Controlled thread brake

Abstract

A controlled thread brake for braking a weft thread ( 10 ) in a weaving machine is presented which comprises a brake band ( 3 ) and a brake body ( 2 ), with the thread brake ( 1 ) additionally comprising an electromagnet ( 6 ) and a rotatable or rocking lever ( 4 ) which can be moved by means of the electromagnet. The lever ( 4 ) is connected to the brake band ( 3 ) so that a pulling force can be exerted in the longitudinal direction of the brake band by means of the electromagnet ( 6 ) in order to be able to press the latter against the brake body ( 2 ) for braking the weft thread.

1 . Controlled thread brake for braking a weft thread ( 10 ) in a weaving machine with a brake band ( 3 ) and a brake body ( 2 ), characterized in that the thread brake ( 1 ) includes an electromagnet ( 6 ,  6 ′) and a rotatable or rocking lever ( 4 ) which can be moved by means of the electromagnet and which is operationally connected to the brake band ( 3 ) in order to exert a pulling force in the longitudinal direction of the brake band and to place the latter against the brake body ( 2 ) for braking the weft thread. 
   
   
       2 . Thread brake in accordance with  claim 1 , with the thread brake comprising two or more brake bodies ( 2 ) and/or with the brake body or bodies ( 2 ) being formed as a passive brake element. 
   
   
       3 . Thread brake in accordance with  claim 1 , with the brake band ( 3 ) being firmly or elastically connected to a holder ( 8 ) at a first securing point, in particular at one end, and, spaced in the longitudinal direction, being firmly or elastically connected to the lever ( 4 ) at a second securing point, in particular at the other end. 
   
   
       4 . Thread brake in accordance with  claims 1 , comprising a spring element for the release of the thread brake, in particular a tension or compression spring, which acts on the lever ( 4 ) and/or a leg spring at the point of rotation of the lever and/or a prestressed brake band ( 3 ). 
   
   
       5 . Thread brake in accordance with  claims 1 , with the lever ( 4 ) being straight or angled, and/or with the lever ( 4 ) being arranged substantially at right angles to the brake band ( 3 ). 
   
   
       6 . Thread brake in accordance with  claims 1 , with the point of rotation of the lever ( 4 ) being arranged between the brake band ( 3 ) and the electromagnet ( 6 ) and/or one-sidedly on the side of the brake band or of the electromagnet. 
   
   
       7 . Thread brake in accordance with  claims 1 , with an armature ( 5 ) of the electromagnet ( 6 ,  6 ′) being provided at the lever ( 4 ), said armature containing a ferromagnetic or permanent magnetic material, and/or with the lever ( 4 ) or a part thereof being formed as an armature ( 5 ), and/or with the electromagnet ( 6 ,  6 ′) having a U-shaped core or being formed as a pot magnet and with the magnetic field passing through the armature ( 5 ). 
   
   
       8 . Thread brake in accordance with  claims 1 , comprising at least one second electromagnet ( 6 ′) by means of which the lever ( 4 ) and/or the brake band ( 3 ) can be moved and which is provided as a release magnet and/or to assist the first electromagnet ( 6 ). 
   
   
       9 . Thread brake in accordance with  claims 1 , with an air gap being provided between the armature ( 5 ) and the electromagnet or electromagnets ( 6 ,  6 ′) during the braking. 
   
   
       10 . Weaving machine comprising at least one thread brake in accordance with  claims 1 .