Patent GB-1007472-A (GB)
Abstract: 1,007,472. Spray-producers. METCO Inc. Dec. 5, 1962 [Jan. 16, 1962], No. 45972/62. Heading B2F. In a gun for spraying heat-fusible materials and comprising conduits for fuel gas, combustion supporting gas and blast gas, each conduit has a valve controlled by a trigger common to the three valves and the trigger is so arranged that on depression the valves are moved in sequence to full-flow and restrictedflow positions. This ensures the full opening of the gas conduits for purging, partial opening for lighting and full re-opening for operation through a single depression of the trigger. In the described embodiment for spraying molten wire particles depression of the trigger 55, Fig. 2, moves a pivoted bar 55 such that three adjustable studs 62 move rearwardly into engagement with three pins 47 each of which is secured to a piston 38 slidable in a tubular valve housing 37. Each valve housing is located in a conduit through which acetylene, oxygen or compressed air is conducted to a burner nozzle 3. The acetylene passes from the housing through a vertical passage 6, Fig. 6, and a duct 10 to a groove 22, Fig. 2, formed in the gun between a siphon plug 2 and the gun casing. The oxygen flows from its valve housing upwardly through a passage 7 into an annular space formed between mating grooves 8 and 21, Fig. 2, from which it passes forwardly along four evenly spaced axial flow passages 23 to the groove 22. The fuel and comburrent then flows to an annular groove 25 prior to passing through six equally spaced jet passages 26 in the nozzle 3. Compressed air passing through the associated valve housing 37 is conducted through a passage 13, Fig. 6, and a duct 29 to a space formed around the nozzle 3 by flanged cap 4 from which it flows inwardly through holes 30 to issue with the combustible mixture from the gun. The wire to be fused is continuously fed to the discharge point of the gun through a guide tube 68, cooperating bevelled feed rollers 69 and 70, Fig. 4, guide tube 28, siphon plug 2 and burner nozzle 3. The drive to the rollers 69 and 70 is effected by a turbine 100, Fig. 3, the blades 102 of which are rotated by compressed air fed from the passage 13 through a passage 103. The turbine drives a shaft 104 which is rotationally connected through worm gearing 80, 79, Fig. 8, to a worm 77 mounted on a shaft 78. The drive to the rollers 69 and 70 is effected through gear wheels 73 and 76 engaging the worm 77. These wheels are mounted on axially movable spindles 72 and 75 which are linked by a horizontally mounted lever arm 81 and the vertical movement of which derives from a horizontally mounted lever plate 89 which has a lower surface in contact with a vertically movable plunger 94. The latter forms the upper boundary of a chamber 92 to which compressed air from the passage 13 may be admitted through a conduit 96, a handoperated valve 97 and a passage 95. The roller spindle 75 is biased by the spring loaded shaft 82 which mounts the arm 81 into the lower position shown in Fig. 8 in which the rollers are unable to grip the wire. On permitting air to pass to the underside of the plunger 94 through opening of the valve 97 the roller spindle 75 is moved upwardly by the lifting plate 89 such that the bevelled surfaces of the rollers 69 and 70 move into wire-engaging positions. The turbine is fitted with a centrifugal type brake whilst accidental withdrawal of the wire from the gun is prevented by a spring-roller arrangement 112, 115.