GB415777A - Improvements in and relating to electrostatic machines - Google Patents

Abstract

415,777. Electrostatic machines. BRITISH THOMSON - HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Coolidge, W. D. ; 1480, Lenox Road, Schenectady, New York, U.S.A.) March 2, 1933, No. 6416. Convention date, March 2, 1932. [Class 35.] An electrostatic machine comprising a moving element such as an endless belt 1 passing through a charge accumulating body 7 has a collector 23, removably or adjustably arranged within the body and electrically connected thereto and means are arranged within the body to charge the moving element from the collector oppositely to the body. The belt 1 of paper, varnished cambric, silk &c. is mounted on rollers 2, 3 and driven by an electric or other motor 6. The belt is separately excited adjacent the roller 2 by a collector 13 having a number of sharp points close to the belt surface and electrically connected field pieces 14, 15. A high voltage source, e.g. the secondary of a transformer T in series with a rectifier R, is connected across the collector and field pieces to charge the belt as it moves towards the body. A portion of the charge is taken by a collector 30 and the remainder is given up inside the body to the collector 23. The collector 30 is electrically connected to field pieces 26-29 within the body and the field pieces 26, 27 in conjunction with the collector 23 impart an opposite charge to that portion of the belt moving towards the roller 3 whereby the charge in the body is increased. The portion of the belt moving away from the roller 3 is charged by a self exciting arrangement comprising an earthed collector 31 and electrically connected field pieces 32, 33 and collector 34. The belt portion moving into the body from the roller 3 gives up its charge to a collector 25 which in conjunction with the internal field pieces 29, 30 imparts an opposite charge to the portion moving towards the roller 2. In order that the internal collectors and field pieces may be removable for adjustment or repair they are carried on insulating slides 46-48 held in an insulating support 42. The collectors 23 and 25 are held by set screws and rods 49, 50 whereby their positions can be adjusted. The field pieces are connected together by conducting plates 53 arranged in recesses in the sides of the insulating support 42 which are engaged by spring pressed contacts 54 at the ends of the field pieces. Removable closure plates with inwardly flared opening 8 and 9 for the passage of the belt and secured to the body by screws provide access to the slides. In order to prevent contact of the oppositely charged belt portions when a long belt loop is employed insulating rollers 11 may be provided. Specification 415,484 is referred to.