Sliver delivery and opening device

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.

What is claimed is:  
     
         1 . A sliver delivery and opening device for an open-end spinning machine, the sliver deliver and opening device comprising: 
 a pivotable sliver intake cylinder;    a worm gear arrangement having a worm wheel connected to the sliver intake cylinder and a worm mountable on a fixedly supported rotatable shaft extending along the machine, the worm wheel having a plurality of teeth and the worm having thread windings with a threading contour conforming to a superimposed profile for preventing placement of a tooth of the worm wheel on a thread head of the worm, the worm being fixable on the rotatable shaft to present a plane of symmetry that is offset in an axial direction of the rotatable shaft with respect to a pivot plane of a center axis of the worm wheel, is perpendicular relative to the rotatable shaft, and intersects a valley of the superimposed profile centered between two adjacent threads of the worm; and    a positioning device for prepositioning the worm wheel as a function of the offset of, the worm to facilitate the pivoting of the teeth of the worm wheel into the worm.    
     
     
         2 . A sliver delivery and opening device according to  claim 1 , characterized in that one tooth of the plurality of teeth of the worm wheel is positioned such that the centerline of the one tooth lies at a predetermined positioning angle φ relative to the pivot plane of the worm wheel, wherein the positioning angle φ is a function of the offset of the worm measured between the plane of symmetry and the pivot plane.  
     
     
         3 . A sliver delivery and opening device according to  claim 2 , wherein the positioning angle φ is calculated by an equation: φ=72* sin( X /2), where X is the offset of the worm.  
     
     
         4 . A sliver delivery and opening device according to  claim 1 , characterized in that the positioning device comprises at least one magnet fixed in place on a bearing housing of an electromagnetic coupling attached to a shaft of the sliver intake cylinder, and a ferromagnetic positioning element that is connected, and fixed against relative rotation, to the worm wheel.  
     
     
         5 . A sliver delivery and opening device according to  claim 4 , wherein the at least one magnet of the positioning device comprises at least one permanent magnet.  
     
     
         6 . A sliver delivery and opening device according to  claim 4 , wherein the positioning element comprises a positioning disk having a number of radially protruding ferromagnetic positioning shoulders disposed thereon.  
     
     
         7 . A sliver delivery and opening device according to  claim 6 , wherein the number of ferromagnetic positioning shoulders corresponds to a total number of teeth that comprise the plurality of teeth of the worm wheel.