DIE SET FOR PUNCHING SHEET PARTS Russian patent published in 2001 - IPC

FIELD: cold sheet forming, namely die sets for punching blanks of grids of meat grinders. SUBSTANCE: die set for punching holes includes die and punches arranged in punch holder. Punches are arranged along concentric circles forming regular polygons such as hexagons. Punches placed in apexes of polygons are shifted one relative to another by angle "α" whose value is determined according to expression α= 360 degrees/C, where C - number of strokes of punch holder necessary for punching all holes and equal to number of polygon sides. Subsequent punches of rows are arranged with possibility of alternation towards side opposite to rotation sign of blank with interval t= m-1, where m - number of holes in side of polygon in respective row of grid. Number N of punches of each row is determined as N=n/C, where n - number of holes in respective row of grid. Die set is also provided with rotary ring for fixing blank. Said ring has ball type stopper mounted with possibility of engaging with grooves in die circumference shifted one relative to another by above mentioned angle "α". EFFECT: enhanced efficiency, simplified operational conditions of die set providing improved quality of ready article.