Sewing unit

Abstract

A sewing unit has a CNC controller and a sewing machine. The sewing machine has a workpiece bed plate, an upper sewing part and a lower sewing part. The lower sewing part has a looper with a lower thread supply in a looper bobbin case. The looper can rotate about an axis which extends parallel to the workpiece bed. A bobbin case holding component disposed in the region of the workpiece bed is in engagement with the looper bobbin case such that it does not co-rotate the looper bobbin case during a rotation of the looper. The lower sewing part has a bobbin case lifter to displace the looper bobbin case between a neutral position and an opened position in which a free space for a thread between the looper bobbin case and the bobbin case holding component is enlarged in comparison with the neutral position.

1 - 8 . (canceled) 
     
     
         9 . A sewing unit ( 1 ), comprising:
 a CNC controller ( 2 ); and   at least one sewing machine ( 3 ), having
 a workpiece bed plate ( 6 ) for provision of a workpiece bed ( 7 ), 
 an upper sewing part ( 4 ) with
 a needle bar ( 9 ) which can move up and down in a controlled manner and 
 an upper thread guide for guiding an upper thread from an upper thread supply ( 10 ) to the needle bar ( 9 ), and 
 
 at least one lower sewing part ( 5 ), cooperating with the upper sewing part ( 4 ) to
 form a seam, 
 with a looper ( 30 ),
 wherein the looper ( 30 ) can be rotationally driven in a controlled manner and has a lower thread supply ( 31 ) in a looper bobbin case ( 32 ), 
 wherein the looper ( 30 ) can rotate about an axis ( 33 ) which extends parallel to the workpiece bed ( 7 ), 
 wherein the looper ( 30 ) has a diameter which amounts to at least 30 mm, 
 
 with a bobbin case holding component ( 34 ) disposed in a region of the workpiece bed ( 7 ) being in engagement with the looper bobbin case ( 32 ) in such a way that, during a rotation of the looper ( 30 ), the looper bobbin case ( 32 ) does not rotate therewith, and 
 with a bobbin case lifter ( 37 ) which can be driven in a controlled manner for displacement of the looper bobbin case ( 32 ) between
 a neutral position and 
 an opened position in which a free space for a thread ( 43 ) between the looper bobbin case ( 32 ) and the bobbin case holding component ( 34 ) is enlarged in comparison with the neutral position. 
 
 
   
     
     
         10 . The sewing unit as claimed in  claim 9 ,
 further comprising a thread cutting device ( 44 ) for cutting off thread ends of the upper thread and/or of a lower thread which protrude above a formed seam and have a maximum excess length of 15 mm.   
     
     
         11 . The sewing unit as claimed in  claim 10 ,
 wherein the thread cutting device ( 44 ) comprises a cutting blade ( 45 ) which is driven in a controlled manner by a dual-acting pneumatic cylinder ( 47 ).   
     
     
         12 . The sewing unit as claimed in  claim 9 ,
 wherein the upper sewing part ( 4 ) comprises a housing arm portion ( 27 ),   wherein the housing arm portion ( 27 ) terminates in a housing head ( 26 ),   wherein the needle bar ( 9 ) is guided in the housing head ( 26 ),   wherein the housing head ( 26 ) in one operational embodiment including the upper thread supply ( 10 ) has a width in a dimension (x) parallel to the workpiece bed ( 7 ) and perpendicular to the housing arm portion ( 27 ) which amounts to a maximum of 300 mm.   
     
     
         13 . The sewing unit as claimed in  claim 12 ,
 wherein the upper thread supply ( 10 ) is mounted on the housing head ( 26 ) as an extension of the housing arm portion ( 27 ).   
     
     
         14 . The sewing unit as claimed in  claim 9 ,
 wherein the at least one sewing machine ( 3 ) comprises an activatable thread tensioner device ( 15 ) for setting a thread tension of the upper thread.   
     
     
         15 . The sewing unit as claimed in  claim 9 ,
 wherein the at least one sewing machine ( 3 ) comprises a presser foot bar ( 19 ) with activatable foot height adjustment ( 20 ).   
     
     
         16 . The sewing unit as claimed in  claim 9 ,
 wherein the at least one sewing machine ( 3 ) is one of a plurality of sewing machines ( 3 ), and   wherein the plurality of sewing machines ( 3 ) are supported by a common support frame of the sewing unit ( 1 ) and can be displaced with respect to each other along at least one displacement dimension in a controlled drivable manner.