To prevent a resin from moving by sucking back and prevent a change in the timing for sealing.
A metering part 18, a screw head 14, the first ring 31 which is placed between the metering part 18 and the screw head 14 and which has the first resin channel, the second ring 32 which is arranged between the metering part 18 and the screw head 14 in a relatively swingable manner next to the first ring 31, a driving means which turns the screw 12 selectively normally or reversely are provided. A swing regulating means is formed between the first ring 31 and the second ring 32 which makes the first resin channel and the second resin channel communicate with each other when the screw 12 is turned normally and prevents the first resin channel and the second resin channel from communicating with each other when the screw 12 is turned reversely.
MORIKITA NOBUO
AKAMATSU MASAHARU
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