compressed air. On the movement of the transverse head 20 an article ejecting plate 44 secured to the filling device sweeps the moulded articles into a shoot 45. The transverse head 20 is latched at the end of the movement by a pneumatically operated latching device 51. The machine may be controlled manually or automatically by successive operation of sequencing switches by various machine parts, a presettable counter determining the number of cycles to be performed. Each cycle includes the following sequence of operations. The transverse head 20 is moved so that the articles moulded in the previous cycle are swept by the plate 44 into the delivery shoot 45. The plate 26 carrying the bottom closure member 25 is moved downwardly so opening the mould cavities to which the material is fed. The transverse head 20 is returned and latched by the device 51. The plate 47a carrying the upper closure members 48 is moved downwardly and heating vapour is supplied to the mould cavities and to the core members to effect expansion of the material in the cavities. Coolant is then supplied to the mould cavities and core members and is then expelled by compressed air. The plate 29 is moved downwardly to remove the cores 28 from the mould cavities, plate 47a is raised to withdraw upper closure members. The transverse head 20 is unlatched and moved to position the sweeping plate 44 adjacent the edge of the mould port carrier 23. Upward movement of the plate 26 carries the closure members 25 to eject the moulded articles from the mould cavities and the core members are then moved back into the mould cavities.