Shift device for spur gear transmission

摘要

The invention relates to a new type of shift device for a full synchromesh spur gear transmission for motor vehicles, by means of which the gears can be shifted in stages under load by the familiar operation of the usual clutch pedal. The force of the driver's foot is freely available at no cost and generates the oil pressure needed for shifting and coupling of the shift points of the transmission. This oil pressure is fed to the individual shift positions by way of a memory programmed control, so that in addition to shifting under load, automatic changing of the transmission when the double clutch is disengaged is obtained by signals from sensors for the engine speed, engine load, speed of travel etc. The manual shift lever of the transmission only serves for changing of the transmission, which may be combined with a range-change transmission into the various ranges or from the neutral position into forwards or reverse gear. Compared to the clutch operation and manual shift of existing full synchromesh spur gear transmission, the foot shift essentially relieves the driver. Since there is no need of drive sources for producing the means of shifting and corresponding control devices the manufacturing costs of this type of transmission can be considerably reduced.