Sewing head

A method for providing a composite sewn part for use in a subsequent curing process, comprising:

• locating a polymer reinforcement between a first stringer portion comprising a composite laminate and a second stringer portion comprising a composite laminate or locating a polymer reinforcement between a first composite laminate and a first stringer portion and a second stringer portion;
• stitching the first stringer portion to the second stringer portion to provide at least one stringer;
• stitching the first stringer portion to the first composite laminate;
• stitching the second stringer portion to the first composite laminate;
• and
• wherein during the at least one of the stitching steps the stitches pass through the polymer reinforcement;
• wherein the first stringer portion has a flange portion that is sewn to the first composite laminate and a web that extends upwardly from the flange portion and the second stringer portion having a flange portion that is sewn to the first composite laminate and a web that extends upwardly from the flange portion of the second stringer portion, and the web of the first stringer portion is sewn to the web of the second stringer portion;
• and
• wherein the polymer reinforcement includes a horizontal portion located between the flange portion of the first stringer portion and the flange portion of the second stringer portion and the polymer reinforcement includes an upwardly extending vertical portion that extends from a portion of the horizontal portion, the upwardly extending vertical portion being located between the web of the first stringer portion and the web of the second stringer portion and the polymer reinforcement includes a polymer reinforcing rod at an end of the upwardly extending vertical portion of the polymer reinforcement.