A method of constructing a mandrel generally complementary to a spar cavity of a spar includes connecting a first component and a second component to form a central space there between and inserting a center component within the central space such that the center component retains the first component and second component in a desired position forming an outer surface of the mandrel which corresponds to an inner surface of the spar cavity.

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.

An injection mold, including: an insert, a fixed half, a moving half and a core. The fixed half has a first groove and a rubber inlet communicating with the first groove. The moving half is configured for matching with the fixed half, the moving half has a second groove, and the fixed half and the moving half are arranged in layers to form a cavity together by the first groove communicating with the second groove. The core is partially embedded in the second groove and connected to the movable mold, the core has a diameter variable end at least partially located in the cavity. The insert is arranged on an end face of the diameter variable end, a first molding section is formed between the insert and a bottom of the first groove, the first molding section is configured for injection molding the flat portion.

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.

A helmet for ball sports has a main body and two strengthening elements. The two strengthening elements are mounted on two inner walls of the main body. A first surface of each strengthening element abuts and is connected to the main body. Second surfaces of the strengthening elements face to each other. Through holes of each strengthening element are formed through the first surface and the second surface so that the strengthening elements are latticed. With the helmet mounted with the strengthening elements on two sides, the strengthening elements enhance an anti-impact capacity on the two sides of the helmet. Besides, with the latticed strengthening elements, the weights of the strengthening elements are lightened and do not cause weighted burden on the neck of the user.

A method and apparatus for manufacturing continuous ribbed pipes of thermoplastic resin material comprises the following successive steps. A length of pipe is injection molded in a mold cavity between a collapsible male mold element and female mold elements, the latter being shaped to provide integral ribbing on the outer surface of the pipe. After sufficient setting, the female mold elements are disengaged and the male mold element is collapsed and disengaged. A plunger then pushes the pipe length axially along the male mold element. The female mold elements and the collapsed male mold element are then re-engaged such that the one end of the formed pipe forms a closure for the mold cavity at the downstream end. Further material is again injected into the cavity which fuses with the one pipe end and which forms a further pipe length. These steps are repeated until the desired length of pipe is formed.

A collapsible core is provided for attachment to a mold half of a casting mold, particularly a diecasting mold. The collapsible core can take the form of a removable collapsible core which can be detachably mounted on the mold half on the mold cavity side. A collapsible core can have a core cylinder body of at least two first core sections in the form of cylinder segments and at least two second core sections in the form of cylinder segments arranged alternating with the first sections over the circumferential direction. The first and the second core sections are retained moveably relative to one another. The relative movement here between the first and the second core sections consists of an axial relative movement component between the first and the second core sections and a radial collapsing movement of the first and/or the second core section.

A curved portion at an inner circumferential face on a bend direction inside of a bend has a circular arc shape. By configuring the curved portion with a circular arc shape, a recess, serving as an example of a cross-sectional area enlargement portion that enlarges the cross-sectional area of a flow path of a pipe body running along a direction of an axial line 13, is formed in the inner circumferential face on the bend direction inside of the bend.

A hybrid mandrel for forming a composite part may comprise a core and a sleeve located around the core. The core may include a rigid material. The sleeve may comprise an elastomeric material. The part may be formed by locating the hybrid mandrel in an injection mold, depositing a molten resin around the hybrid mandrel, curing the molten resin; and removing the hybrid mandrel.

A part for a mold is disclosed. The part includes a body formed of a shape-memory alloy. The body includes a first shape or first configuration at a first temperature and a second shape or second configuration at a second temperature. In one embodiment, the first shape includes at least one protrusion and the second shape is straight. A part of the present disclosure eliminates damage to a molded piece during removal of a molded piece from an injection mold by changing its shape in such a way that is suitable for part ejection.