Abstract: A multiple-ratio automatic transmission comprising a first multiple-ratio gear unit and a second simple planetary gear unit arranged in series in a torque flow path, each gear unit having a reaction brake that can be selectively activated and deactivated to effect a ratio change as the first gear unit is upshifted and the second gear unit is downshifted, ratio changes in each gear unit being effected by pressure-operated clutches and brakes, the brakes having opposed pressure-apply and pressure-release chambers. Separate exhaust flow paths are provided for a reaction brake release chamber and for a companion pressure-operated clutch. A pressure modifier valve circuit is provided for increasing the rate of response to a command for applying and releasing the clutch.

Abstract: A multiple ratio automatic transmission control system for an automotive vehicle comprising a multiple ratio gear set and a simple planetary gear set arranged in series. The control system has multiple control modes including an automatic control mode in which upshifts and downshifts between adjacent ratios are achieved by engaging and releasing friction clutches and brakes in the simple planetary gear set and in the multiple ratio gear set and wherein a manual shift control mode includes a select-shift control. Engine braking is available in each gear for both operating modes. In the select-shift manual control mode, a particular gear can be chosen by the operator for continuous single-ratio operation. The control system includes variable force solenoids that are multiplexed in combination with pressure modulator valves for achieving each operating mode.

Abstract: A control valve system for a multiple ratio transmission with a high ratio clutch and an intermediate ratio brake servo including a first solenoid operated valve that generates a control pressure for intermediate servo apply and a second solenoid operated valve that generates a control pressure for intermediate servo release and for the high clutch. The second and the first solenoid valves control the intermediate servo stroke phase and the second solenoid valve controls, either closed or open loop, the deceleration of a high clutch drum. Pressures electronically controlled by the solenoid valves are distributed to the clutch and brake servo pressure chambers by a shift valve configuration, whereby high quality upshifts and downshifts are achieved.