Patent ID: 6717091
Filing Date: 2004-04-06
Classification: B23K

Abstract:
A method for metallurgically attaching together two tubes comprising the steps of:a) obtaining a first tube having a far wall portion with a first through hole and having a near wall portion with a second through hole; b) obtaining a second tube including a first wall portion having a first outward fold with spaced-apart first and second fold portions and including a second wall portion having a second outward fold with spaced-apart third and fourth fold portions; c) after steps a) and b), disposing the first and second tubes with the first outward fold passed through the second through hole and contacting the far wall portion surrounding the first through hole and with the second outward fold disposed outside the near wall portion; d) after step c), creating a first resistance welding current path through the first and second tubes proximate the first outward fold and the far wall portion and relatively moving the first outward fold deformingly against the far wall portion creating a first weld zone which includes at least some of the first outward fold and at least some of the far wall portion; and e) after step d), creating a second resistance welding current path through the first and second tubes proximate the second outward fold and the near wall portion and relatively moving the second outward fold deformingly against the near wall portion creating a second weld zone which includes at least some of the second outward fold and at least some of the near wall portion.