GB1404895A - Corona discharge equipment - Google Patents

Abstract

1404895 Discharging static electricity W SPENGLER 3 April 1973 [15 June 1972] 15878/73 Heading H1X In equipment for discharging an electrostatic potential from a surface of a material that is a poor conductor of electricity by passing the material through an electric corona discharge generated between a pair of electrodes extending between lateral bearing members 2<SP>1</SP> and 2, one electrode of the pair is a rigid conductor 4 having discrete discharge points 3 spaced therealong which is rigidly fixed to at least one of the bearing members, and the other electrode of the pair is a conductor 5 supported between the bearing members by resilient means 6 allowing relative movement between the conductor and at least one of the bearing members to ensure the maintenance of a substantially constant distance between the electrodes of the pair and between the electrode 5 and the surface of the material to be treated. To prevent distortion due to expansion of the electrodes 4 in the frame structure formed by the bearing members 2<SP>1</SP>, 2 and a connecting plate 1<SP>1</SP>, the electrodes 4 are fixed to the frame structure at one end only. The plate 1<SP>1</SP> may be omitted, in which case the electrodes 5 are defined by lengths of a single conductor formed in a succession of hair pins, and having an insulating coating which is protected by insulating sleeves 9 where the conductor passes through the bearing members 2<SP>1</SP> and 2. Alternatively the electrodes 5 may be separate conductors surface insulated in the zones confrotinng the electrodes 4. The conductor 5 is tensioned by compression springs 6 bearing on washers 7 and retainers 8 fixed to the conductor. Alternative cylindrical cage embodiments are described (Figs. 3 to 6, not shown) having the discharge points projecting inwardly for treating a cylinder or outwardly for treating a tube to act as a stationary or slowly moving deflecting device for a travelling web.