The Works Of Messrs. Schneider And Co.

88 MESSRS. SCHNEIDER AND CO.’S WORKS. the ground level. Its principal dimensions are the followino- ; Diameter of cylinders Stroke ... Maximum speed .260 m. .300 m. 150 revolutions per minute. 0 ft. 10J in. Oft. lljfin. 150 revolutions per minute. The ratio between the speed of the engine and that of the rolls, is 10 to 1, which corresponds to a speed of the rollers of .424 metre (16^-J- in.) per second. In order to prevent fractures, the engine drives the cast-steel toothed wheels, which work the rolls, by friction. The series of rollers which lead from the mill to the shears can be driven by the same engine by means of a clutch. In the middle of the series of front and rear feed- rollers there is a receiver, on which the ingot to be rolied is deposited. Each receiver is fitted with a double telescopic piunger, the smaller of which is .220 metre (8£ in.) in diameter ; it serves for all current work, and can raise loads of 10 to 11 tons ; the larger ram is .390 metre (15T5K in-)> an(l is only used for raising heavy weights up to 40 tons. The smaller plunger is fitted with a U-shaped head which receives the lower branch of the O-carrying device for depositing or taking up an ingot When an ingot has been deposited, the bracket is lowered and the adjoining rollers carry the ingot under the rolls This receiver, when slightly raised, serves as a pivot for turning the ingots horizontally in course of rolling. When a plate has acquired the given width, it is turned a quarter round by means of the receiver, in order to be rolled the other way. For long plates, hydraulic adjusting apparatus on each side of the rear rollers are used, for maintaining the plate constantly in the centre of the housings, and perpendicular to the rolls. A suspended hydraulic device for turning over the plates in course of rolling, is placed over the feed-rollers. It is a most serviceable machine, as it can quickly turn an ingot weighing 8 to 10 tons, and deposit it reversed on the feed-rollers. The oxide can thus be scaled off both sides during rolling. This machine is also used to give certain ingots a quarter turn, in order to roll them alternately fiat or on edge under the horizontal rolls ; this gives a much greater pressure than can be obtained in a universal mill, in which lateral pressures are kept necessarily low, to avoid fractures in the gearing. Another of these machines, but much more powerful. is placed between the mill and the hot shears ; it is used only for turning over deck-plates or heavy armour-plates. The hydraulic cylinder is suspended to an iron frame, leaving a free space of 3.500 metres (11 ft. 6 in.) above the feed-rollers. The hydraulic ram is made telescopic ; the smaller one of forged steel, .315 metre (12| in.) in diameter, serves to lift and turn over plates weighing up to 12 tons. It slides in the larger one, which is .460 metre (18g in.) in diameter, and is used to turn over plates weigh- ing from 13 to 40 tons. The travel is 2 metres (6 ft. in.), and the head is guided in two powerful slides. The centre of the plate is brought between two endless chains of special manufacture, with forged links: these chains, which are placed 1 metre (39f in.) apart, run on two pulleys, that are driven by two ratchet wheels set in motion by a central loose wheel, actuated by a plate cliain which encircles it, and one end of which is fixed to the foot of the cylinder. The turning over of a 35 to 40-ton plate is effected with smoothness and efficiency. All the machines described above, and the accessory apparatus, are controlled from a high platform placed above the coupling shafts, from which the driver can witness all the work on both sides of the mill. The adjusting apparatus, which is not so frequently used, is worked from the floor level. On several occasions this mill has been fitted with two vertical rolls .500 metre (19ff in.) in diameter in the front and with two similar rolls at the back. To erect these, it is necessary to remove the first feed-roller from each side of the rolls and to place another slide for the bearings carrying the lower trunnion of the vertical rolls. The top trunnions are guided by two other slides, stayed on the housing frame ; the vertical rolls are worked from the top by bevel pinions and by two shafts which traverse the whole of the housing frame as far as the pinions ; these drive the shafts by means of helical-toothed wheels. Each vertical roll is fitted with two set-screws, turned by a vertical engine; the set-screws may be worked together, or those of two rolls on any side of the mill may be worked separately. The maximum distance between the vertical rolls is 1.600 metres (5 ft. 3 in.). A large number of deck plates liave been rolled in the mill so fitted with vertical rolls. Reheating Furnace.—The armour-plate rolling mill has three furnaces with electric crânes running above them. Figs. 215 to 218, Plate XLIL, show in detail the smallest of the three furnaces, which is used more particularly for heating ingots for thick merchant plates. They are all on the same principle, and are heated with coal, which is burnt on two grates provided with air biast nozzles, one on the right and one on the left of the hearth ; the flame outlet is in the centre at the back. The flames on leaving the furnace are employed to heat three multitubular boilers, one of 188 square metres (2023.68 square feet), and two others of 250 square metres (2691 square feet) heating surface. The reheating furnace nearest the mill, is similar in construction to thai illustrated, but is of the following dimensions : Length of hearth Depth ,, Height under arch Width of doors Two grates 5.960 3.000 1.500 2.200 and 2.400 1.400 by 1.100 ft. in. 19 6f 9 10} 4 11 7 2f and 7 104 4 7J by 3 7A The third furnace serves specially for heavy armour- plates. Tt was formerly used for heating iron plates