GB1116460A - Process and apparatus for coating a sheet of glass - Google Patents

Abstract

1,116,460. Coating apparatus; spray nozzles. COMPAGNIE DE SAINT-GOBAIN. 29 July. 1966 [29 July, 1965], No. 34243/66. Headings B2F and B2L. In depositing a coating of a substance on a continuously moving sheet of glass by spraying the atomised substance thereon, a continuous and uniform sheet of sprayed substances is formed by means of a plurality of spraying nozzles moved at a uniform speed transversely with respect to the direction of travel of the sheet of glass. In the embodiment shown, Fig. 4, a suitable member of regularly spaced nozzles P are fixed to an endless chain 1 driven by sprockets 3 and 4 so that each traverses across the sheet F to be coated. The spraying operation of the nozzles is restricted to the zone occupied by the sheet by automatic means e.g. cams co-operating with rollers to open and close controlling valves in a pneumatic system. As shown the sheets F are moved vertically and automatic means are provided to start and stop the motor driving the chain sprocket 3 as each sheet comes into or passes out of range of the nozzles. These may be upper and lower sets of nozzles attached to separate chains to spray the same or different coating materials on to the sheets F. In further embodiments the sheets are moved horizontally and the nozzles move either in a horizontal or vertical plane. Each nozzle (Fig. 6) has associated therewith an atomiser 18, a container 19 a valve 20 to control the supply of air for atomising and a valve 21 for controlling the opening and closing of the nozzle orifice. The liquid is sprayed through orifice 25 around which are grouped a number of air nozzles, 32, 33 through which atomising air is blown; the nozzles 32 serving in particular to exert outward suction on the jet of liquid while the nozzles 32 serve to control the shape of the jet. The valves 20, 21 are supplied with compressed air by pipes 42, 43 connected to collectors 44, 45 of flexible material and which form an integral part of the moving assembly. The collectors are connected to a general compressed air system by swivelling unions 44a, 45a; valves 47, 48 and pressure reducers 49, 50. In operation the valves 20, 21 are operated by rollers 36, 37 co-operating with cam surfaces 38, 39 and the latter or so formed that the action of valve 20 is slightly behind that of valve 21 so that atomisation air is supplied slightly prior to the opening of orifice 25 by needle valve 26.