Figure C shows the path of the fabric
through the two types of cylinders.
The fabric passes:
through a tensioner (see figure C, point 1), from a conveyor cylinder (fig. C, 2), alternately on straight cylinders (fig. C, 3) and on curved cylinders (fig. C, 4). Curved cylinders (fig. C, 4) can assume:
concave position when the wefts are convex with respect to the selvedges,
convex position when the wefts are concave.
The straight cylinders (fig. C, 3) can be displaced with respect to the tissue laterally, forwards or backwards, exerting forces on the tissue as indicated in figure A.
Another weft straightening system is employed when a diagonal offset occurs
from selvedge to selvedge and exploits the state of tension that is created in the crooked wefts. There
piece is anchored at the two ends to two discs garnished with needles. The discs (drums) are not
controlled but free to rotate in the direction of advancement of the fabric, while their mutual position is offset according to an oblique line if the weft is crooked. A tension is thus created on the weft itself and the composition of the forces causes a realignment of the end which is delayed.