Patent ID: 8668858
Filing Date: 2014-03-11
Classification: B29C,B29D,B29K

Abstract:
1. A method for manufacturing a stiffening member to reinforce a panel made of a composite material which comprises the steps of: providing a caul sheet having a surface formed with a groove, wherein the groove has a first edge, a second edge and a predetermined length “I” and wherein the groove has a bottom and establishes a mid-point at the bottom of the groove; fabricating a first layer of the composite material to cover the surface of the caul sheet and to span the groove; covering the surface of the caul sheet with the first layer; cutting the first layer at mid-span along the length “l” of the groove to create a pair of opposed flaps; folding the flaps of the first layer, created during the cutting step, into the groove along the respective first and second edges of the groove to create a gap between the flaps in the groove; positioning a first strip of the composite material along the first edge of the groove to extend from the first layer and into the groove to overlay the gap and extend past the mid-point of the groove to a first strip end between the mid-point of the groove and the second edge of the groove; positioning a second strip of the composite material along the second edge of the groove to extend from the first layer and into the groove, and extend past the mid-point of the groove to a second strip end between the mid-point of the groove and the first edge of the groove to overlap the first strip and to therewith create a continuation of the first layer; laying a unidirectional ply on the surface of the caul sheet, wherein the unidirectional ply has a plurality of substantially parallel tows aligned along the length of the groove and substantially parallel to the length of the groove, and wherein the unidirectional ply is in contact with the first and second strips to establish a channel between the unidirectional ply and the continuation; placing a nylon tube in the channel between the unidirectional ply and the continuation; fabricating a second layer of the composite material to cover the first layer with the channel therebetween to configure the stiffening member for reinforcement of the panel; and co-curing the caul sheet, the unidirectional ply, the nylon tube, the first layer of composite material, the second layer of composite material, the first strip of composite material, and the second strip of composite material to form the stiffening member.