Patent ID: 8393374

Claim:
An apparatus for producing a composite sheet comprising a first and a second sheet which are partially bonded to each other at a large number of joints, the first sheet projecting in the area other than the joints to form a large number of hollow projections, the apparatus having a first roll having projections and depressions on the peripheral surface thereof and a second roll having projections and depressions mating with the depressions and the projections of the first roll on the peripheral surface thereof, wherein; at least the first roll is composed of a plurality of gears mounted on a rotating shaft to provide projections and depressions alternating in the rotating direction of the roll, recesses having a prescribed width are provided on the peripheral surface of the first roll for every given number of the gears, and the recesses connect to suction paths which are formed in the first roll and extend in the axial direction of the first roll; wherein the plurality of gears include first gears and second gears, and the recesses are formed by a pair of the first gears and at least one of the second gears interposed between the pair; wherein at least the first roll is composed of at least two sets of gears, wherein each set of gears comprises one or more second gears and one or more first gears placed on at least one side of the one or more second gears, wherein the gears making each set of gears are combined such that the teeth of the gears are aligned in the axial direction of the roll, and the at least two sets of gears are combined such that the teeth of the one or more second gears and the one or more first gears of one set of gears are out of alignment with the teeth of the one or more second gears and the one or more first gears of an adjacent set of gears in the axial direction of the roll, and wherein the number of teeth on the second gears is less than the number of teeth on the first gears.