| 摘要 |
<p>The molding core (1) is extracted by pulling it out. As it leaves the interior of the molding, it unwinds continuously as a strip (6). In addition or alternatively, it is divided into sections which form connected segments. During extraction, these segments are released in sequence, virtually continuously, as they leave the inner contour of the hollow molding which has been formed. The core has a predetermined line of separation (5) along which it is divided during extraction. The separation line is formed by a: cut, partial incision or perforation. It winds along the length of the core. The core is made of a material deformed by pulling. The cross section transmitting the tension (F) of pulling, is adequate to permit core extraction without damage. The core is made of solid material, or a cavity is enclosed by it. A supportive section is or can be introduced into the cavity. The core comprises a single-layered, wound strip. Further layers and strips may be included. The variation in cross section along the length of the core, leaves under-cut sections in the molding, on extraction. Core diameter is 0.2 m at most. It is preferably no greater than 0.1 m. To make a hollow fibrous component, fibrous material is applied over the outer surface (2) of the core, to form the hollow molding. The core is then pulled out by at least one of its ends, as described. Fibrous material is applied to the core using a braid-winding or sewing technique. After application, it is impregnated by a matrix material. At least during application, the core is stabilized in shape by an internal support section. The core is made by winding-up a strip. This is unwound subsequently. Alternatively a line of separation is introduced into core material, especially by cutting. The core can be unwound or divided into individual segments along this line. An independent claim IS INCLUDED FOR the method of making a hollow fibrous molding.</p> |
