GB1415882A - Electrostatic spray apparatus - Google Patents

Abstract

1415882 Electrostatic spray producers NORDSON CORP 14 Nov 1972 [16 Nov 1971] 52625/72 Heading B2F An electrostatic spray gun for spraying conductive or non-conductive paints comprises an electrically conductive reservoir 14, Fig. 3, surrounded by a non-conductive casing 97 to prevent electrical discharge to atmosphere. With conductive paints, the casing 97 is insulated from ground by supports 94, 95, and when spraying non-conductive paints, the reservoir 14 is earthed through a spring-biased conductor 96 and a plug 100. The paint is fed to a nozzle 42 via a non-conductive conduit 38 which has tapered pipe threads 78 to provide a good dielectric yet releasable connection, the paint flow being controlled by a valve 50, 51 operated by a trigger 18 which also controls the atomising air supply to an annular passage in the nozzle 42 surrounding the paint jet via a spring-biased valve 17, Fig. 4, and a passage 26. Air is also directed to the nozzle 42 to control the fan shape of the discharge through a passage 25 under the control of a manually operated valve 20. A double bellows seal 55, 54 is provided to prevent forward and backward leakage of paint in the passage 35. The paint is charged by an antenna 81 which is part of a spring 90.