To the shaft, A, are keyed the coupling disks, Q, which are cast solid at a portion of their circumference situated at 180° with respect to the parts, A², of the cranked shaft, the object of this being to balance the latter as well as a portion of the connecting rod, D.
The shaft, A, also receives the eccentric, E, of the slide valve, the rod, e, of which is jointed to the slide valve rod through the intermedium of a cross-head, e¹, analogous to that of the pistons, and which, like the latter, runs on guides held by the support, b.
The two pistons, p and P, are mounted very simply on the rod, T, as shown in Fig. 1, and slide in cylinders, c and C, whose diameters are respectively equal to 270 and 470 millimeters.
The slide valve box, F, is bolted to the cap-piece, B¹, as seen in Fig. 4. As for the slide valve, t, its arrangement may be distinguished in section in Fig. 2. Its eccentric is keyed at 170° so as to admit steam into the small cylinder during the entire travel, which latter is 470 mm.
To permit of the expansion beginning in the small cylinder, Mr. Farcot has added a sliding plate, t¹, which abuts at every stroke against the stops, s. These latter are affixed to the rod, S, whose lower extremity is threaded, and which may be moved vertically, as slightly as may be desired, through the medium of the pinions, S¹, when the hand-wheel, V, is revolved. A datum point, v, and a graduated socket, v¹, allow the position of the stops, s, and consequently the degree of expansion, to be known.
Steam is introduced into the small cylinder through the conduit, i, and its passage into the large one is effected through the conduit, f. The escape into the interior of the frame is effected, after expansion, through the horizontal conduit, h. The pipe, H, leads this exhaust steam to the open air.
The pipe, I, leads steam into the jacket, C¹, of the large cylinder, this latter being provided in addition with a casing of wood, C², so as to completely prevent chilling.
The regulator, R, is after the Büss pattern, and is set in motion by a belt which runs over the pulleys, a and a¹. It is mounted upon a distributing box, R¹, to which steam is led from the boiler by the pipe, r¹. After traversing this box, the steam enters the slide valve box through the pipe, r², its admission thereto being regulated by the hand-wheel, R², which likewise serves for stopping the engine.
The cocks, x, are fixed at the base of the uprights, B, for drawing from the frame the condensed water that has accumulated therein.
The lubricating apparatus, V, which communicates, through the tube, u, with the steam port, r¹, permits oil to be sent to the large and small cylinders through the tubes, u¹ and u².