BLANK FOR PIECE WITH UNDERCUT, METHOD AND APPARATUS FOR ITS PRODUCTION Russian patent published in 1995 - IPC

FIELD: mechanical engineering. SUBSTANCE: blank has any form and thicker part with metal volume sufficient for undercut on area, adjacent to place of undercut. Using direct action press they press on thicker part till undercut is formed. In the case blank is fixed along boundaries of place for undercut up to area of deformation pressure application along transverse bending of undercut and along thickness of blank from side of salient area formation. Place for undercut from the side is let free for metal plastic flow. Tool to exercise undercut has die and support. Die has detachable part with surface to press thicker part of blank. The surface is limited by concave for undercut or by concave and in series placed barrier for metal plastic flow made as guide. EFFECT: blank, method and apparatus allows to increase production. 10 cl, 14 dwg