| 摘要 |
971,921. Moulding thermoplastic articles. K. MAGERLE. April 12, 1962 [April 19, 1961; June 15, 1961], No. 14165/62. Heading B5A. A thermoplastic article is made by injecting hot plastic from a feed plunger into an open mould, closing the mould and pressing by relative movement of the mould parts, which may be cooled. In the embodiment illustrated in Fig. 1, the neck of a tube 25 is formed in a mould consisting of a core 3, 2 and die 19, 17. The lower half shows a section of plastic tube 6 projecting beyond the core shoulder, while plastic 8 is sprayed through apertures 4 in a feed plunger 1 (by movement of a piston 10) on to the inner face of tube 6. The upper half shows the end of the pressing process, when the carriage 13 has moved forward carrying the annular die 19 and the two movable die jaws 17. When the die jaw closure portions 29 pass apertures 4 they scrape off the surplus plastic, finally jaws 17 close together, forming the plastic and welding it to the tube. In the embodiment illustrated in Fig. 2 (not shown), the arrangement is similar to Fig. 1, but the die jaws 42 have separate closure slides 43 which on coming together, with jaws 42 closed, form, with a die 37 and core 38, a completely closed mould before the hot plastic is actually pressed. The modification in Fig. 4 (not shown) is used to form a tube neck with an aperture. Fig. 5 shows a similar arrangement used to make a tapped cap 101. Here the cap is formed entirely from injected hot plastic, sprayed from two concentric sets of apertures 107 in a feed plunger 102 on to a core 108. A sleeve 119 advances, cutting off the flow of plastic, then carriage 110, with a die 109 and die jaws 125 advances; the mould is closed when the die 109 contacts sleeve 128 on core 108, jaws 125 then being closed. Further advance of carriage 110 effects the pressing of the plastic 101 into the shape in the upper half of Fig 5, while sleeve 128 is moved along core 108 against springs 130. The cap 101 may be shaped further by a series of pressings in progressively smaller dies. Fig. 7 (not shown) illustrates such an arrangement, a series of cores 146 being arranged on a turntable and coming in turn under a feed plunger 140 and die 150, subsequent pressings being effected by dies 151, 152. Figs. 9, 10 (not shown) illustrate equipment identical to Fig. 1, except that mould closure is effected when plates 176 engage around the core 167. Figs. 11-16 (not shown) illustrate progressive formation of a screw-thread by successive die jaws of different shape and orientation. Figs. 17, 18 illustrate the pressing of a cap 224 in two stages. A cylindrical blank 203 is formed in a die 201, mould closure being effected by a sleeve 204 in groove 205 engaging with a conical surface 222, further advance of die 201 doing the pressing. Plunger 212 carrying blank 203 is then moved to engage with die 223, and the second pressing is performed.
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