GB473495A - Improvements in or relating to reciprocating steam engines - Google Patents

Abstract

473,495. Reciprocating steam engines. WALLIS, A. May 14, 1936, No. 13696. [Classes 122 (ii) and 122 (iii)] A compound or multiple expansion steam engine of the kind wherein the high and low pressure cylinders are concentrically arranged one within the other, is provided with steam chests at opposite ends of the double cylinder and at right-angles to the axis of that component, the valves thereof being arranged for movement in opposite directions in timed relation with the movement of the pistons. A block 1 is provided with a central cylinder 2 wherein is used a high pressure piston 3, and piston-rod 16, the surrounding portion being provided with an annular low pressure piston 5 which has two diametrically disposed piston-rods 21. The piston-rods are coupled by connecting rods 19 and 24 respectively with a two-throw crank-shaft, roller bearings 28 and 13 being used for the big ends and main bearings. Upon the main casing 1 is a bracket 59 having a shaft 58 carrying a double arm 43. These arms are connected by adjustable rods 45 with the piston valves disposed in cylinders formed in the top and bottom covers 8, 9 of the block, and having therein ports communicating with passages leading to the respective cylinders together with connections to the inlet and exhaust steam pipes. Oscillation of these valves is effected by an arm 57 keyed to the shaft 58 and coupled by rod 56 with the cranked lever 55 which in turn is connected by a rod 54 with an eccentric rod 50 mounted upon an eccentric 49 on the main crank-shaft. The head of the eccentric rod 40 is formed by the roller 51 which is adjustable in a slot 53 in a disc 52 which can be adjusted for varying the cut-off or for reversing.