Semi-automatic Transmission
For 1963 (initially only in France), Renault offered a semi-automatic transmission of unique design, developed and produced by Jaeger. Although it was described as a form automatic transmission at the time, in retrospect it was more realistically a form of automatic clutch, inspired by the German Saxomat device which appeared as an option on several mainstream German cars in the 1950s and 60s.
The clutch in the system was replaced by a powder ferromagnetic coupler, while the transmission itself was a three-speed mechanical unit similar to that of the Dauphine—but from the beginning, in this form, with synchromesh on all gears.
The system used a dash-mounted push button control panel where the driver could select forward or reverse and a governor that sensed vehicle speed and throttle position.
A "relay case" containing electromagnetic switches received signals from the governor and push buttons and then controlled a coupler, a decelerator to close the throttle during gear changes, and a solenoid to select operation of the reverse-first or second-third shift rail, using a reversible electric motor to engage the gears. The system was thus entirely electromechanical, without hydraulics, pneumatics or electronics.
Benefits included comparable fuel economy to the manual transmission version, and easy adaptability to the car. Drawbacks included performance loss (with only three available gears) and a somewhat jerky operation during gear changes.
The transmission was also used in the Dauphine and the Caravelle.
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