Abstract: An air jet spinning machine, air jet spinning machine for producing a thread from a fed sliver, and method for detecting a thread strength, which falls below a target value, of a thread produced at a spinning unit of an airjet spinning machine are provided. A thread manipulation unit is arranged in the region between the airjet spinning machine and the spooling device, which thread manipulation unit acts mechanically on the thread and exerts an adjustable thread tension influencing force, in particular an adjustable braking force, compression force and/or clamping force, onto the thread in order to variably increase thread tension. In the method, an adjustable thread tension influencing force is exerted onto the thread, and a thread breakage and/or thread breakage rate are/is detected and compared with a specified target rate, and thread breakage and/or deviations of thread breakage rate beyond a predetermined limit value are displayed and/or evaluated.

Abstract: A sliver delivery and opening device having a pivotably seated sliver intake cylinder driven by a worm gear arrangement comprising a worm wheel connected to the sliver intake cylinder that meshes with a worm affixed to a drive shaft. The worm includes thread windings conforming to a superimposed profile that axially offsets the worm relative to the worm wheel, thus preventing placement of a tooth of the worm wheel on a thread head of the worm when the worm wheel pivotally engages the worm. The amount of offset is measured between a plane of symmetry intersecting the superimposed profile of the worm thread windings and a pivot plane intersecting a center axis of the worm wheel. A positioning device, comprising at least one magnet and a ferromagnetic positioning element, prepositions the worm wheel relative to the pivot plane for pivotal engagement of the worm wheel and the worm.