Variable-pitch multi-blade propeller incorporating individually dismountable blades made of composite materials, process for manufacturing such blades and blades thus produced

Claim 1

A blade for equipping a multi-blade propeller and in particular a propeller for being used as a tail rotor or a rotorcraft, comprising: a shell with aerodynamic profile, constituted by at least one layer of fiber fabrics with high mechanical resistance agglomerated by a polymerized synthetic resin for impregnation, a preformed filling body made of a cellular or foam synthetic material and disposed in said shell, a spar having a longitudinal axis substantially parallel to a longitudinal axis of the blade and constituted by a single elongated leaf of rovings of fibers with high mechanical resistance agglomerated by a polymerized synthetic resin, and of which a major part is fixed in said shell whereas an end part of said spar is emerging from said shell and forms a twistable and bendable spar root part from connecting said spar to a hub, and a metal leading edge cover integrated in said shell, wherein said elongated leaf forming said spar is constituted by a single bundle of rovings which is folded on itself in a zone of fold to define two equal halves having inner parts adjacent said zone of fold and outer parts remote from said zone of fold, said inner parts constituting said spar root part having an inner end arranged as a loop surrounding a tubular connecting element for connecting the blade to said hub, and said outer parts being coupled to each other and constituting said spar major part received in said shell and bonded, on one hand, in a cut-out provided in one face of said preformed filling body and whose cross-section corresponds substantially to that of said spar major part, and, on the other hand, directly on an inner face part of said shell opposite said cut-out of said filling body, and said shell comprises an inner end turned towards said spar root part and arranged as a blade root which is traversed by said spar root part and made with extensions of each layer of fiber fabrics constituting said shell and covering a stack of reinforcing fiber fabric layers.