| 摘要 |
A nozzle (10) and gate (18) for a plastic injection mold (12) wherein the gate (18) has a primary sealing surface (50) located adjacent to the vestige (22) and a secondary sealing surface (54) located behind or inwardly of the primary sealing surface (50). The nozzle (10) has an insert retainer (42) threadably mounted therein to hold a tip or torpedo type insert (64). The insert retainer (42) has an outer annular primary seal (46) which engages the gate primary sealing surface (50), and an intermediate annular secondary seal (56) which engages the gate secondary sealing surface (54). The primary seal (46) prevents hot plastic from passing behind the nozzle and the secondary seal (56) ensures that even if some plastic gets behind the primary seal, it will not pass behind secondary seal (56) and contact heating coil (33). The main body portion may be shaped to form a third seal (80) for engagement with the secondary sealing surface (54) behind the position of the secondary seal (56).
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