GB1424631A - Brake and tensioning apparatus for bobbins or spools of a braiding or winding apparatus for sheathing elongate material - Google Patents

Abstract

1424631 Winding machine; thread supply and tensioner W & M OSTERMANN 4 Feb 1974 [16 Feb 1973] 05082/74 Heading B8G [Also in Division D1] A device for tensioning threads withdrawn from bobbins on a spindle controls a bobbin brake, and when thread tension increases a surface on a tensioning arm abuts a stop on a brake-actuating lever to ensure positive brake release. The tensioning device and brake may form part of a winding or braiding machine for sheathing a core. As shown, Fig. 3, the device and brake is combined into a single unit 20 comprising bobbin-supporting spindle 26, disc brake 30 applicable to the bobbins, and strand tensioner 24. A strand of the threads runs in the tensioner over fixed rollers 43, 44 and then runs in a loop about rollers 46, 47. Roller 46 is mounted on pivotable arm 45 which is biased by an adjustable torsion spring in the direction 73 to tension the strand. One leg of the strand loop engages roller 42 on arm 37 which is pivotable about pivot 39 to apply brake 30 via pivot 36. If strand tension increases, Fig. 4, arm 45 is pivoted upwards against spring bias and the force imparted by the strand leg to arm 37, and hence the brake-applying force, is reduced as the angle a approaches 180 degrees. When a minimum length of thread is stored in the loop, surface 81 on arm 45 engages roller 79 on arm 37 to lift the arm to ensure positive brake release. A minimum gap 82 between rollers 42, 46 is maintained. In a braiding or winding machine, Fig. 1, strand supply units 20 are mounted on rotatable plate 11 to deliver strand to, and sheath, running tubing 15. Units 20 are arranged in concentric circles. Each lever 37 extends radially of the plate and, in a non- braking position, parallel to the plate.