Patent ID: 8187517

Claim:
A method for producing a surface member having at least one hollow, curved, elongated stiffening member integral therewith, the method comprising: applying a helical tool having a rigid outer helical support surface on a surface member while shaping the tool on the surface according a to desired longitudinally curved shape, laying flabby layers of a fiber composite material in mutual superposition onto said support surface of said tool, curing the material applied onto said support surface of said tool, and applying a pulling force to one end of the helical tool, thereby reducing a cross-section of the helical tool and withdrawing the tool from the hollow elongated stiffening member formed externally thereof through one end of the material after curing the material, such that the helical tool is used to produce the surface member including at least one longitudinally curved stiffening member shaped by the helical tool, wherein laying flabby layers on the support surface of the tool may be carried out before or after applying the tool on a surface member, wherein the tool is made of a material sufficiently rigid to maintain the desired longitudinally curved shape during forming of the hollow elongated member and sufficiently flexible to permit the tool to be at least slightly prolonged when applying the pulling force in a longitudinal direction of the tool to at least slightly reduce the cross-section of the tool and to be bent without breaking.