Arrangement for automatic clutch actuation

In an arrangement for the automatic actuation of an automobile clutch operatively located between an automobile engine and a manually shiftable transmission, of the kind that includes a servo motor responsive to auxiliary power applied thereto for effecting engagement and disengagement of the clutch, and control means for controlling the auxiliary power delivery to the servo motor as a function of at least one of the speed adjusting means and the clutch input and output rotational speeds, and wherein the control means controls the auxiliary power delivery to the servo motor so that the rotational speed of the engine attains a prescribed rotational speed that is a function of accelerator pedal position, the improvement wherein said control means for controlling auxiliary power delivery to said servo motor includes control valves, one of which valves is associated to the atmosphere, and a control device for providing a first application pulse to said valve associated to the atmosphere, and means for determining the instant at which said friction elements begin to engage whereby said control device activates said control valve associated to the atmosphere by said application pulse until such instant, the arrangement further comprising determining means for determining the rotational speed characteristic of the engine crankshaft comprising markings affixed at defined points to the engine flywheel, means responsive to said markings for delivering signals plotted against time and measured at short time intervals, said determining means delivering a signal for termination of said application pulse upon the indication that said rotational speed characteristic is deviating from a predetermined rotational speed characteristic.