Abstract: The invention provides an improved form of drive arrangement for use in a motor vehicle comprising a first prime mover, a hydromechanical power branching transmission, driven by the prime mover, and having at least two hydromechanical transducers, by the inclusion of an emergency drive device which comprises a second prime mover adapted to act as a standby prime mover and an adjustable hydromechanical transducer arranged to be driven by the second prime mover. The second prime mover is adapted to supply hydraulic power via the adjustable hydromechanical transducer to the hydromechanical transducers of the power branching transmission and thence to a driven axle of the vehicle in the event of the first prime mover becoming inoperative, for example, if the first prime mover fails or (in the event of its being an electric motor) if its supply of energy breaks down.

Abstract: A motor vehicle which is more particularly adapted for stop and go traffic conditions such as a city omnibus plying on a regular service, a garbage collection vehicle or the like has a drive arrangement including a driven rear axle connected with an IC engine and a variable speed transmission, is fitted with a braking energy recovery means in the form of a self-contained system which is only connected with the variable speed transmission for charging and discharging of a high pressure accumulator. This coupling operation is performed by a clutch operated in accordance with certain operating conditions. One side of the clutch is joined to a secondary output of the variable speed transmission and the other side is connected with the drive shaft of a hydraulic transducer, of which only one is required.

Abstract: A valve arrangement for connecting a hydraulic machine, such as a pump or a motor, with a pressure accumulator in which a conventional manual shutoff valve is replaced by a leak-proof pressure controlled valve whose operating pressure signal is supplied by a shuttle valve from that one of two ports of the pressure controlled valve at which the higher pressure prevails at a given time. The pressure controlled valve is supplied with fluid under pressure by way of a leak-proof remote controlled slide valve.

Abstract: Method and device for controlling a motor vehicle power unit consisting of an internal combustion engine and a variable-ratio power divider transmission. For adjusting the output, use is made of the data from the only sensor sensing the speed at the transmission output end, and from the accelerator and brake pedals. The resultant reference value is directly transferred to an engine function generator in which engine characteristics are stored. The output signal from the engine function generator is used to control the throttle or the fuel supply system actuating lever. The reference generator also directly influences a speed function generator, in which the optimum speed is stored. Its output signal is linked with the indication from the sensor so as to form a reference value for the transmission ratio and is processed in a transmission control unit for form actuating signals for the transmission.