Abstract: A completely electronic circuit operating from the respective outputs of a motor speed transducer and a transmission input speed transducer and from other inputs which are usually constant voltages calculates a control signal for moving the control member of an automatic clutch for coupling a vehicle motor to a vehicle transmission during slipping engagement of the clutch until gripping engagement is made in such a way as to minimize the jolt effect without the necessity of hydraulic or mechanical damping devices.

Abstract: A rotary positive-displacement pump in which the vane or vanes separating the chambers are locked in the inner dead center point after a certain outlet pressure has been attained, in order to shut off the pump. A corresponding locking apparatus has a detent which assures that each vane is locked in a form-locking manner in the position which shuts off the pumping action. Preferably, the locking apparatus has an overstroke step by means of which it is assured that each vane is constantly held at an increased distance from its sliding surface so that friction and impact noises are positively avoided.

Abstract: Rapid movement of the gas pedal initiates a shifting operation to the next higher or next lower gear depending upon whether the speed of the gearing lies above or below a predetermined speed range. The speed range extends from a first to a second predetermined speed. Both the width of the range and the actual values of the first and second predetermined speed are automatically adjusted as a function of the throttle valve position and the then-present gear. If the gas pedal is not activated but the gear speed is less than a predetermined first threshold speed, an automatic down-shift takes place. Up-shifting can only occur when the speed of the gearing exceeds a minimum up-shift speed. Engagement and disengagement of the clutch is controlled and may include jolt limiting. The engine speed is limited during gear shifting.

Abstract: 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.

Abstract: A wheel lock-up prevention system for motor vehicles includes electromagnetic valves which decompress the main control chamber of the system when a wheel lock-up occurs and hence terminate the braking effort at the locked wheel. During re-compression, which takes place by cyclic actuation of one of the electromagnetic valves, excessively high pressure pulses are prevented by connecting the main control chamber with a surge chamber during part of the cycle so as to diminish the pressure in the main control chamber and to make the magnitude of the cyclic pressure increases inversely proportional to the total pressure in the control chamber.

Abstract: An improved wheel lock prevention device for use in the brake system of motor vehicles. The device has a relay valve included in assembly with a motor vehicle operator controlled brake velve, a wheel brake cylinder and a source of pressurized air. The relay valve has a primary and secondary pressure side. The primary pressure side is connected to the brake valve and the secondary side is connected to the wheel brake cylinder. A short circuit connection between the primary and secondary pressure sides is provided with a control for effecting a balancing of the pressures on both the primary and secondary pressure sides after the pressure on both sides has been reduced from a peak value by a desired extent during application of the brake system.