Inventors:
Keith Nagel - Juneau WI, US
Robert Riehbrandt - Beaver Dam WI, US
Assignee:
Miller Tool and Die Company Inc. - Mayville WI
International Classification:
B21D 22/00
B21D 22/21
Abstract:
A blank is stretch formed into a formed piece by bending the blank over a stationary punch. A draw ring has a step that cooperates with a pad ledge to create a step-ledge. The blank is bent with a reverse bend at the step-ledge. Subsequently, the step-ledge travels a short distance relative to the punch to stretch the blank material. Step-ledge travel is achieved by pre-charged cylinders that travel slightly in response to a force exerted on the draw ring and step-ledge by the press ram after the blank is bent into the reverse bend. The formed piece is cut along a plane through a wall thereof to make a finished piece. The finished piece free edge remains stable and in the same position as when in the press. Consequently, the free edge can be readily aligned with and welded to the free edge of a second finished piece.