Arrangement for operating the clutch in the power train of a motor vehicle

DETAILED DESCRIPTION One feature of the present invention resides in the provision of a power train for use in a motor vehicle.
The improved power train comprises a variable-speed prime mover (such as an internal combustion engine) arranged to furnish a plurality of different torques including a maximum torque and having an output element (such as a camshaft or a crankshaft) arranged to rotate at a plurality of different speeds, means for varying the speed of the prime mover including an energy supplying device (such as a throttle valve) which is adjustable between a plurality of positions including a threshold position, a transmission which is selectively shiftable into a neutral gear and a plurality of additional gears (such as at least one reverse gear and one, two, three or more forward gears), means (such as a ratio selecting lever) for shifting the transmission into different gears, a torque transmitting friction clutch which is engageable and disengageable to respectively transmit and interrupt the transmission of torque between the output element of the prime mover and a rotary input element (e.
g.
, a shaft) of the transmission, and control means for the clutch.
The control means includes means for disengaging the clutch prior to shifting of the transmission from neutral gear into one of the additional gears preparatory to setting of the vehicle in motion in response to shifting of the transmission into the one additional gear, to subsequent adjustment of the energy supplying device beyond the threshold position and subsequent to partial engagement of the clutch to a condition in which the clutch transmits torque without play in the power train.
The control means is arranged to effect a greater engagement of the clutch beyond the partial engagement in response to the establishment of a predetermined difference between an actual speed of the output element of the prime mover and a reference speed; such greater engagement of the clutch results in the transmission of a torque corresponding to that when the speed of the prime mover at least approximates the reference speed regardless of the adjustment of the energy supplying device at the time when the motor vehicle is being set in motion