Thomas H Mcclure

US Patent:

8220301, Jul 17, 2012

Filed:

Jul 13, 2008

Appl. No.:

12/172242

Inventors:

Mike M. Ghiran - Lake Orion MI, US
Spyros P. Mellas - Waterford MI, US
David H. Shea - Lake Orion MI, US
Thomas W. McClure - Brookfield WI, US
Darrell W Rebman - Kimball Township MI, US

Assignee:

GM Global Technology Operations LLC - Detroit MI

International Classification:

B21D 28/28
B21D 31/02

US Classification:

72 55, 72 71, 72325, 7237027

Abstract:

A tool adapted to form and method of forming a tapped hole within a workpiece in a single pass, includes a piercing section operable to punch a pilot hole in and produce a slug attached to the workpiece, and a tapping section operable to form a female thread along the periphery of the hole, and more preferably, an extruding section operable to push workpiece material away from the exterior surface defined thereby, an expanding section operable to expand the diameter of the hole, a sealing section operable to seal the hole during a hydroforming process, and a burnishing section operable to further expand and treat the periphery of the hole prior to tapping.