GB446239A - Improvements in valves and valve gear for fluid-pressure engines - Google Patents

Abstract

446,239. Engine valves and valve-gear. WORTHINGTON-SIMPSON, Ltd., Lowfield Works, Newark-on-Trent.-(Worthington Pump & Machinery Corporation; Harrison, New Jersey, U.S.A.) Nov. 28, 1935, No. 33005. [Classes 122 (ii) and 122 (iii)] In a combined fluid-actuated and mechanical valve gear for a reciprocating, fluidpressure pump, the main piston valve controls passages for the main steam and exhaust, and also controls passages for an auxiliary starting-steam supply. The main and auxiliary passages are connected by valve-controlled connections which constitute adjustable cushioning means. The pilot valve is flat, faces outwardly' and slides upon and controls ports in the inner surface of a cover plate for the valve-chest. The tappetoperated pilot valve 7, Fig. 1, controls a transversely-moving piston valve 6 in the chest 4. Steam passes from the supply 10, Fig. 4, into the auxiliary starting-passages 11, 12 and moves the piston to open the port 14 of the cylinder main passage 15. Steam passes thereto through the annular groove 18 and ports 19 in the valve. Steam passes to the right-hand end of the main cylinder through the bore of the valve 6 and ports 20. The centre annulus of the valve controls the exhaust from the cylinder ends through passages 15, 23. The auxiliary valve 7 is shown supplying steam to the passage 27. The valve controls separate admission and exhaust passages to and from the ends of the chest 4. The movement of the main valve to the left connects the passage 15 to exhaust, and the starting passage 35 to steam through the annular recess 34 fed from the interior of the valve, and the right-hand annulus in the valve. The trapped cushioning-steam passes by way of the auxiliary starting-passages and valves 38, 41 to the main passages. The valve 7 slides upon the cover 26. In a modification, the starting-steam passes from the righthand end of the valve-chest to the left-hand end of the main cylinder, and the steam supply for the left-hand, main-steam passage passes from the right-hand end of the valvechest through the valve to the passage. Similarly during the return stroke, the starting- steam passes from the left-hand end of the main-valve chest to the right-hand end of the main cylinder. In a further modification, the main and auxiliary valve-chests are arranged parallel to the main cylinder, and the auxiliary valve chest has independent inlet and outlet connections. Steam passes to the end of the main cylinder through main steam passages and auxiliary starting-passages connected to the main passages by screw-downvalve, controlled passages which control the exhaust of cushioning-fluid. Steam is supplied to the main valve-chest by a pair of steam passages, and the main valve has a pair of annular grooves for controlling the main admission and exhaust. The piston valve has a hollow interior and also a pair of ports connected therewith which connect with either of the main supply ports or with the starting- passages. The pilot valve has a central, auxiliary, steam supply.