GB189918643A - Improvements relating to the Amalgamation and Coating of Metals or Alloys of Metals, with Metals or Alloys of Metals, by the Aid of Electricity, and to Apparatus therefor. - Google Patents

Abstract

18,643. Foss, F. Sept. 15. Plating by movable brush and like electrodes. -As described in Specification No. 25,360, A.D. 1896, plating is done by a brush or the like, supplied with a solution of any desired metal or alloy, and connected with the positive pole of an electric generator, which is kept moving over the article to be coated. In the present case, this movement is rotary so as to be much more rapid, or, in some cases, the article to be coated is rotated and the plating brush &c. is stationary. Wire, metal tape, tubes, rods, bars, and other articles may be coated by this method. In the example shown in Fig. 1, a handle g, having a removable part adjustably connected thereto at g<1>, supports a cylinder a, which is rotated by a pulley n and a band, and is continuously charged with a suitable electrolyte through the hollow shaft p. The cylinder is provided with bristles or brushes b, and is perforated as at c. It is connected by a wire and brush s to the positive pole, while the article to be plated is connected to the negative lead, of a source of electricity. The cylinder ends are connected by bars l having sheaths m of insulating-material. The current is at first of high voltage, say of 75 to 100 volts., but subsequently it is lowered to, say, 30 volts., while the current density is greatly increased. The brush cylinder may be protected by a guard on the side not facing the work. Instead of bristles, felt or other absorbent material may be used ; or steel or other wire may be used, in which case the wire serves to clean the surface of the article to be treated ; or, finally, asbestos, glass, slag, or mineral fibres may be used. In a modification, the brushes are arranged in the end, instead of in the periphery, of a rotating cylinder which turns on its vertical axis. For plating tubes, internally or externally, the brushes are supported on a semicircular or like stationary cathode, while the tube is mechanically rotated. For plating wire, metal rods, tape, &c. the article is drawn through a casing provided with stuffing-boxes, and with an internal rotating anode having brushes projecting inwardly. The wire &c. may be drawn or forced through dies to smooth and polish it, or between wire brushes, before it enters the electrolyte. For plating metal sheets, flat brush anodes may be used, the sheets being mounted on a reciprocating table similar to a planing-machine. The brushes may be mounted upon an insulating-support parallel to and at a distance from the anode.