METHOD OF JOINING SHEET PARTS, JOINED SHEET ASSEMBLY AND APPARATUS FOR PERFORMING THE METHOD Russian patent published in 1997 - IPC

FIELD: plastic metal working, namely manufacture and mounting of ventilation systems in flour milling and grain milling industry branches. SUBSTANCE: at joining sheet parts breakthrough is made in said parts by cutting them through in the form of petals, received petals are expanded. In zone of cutting through сlamping effort is applied at process of that cutting through. At expanding one long side of rectangular cross section of breakthrough is compressed, second side is compressed at simultaneously pressing out for making depression in the form of sphere segments. Breakthroughs are made with pitch no less than 2.5 S and no more than 6 S, where S - length of rectangular cross section of breakthrough. Apparatus for joining sheet parts includes die, C-shaped punch with cutting member and holder arranged inside said punch. On one side cutting member has extensions in the form of sphere segments. EFFECT: enhanced efficiency of method, improved design of apparatus. 17 cl, 27 dwg