Abstract: Automatic transmission control device with stepped gears comprising a torque converter (1) equipped with bridging means (6, 6'), a planetary gear train (2), several hydraulic receivers (E.sub.i, F.sub.i) assuring the switching of planetary gear train (2), and a hydraulic distributor (16, 17) delivering a line pressure PL, which makes it possible to feed selectively receivers (E.sub.i, F.sub.i) under the control of a computer, according to the data concerning the operation of the vehicle equipped with the transmission, characterized in that at least one switching element (8) is dimensioned to be able to slip in a controlled manner, particularly when converter (1) is bridged, in response to a momentary reduction of line pressure PL, and in that this slipping is servocontrolled, by line pressure PL, at set values depending on torque Cm and engine speed .omega.m.

Abstract: An interengaging clutch comprises first and second rotatable clutch halves, the first clutch half being a driven clutch element connected to a first wheel drive train and being movable along an axial direction, the second clutch half being a driving clutch element and being connected to a main drive train and to a second wheel drive train. The clutch halves have circumferentially disposed dogs or teeth with intermeshing contact surfaces for engaging the clutch halves together so that torque can be transmitted from the second clutch half to the first clutch when they are interengaged and rotating at different rotational speeds. Connected to the first clutch half is a unidirectional servo component which is pressure actuated on one side only so as to move the first clutch half into engagement with the second clutch. The interengaging clutch further includes first and second rotational speed sensors which produce signals indicative of the rotational speeds of the clutch halves.

Abstract: In order to attenuate the occurrence of a double select shock which results from the use a first one-way clutch which is used in a first gear train and is involved in the generation of lowest speed thereof, and a second one-way clutch in an auxiliary gear train which is arranged between the main gear train and the final drive, the vehicle speed is sensed and while it is below a predetermined low value, a friction element which is arranged in parallel with the second one-way clutch is engaged. Above the predetermined low value the friction element engagement is maintained in the event that an engine braking demand signal is present.

Abstract: A torque transmission unit is connectable to an internal combustion engine in order to drive a secondary unit with different transmission ratios in dependence upon the rotation rate of the internal combustion engine so that in the case of a low rotation rate of the internal combustion engine the transmission ratio is greater and in the case of a great rotation rate of the internal combustion engine the transmission ratio is less. The torque transmission unit comprises a planetary gear, a free-wheel and a clutch. By the clutch a part of the planetary gear can be coupled to or separated from another part of the planetary gear or a stationary support part, according to choice. The clutch is hydraulically actuable. The pressure for the hydraulic actuation of the clutch is delivered by a hydraulic pump which is integrated into the torgue transmission unit and is independent from the lubricant circuit of the internal combustion engine.

Abstract: An automatic activation apparatus for a differential pawl which is independent of intervention by an operator of a vehicle, the invention controls the energy supply to the actuator by means of a control logic with two signal inputs. The control logic is fed a wheel slip signal directly at one signal input, and via a break-delay timing element at its other signal input. The control logic is thereby designed so that, by the excitation of both signal inputs, it switches into a standby position and then into its active position only upon the excitation of its signal input connected with the timing element.