GB517855A - Improvements in or relating to the discharging of electricity from materials used inindustries - Google Patents

Abstract

517,855. Discharging electricity from fabrics. &c. ENGLISH ELECTRIC CO., Ltd., and AYRES, W. E. M. Aug. 12, 1938, No. 23817. [Class 35] Apparatus for reducing or removing the electrostatic charges produced on paper, textiles and other materials during manufacture consists of a conductor mounted near the material, maintained at a high potential and completely surrounded by an insulator. A number of such conductors may be used placed parallel to each other and alternating with similar conductors maintained at earth potential and not insulated, or at a high potential of opposite polarity. In the example shown, in the form of a grid placed close to or in rubbing contact with the material (not shown), the uninsulated bars 1 are screwed into the earthed bar 4 at one end and pass through the insulating bushes 11 in the bar 5 at the other. The bars 2, surrounded by insulation 3, are screwed into the bar 5 at one end.and are insulated from the bar 4 by bushes 12. The bar 5 is completely enveloped in insulation 7 and is connected to a source of high potential 8, preferably a step-up transformer of poor regulation characteristic, the other end of which is earthed. Alternatively the mid-point of the winding may be earthed and its ends connected to the two systems of bars, both of which are enveloped in insulation. The device depends on the high voltage gradient between the conductors and the' material, and the insulation is preferably moulded on the conductors to eliminate air films.