The throttle-valve, shown in Fig. 22, consists of a flat seat. circular in form, having a semicircular opening through it, and a valve whose face is a counterpart of the valve-seat, and by means of a semicircular bevel-gear on its upper surface and a pinion it can be rotated half-way around. When the valve is set in such a position that the two openings coincide, there is a straightway passage for the steam, and when turned in the reverse way the valve is closed.
The Ri-CC Automatic Engine.—Fig. 23 illustrates the Rice tandem compound-engine, one of several styles built by the John T. Noye Mfg. Co., of Buffalo. N. Y. It is of the same gen eral construction as the Rice single-cylinder engine. Both valves are operated by the same governor through the same eceentric-rod. The valves can be set independently of each other, the low-pressure valve being arranged to admit of considerably more travel than the high pressure.
The valve of the Rice engine is shown in Fig. 24. It is balanced from all pressure higher than the exhaust, the steam being admitted from the inside and allowed to nearly surround the entire valve. The valve can be easily operated with one hand upon the smooth valve-stem, when under full pressure of steam. The relief-valve is in the form of a steam tight piston, which rests on shoulders even with the valve (not on the valve itself), and is kept in place by a steel spring at the hack. Fig. 21 is a section through the main bearing, showing the Iwo bearings in a single casting. with the overhang at each end nearly halaneed and redneed to a minimum by means of offset hubs. Fig. 26 is another view of the bearing, showing the ItiibbilA liners. These are all east in an iron mold, so that each one is an exact duplicate of ever• other cue, and eau he quickly removed and replaced. The liners are used in the main-bearmg, the emss-Itentl, and the crank-piu. In the two hitter places they are bedded in brass boxes, which mire free to expand. Thus, should the pin heat, the brass, having a greater expansive power than steel or iron. and being free, will expand and loosen the fit, instead of tightening it, as is the case when bound with an iron band.
The Ball Engine.—Fig. 27 represents a double-tandem condensing triple-expansion engine made by the Ball Engine Co., Erie. Pa. This engine is built in sizes of 300, 400, 500, 600, and 700 horse-power.
Fig. 28 shows a section through the steam-chest and valve of the Ball engine. Fig. 20 shows three views of the construc tion of the valve. It consists of two parts, which are con nected by telescopic sleeves, allowing each half to adjust it self to its seat. The sectional view shows the manner• of steam distribution to the cylinder, and the operation of the valve. This double-faced valve is held in constant and steam-tight contact with an upper and lower horizontal valve-face, whose areas, in proportion to the surface of the valve, are identical. The live steam enters the upper side of the valve, and. being inclosed by the telescopic shells, presses the faces apart with relation to each other. and against the port or passage-way sur face, as shown. By this arrangement there is only a sufficient percentage of the whole area of each valve subjected to unbalanced pressure to instm•e steam-tightness.
The Ball & Wood Cross-Compound Engine.—Fig. 30 shows a perspective view of a cross compound engine built by the Ball & Wood Co., of Elizabeth, N. J., for the Newark Electric Light Co., of Newark. The size of the low-pressure cylinder is 13 in. and the high-pressure 25 in., with a stroke of 16 in. It is rated at 300 horse-power.
The _McIntosh & Seymour Engine is shown in Fig. 31. Fig. 32 shows a sectional view of the valve and cti•linder.
The general design of the engine presents no radically novel features except in two vital points, the valve and governor. The frame is made very massive and rigid by heavy internal ribbing. The lower guides are separate pieces, though supported throughout their entire length by the frame. The main bearings have cheek-pieces for taking up horizontal wear. Each one of these is backed np solidly for its entire length by a taper-wedge, and can be ad justed by elevating the wedge with screws provided for thatpurpose. The main caps can be removed entirely without disturbing the cheek-pieces or wedges, and the latter can then be removed without disturbing the shaft, exposing over one half of the circumference of the journal. The cross-head is of the locomotive type and is made of one piece, including cross head pin. The construction of the valve and valve-seat is shown in the sectional views through cylinder and steam-chest, in Fig. 32. The valve proper is an ordinary piston-valve.