The Works Of Messrs. Schneider And Co.

TYRE SHOPS. 53 through the group of tubes upwards, the draught being provided by a chimney placed directly over the boiler. Height of chimney above level of works Diameter at top Heating surface of one boiler Production of steam per pound of coal burnt on the grate ........ 30 m. .700 m. 126 sq. m. 4 1b. 4 Ib. Reheating Furnaces. — The other part of the plant consists of the tyre-rolling mili and two reheating furnaces, with boilers of the same type as those above nientioned. The following are some particulars of the engine : 98 ft. 6 in. 2 ft. 3J in. 1356.29 sq. ft. Diameter of cylinder 0.800 m. 31| in. Length of stroke ... 1.750 m. 5.9 in. Revolutions per minute ... 45 45 Pressure of steam ... 6 kilogs. 85.338 Ib. per sq. in. The rougli-forged tyre is fed vertically into the rougli- ing rolis ; each friction roll is made with a groove which takes half the thickness of the tyre. The lower roll is fitted with two spindles, and is mounted on a block that can beshifted vertically by meansof an hydraulic cylinder; I this arrangement maintains an efficient grip during the Fig. 129. Tyre Shops and Testing Tower. The dimensions of the reheating furnaces are : Length of hearth Width Grate area ... 4.200 ni. 1.900 m. 1.22 sq. in. 13 ft. in. 6 ft. 3 in. 13 sq. ft. Crane.—A 2-ton hydraulic crane serves each furnace, which is large enough to hold from fifteen to twenty rings for wagon tyres, and can treat three charges per twelve hours, equal, for the two furnaces to 30 tons of tyres per day. The rough-forged ring taken from the furnace by the crane, is carried to the miil by a hook suspended from a trolley that travels on an overhead track. Rolling Mills.—The rolling-mill plant consists of a series of roughing rolis, of finishing, and of special rolis, the latter being used only for the manufacture of gun hoops and some other kinds of rings. A non-condensing 300 horse-power engine, with two cylinders, drives the three milis by means of tootliecl- wheel gearing. I operation of rolling. The pressure on the hydraulic piston i is 78 tons. The top roli is fitted in the end of the shaft, and is without any outside support. The two rolis are driven by toothed wheel gearing ; the number of revo- lutions is 60 per minute. In finishing the tyres the table is horizontal and the rolls vertical. Unlike the roughing roils, those for finish- ing have cheeks sufficiently high to fit the total thickness of the tyre. The central roll carries the lower cheek and the outside one the top cheek. The outside roli is fitted with two spindles, and is mounted on a block movable horizontally by means of a hydraulic cylinder, in the same way as the roughing rolls. The pressure on the piston is 100 tons. The centre roil is fixed on the end of the shaft. The two rolls are worked by toothed gearing, and the speed is 60 revolutions per minute. The third miil, which is used for gun hoops, is similar to the rough-rolling tyre miil, excepting tliat the roil grooves are of the same type as those of the tyre-finishing rolls.