GB844102A - Coating apparatus - Google Patents

Abstract

<PICT:0844102/III/1> An apparatus for applying a coating of solder glass frit to the mating surface of a television picture tube panel or funnel, comprises a bed having a vertical passage therethrough, a rotatable annular support arranged about the passage for holding a panel or funnel with its mating surface facing upwards, means for rotating the support, a container for frit having a bottom passage, means for moving the container to a position in which its outlet is in vertical register with a crosssection of the said mating surface, and for maintaining such relationship while the support is being rotated to present the entire mating surface progressively to frit issuing from the outlet, and means for continuously stirring the frit within the container. As shown, a support 15 for the panel 18 is supported on rollers 16 and confined laterally by rollers 17, and is arranged to be rotated by a friction drive roller 20, driven by a motor 21, which is slidably mounted on rods 24, and may be moved to engage or disengage the drive by a pneumatic cylinder 26. A carriage 30 is slidably mounted on rods 31, 32, and supports a tank 35, for the frit, and a motor 43 for driving an agitator therein. The tank 35 has a bottom orifice controlled by a pneumatically-operated needle valve, and a slight positive pressure is maintained in the tank to aid in the extrusion of the coating-material, which may be a suspension of ground thermal setting sealing glass in a nitrocellulose solution. To maintain the tank orifice over the portion of the article to be coated, a rotatable roller 52 is mounted stub shaft on a disc fitted in the inner race of a ball-bearing, mounted on the tank, and the platform 30 is lightly urged by a pneumatic cylinder 55 to maintain the roller continuously in engagement with the side wall of the panel. Pneumatic and electrical circuits, for controlling the operation of the machine, are described.