Forming of bellows folds and bellows corners of envelopes and bags made of paper

摘要

The invention essentially relates to devices making it possible to fold, easily and rapidly, the bellows corners and bellows folds of envelopes and bags made of paper or of cardboard boxes. The devices comprise a lattice of deformable metal diamond shapes 1 supporting folding blades 2, 3 and 4. This lattice is associated with an array of suckers making it possible to hold the sheets 9 and 10 during the folding operation. A push rod 12 makes it possible to fold down the flaps 14 inside the envelope or bag.