GB1412853A - Control systdm for an automatic power transmission mechanism - Google Patents

Abstract

1412853 Variable ratio gearing; valves FORD MOTOR CO Ltd 2 April 1973 15684/73 Headings F2D and F2V [Also in Division F1] A variable ratio gearing (e.g. a Simpson gear) driven by an internal combustion engine 12 with an inlet manifold and an exhaust manifold, has its ratios changed by fluid pressure operated clutch and brake means 32, 56, 60, 62 controlled by at least one shift valve 90, 92 fed with fluid from a transmission driven pump 30 at a pressure controlled by a main regulating valve 78, there being fluid pressure connections 100 between the shift valves 90, 92 and valve 78 respectively and an assembly including a throttle valve 98, 98<SP>1</SP> adjusted by an actuator 108, 108<SP>1</SP>, Fig. 3, comprising two spaced diaphragms 120<SP>1</SP>, 152<SP>1</SP> of different sizes, joined together and to a rod 146<SP>1</SP> adjusting the valve, their being two chambers 158<SP>1</SP>, 162<SP>1</SP>, one between the diaphragms, which have independent connections 160, 164 to the engine inlet manifold, to move the diaphragms against a spring 134<SP>1</SP>, one of the connections 160 being interruptable (e.g. by a control 166 to connect it to atmosphere or to the exhaust manifold pressure). To compensate for barometric pressure, the actuator 108<SP>1</SP> may have a sealed annular chamber 174, formed by co-axial bellows 170, 172. Other forms of the actuator are also described, Figs. 2, 4 to 6 (not shown). The interruption of the supply of inlet manifold pressure may be effected by connecting the respective chamber to the engine carberettor adjacent the throttle valve so that this chamber is only subject to inlet manifold vacuum pressure when the throttle valve is closed or nearly so. This is described in Figs. 7 and 8 (not shown) together with apparatus to provide exhaust gas recirculation and spark delay (see Division F1).