Patent ID: 6079972
Filing Date: 2000-06-27
Classification: B29C,B29K

Abstract:
In an injection molding apparatus having an elongated cavity (66) in a mold (16) and a cooled mold core (10) made of a hollow elongated inner part (78), a hollow elongated outer part (80), and a front cap (132) having an inner surface (138) and an outer surface (136), the elongated inner part (78) having a front portion (112) with an open front end (116), an outer surface (120) and a longitudinally extending central duct (104) to convey cooling fluid therethrough, the elongated outer part (80) having a front portion (114) with an open front end (118), an outer surface (124), and an inner surface (126) which fits around the outer surface (120) of the front portion (112) of the inner part (78), at least one of the inner surface (126) of the front portion (114) of the elongated outer part (80) and the outer surface (120) of the front portion (112) of the elongated inner part (78) having a plurality of cooling fluid conveying grooves (122, 128) extending longitudinally therein, whereby the outer surface of the front portion (114) of the outer part (80) and the outer surface (136) of the front cap (132) form an inner side (126) of the cavity (66), the improvement wherein;the front portion (112) of the elongated inner part (78), the front portion (114) of the elongated outer part (80) and the front cap (132) are integrally joined together whereby the front cap (132) encloses the open front end (118) of the front portion (114) of the outer part (80) to form a cooling fluid conveying space (134) extending between the central duct (104) in the inner part (78) and the cooling fluid conveying grooves (122, 128), and both the outer surface (120) of the front portion (112) of the inner part (78) and the inner surface (126) of the front portion (114) of the outer part (80) have a plurality of cooling fluid conveying grooves (122, 128) therein, the grooves (122) in the outer surface (120) of the front portion (112) of the inner part (78) and the grooves (128) in the inner surface (126) of the front portion (114) of the outer part (80) spiralling in opposite directions to produce turbulent cooling fluid flow through said grooves (122, 128).