Rigid elongated member for use in vehicles and producing method and apparatus therefor

A method of forming an elongated member, comprising forming a main body portion with a substantially annular cross-section and terminal portions extending from ends of the main body portion and having a different cross-section from the cross-section of the main body portion, the terminal portions including transition portions having a cross-section that changes continuously from the substantially annular cross-section to the different cross-section along a longitudinal axis from the main body portion to each of the terminal portions, by:

• a first step of bending an elongated strip fed between circumferential faces of first forming rolls having parallel central rotational axes to partially form the main body portion and the transition portions by synchronously rotating the first forming rolls to successively engage the strip with annular main body portion bending sections and adjacent transition portion bending sections of the first forming rolls, thereby continuously forming an intermediate stage elongated member;
• and
• a second step of bending the intermediate stage elongated member fed between circumferential faces of second forming rolls having parallel central rotational axes by synchronously rotating the second forming rolls to successively engage annular main body portion bending sections and adjacent transition portion bending sections of the second forming rolls corresponding to the respective bending sections of the first forming rolls in circumferential length but having a different axial dimension such that the intermediate stage elongated member approaches a shape of the elongated member.