Patent ID: 7318798

Claim:
An apparatus for folding and tucking crotch regions of disposable diapers, said apparatus comprising: a conveyor mechanism for conveying a contiguous diaper structure, said contiguous diaper structure having a plurality of crotch regions arranged at regular intervals in a machine direction, a plurality of first and second waist regions lying on both sides of said crotch regions as viewed in a cross direction orthogonal to said machine direction and lying contiguous one to another in said machine direction, and a plurality of leg-holes each formed between one pair of said crotch regions adjacent to each other, and said leg-holes being arranged at regular intervals in the machine direction, wherein said contiguous diaper structure is adapted to be folded, while being conveyed by said conveyor mechanism, along a fold in said crotch regions so that said first and second waist regions are opposed to but spaced apart from each other; and a folding mechanism for folding and tucking each said crotch region of said contiguous diaper structure from said leg-holes lying on both sides of said crotch region toward an inside of said folded contiguous diaper structure; said folding mechanism including a first rotary disc located outside said fold in said crotch regions as viewed in said cross direction and adapted to rotate, about a first axis extending in a thickness direction of said diaper structure, in a direction in which said diaper structure is conveyed, and a plurality of folding plates arranged on said first rotary disc in a peripheral zone of said first rotary disc at regular intervals in a circumferential direction of said first rotary disc and adapted to approach and then move away from said crotch regions as said first rotary disc rotates; each of said folding plates comprising a first base, and a pair of guide arms arranged in said circumferential direction of said first rotary disc and extending radially outward from said peripheral zone of said first rotary disc; and as said first rotary disc rotates, said folding plates being adapted to revolve around said first axis of said first rotary disc, said guide arms being adapted to (i) move forward progressively from a side of the respective crotch region so as to go to the inside of said folded diaper structure as said crotch region of said folded diaper structure approaches said peripheral zone of said first rotary disc so that opposite side edges of said guide arms are pressed against transversely opposite side edges of said crotch region in a vicinity of said fold from outside so as to compress said opposite side edges into the inside of said contiguous folded diaper structure, and (ii) subsequently move backward progressively so as to draw out of said folded diaper structure as said crotch region moves away from the peripheral zone of said first rotary disc.