The Works Of Messrs. Schneider And Co.

THE ARMOUR-PLATE MILL. 87 (.039 in.). The roll-setting screws are of hard-forged steel, and the nuis are of phosphor-bronze. The outside diameter on threads, is .300 metre (ll-rf- in.) ; the threads are single, with 36 millimétrés (If in. füll) pitch. The screws end in a cylindrical length provided with a groove which slides in the boss of the endless screw-wheels tliat work them. Under each roll-setting screw is placed a special safety device, with double-end ed wedge, and the bolts that hold it together are designed to break under any unusual strain. When, owing to any accident to the roils or to the engine, a plate remains lodged in the mill, these safety appliances are quickly taken to pieces ; this enables the plate to be removed rapidly, thus preventing all damage to the rolis by their remaining in contact with bearings is used ; in this case the position or the farther bearing is given by a second index, on the same scale, the first index still showing the position of the lower trunnion. This double indication is readily observed by the attendant ; he holds a lever which enables him to throw out of gear, through a clutch, the two endless screws which work the roll-setting screws, and to set only one working when necessary. Regulation is obtained by screwing down the two roll-setting screws to the maximum ; then by working on the lever and reversing the engine, the one setting screw which can work is un- screwed and brought up to the required height. With this arrangement it is easy to roll all taper armour-plates. Hard-steel plates of the following dimensions have been The Armour-Plate Mili. the rolied material. Under these appliances is a wedge worked by a screw, which serves to maintain the rolis parallel. The top roli, which is movable as well as its fittings, brasses, wedges, &c., is balanced and maintained constantly pressed against the roll-setting screws by four piunger pistons .180 metre (7-J in.) in diameter, working under the hydraulic pressure of 35 kilogrammes per square centimetre (497.81 Ib. per square inch). The position of the top roil with relation to that of the fixed lower roll, is continuously shown by an index which slides up and down a scale fixed on the housing. A dis- placenient of the roil of 10 millimétrés (f in.) corresponds to a travel of 25 millimétrés (1 in.) of the index. When taper plates have to be rolied, for which it is necessary to incline the top roil more or less, a roll with spherical rolied in this way : 7.610 metres by 2.360 metres by 80 millimétrés by 39 millimétrés (24 ft. 11T97 in. by 7 ft. 9 in. by 3^- in. by 1,%- in.), and though the operation is a délicate one, the plates were turned out perfectly flat, the exact ratio of effort exerted on each side being well maintained. The first taper armour-plates rolied in this mill were of iron, and subséquent operations never re- vealed imperfect welding. Feeding rollers are required in front and in the rear of the mill when armour-plates weighing up to 40 tons are being rolied. Each series consists of nine rollers .540 metre (21^ in.) in diameter and 1.800 metres (6 ft. 11 in.) long, the rollers rising .140 metre (5J in.) above ground level. The feed-rollers are worked by a small reversing two-cylinder engine placed below