AUTOMATIC CHANGE-SPEED GEAR CONTROL

摘要

A control valve system for an automatic power transmission mechanism having planetary gearing defining plural torque delivery paths comprising fluid pressure servo operated brakes and clutches and a vehicle speed sensitive servo release shuttle valve which cooperates with the timing valve circuit to establish a first timed relationship between the application and release of the servos during a ratio change from the high ratio to an intermediate underdrive ratio at a relatively high speed and for establishing a different timing relationship between those circuit elements during a corresponding ratio change at a lower vehicle speed, the rate of application of the underdrive ratio servo during a ratio change from the lowest ratio to an intermediate underdrive ratio being calibrated independently of the calibration required for a ratio change from the high speed ratio to the same intermediate underdrive ratio.