| 摘要 |
991,285. Spraying fusible materials. F. W. BERK & CO. Ltd. Feb. 1, 1962 [Feb. 1, 1961], No. 3816/61. Heading B2F. In a pistol for spraying fusible materials wherein the material is conveyed to the pistol outlet by a conveying gas, fused in a flame and sprayed from the pistol by a projecting gas, valve 5, Figs. 1 and 4, is provided whereby when the pistol trigger 9 is operated to stop the flow of projecting gas through the pistol the supply of a material supplying gas and hence the material is thereby indirectly cut off. The material may be in powder form fed from a hopper 2 into a conveying gas stream in pipes 3, 4, or it may be in wire or strip form (not shown), the conveying gas actuating a turbine to advance the wire to the spraying nozzle. The cylindrical valve assembly 5, Fig. 4, has a conveying gas inlet 12 and outlet 13, projecting gas inlet 14 and outlet 15, and piston heads 16, 17. In operation the piston head 17 lies in chamber 11 and head 16 in chamber 10. When the trigger 9 is operated to stop the flow of the projecting gas through the pistol the projecting gas pressure on piston head 17 builds up and overcomes the opposing pressure of conveying' gas on head 16 so that the piston slides to close inlet 12 and stops the flow of conveying gas to pipe 4 and hence stops the supply of material to be sprayed.
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