Method for making three-dimensional fibrous annular structures

摘要

The invention concerns a method whereby a first fibrous web formed by substantially unidirectional elements is brought (by device 300) and raised (by shuttle 322) alternately in one direction and in the other between coaxial outer (100) and inner (200) circular crowns, while being maintained at said crowns by picots (102, 202), and a second fibrous web formed by substantially unidirectional elements and deposited (by device 400) in a circumferential direction between said outer and inner crowns, the transverse and circumferential annular webs are bound together by a binding device (500) and are driven in rotation about the axis of the outer and inner crowns by completing three full cycles to obtain a thick annular fibrous structure having layers formed by the transverse web which alternate and are bound to layers formed by the circumferential web.