|
(11) | EP 1 602 756 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
|
|
|
|
|||||||||||||||||||||||
| (54) | Method and apparatus for manufacturing special yarn |
| (57) A motor (18), which drives a pair of front rollers (17) of a draft part (16), is
controlled such that the rotation speed of the pair of front rollers is decreased
from a reference speed (N0) to a decelerated speed (N1) and thereafter increased to
the reference speed based on a designed thickness profile (DP) including a slub length
(L). The yarn length (La) spun while the rotation speed of the pair of front rollers
is increased from the decelerated speed to the reference speed is computed in advance.
When the rotation speed of the pair of front rollers is decreased from the reference
speed to the.decelerated speed, the motor is controlled such that the rotation speed
of the pair of front rollers is increased at a point in time at which the yarn length
spun from when the rotation speed of the pair of front rollers is started to be decreased
reaches a value obtained by subtracting the yarn length computed in advance from the
slub length of the designed thickness profile. Therefore, a special yarn that accurately
conforms to the designed thickness profile is manufactured.
|