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AssigneeUnipres Corporation
InventorsMitsumasa Yabutani, Satoru Nitou
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A method is provided for forming spline teeth on the walls of a press-formed sheet-metal article on which two peripheral walls of different diameters are disposed in a continuous manner via a step portion by means of a die with a plurality of steps of ironing surfaces, and a punch having a plurality of corresponding ironing surfaces. The punch is provided with a first punch and a second punch which are arranged in a split manner. The second punch first irons teeth on the larger diameter peripheral wall. While the first punch is next used to iron teeth on the smaller diameter peripheral wall, at least some of the pressurizing force on the second punch is maintained to avoid the creation of flaws in the step portion of the sheet metal article.
A method for forming two sets of spline teeth on a sheet metal article by ironing said sheet-metal article between a forming die, and a forming punch, wherein said sheet metal article has a smaller and a larger diameter portion connected by a stepped portion and said two sets of spline teeth are formed on said smaller and larger diameter portions, respectively,
Dependencies are inferred from the claim text.