Controlling apparatus of automatic transmissions

The device is for controlling the speed at which gears change in automatic transmissions, by the automatic selective engagement of at least two centrifugal clutches in response to the engine speed. A sliding piece is connected to a rotary shaft to which the rotation of a centrifugal clutch for a low speed is to be transmitted, so as to be able to transmit rotation and to be slidable in the axial direction in response to the driving torque. The speed at which another centrifugal clutch for high speed engages may be varied by the sliding of the sliding piece in response to the driving torque. This may be used in the case of high acceleration during second speed operation in an automatic three-speed transmission, when the high speed centrifugal clutch maintained until a sufficient acceleration has been achieved, when the high speed centrifugal clutch is finally engaged.