| 摘要 |
<p>1,099,985. Spray-producers. METALLISATION Ltd. Feb. 14, 1966 [Feb. 25, 1965], No. 8102/65. Heading B2F. A flame spray gun suitable for spraying molten tin or zinc comprises a central orifice 48 for the supply of the metal in wire form 19, a plurality of bores 74 leading combustible gases to a ring of burner ports in the front face 75 of a nozzle 39, an annular compressed air passage 58 for blast gas defined between the nozzle 39 and an air cap 54, and passage means designed to supply compressed air between the wire 19 at the outlet of the nozzle 39 and the burner ports. The passage means may include transverse passages 78 and (76), Fig. 6 (not shown) which supply compressed air so that it is discharged with the wire from the orifice 48, or a plurality of air discharge ports may be located between the orifice 48 and the burner ports, the air supply being such that the pressure thereof prevents the flame entering the bore of the wire 19. When a valve (14), Fig. 2 (not shown) is set to supply compressed air to a chamber (113), Fig. 8 (not shown) of a control device 12, a pair of diaphragms actuate rods (118), (119) so that rollers (139) are moved together to engage the wire 19 and drive it forward. When the valve (14) is set to supply air to a passage 79 so that additional compressed air is discharged between the wire and the burner ports, the rollers (139) are moved apart and the wire drive is stopped. The gun may be designed so that air is only discharged between the wire and the burner ports when the wire feed is stopped. A pawl device (151), Fig. 12 (not shown) is provided to prevent reverse movement of the wire when the rollers (139) are moved apart.</p> |
