Abstract: In a continuously variable transmission with a toroidal variable speed drive, in which a roller is supported pivotably between two toroidal disks for transmitting motion between the two toroidal disks at transmission ratios which depend on the pivot position of the roller according to pressure forces acting on a hydraulic actuating piston, for the purpose of varying the transmission ratio, two regulating slide valves are provided, each including a regulating slide with control edges to act upon the hydraulic actuating piston via a hydraulic medium under the control of the regulating slide valves each controlling the pressure in one of the chambers arranged at opposite ends of the actuating piston.

Abstract: In a continuously variable transmission with a toroidal variable speed drive, in which a roller is supported pivotably between two toroidal disks for transmitting motion between the two toroidal disks at transmission ratios which depend on the pivot position of the roller according to pressure forces acting on a hydraulic actuating piston, for the purpose of varying the transmission ratio, two regulating slide valves are provided, each including a regulating slide with control edges to act upon the hydraulic actuating piston via a hydraulic medium under the control of the regulating slide valves each controlling the pressure in one of the chambers arranged at opposite ends of the actuating piston.

Abstract: In a coupling arrangement disposed between a drive shaft and a driven shaft for transferring a torque between the drive shaft and the driven shaft and comprising a hydrodynamic startup unit, and a bridging clutch bridging the startup unit and having an engagement pressure provided by a combination of a control pressure and a counter pressure, a control unit is provided for controlling the counter pressure in at least one state of operation of the coupling arrangement so as to permit a certain slippage of the bridging clutch.

Abstract: An automatic gearbox includes a control device for selecting a gearbox driving position, which device includes at least one spool valve via which at least one pressure connection may be connected to at least one consumer, and having at least one shift valve via which at least one pressure connection from at least one pressure supply of the control device may be shifted to the spool valve in order to actuate the spool valve. The control device includes a retaining device via which, if the shift valve should fail, the spool valve may be fixed in at least one control position and the selected gearbox driving position may be retained.

Abstract: An automatic gearbox includes a control device for selecting a gearbox driving position, which device includes at least one spool valve via which at least one pressure connection may be connected to at least one consumer, and having at least one shift valve via which at least one pressure connection from at least one pressure supply of the control device may be shifted to the spool valve in order to actuate the spool valve. The control device includes a retaining device via which, if the shift valve should fail, the spool valve may be fixed in at least one control position and the selected gearbox driving position may be retained.