METHOD OF JOINTING SHEET PART, PRIMARILY, FLANGES AND BRANCH PIPES, TO AIR DUCTS, AND DEVICE TO THIS END Russian patent published in 2012 - IPC B21D39/03 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming, particularly, to jointing of the parts. Opposite joints are made on sheet stack both sides by punching with the help of solid and split female dies arranged in equal-cross-section slots. Note here that said stack is punched to make bulges and recesses on section confined by female die slot and on that not confined by said slot, to be removed from the slot without punching. Proposed device comprises split and solid female dies with cutting edges, float set of male dies with extreme parts making different-length replaceable cutting plates to form cutting edges. Central part of said set is composed of the plate with ledge extending beyond the cones of extreme part plates. Note here that female dies allows replacing blunt cutting edges by sharp ones.

EFFECT: stronger joint, expanded performances.

11 cl, 12 dwg