Ford Motor Company Limited

Stanley D Rosen

Timothy A Droste

Scott Raymond Crandall

William D Ross

A torque converter lockup clutch is pressurized from a source of regulated line pressure through a lockup clutch control valve, which directs pressure to either of two passages to apply and release the clutch. The control valve is supplied with control pressure from a solenoid-operated valve that produces high and low fluid pressure states corresponding to commands to engage and release the lockup clutch. A second control pressure, opposing the effect of the solenoid-operated control pressure, is applied to the control valve when the vehicle operator manually selects certain gear ratios, principally the lowest forward and reverse gear ratios. A line pressure regulator valve produces line pressure whose magnitude is proportional to the magnitude of a control pressure representing a commanded engine torque output. The pressure produced when the vehicle operator manually selects low gear ratios is applied also to the main regulator valve, which produces a line pressure that varies linearly with engine torque control pressure and increases, in comparison to line pressure at all other gear ratios, when low gear ratios are selected. A converter regulator valve limits the level of line pressure directed by the main regulator valve to the converter clutch control valve.

Torque converter lockup clutch control for an automatic transmission

A manual valve alternately connects a source of regulated line pressure to a forward drive passage and to a reverse drive passage. A shift valve alternately connects these passages to an input port of a coast clutch valve in accordance with the state of a solenoid-operated valve. A control port of the coast clutch shift valve is pressurized either from a manual valve, when the gear is selected manually by the vehicle operator, or from the source of variable pressure control by operation of a variable force solenoid. In accordance with the control pressure, the coast clutch shift valve either connects its input to a line connected to the coast clutch or vents the input to a drain passage in the shift valve.

Coast clutch control for multiple speed automatic transmission

Automatic transmission brake-neutral control circuit

A control valve system for an automatic power transmission mechanism having planetary gearing defining plural torque delivery paths comprising fluid pressure servo operated brakes and clutches and a vehicle speed sensitive servo release shuttle valve which cooperates with the timing valve circuit to establish a first timed relationship between the application and release of the servos during a ratio change from the high ratio to an intermediate underdrive ratio at a relatively high speed and for establishing a different timing relationship between those circuit elements during a corresponding ratio change at a lower vehicle speed, the rate of application of the underdrive ratio servo during a ratio change from the lowest ratio to an intermediate underdrive ratio being calibrated independently of the calibration required for a ratio change from the high speed ratio to the same intermediate underdrive ratio.

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Southfield, MI, United States of America

Stanley D Rosen