HAMMERS, POWER. No important improvement has been made in steam-hammers during the last ten years, but a notable event in the history of steam-hammers is the erection and completion in 1891 of the largest ham mer in the world, at the Bethlehem (Pa.) Steel-Works. A description of this enor mous hammer is given below : The hammer stands in the center of a very large building, and over a year has been spent in its construction. A pit 58 ft. X 62 ft. was dug for the foundation, and on walls 30 ft. high the anvil stands. To give the foundation a certain elasticity, a layer of twenty steel slabs on top of Ohio white-oak timbers was made, and the surface was ren dered perfectly smooth. The anvil was built by depositing on top of the steel slabs and their timbers twenty-two blocks of solid cast iron. The average weight of these blocks is 70 tons, and the entire weight of the mass of iron and steel forming the anvil and foun dation is nearly 1,800 tons. The anvil foun dation and the hammer foundation are en tirely separate and independent of each other. The hammer itself is a majestic looking structure, rising to a height of 90 ft.
The housings, composing the first section, from a large arch. These housings are each composed of a single 120-ton casting. The width of the hammer is 42 ft. The housings, whose bases are 10 ft. by 8 ft., are firmly clamped into the foundation-walls at each side, and are fastened to washers lying beneath the walls at a depth of 33 ft.
Around the entire periphery of the hammer, to the height of the first section, 15 ft., is a platform of levers controlling the working of the machine. Above is another arch of hous ings, which weigh 80 tons apiece. This arch is capped by a steam-chest, a casting of 65 tons. Here, at the height of some 70 ft., is another plat form. On the top of this steam-chest, and in the center of this platform, is superadded the huge cylinder, 24 ft. high, with an internal diameter of 79 in. In the zenith of the arch is the large tup or rain of the hammer, an enormous piece of metal about ft. long,
10 ft. wide, and 4 ft. thick, the weight of which is almost 100 tons. Connected to this is the piston-rod, of steel, 40 ft. long and 16 in. in diameter. At the bottom of the tup and keyed to it is the die-hammer. This is a large, square block of iron, faced with steel, and is the piece which will strike the metal that is being forged. The piston-rod has a stroke of 161 ft., and the weight of tup, piston-rod, and piston aggre gates 125 tons.
Jenkins' Upright Cushioned Helre-Hammer.—Fig. 1 shows a power-hammer made by Jen kins C Lingle, of Bellefonte, Pa.
The blow or stroke is cushioned by means of four rubber cushions, two of which are placed above and two below the fulcrum bearing the helve. This fulcrum is made in the form of a cross-head, to which the head is pivoted ; the cross-head being free to move up and down as the strain comes on the helve. The makers claim that a cushion placed directly at the ful crutu is more effective than when placed at a distance from it. as every inch farther from the fulcrum requires proportionately more movement of the cushions to produce the same result on the rain. The end of the helve joining the rain is wood, and simply enters into an opening provided in the ram.
The _Bradley Upright Cushioned Strap-llammer, shown in Fig. 2, has a helve of steel, in an arched form, with the head or rain carrying the die sustained and operated by an endless leather strap, suspended between spool-shaped bearings, and extending length wise of the helve. This device allows of the utmost opening between the dies, either at rest or in action, and its elasticity and freedom of motion illere:1,0S the throw of the rain, while at the same time the stroke of the eccentric is shortened. The hammer is operated by an eccentric at the rear, connected by it pitman to the saddle or oScil tutor which carries the helve, and by this helve motion is imparted to the head or ram. In this way the blow is made to imitate the action of a hand-hammer.