Abstract: A multiple ratio transmission having a main gear unit with at least three forward driving ratios and a single reverse drive ratio and a simple planetary gear unit in series with the main gear unit, the simple planetary gear unit being downshifted and the main gear unit being upshifted on an upshift from a first intermediate ratio to a higher intermediate ratio, the simple planetary gear unit being upshifted and the main gear unit being downshifted on a downshift from the higher intermediate ratio to the first intermediate ratio.

Abstract: A control system for a multiple ratio transmission including a hydrokinetic torque converter with a pressure actuated friction bypass clutch, pressure actuated clutches and brakes controlling ratio changes in forward drive and for effecting reverse drive, a solenoid operated pressure control that develops an optimum clutch and brake pressure for smooth engagement and for increased torque capacity during start-up, and separate solenoid regulator valves for ratio shift valve control and for bypass clutch pressure control.

Abstract: A multiple ratio transmission for an automotive vehicle comprising a main gear unit with at least three ratios and an overdrive gear unit with a direct drive ratio and an overdrive ratio, and a control valve system that will permit upshifting and downshifting of the overdrive gear unit while inhibiting ratio changes in said main gear unit from either a second ratio manual drive mode or from a third ratio manual drive mode.

Abstract: A control system for engaging and releasing a torque converter bypass clutch and for varying the torque capacity of the clutch by adjusting the torque converter torus chamber pressure in accordance with changing operating variables, the bypass clutch including a clutch release pressure chamber that is maintained at a calibrated pressure threshold valve whereby pressure clutch capacity control is achieved by controlling pressure differential in the converter.

Abstract: A control system for a torque converter lock-up clutch operates in a hydraulic circuit having line pressure applied to a lock-up clutch control valve and supplied selectively to a clutch-apply pressure chamber or a clutch-release pressure chamber. The control valve includes a valve spool, four control lands and a valve spring urging the control body to a starting position where the valve directs line pressure to the release pressure chamber and connects the apply pressure chamber to a cooler. When control pressure is applied, the valve spool moves to a shift-up position, supplies line pressure to the apply pressure chamber and connects the release-pressure chamber to an outlet line. A pulse-width modulated solenoid valve varies pressure in the release-pressure chamber by means of a throttle opening in the clutch plate, whereby control pressure is modulated so that force between the friction surfaces of the clutch is reduced to allow clutch slippage.

Abstract: A control valve for controlling the engagement of a friction drive clutch for an automatic transmission having multiple clutches and brakes for establishing a drive mode following a neutral mode wherein the valve regulates pressure distributed to the drive clutch and wherein the valve is in fluid communication with a second clutch whereby the latter acts as an accumulator for altering the rate of pressure buildup in the drive clutch thus eliminating harshness in the clutch engagement.