Exide Batteries in the Making
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Some Observations Following a Visit to the Extensive Works at Clifton function of the Chloride Electrical Storage Co., Ltd.
AA T Clifton Junction, near Manchester, is the biggest works in the country devoted entirely to the manufacture of electric accumulators. Here are made the many different types for which the Chloride Electrical Storage Co., Ltd., is far-famed.
At this works despite the dangers inherent to the handling of lead products, the precautions taken to maintain the health of the employees are such that there has been no known case of lead poisoning since 1929.
Exide batteries aft used for a vast variety of purposes, and in a remarkable range of sizes and types. The Exide-Ironclad pattern is employed extensively in submarines, electric vehicles, locomotives, etc.
Every form of storage battery consists of cells, each containing one or more positive and negative plates separated one from the other; these are in an electrolyte consisting of sulphuric acid and water. Each of the positive and negative plates contains an active material composed of lead oxide. When fully charged, that in the positive plate becomes lead peroxide, whilst that in the negative is metallic lead in spongy form. During discharge the active material in both plates is converted into lead sulphate.
A few days ago we had the opportunity of visiting the works, which, together with the offices, occupy 15 acres. A particular feature is that practiCally all the processes and machinery used have been. devised _or manufactured—as the case may be—by the company.
Making the Work Healthy. • In the shops the extensive precautions to prevent danger inclride excellent ventilation, flooding of the floors with water, and providing the workers with rubber boots, rubber gloves and even respirators, whilst further precaution is afforded at many points by carrying on the work under hoods, the operators remaining outside.
Lead components of all classes are produced in the moulding department, the three means being the hydraulic press, which extrudes the material as bars, rods and tape; rolling mills, the sheets from which pass through perforating machines; and casting moulds for the lace-like plates.
Of particular interest in the shop are machines for making furrowed rosettes from lead tape, which are hand-fitted into antimonial lead grids and pressed home hydraulically. These are for the R-type plate. In the plate-pasting department plate grids are filled with lead oxides, applied either by hand or machine, much use being made of conveyor belts. After pasting, the plates go to drying ovens.
The manufacture of plates is speedy, but production is delayed in the forming, department, where they must be suspended in dilute sulphuric acid for from three to seven days. It is here that the positive plates assume their familiar chocolate colour, whilst the. negatives become grey, but the huge numbers constantly under treatment ensure that there should be no delay in the final stages of assembly.
In the plate stores many plates hitherto in multiple form are sawn or sheared and cleaned for " burning " into groups.
One of the most novel machines employed is the type used for slitting the ebonite tubes of the Ironclad plates. This is done at extremely high speed with circular saws, which require frequent sharpening. Filling of the tubes is performed in a machine which shakes them violently and compacts the dry oxide as it pours into them.
Where there is a steady output of batteries, the operators work in lines at the side of conveyor belts. The plates are first placed into jigs and " burnt ' into groups by oxyhydrogen flames which weld the lugs of the plates and equalizer bars.
Carefully cleaned and treated wood separators are now inserted between the plates, following which the whole element is lowered into the container. Farther along the belt, the battery is equipped with its lid and sealed with a molten composition. Then it receives its terminal locknuts, finally being tested for air-tightness, and inspected.
In the case of the large batteries, such as are used in power stations or telephone exchanges, assembly is carried out on the site, a staff of outside erectors being employed.
The charging-shop is an impressive sight with its thousands of batteries of all types. Here, the utmost care must be taken in regulating the current and the temperatures.
In the joinery shop special wood is planed almost to paper thickness and grooved to act as separators. The inspection of these by girls is an interesting sight, for they examine them with meticulous care and yet at remarkable speed over bright lights.
Some types of battery, such as those used for portable wireless sets, in aeroplanes, etc., must be rendered nonspillable, and most elaborate air vents with baffles and chambers have been devised to prevent loss of electrolyte, whilst " Gel-Cel " batteries have been developed for those who prefer an electrolyte of the jelly type which cannot spill in any circumstances.
Keepalite Emergency Lighting.
One of the most successful of the Exide products which we saw in the course of • manufacture is the " Keepalite " emergency lighting set, which is in extensive use by hospitals, cinemas and any building where it is important that a sudden breakdown of the current should not plunge it into darkness. The battery employed is kept in condition by a tiny trickle charge passing continuously. In the case of any interruption of the main supply, automatic switches connect the battery to the emergency light.
In every part of the works the outstanding feature is the ordered efficiency. There is no rushing about. Every task is performed carefully and methodically, yet at a surprising speed.