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The annexed engravings represent an improvement in the valves of oscillating engines, invented and patented by Wm. M. Smith, ol" Washington, D. C. Oscillating engines possess the advantage of occupying but little space, are generally light, compared with others, and simple in construction. One objection which thej' have heretofore been found to present, has been the difficulty attendant upon the admission and discharge of the steam, and another difficulty has been the friction occasioned by the steam trunnions upon which the engine oscillates, being too tightly bound in order to prevent the escape of steam. This occasions unequal wear in the trunnions and stuffing box of the piston rod, and also detracts from the power of the engine. The object of the invention is to remedy these defects. Figure 1 is a side view of the engine with a face view of the steam trunnion. Fig. 2 is an inside or face view of the valve, and tig. is a horizontal section of the valves and steam chest as connected with the trunnion of the engine. The trunnion, , of the cylinder is made as large on the face or end as convenient to admit of long radial passages being made through it; b is a short cylindrical steam chest, which is turned on the interior and firmly bolted to the lower half of the plummer block, i, forming a cover or cap to the end of the trunnion ; in this steam-chest, 6, is a piston valve, c, the face ot which is ground, and fits against the'end of the trunnion ; this valve is fitted with metallic or other packing on its periphery, where it touches the sides of the cylindrical steam chest, and is stationary, thereby dispensing with all valve gear. The steam alternately enters and exhausts to and from either side of the engine piston by the oscillating motion of the trunnion, a, which is made with suitable steam ways in it. The action is as follows :The steam enters through the opening, d, of the valve and the exhaust escapes through the concave, e, to the pipe,_/, which passes through a stuffing-box in the centre of the steam-chest cover, g. To reverse the engine, the valve is turned halt round by the lever, A, last on the exhaust pipe, f; steam is admitted to the cylindrical chest, fc, by a pipe, S, and presses upon the back of the valve to keep it tigh. The advantages of this form ot valve will be apparent by an examination of its simple structure and mode of operation. For further information concerning rights c, apply to the inventor.
