Patent GB-443943-A (GB)
Title: Improvements in diesel type locomotives
IPC: B61C9/08
Filed: 1935-07-24
Abstract: 443,943. Diesel locomotives. HOCKE, E., 13, Via Carlo Barabino, Genoa, and ZARLATTI, F., 70. Via Montebrianzo, Rome, both in Italy. July 24, 1935, No. 21041. Convention date, July 26, 1934. [Classes 79 (i) and 79 (v)] [See also Group XXVII] In a locomotive propelled by a Diesel engine directly coupled to the wheels, the engine is supercharged at low locomotive speeds by an additional air supply which, together with the fuel supply, is automatically controlled in accordance with the locomotive speed, the additional air being decreased as the speed increases up to a certain limit ; beyond this limit the additional air is used only as scavenging air. In the construction shown the cylinder or cylinders 1 of a Diesel two-strokecycle engine drive the locomotive axles in the usual manner and are connected by a pipe 6 to air-pump cylinders 7 which supply the air for working the engine at normal speeds. An auxiliary Diesel engine 8 drives a compressor 9 for supplying air through a reservoir 10 to the pump 7 and also drives a blower 14 supplying the additional air to the engine through a pipe 15 and a rotary valve 4 driven from the locomotive wheels. The position of the valve 4 relative to the engine piston 2 is varied by a centrifugal device in accordance with the speed of the locomotive. Thus, at low speeds (say 100 R.P.M.) the valve 4 is open when the piston 2 has just covered the exhaust port 18 Fig. 2, and at higher speeds (say 200 R.P.M. or over) the valve 4 is closed as the piston covers the exhaust port, Fig. 3. During normal running, with the valve 4 timed as shown in Fig. 3 air from the blower 14 can only be used for scavenging. As the locomotive speed falls the valve opens earlier as shown in Fig. 2 and additional air (and fuel) are supplied to the cylinder so that more power is developed. To start the locomotive the auxiliary engine 8 is first started, by electrical or other means, and drives the compressor 9 to charge the reservoir 10 and supply air to the pump 7 acting as a motor to drive the locomotive. The drive to the blower 14 may be disconnected by means of a clutch 13, Fig. 2. As the locomotive starts the exhaust from the pump or motor 7 passes through the pipe 6 to a chamber 19 and through a port 17 to the cylinder 1 thus supplying air to the cylinder to enable it to work as an engine when the locomotive speed is sufficient. As soon as the engine 1 is working normally, a valve 21 admitting compressed air to the cylinders 7 is closed and an inlet valve 23 is opened so that these cylinders now act as pumps driven from the locomotive wheels and supplying the combustion and scavenging air for the engine 1. The cylinders 7 may be used as air motors to assist in driving the locomotive at any time when greater power is desired, the valve 23 being shut and 21 being opened. At high speeds the clutch 13 may be disengaged so that the blower 14 is not driven; air then passes from chamber 19 through a non-return valve 22 to chamber 20 and thence through valve 4 and port 5 to the cylinder 1, for scavenging purposes, so that at these high speeds the scavenging air passes through both ports 17, 5, the port 17 alone being insufficient. A non-return valve 16 prevents air from passing from chamber 20 into pipe 15 leading to the blower.