Abstract: A system for controlling hydraulic fluid supplied to a torque converter of an transmission includes a torque converter including a chamber containing an impeller and a turbine, and a bypass clutch having a variable torque capacity, a source of variable control pressure, a latch valve changes in response to the variable control pressure alternately between an unlatched state, wherein the latch valve produces a low pressure output, and a latched state, wherein the latch valve produces a high pressure output, a first valve for limiting hydraulic pressure in the chamber alternately at two magnitudes of pressure in response to the low pressure output and the high pressure output, and a second valve responsive to the variable control pressure for regulating a magnitude of hydraulic pressure that actuates the bypass clutch and changes the torque capacity of the clutch.

Abstract: A system for controlling hydraulic fluid supplied to a torque converter of an transmission includes a torque converter including a chamber containing an impeller and a turbine, and a bypass clutch having a variable torque capacity, a source of variable control pressure, a latch valve changes in response to the variable control pressure alternately between an unlatched state, wherein the latch valve produces a low pressure output, and a latched state, wherein the latch valve produces a high pressure output, a first valve for limiting hydraulic pressure in the chamber alternately at two magnitudes of pressure in response to the low pressure output and the high pressure output, and a second valve responsive to the variable control pressure for regulating a magnitude of hydraulic pressure that actuates the bypass clutch and changes the torque capacity of the clutch.

Abstract: A system for directing line pressure alternately to a forward drive circuit and a reverse drive circuit includes three solenoid-operated select valves that direct pressure from a line pressure source to a reverse drive select valve, a forward drive select valve, reverse drive select valve, a range select switch assembly, pressure switches, and two coaxial range control valves. The two drive select valves are interconnected to form a hydraulic latch whose outputs are connected to the range control valve such that either the forward drive friction elements are pressurized, the reverse drive friction elements are pressurized, or none of the friction elements are pressurized.

Abstract: A hydraulic latch for directing line pressure alternately to a forward drive circuit and a reverse drive circuit includes three solenoid-operated select valves that direct pressure from a line pressure source to a reverse drive select valve, a forward drive select valve, and two coaxial range control valves. The two drive select valves are interconnected to form a hydraulic latch whose outputs are connected to the range control valve such that either the forward drive friction elements are pressurized, the reverse drive friction elements are pressurized, or none of the friction elements are pressurized.

Abstract: Two solenoid-actuated shuttle valves selectively direct hydraulic fluid from a line pressure source to a clutch and brake servo or direct fluid from the clutch and servo to a low pressure drain, in accordance with the combined states of the solenoids. The system includes several orifices, which in combination control the rate of flow between the pressure source and the friction elements. The orifices control also the flow rate in the system between the friction elements and drain ports. Accumulators are located in the system between the shuttle valves and the friction elements. An arrangement of check valves and orifices located between the shuttle valves and the accumulators establish the rate of flow between each of the accumulators and the associated friction element.

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: The hydraulic control circuit for an automatic transmission includes solenoid-operated clutch pressure valves which selectively connect line pressure to the selected clutch as the winding of the solenoids are energized and de-energized by an electronic control system. A solenoid feed valve and feedback valve operate to connect line pressure to the input port of the several clutch actuator valves, provided the clutch pressures are within certain limits. If these limits are exceeded, line pressure is disconnected from the actuator valves and is applied, instead, automatically and without respect to electronic control, to the clutches that produce a predetermined gear ratio. A coast control valve operates to regulate pressure to a servo that is pressurized at a lower level for low gear ratio operation and at a higher level for reverse drive operation. The coast control valve vents the servo if either of the clutches that produce the predetermined speed ratio are pressurized.

Abstract: The hydraulic control circuit for an automatic transmission includes solenoid-operated clutch pressure valves which selectively connect line pressure to the selected clutch as the winding of the solenoids are energized and de-energized by an electronic control system. A solenoid feed valve and feedback valve operate to connect line pressure to the input port of the several clutch actuator valves, provided the clutch pressures are within certain limits. If these limits are exceeded, line pressure is disconnected from the actuator valves and is applied, instead, automatically and without respect to electronic control, to the clutches that produce a predetermined gear ratio. A coast control valve operates to regulate pressure to a servo that is pressurized at a lower level for low gear ratio operation and at a higher level for reverse drive operation. The coast control valve vents the servo if either of the clutches that produce the predetermined speed ratio are pressurized.

Abstract: The hydraulic control circuit for an automatic transmission includes solenoid-operated clutch pressure valves which selectively connect line pressure to the selected clutch as the winding of the solenoids are energized and de-energized by an electronic control system. A solenoid feed valve and feedback valve operate to connect line pressure to the input port of the several clutch actuator valves, provided the clutch pressures are within certain limits. If these limits are exceeded, line pressure is disconnected from the actuator valves and is applied, instead, automatically and without respect to electronic control, to the clutches that produce a predetermined gear ratio. A coast control valve operates to regulate pressure to a servo that is pressurized at a lower level for low gear ratio operation and at a higher level for reverse drive operation. The coast control valve vents the servo if either of the clutches that produce the predetermined speed ratio are pressurized.