GB190502889A - Improvements in Oscillating Steam and Air Engines. - Google Patents

Abstract

2889. Dawe, C. Feb. 13. Oscillating e n g i n e s ; valves and valve-gear.- Steam is admitted in an oscillating engine by a piston valve contained within an oscillating sleeve or seat which acts as the exhaust valve. This sleeve is actuated by tappets carried by a reversing frame supported by the trunnions. The admission valve E is secured to the valve spindle K by a screw, and takes steam at the centre, is provided with helical edges, and may be revolved by the toothed gearing M to vary t h e expansion. There are separate admission and exhaust ports. The latter enter the cylinder at some distance from the ends. If desired, single ports may be used. These ports are parallel to the edges of the slide valve. If single ports are used, the sleeve C is modified to suit this arrangement. The means for actuating the sleeve is shown in Fig. 8. The spindle F, Fig. 1, is provided with lugs engaging ,the sleeve C and a shoulder bearing against the valve-chest cover D. Attached to the top of the spindle F are plates G which engage with bars TV, UW, Fig. 9, in such a way as to rotate the sleeve. For reversing, the frame J is moved over until the plates engage the bars wv, ut. The frame is inoperative in the central position. In a non-reversible engine, one set of fixed bars is used. To the plate are attached pins x which may operate the boiler-feed and liquid-fuel pumps y. The eccentric rod moves a pin L formed in one with a guide-block sliding in a groove in the cylinder. There is lost motion between the pin L and rod H. The toothed gearing M may be actuated by a flexible shaft upon which a pulley may be placed and wires wound thereon to actuate the suction valves of the boiler feed and liquid-fuel pumps. One part of the admission valve is made to cover the ports completely, and is provided with a shallow narrow groove b. The steam and exhaust passages may pass through flexible pipes instead of the trunnions. When the valve-edges are made flat, the valve-rod is keyed to the boss of the pin L. A modification of the ports is described suitable for a single-acting engine. According to the Provisional Specification, a single disk provided with pins may be used instead of plates G, and the pins X may also work the lubricating-oil pumps, the air-pumps for the condenser, and air-supply pumps for the furnace. Instead of lost motion taking place between the washer and toothed wheel as described, it may take place between the valve and valve-spindle. Instead of a toothed wheel to turn the slide-valve spindle, a lever and notched plate may be used. The cut-off edges of the slide valve may be stepped or the valve made with detachable rings.