Patent ID: 8966764
Filing Date: 2015-03-03
Classification: B21D,B60R,Y10T

Abstract:
1. A method of fabricating a roll-over protective structure comprising: placing a first corner inner tube within an outer tube at a first pre-determined corner location to form a composite tube, wherein the outer tube has a first pre-determined wall thickness in the range of about 4 mm to about 12 mm, and the first corner inner tube has a second pre-determined wall thickness in the range of about 2 mm to about 6 mm, and wherein a first corner inner tube length is less than an outer tube length; bending the outer tube and the first corner inner tube at the first pre-determined corner location such that the composite tube includes a first end portion and a first curved corner formed by a first bent portion of the outer tube at the first pre-determined corner location and by the bent first corner inner tube; and hydroforming the composite tube to create a desired corner cross-section at the first pre-determined corner location.