GB443957A - Improvements in or relating to reversible internal combustion engines - Google Patents

Abstract

443,957. Starting, stopping, and reversing ; relief valves. WANS, O., and RUSTON & HORNSBY, Ltd., Sheaf Iron Works, Waterside South, Lincolnshire. Aug. 27, 1934, No. 24565. [Classes 7 (ii) and 7 (v)] In a reversible engine, the working or combustion or cylinder chamber b is provided with a loaded outwardly-opening relief valve c which is provided with pneumatic means for partly relieving the load on the valve during the stopping period, so that the valve then opens under the pressure of the air in the cylinder, allowing air to be forced into a receiver o against the pressure therein during the instrokes of the engine piston, but closes during the outstrokes of the piston. As shown, each cylinder head a is provided with a passage d leading to a socket fitted with a valve casing e having a guide sleeve f for the spindle h of the mushroom-type relief valve c. A heavy spring k is interposed between a screwed plug l in the end of the casing and a piston i bearing against a flange j on the spindle h. Between the head of the valve c and the piston i, a conduit n leads to the air receiver o. Two shut-off valves p, q arranged in series in the conduit n are controlled by cams r, s on the shaft of a hand wheel u. In one position of the hand wheel, for normal running, the valve p shuts off communication with the air receiver and the valve q opens communication between the relief valves and the atmosphere; the relief valves are then fully loaded by the springs k and open only under excessive pressure in the cylinders. In a second position of the hand wheel, for starting or reversing by means of air in the receiver o, the valves p, q provide through communication between the receiver o and the valve casings e to relieve the pressure of the springs k. A chamber y between the valves p, q is connected by a manifold v to cam-actuated distributing valves 1 leading to inwardly opening starting valves z on the cylinder heads, and the cams controlling the valves 1 are adjustable for " forward " and " reverse " starting. To stop the engine suddenly while running " ahead," the cams are set as for " reverse starting and the hand wheel u is set to open the valves p, q; air from the receiver is then admitted to the cylinders on the instrokes of the pistons, bringing the engine to rest and then reversing it, while the relief valves c open when the pressure in the cylinders exceeds that in the receiver o, returning the pressure air to the receiver. In modifications: (1) the valve p is replaced by two valves leading to two air manifolds each supplying a group of the starting-air control valves ; (2) the valves p, q are replaced by a single two-way valve ; (3) the valve q is omitted and pressure air in the pipe n escapes gradually after the stopping period.