Method and apparatus for joining deformable sheet stock

摘要

A method of joining first and second sheets of deformable material by providing a first sheet having oppositely facing first and second surfaces, providing a second sheet having oppositely facing third and fourth surfaces, placing the second surface on the first sheet facially against the third surface on the second sheet, directing a first discrete element against the first sheet in a first direction to cause a part of the first sheet contacted by the first discrete element to deform and project beyond the fourth surface on the second sheet and directing a second discrete element against at least one of the first and second sheets to at least one of a) cause the part of the first sheet to deform transversely to the first direction to define a first shoulder facing oppositely to the first direction that abuts to the fourth surface and b) cause the second sheet to deform transversely to the first direction to define a second shoulder facing in the first direction that abuts to the part of the first sheet.