Abstract: A hydraulic control system for controlling application of a pressure medium in a hydraulically actuable shift member intended for an automatic automotive transmission, the control system including a throttle disposed in a pressure application line leading to the shift member, and a control valve controlling an unthrottled communication between a pressure medium supply line and the shift member, bypassing the throttle, as a function of the application pressure prevailing ahead of the shift member, in such manner that the communication is opened at the beginning of the application of pressure to the shift member and interrupted when a preassigned application pressure is reached.

Abstract: In a hydrodynamic-mechanical transmission for motor vehicles, consisting of a torque converter followed by a planetary gear with hydraulically actuable shift mechanism associated with the several transmission elements to select the various speeds, the planetary gear including a first sun gear connectable by way of a first clutch to the turbine rotor of the torque converter, a second sun gear connectable by way of a second clutch to the turbine rotor, a planetary mount connectable by way of a third clutch, bypassing the torque converter, directly to the engine drive shaft, on which mount first and second planet gears in engagement with each other and with the sun gears are mounted, and an internal gear constituting the drive output and in engagement with second planet gears meshing with the second sun gear, the possibility exists of reaching the third, direct speed either by purely hydrodynamic means including the torque converter by engaging the first and second clutches, by purely mechanical means bypassing

Abstract: A control device for effecting variable hydraulic fluid delivery to a gearshift element of an automatic transmission and controlling actuation of the gearshift element. Such a control device includes a delivery line for supplying a pressurized fluid to the gearshift element, a throttle in the delivery line, a bypass line for bypassing the throttle and supplying the pressurized fluid to the gearshift element, and a valve arranged in the bypass line that has a piston that is moveable between an open position, which permits flow through the bypass line, and a closed position, which prevents flow. Pressure downstream of the throttle acts on the valve and urges the piston into the open position; a vehicle speed-dependent pressure acts on the valve and urges the piston into the closed position. The piston can be biased, for example, with a spring, such that the piston remains in the open position up to a predetermined vehicle speed.

Abstract: A hydraulic control device for automatic transmissions of the type where pressurized fluid activates a gear shift element, e.g., a forward clutch, includes a shift valve to selectively interrupt the delivery of pressurized fluid to disengage a gearshift element. The position of the shift valve is determined by an accelerator-pedal-position-dependent pressure, which is delivered through a throttle point and a control valve, preferably the so-called kick-down valve, the latter regulating the delivery of the load-dependent pressure. When the accelerator pedal is released, the control valve vents the fluid line leading to the shift valve, which causes shifting of the shift valve and disengagement of the gearshift element. When the accelerator is again depressed, pressurized fluid is delivered to the shift valve through the throttle point, to re-engage the gearshift element smoothly.

Abstract: A pneumatic control system is disclosed for an automatic transmission for a vehicle of the type having a mechanical planetary gear train with hydraulically actuatable gear elements. A manual control valve dependent upon the position of the transmission gear select lever conveys a pressure medium, for actuating a gear shift element associated with the selected gear when said lever is moved to one of the forward gears of the transmission, through a pressure medium line connected between the manual control valve and the gear shift element. The control system comprises a main control valve dependent upon the position of the accelerator pedal for exhausting the fluid in the gear shift element for disengaging the gear shift element in operating states of the vehicle at least when the vehicle is stationary, the transmission gear select lever is moved to the drive position (D), and the accelerator pedal is released.

Abstract: A control system for an automatic transmission of a motor vehicle having a mechanical planetary gear train with hydraulically actuatable gear shift elements, and a manual control valve for delivering a first pressurized fluid to a selected gear shift element when said lever is in one of said forward drive positions comprises a main control valve, responsive to the position of the accelerator pedal and the speed of said vehicle, for controlling the supply of the first pressurized fluid from the manual control valve to the selected element. The main control valve comprises a piston having a first piston surface, which is displaceable between a first position for connecting the supply of first pressurized fluid and a second position for interrupting the supply of first pressurized fluid thereby to disconnect the clutch. A spring acts on the piston against an accelerator pedal position-dependent second fluid pressure which acts on the first piston surface.

Abstract: A hydraulic control device for an automatic vehicle transmission includes a main pressure control valve for delivering an engine load-dependent main output pressure for operating actuating components of the vehicle transmission and a pressure-limiting valve for delivering an engine load-dependent, upwardly limited control pressure. The pressure-limiting valve includes a control piston exposed to the control pressure and to the force of a spring opposing the control pressure. The device further has an additional control valve for applying to the main pressure control valve an output pressure which is a function of a vehicle speed-dependent pressure and the control pressure and which is modulated by the control pressure and a higher main input pressure.

Abstract: A .[.pneumatic.]. .Iadd.hydraulic .Iaddend.control system is disclosed for an automatic transmission for a vehicle of the type having a mechanical planetary gear train with hydraulically actuatable gear elements. A manual control valve dependent upon the position of the transmission gear select lever conveys a pressure medium, for actuating a gear shift element associated with the selected gear when said lever is moved to one of the forward gears of the transmission, through a pressure medium line connected between the manual control valve and the gear shift element. The control system comprises a main control valve dependent upon the position of the accelerator pedal for exhausting the fluid in the gear shift element for disengaging the gear shift element in operating states of the vehicle at least when the vehicle is stationary, the transmission gear select lever is moved to the drive position (D), and the accelerator pedal is released.