Abstract: To prevent jolts or shocks interfering with smooth operation of an automotive vehicle upon disengagement of an automatic free-wheeling arrangement and reestablishment of engine braking, a control element (22, 23) is provided, controlled by the system, typically coupled to the brake light switch, which reestablishes positive drive connection between engine and wheels to permit engine braking, to reduce the torque supplied by the engine at the re-engagement instant, to thereby insure smooth transition from free-wheeling to engine braking. Preferably, the engine speed is sensed, and the speed of the shaft beyond the free-wheeling arrangement is sensed (points A, B), and engine torque is reduced just before synchronism is achieved.

Abstract: To control transmission ratio of a continuously variable transmission connected to a combustion engine (e.g., for optimal fuel efficiency of a powered vehicle), effective diameter of pulleys is controlled in response to an electrical signal. A control signal suitable for comparison with hydrostatic pressure values is produced by a computing device based on input signals representing load, speed, and other operating conditions and based further on stored data representing engine characteristics. A control signal is conveniently used to control hydrostatic pressure by means of electromagnetically operated valves. Especially when pulsed valves controlled by digital electric signals are used, a reservoir is used to establish a steady hydrostatic pressure. Such control device is readily adapted to different engines by replacement of stored characteristic data.

Abstract: The automatic transmission control unit in a motor vehicle furnishes a signal which signifies that motor torque is to be decreased, thereby decreasing jolts or wear on friction elements in the transmission. In response to this signal, the input or output signals of a motor control unit, for example either an ignition control stage or an injection control stage, are changed in such a way that the motor torque will be decreased. Circuits for delaying ignition timing, shortening the pulse width of injection pulses, etc. are disclosed. The present invention is essentially an adapter unit so that the desired decrease in motor torque can be effected with the injection or ignition timing units already present in the motor vehicle.

Abstract: To control transmission ratio of a continuously variable transmission connected to a combustion engine (e.g., for optimal fuel efficiency of a powered vehicle), effective diameter of pulleys is controlled in response to an electrical signal. A control signal suitable for comparison with hydrodynamic pressure values is produced by a computing device based on input signals representing load, speed, and other operating conditions and based further on stored data representing engine characteristics. A control signal is conveniently used to control hydrodynamic pressure by means of electromagnetically operated valves. Such control device is readily adapted to different engines by replacement of stored characteristic data.