Abstract: A torque transmitting system for transmitting torque from a drive shaft of an engine to an output shaft without transmitting torque variation comprises a friction clutch unit interposed between these shafts, a fluid pressure-operated actuating unit for engaging and disengaging the friction clutch unit, and vibration detecting means detecting vibration occurring in the engine or the torque transmitting system. In the system, means are provided for controlling the pressure of actuating fluid supplied to the fluid pressure-operated actuating unit on the basis of the output signal from the vibration detecting means thereby adjusting the difference between the rotation speed of the drive shaft and that of the output shaft, whereby the torque can be transmitted from the drive shaft to the output shaft without any substantial variation.

Abstract: A torque transmission device for eliminating the transmission of tortional vibration from a driving shaft to a driven shaft comprises a clutch capable of controlled slippage so that the speed of rotation of the driven shaft is lower than the speed of the driving shaft. Slippage of the clutch is controlled by sensing the speed of rotation and the fluctuation of the speed of rotating of the driving shaft and the speed of rotation of the driven shaft and regulating slippage so that the difference in rotation speed between the two shafts is greater than the fluctuation in rotation speed of the driving shaft. The clutch may be an electromagnetic clutch of which the exciting current is controlled or a friction clutch actuated by controlled hydraulic pressure. The clutch may be in parallel with a fluid coupling.

Abstract: A control device for a hydraulic pressure operated friction clutch in an automatic speed changer has a device which detects a speed difference (S) between an engine drive shaft and an input shaft. Load and speed detecting devices detect the engine load and drive shaft speed respectively, this load and speed information being used to set a second speed difference (So). A hydraulic pressure controlling device then controls the hydraulic pressure supplied to the friction clutch control device so that the first speed difference (S) approaches the second speed difference (So). In addition, a fail-safe circuit releases the friction clutch if the first speed difference remains abnormally large for a predetermined period of time.

Abstract: Improvement in a hydraulic type automatic transmission including a fluid torque converter and a plurality of friction-engagement devices associated with hydraulic servo devices in which different speed change ratios including a plurality of forward movement steps can be realized by selectively actuating the friction-engagement devices with a hydraulic pressure either automatically or manually. Upon deceleration from a higher speed gear ratio to a predetermined gear ratio, a friction-engagement device for realizing the predetermined gear ratio is quickly engaged without delay, whereas upon acceleration from a lower speed gear ratio or a neutral condition to the predetermined gear ratio, engagement of the friction engagement device is effected slowly by actuating an accumulator and a flow rate limiter and thereby generation of an excessive shock is prevented.

Abstract: An electric and hydraulic servomechanism controlling device comprises a pressure governor valve, a hydraulic servomechanism actuated by the supply of the line pressure regulated by said pressure governor valve, and a change-over valve for shifting an oil passage that connects said pressure governor valve and hydraulic servomechanism. The change-over valve serves also as a pressure reducing valve thereby reducing not only the capacity but also the size of the necessary solenoid.