Patent GB-542183-A (GB)
Title: Improvement in method and apparatus for applying metal coatings
IPC: B23K5/18
Filed: 1940-08-08
Abstract: 542,183. Making cased forms. HAYNES STELLITE CO. Aug. 8, 1940, No: 12716. Convention date, Sept. 1, 1939. [Classes 83 (ii) and 83 (iv)] Uniting by fusion.-In progressively fusion welding a coating of wear or corrosion resisting metal or alloy such as bronze, copper, nickel, steel or non-ferrous alloys containing cobalt, chromium and tungsten, on flat or curved plates and solids of revolution such as cylinders or metal rolls, or conical or frusto-conical surfaces, automatic relative motion is effected between the base metal and a body of coating metal while maintaining the uppermost part of the base in a horizontal position, the coating metal body being fed through at least one welding flame applied to the base to deposit parallel beads thereon and the intensity of the flame and rate of relative movement being correlated to produce a substantially uniform deposit. The cylinder M is secured on members 27, 29 rotated on centres 24, 23 by a face plate 21 on a shaft 17 driven by a belt 19. A number of oxyacetylene torches 85, 87, 89 and an adjustable weld rod guide 121 are carried by a slide 45 which may be traversed by a screw 51 driven by reduction gear 55, 57, 59, 61 from the shaft 17. The slide may also be traversed by a hand wheel 77 through spur and rack gear 78, 79, 81. The screw 51 is engaged by a half nut carried by a slidable member operated by a handle 71 and held in position by a spring locking member. The flames may be of the excess acetylene kind so as to carburise the surface of the article. The torch 89 has a number of jets 125 so as to preheat the work, and the torch 85 has a welding jet 127 impinging on the work in the vicinity of the weld rod 128, a work preheating jet 129, and a jet 131 impinging on the weld rod for the fusion thereof, the rod resting by gravity on the surface of the work. The torch 87 has an inclined jet 133 which impinges on the work at a distance from the jet 127 about equal to the traverse of the slide in one rotation of the cylinder and acts to remelt and smooth the surface of the coating. All the torches are transversely adjusted by racks and pinions 95, and the torches 85, 87 longitudinally adjusted by screws 103 and the torch 89 by rack 107 and pinion. The torches 85, 87 are adjusted vertically by racks and pinions 113 and the torch 89 by rack' 109. The slide is also provided with an adjustable perforated pipe 141 for cooling the work. A number of torches and rods may be used simultaneously so that a number of overlapping spiral beads of coating metal may be deposited at the same time. In the case of small articles the torch 84 may be dispensed with and in the case of large articles an additional torch may be used at a different angular position. Flux may be applied either by adding borax powder by using a weld rod coated with borosilicate glass or by using a volatile flux. In the last case the welding gas is bubbled through a solution of an alkyl borate, a valve being provided so that a portion of the gas may be fed direct to the torch for dilution purposes. The thickness of the coating may be varied by altering the height of the torch with respect to the weld rod on which it impinges. In another form in which an elongated flame or number of flames is used the work M is mounted on members 172, 173, Fig. 5, the latter of which is keyed to a member 174 carried by a sleeve 167 which is mounted on an adjustable support 168 and which is keyed to a shaft 161 rotated by chain and spur gear from a motor E. The support is moved in guides 177 in the bed by a hand lever 179. An elongated water-cooled torch block 180 carries tubular guides for a series of weld rods 128 and is provided with a row or preferably two rows of nozzles 185, one on each side of the rods, one row of nozzles preheat the work and the other row melt the rods 128 and weld the coating. The block also carries in brackets a perforated tube 214 through which cooling air, steam or water is impinged on the work. The block is carried by a member 197 welded to a member 196 with a grooved surface interlocking with the surface of a bracket 198 to provide for angular adjustment. The bracket 198 is secured to a block 200 which is vertically adjusted by a screw 204 on a member 201 carried by a block 205 which is longitudinally adjusted by a rack 208 and pinion 206 on a slide 210 transversely adjusted along guides 211 and secured in position by set screws 212. The weld rods 128 may be fed by gravity or by rubber roller 216, 217 carried by the block 180. The roller 216 is driven by a reversible electric motor 220 through reducing gear 222 and the roller 217 is adjusted relatively thereto by screw 227 against the action of a spring 226. The rods 128 engage the work just before it reaches its highest point in its path of travel. In either form the coated article may be subsequently heat treated after withdrawal of the weld rods by reducing the intensity of the flames or increasing the speed of rotation. Welding rods may be replaced by one or more flat, corrugated or curved plates.