Patent ID: 8029429

Claim:
A mechanism for bonding paper sheets on an interfolding machine, comprising: a first and second counter-rotating folding roller, each said counter-rotating folding roller adjacently displaced from the other to define a pre-compressing space therebetween operable to compress-to-bond at least two overlapping paper sheets together; a plurality of projected sections including: a first and second compressing mechanism each compressing mechanism including a plurality of adjacent ridge-like protrusions adapted to compress-to-bond two paper sheets together; a wedge-shaped protrusion, wherein the projected sections formed on the outer circumferential surface of the first and second counter-rotating folding rollers, each wedge-shaped protrusion disposed circumferentially between the first compressing mechanism and the second compressing mechanism on a projected section; a plurality of sunken sections, each having an anvil recess and being formed on the outer circumferential surface of the first and second counter-rotating folding rollers, and said sunken sections being interleaved with said projected sections; whereby the pre-compressing space is further defined by counter rotating the first and second counter-rotating folding rollers to alternately mate the first compressing mechanism of the first counter-rotating roller and the sunken section of the second counter-rotating folding roller; wherein each of the two folding rollers further includes at least one first sucking channel provided at each of two lateral sides of each of the wedge-shaped protrusions, and at least one second sucking channel provided at each of the anvil recesses; wherein the first and the second sucking channels may be controlled to suck or to stop sucking thereat, so that paper sheets separately transferred to the two folding rollers are orderly sucked to or released from the outer circumferential surface of the folding roller; and wherein when one of the anvil recesses on one of the two folding rollers is moved to the pre-compressing space, suction at the second sucking channel at the anvil recess is generated in order to produce a suction force, which cooperates with the action of the wedge-shaped protrusion fitted in that anvil recess to produce a folding line on the paper sheet bearing on the anvil recess.