Arrangement for setting thread tension

Abstract

The arrangement can control the pulling tension of a thread 1 during its wind-off or wind-up, from or to a spool 3. The arrangement includes a thread brake 5 having a local portion 6 and a portion 8 movable relative thereto, between which the thread 1 is pulled during the wind-up or wind-off and which provides a frictional force upon thread 1. Furthermore, the arrangement includes an actuator 13 for applying a frictional force applied by thread brake 1 to thread 1 may be controlled. Preferably included is a piezoelectric sensor 14 which may be deformed by the force applied by the thread to the sensor 14. In the prior art, the actuator comprises a setting nut and a spring whose operation is time-consuming. In order to simplify the operation of the actuator 13, in accordance with the present invention, the preferred actuator 13 is piezoelectrically deformable element which is constructed as a unit with sensor 14 and is so connected with the movable portion 8 of the thread brake 5 that the deformation movement of the actuator can be transferred to the movable portion 8 of thread brake 5 and the sensor 14.

Dependencies are inferred from the claim text.