Improvements in apparatus for applying heat-fusible coatings on solid objects

摘要

832,322. Spraying fusible materials. METALLIZING ENGINEERING CO. Inc. April 17, 1958 [April 18, 1957], No. 12195/58. Class 69 (3). In a flame spray gun in which fusible powder is carried in suspension centrally through a discharge nozzle surrounded by a series of combustible gas jets providing a sheath of flame, the powder outlet of the nozzle is provided with means to diffuse the powder into the space occupied by the sheath. Powder is delivered from a hopper 2, Fig. 2, under the control of a triggeroperated valve piston 16 to the central passage of a plug 23, and is delivered by a fuel gas, fed into the central passage of the plug, to the central discharge passage 27 of a nozzle 26. Fuel gas is fed through the gun, via valves, to circumferentially-spaced passages 37, Figs. 2 and 6, which provide a sheath of flame into which the powder is diffused by a wire screen 602. Converging passages 38 are located in the nozzle intermediate the passages 37 to induce air into the flame and prevent deposition of material on to the nozzle face. Fig. 8 shows an alternative nozzle construction including a diffuser plug 802 providing an annular passage 801 for induced air admitted through radial holes 805. A cone 807 is located by legs 809 in the outer conical bore of the plug. In further embodiments the plug is of integral construction comprising separate diverging outlets for the powder.