Composite reinforcement elements woven in three dimensions

Claim 2

A composite reinforcement element of complex evolutive shape woven in three dimensions and at least three directions, comprising at least three superimposed and crossed even layers of threads, and a continuous thread extending perpendicularly through said layers, said layers being impregnated with a binder, said binder being polymerized after impregnation, wherein said layers are initially maintained assembled, before the impregnation and the polymerization of the binder, merely by a conjugate action of gripping and friction of the threads of the layers on said continuous thread which extends therethrough and which forms on an internal surface of the element successive protruding open loops which are interconnected on the external surface of the element, said continuous thread being maintained in position solely by frictional forces.

Claim 3

A composite reinforcement element formed by the steps of: employing a disposable mandrel composed of foam, said mandrel having an external surface, said mandrel external surface corresponding to an internal surface of the reinforcement element to be produced; implanting rigid pin members in the mandrel; applying successive layers of threads on the surface of the mandrel stretched out between said rigid pin members, said threads being superimposed and crossed in at least two directions; interconnecting said layers of threads by means of a continuous thread extending substantially perpendicularly through said layers by driving a needle carrying said continuous thread through said layers and into the mandrel such that an eye of the needle fully penetrates the external surface of the mandrel said continuous thread forming successive open loops protruding from said internal surface of the reinforcement element and protruding into the foam material of the mandrel, said continuous thread being held in place solely by a frictional effect from engagement with said foam material; impregnating said layers of threads and said continuous thread with a binder; hardening said binder after impregnation; withdrawing the pins and removing the mandrel.

Claim 4

A composite reinforcement element formed by the steps of: employing a disposable mandrel composed of foam, said mandrel having an external surface, said mandrel external surface corresponding to an internal surface of the reinforcement element to be produced; implanting rigid pin members in the mandrel; applying successive layers of threads on the surface of the mandrel stretched out between said rigid pin members, said threads being superimposed and crossed in at least two directions; interconnecting said layers of threads by means of a continuous thread extending substantially perpendicularly through said layers by driving a needle carrying said continuous thread through said layers and into the mandrel such that an eye of the needle fully penetrates the external surface of the mandrel said continuous thread forming successive open loops protruding from said internal surface of the reinforcement element and protruding into the foam material of the mandrel, said continuous thread being held in place solely by a frictional effect from engagement with said foam material; impregnating said layers of threads and said continuous thread with a binder; hardening said binder after impregnation; withdrawing the pins and removing the mandrel.

Claim 5

A composite reinforcement element according to claim 2, wherein said continuous thread is introduced through said layers of threads by means of a needle having a throughway eye having an edge defining an internal rounded portion and a longitudinal groove which opens laterally and obliquely onto the eye.

Claim 6

A composite reinforcement element according to claim 2, wherein said needle introducing said continuous thread through said layers comprises a non-throughway eye having an edge defining an internal rounded portion and an axial passage opening laterally and obliquely onto the eye.

Claim 7

A composite reinforcement element having a complex evolutive shape including threads woven in three dimensions extending in at least three directions, said threads woven in three dimensions comprising three layers of threads superimposed and crossed on a form having said complex evolute shape said form having an external surface corresponding to an internal surface of said reinforcement element a continuous thread extending substantially perpendicularly through said three layers and through said complex evolute shape said at least three superimposed layers and said substantially perpendicularly extending continuous thread being impregnated with a binder which is thereafter polymerized, said three layers and said continuous tread being maintained in an assembled position, prior to being impregnated with said binder, said continuous thread forming successive open loops protruding through said external surface, said continuous thread being held in place by friction of contact with said three layers and said form said loops being interconnected on the external surface of the element.

Claim 8

A composite reinforcement element having a complex evolutive shape including threads woven in three dimensions extending in at least three directions, said threads woven in three dimensions comprising three layers of threads superimposed and crossed on a form having said complex evolute shape said form having an external surface corresponding to an internal surface of said reinforcement element a continuous thread extending substantially perpendicularly through said three layers and through said complex evolute shape said at least three superimposed layers and said substantially perpendicularly extending continuous thread being impregnated with a binder which is thereafter polymerized, said three layers and said continuous tread being maintained in an assembled position, prior to being impregnated with said binder, said continuous thread forming successive open loops protruding through said external surface, said continuous thread being held in place by friction of contact with said three layers and said form said loops being interconnected on the external surface of the element.

Claim 9

A composite reinforcement element, comprising three layers of superposed and crossed threads positioned on a mandrel having an external surface corresponding to an internal surface of the three superimposed and crossed layers of thread; a continuous thread extending substantially perpendicularly through said three layers of superposed and crossed threads, said continuous thread defining closed loops extending across ones of said superimposed and crossed threads at an external side of said superimposed and crossed threads and forming open loops, not extending across ones of said three layers of superimposed and crossed threads, at an internal side of said three layers of superimposed and crossed threads, said open loops protruding out from said internal surface, said three layers of superimposed and crossed threads being impregnated with a binder which is thereafter polymerized, said layers being maintained in an assembled position, prior to being impregnated with said binder, solely by the friction of the three layers and the mandrel.

Claim 10

A composite reinforcement element, comprising three layers of superposed and crossed threads positioned on a mandrel having an external surface corresponding to an internal surface of the three superimposed and crossed layers of thread; a continuous thread extending substantially perpendicularly through said three layers of superposed and crossed threads, said continuous thread defining closed loops extending across ones of said superimposed and crossed threads at an external side of said superimposed and crossed threads and forming open loops, not extending across ones of said three layers of superimposed and crossed threads, at an internal side of said three layers of superimposed and crossed threads, said open loops protruding out from said internal surface, said three layers of superimposed and crossed threads being impregnated with a binder which is thereafter polymerized, said layers being maintained in an assembled position, prior to being impregnated with said binder, solely by the friction of the three layers and the mandrel.