In a valve-driving device for variable adjustment of the lift of a gas exchange
valve of an internal combustion engine, wherein the gas exchange valve co-operates,
via a transfer element, with a roller which can move about an axis of rotation,
with a control path having an idling lift curve and a lift curve in an end area
of a spring-loaded pivoting level which is controlled by a cam associated with
a cam shaft in order to actuate the lifting of said gas exchange valve. In order
to obtain a pure pivoting movement of the pivoting lever, the pivoting center of
motion forms a constant instantaneous center of rotation during any actuation of
said lift. In order to prevent an impact arising from the valve clearance, the
control path of the pivoting lever comprises a ramp, which is correspondingly adapted
to the respective valve clearance, between the idling lift curve and the lift curve.
