Patent GB-486266-A (GB)
Title: Wire coating process and apparatus
IPC: C23C2/38
Filed: 1937-07-30
Abstract: 486,266. Coating with metals. METALLOYS CO. July 30, 1937, No. 21227. Convention date, Aug. 13, 1936. [Class 82 (ii)] [Also in Group XXII] Wire 10, or an elongated metal article of uniform cross section, is coated with a protecting metal by moving the wire through a casting die 44 through which the molten coating metal is sucked. The coated metal may then be quenched. The wire first passes through a fluxing bath 11 and then through a preliminary coating bath 16 of the same or a different coating metal, which also preheats the wire, and then passes through a casting die 44 supplied with molten metal from a pot 25, the molten metal being sucked through the die by an ejector 90 screwed to the lower end of the casting die housing. When the lid of the preliminary coating and heating bath 16 is closed, guides 23 thereon press the wire down and submerge it in the coating metal. The bath 16 is contained in a heat-insulated tank 17 and the metal may be heated by submerged electric heaters. The wires pass through wiping devices on leaving the bath. The drawings show a number of wires being coated each having its own preliminary and final coating apparatus. The preliminary coated wire is then led over a grooved wheel (with a heat insulating shroud 88) through top and bottom apertured guides 57 and 59, Fig. 10, and apertured casting die 44 supplied with molten metal and then passes a guide wheel 121 and winding drum 122. Each casting die is supplied with molten metal through a hand adjusted needle valve from one, or a common melting pot 25 electrically heated and insulated, the metal flowing into an annular channel 55, Fig. 10, and then through slots 72 to the die 44. The die is positioned in a bore in its casing by a spacing ring 56 on which rests the lower guide 59, spacing sleeve 68, and top guide 57, so that all are secured in position by the screwed cap 51. The die housing is also provided with electric heating elements 75 and with heat insulating rings 77, 78, 79. The molten metal is sucked through the die and on emergence has adhered to the wire, the sucking action causing less agitation in the molten metal than forced or simple hydrostatic flow and also causing a partial air vacuum above the die so preventing oxidation of the surface of the molten metal. The suction is obtained by an ordinary ejector, Fig. 9, screwed to an extension 94 on the die housing. A pump 91 with an adjustable pressure relief valve supplies the ejector with water, oil or other liquid or gas which flowing through the inclined bores 103 induce vacuum in the funnel 111, and so cause a suction at the orifice of the die 44. The water, oil or air passing through the nozzle 113 also acts to cool the now coated wire also passing therethrough. The small hydrostatic pressure of the molten metal in the melting pot is sufficient to allow metal to flow in through top slots 71 also whereby the bottom guide 59 contains a pool of the metal which heats and alloys the coating to the wire before passing to the casting die 44. By varying the pressure of the pump delivery to the ejector, the speed of the wire being coated can be correspondingly varied.