Abstract: A metal spraying apparatus comprises a gun having convergent guide passages (36,38) through which metallic wires are fed. An electrical potential is applied across the wires, by conductor elements (54), to cause arcing between the wires where they emerge from the guide passages, which melts the wires. A stream of compressed air causes molten metal droplets to be carried from the arcing zone towards the surface to which a metallic coating is to be applied. The apparatus also comprises a supplying device, to supply electricity and air under pressure to the gun. The conductor elements extend within conduits (18) through which air is fed to the gun, and the gun comprises a valve (9) for cutting off the flow of air through the gun. The supplying device comprises a control device (82) which is responsive to such cut off, to cut off the supply of electricity to the gun.
Abstract: A metal spraying device of the kind in which two wires are fed along convergent guide ducts, and an electric potential is established between the wires, so that an electric arc is produced between the terminal ends of the wires. A jet of air is blown across the arc, removing metal from the ends of the wires in the form of minute droplets, the jet of air being directed against a workpiece to be sprayed with a metallic coating. The metal spraying device comprises a head made of insulating material (e.g. ceramics material), the head being provided with passages forming the guide ducts for the wires and for the jet of air. In this manner, the wires may be guided more accurately to the arcing zone, and turbulence in the jet of air may be minimized, producing an overall improvement in the quality of the spray which may be achieved.