Patent ID: 7204114
Filing Date: 2007-04-17
Classification: B21D

Abstract:
1. A method of progressive hydro-forming of a tubular member in a two-stage die, said method comprising the steps of: providing a tubular member; positioning the tubular member between open die halves mating with one another to define a first tubular cavity portion in a first stage of the two-stage die; progressively closing the die halves to progressively deform the tubular member within the first tubular cavity portion; applying hydraulic pressure to expand and conform the tubular member to the first tubular cavity portion in the first stage to create pre-expanded portions in the tubular member; separating the die halves; removing the expanded tubular member from the first tubular cavity portion; positioning the expanded tubular member between open die halves mating with one another to define a second tubular cavity portion in a second stage of the two-stage die; progressively closing the die halves to progressively deform the expanded tubular member within the second tubular cavity portion; applying hydraulic pressure to expand and conform the expanded tubular member to the second tubular cavity portion in the second stage to ovalize the pre-expanded portions and to create ribs between a first section and a bend section of the expanded tubular member; separating the die halves; and removing the final expanded tubular member from the second tubular cavity portion.