False twisting assembly - has sensor to register back twist tension for control to correct the operation to maintain nominal values

摘要

At a false twisting station (6), a sensor (25) registers the back twist tension (T) of the yarn after false twisting. A control restores the monitored (25) back twist tension (T) to a nominal value. Pref. the false twisting is applied (6) to the yarn (Y) by intersecting belts. The control mechanism has a cylinder (19) to set the belt clamping pressure, with valves (21, 22) to set the compressed air feed (Pd) for an upper threshold value and an air feed (Pu) for a lower threshold value at the cylinder (19). The control (26) opens and closes the valves (21, 22) as required to maintain a constant back twist tension according to the signals from the sensor (25). In anther form, the control operates a motor to move forwards or back. The control can also adjust the belt drive motor speed. USE/ADVANTAGE - The system is for a false twisting assembly, where the yarn is texturised between intersecting belts. The method gives a simple control action to correct the contact pressure of the belts against the yarn with reduced costs.