Patent ID: 6247346
Filing Date: 2001-06-19
Classification: B21K,C22F,F16C

Abstract:
In a method of producing an aluminum tube member for a vehicular drive shaft having a transition section with a length and wall thickness sufficient to cause noises during periods of high stress, the improvement wherein said aluminum tube member is made by a method comprising:(a) providing an 6000 series type alloy hollow elongate tube; and(b) reducing the diameter of at least one portion of said hollow elongate tube to form a reduced diameter section and transition section between said reduced diameter section and said tube; said transition section having at least three subsections:i. a first subsection having a first slope;ii. a second subsection having a second slope; andiii. a third subsection located between said first and second subsections having a third slope which is less than said first and second slopes, said third section forming a circumferential step to stiffen said transition section.