Patent ID: 8940126
Filing Date: 2015-01-27
Classification: B29C,B29D

Abstract:
1. A method for the production of a stiffener on a surface of an element that is to be made rigid, wherein at least one of the stiffener and the element to be made rigid comprises a composite material that is not completely polymerized, wherein the stiffener comprises in a transverse direction two contact zones with the surface, and between the two contact zones the stiffener and the element to be made rigid form a cavity that is open at at least one end of the stiffener, said method comprising: polymerizing at least one of the stiffener and the element with a core positioned in said cavity; and removing the core from the cavity after polymerization; wherein the core comprises a first part contacting a first region of an inner surface of the cavity, said first part having a thermal expansion coefficient less than that of the stiffener, and at least one second part contacting a second region of said inner surface of the cavity, whose configuration and elongation percentage permit the second part to be withdrawn from the cavity by pulling on one end of the second part so as to cause a decrease in its cross-section, wherein the surface of the element that is to be made rigid has an undercut shape of depth E, and wherein the second part has a thickness greater than E.