Abstract: To obtain a flexible transmission system which can be adjusted to the meet the individual desires of a driver, the choice of the desired value of the rate of revolution of the primary axle in the system, based on the current position of an accelerator pedal, and based on the current rate of revolution of the secondary axle of the system, is influenced, whereby several sub ranges are composed from the range of possible desired rate of revolution values of the primary axle, so that the possible positional values of the accelerator pedal can be combined with one of the sub ranges, to choice. A sub range preferably serves as a model for a desired type of driving program. If desired, the boundary values of the sub range can be continuously adjusted through the use of potentiometers which are operated by the driver. To assist in the realization of a simple-to-implement digital construction, the sub range values are stored in a memory.

Abstract: An electronically controlled continuously variable transmission system is provided with a driving belt trained over a primary and secondary pulley. The primary pulley is provided on a primary shaft and the secondary pulley is provided on a secondary shaft. Each pulley has corresponding spaced, conical pulley halves and at least one of the corresponding pulley halves is axially movable by respective primary and secondary moving devices. The transmission further includes a primary electronic control system for controlling the transmission ratio and a secondary electronic control system for controlling the belt tension. The primary electronic control system permits the operator to select from fuel economy, sporting, and maximum comfort performance modes. The primary electronic control means controls the transmission ratio in accordance with the performance mode selected. The moving devices include standby operating valves to permit continued operation of the transmission in case of power failure.

Abstract: In a continuously variable transmission which is provided with a primary pulley and a secondary pulley, between which a driving belt is mounted, primary and secondary control systems, which are coupled to the respective pressure chambers of the axially translatable pulley discs, are employed to precipitate current pressure values, in dependence upon desired pressure values. To this end, the control system employs a regulator to which only the difference between the desired and the measured pressure-value is supplied, whereby the regulator nevertheless only has to regulate the relatively rapidly changing variation in a rest value supplied separately by a rest state device. This greatly improves the dynamic behaviour of the controller, so that rapid variations in the desired value of the entrant pressure can be effectively followed by the control system.