Device for guiding a thread

Abstract

A device ( 3 ) for guiding a thread or the like is described, which includes a holding element ( 4 ), a thread roll ( 5 ) rotatably disposed on the holding element ( 4 ) to form a bearing gap ( 12 ), and a protective shield ( 14 ), which covers the bearing gap ( 12 ) at at least one axial end. According to the invention, the protective shield ( 34 ) is non-rotatably connected to the holding element ( 4 ).

1 . Device for guiding a thread ( 2 ) or the like, comprising a holding element ( 4 ,  23 ), a thread roll ( 5 ) rotatably disposed on the holding element ( 4 ,  23 ) to form a circular cylindrical bearing gap ( 12 ,  12   a ) and a protective shield ( 14 ,  20 ,  24 ,  34 ) covering said bearing gap ( 12 ,  12   a ) at at least one axial end of said thread roll ( 5 ), having a passage through which said holding element ( 4 ,  23 ) projects and being non-rotatably connected to said holding element ( 4 ,  23 ).  
     
     
         2 . Device according to  claim 1 , wherein said protective shield ( 14 ,  20 ) consists of a plate arranged at an axial distance from said thread roll ( 5 ).  
     
     
         3 . Device according to  claim 1 , wherein said protective shield ( 14 ,  20 ,  34 ) has a maximum external cross-section which is larger than a cross-section of said bearing gap ( 12 ,  12   a ) at an axial end facing said protective shield ( 14 ,  20 ,  34 ).  
     
     
         4 . Device according to  claim 1 , wherein said protective shield ( 20 ,  34 ) lies at least partially in a recess ( 21 ,  10   a ) of said thread roll ( 5 ).  
     
     
         5 . Device according to  claim 4 , wherein a side remote from said thread roll ( 5 ) said protective shield ( 14 ,  24 ) has a smallest external cross-section, which gradually increases from there towards said thread roll ( 5 ).  
     
     
         6 . Device according to  claim 5 , wherein said protective shield ( 14 ,  24 ) has a conical outer periphery.  
     
     
         7 . Device according to  claim 4 , wherein said protective shield ( 34 ) has an axial projection ( 34   a ,  34   b ) which projects at least partially in a recess ( 33 ) of said thread roll ( 5 ) and on which is fastened an inner race of a ball or roller bearing ( 36 ) for the rotatably mounting said thread roll ( 5 ).  
     
     
         8 . Device according to  claim 7 , wherein a central section ( 34   a ) of said projection forms an air gap ( 37 ) and wherein at an axial end remote from said ball or roller bearing ( 36 ) said protective shield ( 34 ) has a section ( 34   c ) with an external cross-section, which is larger than a cross-section of said air gap ( 37 ).  
     
     
         9 . Device according to  claim 7 , wherein said projection ( 34   a ,  34   b ) is connected to said holding element ( 4 ) by means of a snap connection ( 16 ,  36 ) in a releasable but substantially non-displaceable manner in axial direction.  
     
     
         10 . Device according to  claim 1 , wherein said thread roll ( 5 ) is configured in two parts and has a bearing section ( 8   a ) being located radially on an inside and having a recess for said holding element ( 4 ) and a thread guide section ( 8   b ) being located radially on an outside and being projected by said bearing section ( 8   a ).  
     
     
         11 . Device according to  claim 10 , wherein said thread guide section ( 18   b ) is provided with a V-shaped circumferential groove ( 5   a ).  
     
     
         12 . Device according to  claim 10 , wherein said bearing section ( 8   a ) and said thread guide section ( 8   b ) are fixedly connected to one another.  
     
     
         13 . Device according to  claim 10 , wherein at an end remote from said protective shield ( 14 ,  20 ,  24 ,  34 ) said thread roll ( 5 ) has a fully closed cap-like attachment ( 18 ,  30 ).  
     
     
         14 . Device according to  claim 13 , wherein said attachment ( 18 ) is provided on said thread guide section ( 8   b ).  
     
     
         15 . Device according to one of claims  10 , wherein said bearing section ( 8   a ) is connected to the holding element ( 4 ) in a manner releasable but substantially non-displaceable in axial direction by means of a snap connection ( 16 ,  17 ).  
     
     
         16 . Device according to  claim 1 , wherein said holding element ( 23 ) has an end section ( 23   a ) being located axially at a front portion, being intended for arrangement in a recess ( 25 ) of said thread roll ( 5 ) and being provided with a cylindrical outer periphery, and a mounting section ( 23   b ) being located axially at a rear portion, being intended for assembly and having a smaller external cross-section than said end section ( 23   a ), and that said protective shield ( 24 ) is formed from a transition section having a widening external cross-section and being arranged between said mounting section ( 23   b ) and said end section ( 23   a ).  
     
     
         17 . Device according to  claim 16 , wherein said transition section has an external cross-section, which widens conically from said mounting section ( 23   b ) towards said end section ( 23   a ).  
     
     
         18 . Device according to  claim 16 , wherein said end section ( 23   a ) is hollow cylindrical.  
     
     
         19 . Device according to  claim 18 , wherein arranged in said end section ( 23   a ) is a hollow cylindrical insert ( 28 ), which receives a shaft member ( 29 ), which is coaxial to said mounting section ( 23   b ) and projects partially out of said insert ( 28 ) and at an end of said end section ( 23   a ) remote from said mounting section ( 23   b ) has a section, which projects out of said insert ( 28 ) and projects through said attachment ( 30 ) provided on said thread roll ( 5 ).  
     
     
         20 . Device according to  claim 19 , wherein said shaft member ( 29 ) is fixedly connected to said attachment ( 30 ) to form a seal and is rotatably disposed in said insert ( 28 ).  
     
     
         21 . Device according to  claim 19 , wherein said insert ( 28 ) is fixedly connected to said end section ( 23   a ) and is connected to said shaft member ( 29 ) in a releasable manner but in an axially substantially non-displaceable manner by means of a snap connection ( 31 ,  32 ).  
     
     
         22 . Device according to  claim 1 , wherein said thread roll ( 5 ) or its parts ( 8   a  and  8   b ), said protective shields ( 14 ,  20 ,  24 ,  34 ) and also said insert ( 28 ) are made from a sliding material with antistatic effect.