System for switching a drive device dependent on speed

Claim 1

In a system for controlling a drive device, particularly a boat drive device, which comprises an internal combustion engine and a reversible gearing connected to the engine, there being an operating element connected to the engine and the gearing for adjusting the power and the direction of turning of an output rotation of the drive device, the improvement comprising a control device containing a microcomputer, said operating element transmitting electric signals for power and for direction of turning to said control device; separate power actuators connected to said control device for selecting a power of the internal combustion engine and for switching the reversible gearing; and wherein said control device enables the switching of the reversible gearing only when a speed of rotation of the internal combusion engine is below a predetermined value; and wherein said operating element comprises a lever having a central position associated with an idling speed of the internal combustion engine; and wherein after a passing of the lever through said central position, one of said power actuators is held in an idling position and switching of the reversible gearing is delayed until the internal combustion engine has assumed the idling speed of rotation, while after the switching of the reversible gearing said one power actuator is advanced to a position which corresponds to the position of the lever; and wherein delay in the switching of the reversible gearing continues for a period of time which is calculated by said microcomputer on a basis of properties of the drive unit and the speed of rotation before a passing of said lever through the central position.