1112 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1953 



pair of heavy lengthwise "I" beams which fonn a part of the building 

 structure. Supported within this framework is the "U" shape trough of 

 stainless steel or low carbon sheet steel covered with Koroseal lining if 

 required by the electrolyte utilized. A step is formed in the bottom 

 corners of the 'U" to support the plating cells leaving a trough-shaped 

 channel in the center for the return of the electrolyte. The header from 

 which the electrolyte is supplied to the individual plating cells is located 

 between the legs of the "H," flanked on one side by the positive electrical 

 bus and on the other by the negative bus. Partitions are provided as 

 required in the length of the trough to separate sections in which different 

 electrolytes are confined. The entire machine is sloped towards the central 

 portion of the building so that the effluent electrolyte is directed to the 

 low portion where a downspout to the solution storage tank on the floor 

 below is provided. 



The actual plating operations are carried out in a series of cells which 

 are supported on the steps in the return trough by insulating blocks 

 (Fig. 5). All cells are of the same basic design. A typical cell consists of 

 a **U" shaped body of formed and welded sheet steel which may be low 

 carbon steel, stainless steel or low carbon steel Koroseal lined and cov- 

 ered, depending on the particular electrolyte involved. Studs are mounted 

 in both ends of the body for fastening the weir plates. These are of 

 molded hard rubber and provided with twenty-five equally spaced slots 

 on 1-J^" centers to pass the wires. The weir plates on the two ends of 

 the cell body differ in thickness, the thick weir containing an interior 

 manifold which serves to distribute electrolyte uniformly across the cell 

 and which is connected to the electrolyte supply pipe by a flexible rubber 

 ell. Molded rubber spill catchers are bolted to the outside of the weir 

 plates to collect the electrolyte discharged from the weir slots and direct 

 it through a rubber tube into the return trough with a minimum of splash. 



In the case of unlined cells, the cell body serves as anode or cathode 

 as the operation may require and the electrical connection from the bus 

 bar is made directly to a tap on the cell body. For the lined cells, an anode 

 plate of a suitable metal is provided in the bottom of the cell and covered 

 with anode material in the form of cast shot. In this arrangement, all the 

 electrolytic corrosion takes place on the shot bed, leaving the lead-in 

 plate undisturbed. 



The thick, or feed weir, is placed on the low end of the cell to take 

 advantage of friction loss in the long weir slots to reduce the discharge 

 of electrolyte from the cell. Maple wedges coated with vinyl paint placed 

 between the cell bodies and the trough sides allow easy and accurate 



