Patent GB-649292-A (GB)
Title: Improvements in or relating to multiple cylinder internal combustion engine control means
IPC: F02D17/00
Filed: 1948-05-18
Abstract: 649,292. Regulating. BENDIX AVIATION CORPORATION. May 18, 1948, No. 13449. Convention date, May 29, 1947. [Classes 7(iii), 7 (iv) and 7 (vi)] The intake and exhaust valves of some of the cylinders of a multi-cylinder engine are actuated by hydraulic tappets which may be rendered inoperable to put their associated cylinders out of action. Each tappet comprises a telescoping cylinder and piston 26, 41, Fig. 2, forming a pressure space 57 supplied with hydraulic fluid past a non-return valve 62 from a reservoir 56 fed through a passage 54 from supply passages 38, 40 in the casing 30. The piston 41 carries a spring-closed poppet valve 66 which can be held open by a lever 82 actuated by a cam 78 or 83 on a rotatable rod 80, to allow the fluid to escape from chamber 57 and prevent the tappet opening its associated cylinder valve. As applied to a six-cylinder engine arranged into two sets of main and auxiliary cylinders, rotation of the rod 80 to put the auxiliary cylinders out of action first causes cams 83 to render the intake valve tappets inoperative and then the cams 78 to render the exhaust valves inoperative. The main and auxiliary cylinders are fed through separate intake manifolds 100, 102. Fig. 8, by a twin carburetter 110, each section 118, 118<SP>1</SP> of which comprises a suction controlled power enrichment jet 149 and an accelerator pump 158 actuated by the throttle valve control mechanism. When operating on all cylinders a spark advance device 198, Fig. 9, comprising a diaphragm 204, is actuated by the suction adjacent the throttle valve 129, transmitted through pipe 196, modified by an air bleed 220 leading through a valve 224, held open by a spring-loaded member 228, and pipe 222 to the carburetter air intake. When the auxiliary cylinders are put out of action, a solenoid 180, Figs. 8 and 9, is energized to raise the member 228 and close valve 224. increasing the suction in the chamber 200 to correct the spark advance. Energization of the solenoid 180 also puts the acceleration pump 158<SP>1</SP> out of action. In a modification the bleed valve 224 is controlled by the suction at the throat of the Venturi in the carburetter auxiliary section 118<SP>1</SP> and the diaphragm 204 may be operated by the suction of the Venturi in the main section 118. The rod 80, Fig. 2, is operated through gearing by a lever 94, Fig. 13, actuated by solenoids 90, 88, controlled by a double switch 324 spring biased towards the position in which solenoid 88 is energized. At starting, closing of the ignition switch 310 energizes a relay 314 to close a switch 318 and current passes through switch 324 to solenoid 88, which moves the rod 80 to place all the cylinders in operation. The circuit of a relay 360 for actuating the switch 324 to energize the solenoid 90 to operate the rod 80 to cut out the auxiliary cylinders contains a hand switch 330 and a thermally operated switch 332 which remains open until the engine warms up. After closing of the switches 330, 332, movement of the throttle valve to idling position closes a switch 340, which energizes a relay 344 to close a switch 350, and current flows through lead 354 and normally closed switch 356 to the relay 360 to cut out the auxiliary cylinders. A diaphragm 374 is actuated, when the intake manifold vacuum is above a predetermined value. to close a switch 376, which energizes a relay 384 to close a switch 385 and complete an alternative circuit for the relay 360 to maintain it energized when the switch 340 is opened on opening the throttle valve. A switch 402 is closed by centrifugal governor 20 above a certain speed and if current is being supplied to the relay 360, due to either of the switches 340, 376, being closed, current will flow from the point 400 through the relay 384 and switch 402 to earth, so that the switch 385 is closed and will remain held closed if the switches 340, 376 are thereafter opened, as long as the speed remains above the predetermined value. If the speed or intake manifold suction drop while the throttle valve is open, i.e. switch 340 open, the relay 360 is deenergized and solenoid 88 brings the auxiliary cylinders into operation. The switch 356 is opened to de-energize the relay 360 when the throttle valve is moved to the wide open position. The switches 340 and 420 may be omitted, or the relays 344, 360 and 384 may be arranged so that the switch 376 cannot close the circuit of relay 360 unless either switch 356 or 402 is first closed.