Abstract: A hydrokinetic, multiple-ratio torque converter transmission mechanism having a simplified valve system with variable force solenoids for controlling line pressure as well as ratio shifts, a simplified clutch-and-brake hydraulic circuit with separate fluid pressure feed and exhaust passages, a common accumulator arrangement for controlling each of two ratio upshifts and a simplified brake servo mechanism having the dual function of establishing a torque reaction point for each of two distinct transmission ratios.

Abstract: An automatic transmission mechanism having multiple ratio gearing and clutch and brake elements operated by fluid pressure operated servos for changing speed ratio in the transmission and a controller for actuating and releasing the clutches and brakes in response to operating demands determined by sensed variables such as vehicle speed, engine torque, manual valve position, transmission turbine speed, and engine temperature, and means for achieving improved control of a synchronous downshift event by electronically regulating the exhaust pressure from an off-going friction element of the clutch and brake structure, thus controlling the torque-carrying capacity of that off-going element during the downshift interval.

Abstract: A control system for an automatic transmission including pressure actuated clutches and brakes adapted to control ratio changes in a planetary gear system comprising multiple function shift control valves disposed between a pressure source and pressure actuated servos for the clutches and brakes and solenoid valves under the control of a microprocessor for developing solenoid valve signals that control actuation of the shift control valves, the shift control valves being interactive, one with respect to the other, to effect multiple shift functions in response to selective actuation of the solenoid valves whereby the number of solenoid valves required is reduced and the hydraulic circuitry for the valve elements is simplified.

Abstract: A control system for a four speed ratio automatic transmission wherein a ratio change from a first speed ratio to a second speed ratio is effected by a 1-2 shift valve that activates a fluid pressure operated second ratio clutch and a ratio change from a third speed ratio to a fourth speed ratio is effected by a 3-4 shift valve that activates a fluid pressure operated fourth ratio brake, both the clutch and the brake having an independent pressure accumulator and an accumulator pressure regulator valve that is common to both accumulators for developing unique accumulator control pressures whereby the system may be calibrated for maximum shift smoothness for both 1-2 upshifts and 3-4 upshifts.

Abstract: A valve which is normally biased in a first operative position is provided with control means including a first pressure fluid orifice for directing such fluid to a control member for changing the operative position of the valve. The device further includes a housing which communicates with said first orifice and which has a bleed orifice assembly having a second or bleed orifice. The bleed orifice assembly further includes a bleeder valve seat and a piezoelectric crystal mounted adjacent thereto so that upon bending of the crystal, as by energization thereof, pressure contact is made with an intermediate valve element. The valve element is in turn adapted to move against the bleeder valve seat to close the same. When the bleed orifice assembly is closed in the manner above described, pressure is permitted to build up in the first orifice to activate the valve.