| 摘要 |
969,699. Covering cores by winding; tension means. MICAFIL Ltd. July 26, 1962 [July 26, 1961], No. 28739/62. Heading B8G. [Also in Division G3] In a coil-winding machine, a wire 2 is pulled through guiding rings 3-5 and between brushes 6, 6<SP>1</SP>. The wire then passes through the airgap of an electromagnet 7 and is braked by a thin synthetic diamond plate 9 supported on an aluminium frame vertically guided in slots in the lower magnet pole. The plate is pressed against the wire by the arching of a plastic bag 10, filled with iron dust, in dependence on the magnetic flux set up by the current in an excitation coil of the electromagnet. The stress in the wire is sensed by a device comprising a core 14 positioned against the action of a spring by a jockey pulley 13 over which the wire runs. The movement of the core upsets the symmetry of the magnetic circuits associated with coils 16, 16<SP>1</SP>, energized in series from a high-frequency source. The asymmetry causes the voltage at a common connection to change and through an amplifier vary the excitation of the electromagnet 7 so as to tend to maintain the stress in the wire constant. |
