A mold assembly (1) for injection molding of a plastic pipe fitting (2, 3). The pipe fitting comprises an elbow-shaped or a tee-shaped internal flow channel (4). At least one of the first core member (14) and the second core member (15) of the core package (12, 13) comprises a built-in cooling arrangement (20) for cooling of the core package (12, 13), the cooling arrangement (20) extending longitudinally inside said core member over a substantial length of said core member. The pipe fitting (2, 3) comprises an elbow-shaped or tee-shaped internal flow channel (4) comprising at least two channel parts (5, 6, 7) arranged at a first angle () in relation to each other, the channel parts (5, 6, 7) each having a circular cross-section and a smoothly radiused inner corner face (8) between each two channel parts being at said first angle in relation to each other, the at least one of the channel parts having an inner diameter D, a length L from central corner point to the end of the channel part, the inner corner face having a rounding radius R. The ratio (D/R) of the inner diameter D and the rounding radius R is in the range 2 to 5, and the ratio (L/D) of the length L and inner diameter D is in the range 8 to 3.

A system for manufacturing a shell for a batting helmet includes interchangeable mold-core portions configured to form a cavity for receiving molding material. The mold-core portions include a first base mold-core portion and a plurality of inner side mold-core portions configured to form an interior contour of the shell. The mold-core portions further include a second base mold-core portion and a plurality of outer mold-core portions configured to form an exterior contour of the shell. Mold-core portions are interchangeable, removable, and replaceable from an interlocked position relative to other mold-core portions. A method of manufacturing batting helmet shells includes selecting mold-core portions corresponding to various helmet shell configurations having various protective features, assembling the mold-core portions into a mold assembly, and providing molding material into a cavity in the mold assembly. A kit of parts for making a shell for a batting helmet includes a variety of interchangeable mold-core portions.

Collapsible core devices, related methods and injection molding tools for use in injection molding processes, the core device configured to collapse upon rotation of a centrally disposed rotating shaft. In some aspects the core device includes a rotatable shaft, moveable outer wall components positioned radially from the shaft, a first disk operatively engaged with the shaft and having at least a first slot configured to receive a first pin connected to a moveable outer wall component, and a second disk secured in a fixed position and having at least a second slot configured to receive the first pin, such that rotation of the rotatable shaft causes the pin to slide within the second slot toward the shaft and causing the outer wall component to move toward the shaft.

A process is provided for making a walled structure using an injection molding apparatus. The apparatus has a molding space formed between a mold cavity and an inner core disposed within the mold cavity. The molding space defines a shape of the structure. The process includes injecting molding material into the molding space, moving or retaining a portion of a movable impression member protruding from the inner core within a portion of the molding space so as to create a recess within an inner wall of the structure, and retracting the impression member into the inner core such that the impression member is cleared from the molding space. Precision control in forming the impression member is provided by a closed-loop configuration using a sensor that measures a molding space parameter (e.g., temperature), optionally in combination with a servo drive for activating the impression member.

A mold stack for a mold comprises a mold core configured for reception in a mold cavity plate with an outer molding surface. The mold core comprises an inner core with a first tapered guide surface and an outer core with a second tapered guide surface. The inner core is received through a passage in the outer core. A spacer slidably supports the outer core on the inner core. The outer core is movable relative to the inner core between a molding position in which the inner and outer cores define a mold cavity with the outer molding surface, and an open position in which the outer core is extended relative to the inner core. In the molding position, the first and second tapered guide surfaces engage one another to align the inner and outer cores.

A shutter device includes blades rotatable to interrupt an air flow therethrough, and first and second frames supporting the blades. One end of a blade in a longitudinal direction thereof includes a first support rotatably supported by the first frame, and a second support rotatably supported by the second frame. The first support and the second support are disposed along a widthwise direction of the blade. Another end of the blade in the longitudinal direction thereof includes a third support rotatably supported by the first frame, and a fourth support rotatably supported by the second frame. The third support and the fourth support are disposed along the widthwise direction of the blade.

A slide piece driving mechanism includes a side surface guiding portion, a shaft portion, and stopper releasing means. The side surface guiding portion is disposed at a movable side mold to guide a side surface of a slide piece to be slidably movable. The shaft portion of a stopper is disposed at the side surface guiding portion. When the slide piece reaches an upper end position, the shaft portion engages with a stopper hole of the slide piece to prevent the slide piece from falling from the upper end position due to own weight. The stopper releasing means releases the engagement of the shaft portion of the stopper with the stopper hole to allow the slide piece from falling from the upper end position due to its own weight.

A mold insert assembly includes a base section having a base side removably attachable to a base plate of a mold and a first interface surface having a notched portion thereon. A first section includes a first interface side with a first interconnecting tab sized to engage the notched portion of the base section when the first interface side abuts the first interface surface, the first section further including an adjoining side having an interconnecting notch. A second section includes a second interface side having a second interconnecting tab, where the second interconnecting tab is sized to engage the interconnecting notch of the first section when the second interface side abuts the adjoining side, and where the base section, the first section, and the second section when assembled form a contoured insert configured to create a contoured cavity in a part formed within the mold.

Provided is an injection mold and a method of injection molding having a molding core system. The molding core system including a plurality of co-operable components manipulable between a first molding position at which the core system is fully deployed and a second position in which the core system is configured to axially retract and radially contract into a second drawing position, the outer shape of said core system being substantially complementary to the inner shape of the molded article.

A method of molding a product including an undercut part or a right-angle part includes providing a female mold, a first male mold and a temporary mold to form a first molding chamber, wherein a boundary between a core and a lifter of the first male mold is located outside the first molding chamber; performing a first injection into the first molding chamber to mold a first portion of the product including the undercut part or the right-angle part; removing the temporary mold; replacing the first male mold with a second male mold to form a second molding chamber, wherein a boundary between a core and a lifter of the second male mold is located outside the second molding chamber; and performing a second injection into the second molding chamber to mold a second portion of the product integrally formed with the first portion of the product.