Patent ID: 6506998
Filing Date: 2003-01-14
Classification: B23K

Abstract:
A process for forming a projection in a first thin aluminum sheet so as to allow said first sheet to be fixedly secured, such as projection welded, to an adjacent second metal body, comprising the steps of:providing a first thin metal sheet of aluminum or aluminum alloy; positioning the first sheet between first and second coining dies configured to form a projection in the first sheet; contacting the first and second coining dies respectively with opposed first and second side surfaces of the first sheet; squeezing the first sheet between the first and second coining dies to cause the metal of the first sheet to cold flow radially and axially into an annular channel in the first coining die so as to create a projection configured as an upright annular wall which extends transversely outwardly from the first surface and which defines a hollow interior therein with said upright annular wall being backed by an annular portion of said first sheet which extends generally between said first and second surfaces and effectively constitutes an axial extension of the upright annular wall; positioning said first sheet and said second metal body adjacent one another and in engaged relation; and applying a pressing force substantially in alignment with the projection to effect collapse of said projection to create a securement between said first sheet and said second metal body.