Importance

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Abstract

Yarn 1 fron an extruder is stretched by heated rollers (3,5) and passes to a texturizer unit 2 where it is plasticized and crimped, leaving in the form of a crimp plug along a stack (8). The yarn is heated in the unit (2) by air passing along a pipe (7) and heated by a base heating element (9) in conjunction with a booster element (11). The plug of crimped yarn (6) passes to the surface of a rotating cooling drum (4), around which it makes a number of turns before crimped yarn (1') is withdrawn from the leading end of the plug at (6'). The plug length is monitored by a sensor unit comprising a light source (16) which directs light through holes 10 in the drum onto a receiver unit (14) including three diodes A, B and C. When the plug end (6') is at the datum position, the diode A is covered, the diode (C) is uncovered and the plug end flutters backwards and forwards over the diode (B). This generates control signals which adjust the degree of crimp so as to maintain the plug end at or close to the datum position. After leaving the drum (4) the crimped yarn (1) passes to a take-off roller (4) via a further roller (22) and an inter-mingling jet (21) and then passes to a winder (26). The novelty lies in the inclusion of a spring loaded tension guide (24) which moves up and down with the tension in the yarn and also serves as a detector for a yarn break. In this event, the guide (24) moves upwardly to a position to provide a signal from an electrical unit which replaces the signal from the light sensing unit (14,16) so as to control the unit (2) to keep the degree of crimp either at the position it was immediately before the yarn break or to move it towards the datum position if, at the time of the break, it was spaced from that position.

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First Claim