Patent ID: 7380387

Claim:
A fillet folding device for a packaging bag including a bag body for wrapping a sheet stack including plural stacked sheets, and front and rear fillets, formed to protrude forwards and backwards from said bag body, for being folded back on an outside of said bag body, to tighten a wrapped state of said packaging bag, said fillet folding device comprising: a conveyor for feeding said packaging bag forwards in a feeding direction; a centering mechanism, supplied with said packaging bag by said conveyor, for centering said packaging bag by pressing first and second sides thereof with reference to a crosswise direction crosswise to said feeding direction; a pair of chucks, arranged in said crosswise direction, for clamping first and second end portions of a first fillet selected from said front and rear fillets; a chuck moving mechanism for moving said pair of said chucks in synchronism, to fold said first fillet, said first fillet thereby extending and being kept from twisting; and a position detector for detecting an edge position of said first fillet after operation of said centering mechanism; wherein before clamping of said pair of said chucks, said chuck moving mechanism sets said pair of said chucks at said first and second end portions of said first fillet according to said edge position being detected.