Multi-layer braided article

Patent metadata

Field	Value
Publication number	US-11884378-B2
Application number	US-202117307014-A
Country	US
Kind code	B2
Filing date	May 4, 2021
Priority date	May 4, 2020
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

A multi-layer braided article and a method of making the multi-layer braided article. The multi-layer braided article includes a braid extending along a first axis, wherein the braid is folded over itself to form a first layer and a second layer; and a wrapper laid over the first layer of the braid and extending circumferentially around the first axis, wherein the wrapper defines an edge of the first layer about which the braid is folded. The multi-layer braided article may form part of a blade for an aircraft. A sleeve may be provided around a conical portion of the article to connect the article to something else, such as a propeller hub, where the multi-layer braided article is formed as part of a blade. The sleeve may provide a primary or secondary load path.

First claim

The invention claimed is:

1. A multi-layer braided article comprising
a core extending along a first axis (z);
a braid wound circumferentially around the core and extending along the first axis, wherein the braid is folded back over itself to form a first layer and a second layer each extending along the first axis; and
a wrapper laid over the first layer of the braid and extending circumferentially around the first axis,
wherein the wrapper defines an edge of the first layer about which the braid is folded back along the first axis to form the second layer;
wherein the edge is a first edge ( 18 a ) and the wrapper ( 18 ) is a first wrapper, wherein the first wrapper extends a first axial length ( 18 d ) from the first edge, the multi-layer braided article further comprising:
a second braid ( 31 ) on top of the first braid and extending along the first axis, wherein the second braid is folded back over itself to form a first layer and a second layer extending along the first axis; and
a second wrapper ( 38 ) laid over the first layer of the second braid and extending circumferentially around the second braid around the first axis;
wherein the second wrapper defines a second edge ( 38 a ), that is located at the same axial location as the first edge, about which the second braid is folded back along the first axis to form the second layer of the second braid;
wherein the second wrapper extends a second axial length ( 38 d ) that is less than the first axial length; and
wherein the first layer of the second braid extends from the second edge by a length that is greater than the first axial length, such that the first and second braids form a conical portion of the multi-layer braided article.

2. The multi-layer braided article according to claim 1 , wherein the wrapper comprises one or more unidirectional tows wrapped circumferentially around the first layer and/or wherein the wrapper comprises a fabric wrapped circumferentially around the first layer.

3. The multi-layer braided article according to claim 1 , wherein the wrapper provides hoop tension around the first layer of braid to fix the edge in position along the first axis.

4. The multi-layer braided article according to claim 1 , wherein the braid is formed from high strength fibres suitable for aeronautical applications.

5. The multi-layer braided article according to claim 1 , wherein the braid is a uniaxial braid, a bi-axial braid, a tri-axial braid, or an interlock braid.

6. The multi-layer braided article according to claim 1 , further comprising a plug inserted into a central aperture of the conical portion.

7. The multi-layer braided article according to claim 1 , further comprising
through-thickness reinforcement penetrating at least two layers of braid of the multi-layer braided article at a location other than an edge about which the braid folds over itself;
wherein the through-thickness reinforcement is configured to provide delamination resistance for the multi-layer braided article.

8. The multi-layer braided article according to claim 1 , wherein blind stitches are applied in the second layer of the first braid, or in any subsequent layer of braid, to secure the second, or subsequent, layer to a layer of braid beneath.

9. An aircraft blade comprising:
the multi-layer braided article of claim 1 , wherein the braids have been formed into a fibre-reinforced composite multi-layer braided article, and
a sleeve having an inner diameter, wherein the sleeve extends around the fibre-reinforced composite multi-layer braided article and abuts the conical portion, wherein the inner diameter is smaller than an outer diameter of the conical portion such that the sleeve cannot move along the fibre-reinforced-composite multi-layer braided article past the conical portion.

10. A propeller comprising:
a hub; and
a plurality of aircraft blades connected to the hub, wherein each aircraft blade is an aircraft blade according to claim 9 ; and
wherein the sleeve of each aircraft blade is a metallic sleeve that forms part of the connection between the hub and the respective multi-layer braided article.

11. The multi-layer braided article according to claim 4 , wherein the fibres are one or more of: carbon fibre, glass fibre, an aramid, or a mixture thereof.

Assignees

• Ratier Figeac Sas

Inventors

• Seminel Bruno
• Amat Pascal
• Andrzejewski Arnaud

Classifications

• B29C70/24

  oriented in at least three directions forming a three-dimensional [3D] structure · CPC title

• B29C70/222

  the structure being shaped to form a three dimensional configuration · CPC title

• B64C11/26 Primary

  Fabricated blades · CPC title

• B29C70/30 Primary

  Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core · CPC title

• D04C1/06

  Braid or lace serving particular purposes · CPC title