Ramped stiffener and apparatus and method for forming the same

摘要

A stiffener has an elongate web element and an elongate foot element connected by a curved elbow that has a radius greater over a first portion than over a second portion of the stiffener. The stiffener is formed by feeding an elongate member through a roll forming die having first and second rollers, the first roller having a shaped section arranged to be located within a correspondingly shaped recess in the second roller, the first and second rollers defining a gap there between corresponding to the desired shape to be imparted on the elongate member, the desired shape including a curved elbow between a web and a foot portion, wherein the shapes of the recess and the shaped section vary such that the radius of curvature of the gap between the rollers corresponding to the curved elbow varies between a minimum and a maximum value.

主权项

1. A method of forming a T-shaped stiffener having an elongate web element and at least one elongate foot element, the web element and foot element being connected by a curved elbow, the method comprising feeding a solid elongate member through a roll forming die comprising first and second rollers, the first roller having a shaped section arranged to be located within a correspondingly shaped recess in a circumferential surface of the second roller, the first and second rollers defining a gap between them corresponding to a desired shape to be imparted on an elongate member passed between the rollers, the desired shape including a curved elbow between a web and a foot portion, wherein:
the shape of the recess in the second roller and the shape of the corresponding section of the first roller vary around a portion of the rollers circumference such that a radius of curvature of the gap between the rollers corresponding to the curved elbow varies between a minimum and a maximum value; and the method further comprises: holding the first and second rollers stationary while feeding the solid elongate member between the first and second rollers as a first portion of the solid elongate member is fed between the first and second rollers, whereby a radius of the curved elbow formed in the stiffener is constant along that first portion, and then rotating the first and second rollers between a first and a second position while feeding the solid elongate member between the first and second rollers as a further portion of the solid elongate member is fed between the first and second rollers, whereby a radius of the curved elbow formed in the stiffener is varied along that further portion, wherein the stiffener formed is C-shaped which is transformed into T-shape by folding along a central axis of the C-shaped stiffener.