Swap-shift control system for a multiple ratio transmission

An automatic transmission for a vehicle having gearing defining multiple torque flow paths between a throttle controlled engine and a torque output shaft comprising a first gear unit with at least three forward-driving ratios and a second gear unit with at least two forward driving ratios, said gear units being disposed in series relationship in said torque flow paths, said torque flow paths including a torque converter with an impeller driven by said engine and a turbine connected drivably to said second gear unit;

• pressure-operated clutch and brake means for establishing and disestablishing ratio changes in said gearing including a first reaction brake means for anchoring a reaction element of said first gear unit during operation in an intermediate ratio of said first gear unit and a second reaction brake means for anchoring a reaction element of said second gear unit during operation in the higher of said two forward driving ratios of said second gear unit;
• said first reaction brake means including a first brake servo having a first servo piston and brake release and apply pressure chambers on opposite sides of said first servo piston;
• said second reaction brake means including a second brake servo having a second servo piston and brake apply pressure and release chambers on opposite sides of said second brake servo piston;
• two independent solenoid operated regulator valve means for establishing separate brake servo actuating pressures for said first and second brake servos;
• a control valve system for controlling distribution of pressure to said brake means including said apply pressure chambers for said first and second brake servo pressure chamber, said valve system including a source of line pressure and a pressure regulator valve means for regulating said line pressure;
• said independent solenoid operated regulator valve means being in fluid communication with said control valve system and said pressure regulator valve means;
• said control valve system including shift valve means for selectively and separately distributing said servo actuating pressures to said apply pressure chambers whereby brake capacities during application and release of said first and second reaction brake means are controlled independently, one with respect to the other, to effect smooth transition of reaction torque from one of said gear units to the other during upshifts and downshifts.