Automatic transmission utilizing a slider for pressure distribution to servo-elements controlling the gear ratio

摘要

In a hydraulic transmission in which couplings and brake bands (servo-elements) control the gear ratio and are themselves engaged and disengaged in accordance with pressure applied thereto, a motor-driven slider is provided to connect a main pressure source directly to servo-elements which will remain engaged in the newly selected gear ratio. Solenoid operated valves are interposed between the main pressure source and a second intake port of the slider. Milled channels in the slider connect this second intake port to the servo-elements to be newly engaged during the gear shift. A known gear control unit operates the valves to control the rate of change of pressure increase at the second intake port to a selected value which will limit the jolt of the vehicle to a predetermined maximum jolt.