| 摘要 |
<p>A thread brake (1) is described which is particularly suitable for regulating the tension of sewing thread (5) during winding. In a preferred arrangement, the thread brake comprises two coaxial brake discs (2, 3) rotatably mounted on a wear-resistant sleeve (8) which is supported on a pin (8a) passing axially through the body of an electromagnet (4). The outermost disc (3) is made of ferromagnetic material and, when the electromagnet (4) is energised, it is urged towards the other disc (2) so as to apply a braking pressure to the thread (5). A series of countersunk and radial apertures (7) are provided in the outermost disc (3) and are disposed in a circle concentric to axis of rotation. This disc (3) also has a slight concave depression (13) on its braking side directly opposite the other disc (2). Both discs have central apertures and the central aperture (16) of the outermost disc (3) is also countersunk. Both discs can tilt through a predetermined angle on the sleeve (8). The apertures (7, 16) provide an exit for material abraded from the thread due to passage between the braking discs (2, 3).</p> |
