Method of manufacturing lateral header extensions
AssigneeBrazeway, Inc.
InventorDonald E. Miller
Life of this patent
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Abstract
An aluminum header tube having a plurality of integral and regularly spaced lateral extensions is formed according to a method which includes the steps of forming stubs for the extensions, inserting a tool through each stub and into the interior of the header tube, sizing each stub to reduce its inside and outside diameter and, while maintaining the clamp, withdrawing the tool through the stub to cause metal to flow outwardly, thus raising or lengthening the stub to the desired degree.
Claims6
A method of raising a hollow lateral extension on a header tube comprising the steps of:
- (a) inserting a tool of working diameter d.sub.1 through the extension and into the header tube;
- (b) mechanically deforming the extension to a reduced inner diameter d.sub.2, which is less than d.sub.1 ;
- and
- (c) while maintaining the outer diameter of the extension withdrawing the tool through the extension to restore the inner diameter to d.sub.1 by lengthening and reducing the wall thickness of the extension.
A method of manufacturing a header tube having a plurality of lateral extensions formed thereon and communicating with the header tube comprising the steps of:
- extruding the header tube integral with a continuous lateral arm;
- removing material from the arm at spaced intervals to form blank stubs;
- rounding off the stubs;
- drilling the stubs through to the header tube interior;
- inserting a tool of working diameter d.sub.1 through at least one of the stubs;
- mechanically deforming the stub to an inner diameter d.sub.2 which is smaller than d.sub.1 ;
- and
- while maintaining the outer diameter of the extension, withdrawing the tool through the extension to restore the inner diameter to d.sub.1 by lengthening and reducing the wall thickness of the extension.
Dependencies are inferred from the claim text.