Abstract: A variable stroke valve drive for an internal combustion engine, including an intermediate lever which is slidingly arranged on a crank path of a crank arm the intermediate lever has a working cam with null lifting cam and lifting cam portions. The working cam contacts a gas exchange valve via an intermediate element. A first adjustment element rotates the intermediate lever against a spring element around a point located near the crank, the intermediate lever being displaceable along the crank path by a second adjustment element. The first adjustment element is provided with a cam plate whose radius continuously increases or reduces on a circumference with respect to an axis of rotation. The inventive variable stroke valve drive substantially reduces wear in a valve drive.

Abstract: A variable stroke valve drive for an internal combustion engine, including an intermediate lever which is slidingly arranged on a crank path of a crank arm the intermediate lever has a working cam with null lifting cam and lifting cam portions. The working cam contacts a gas exchange valve via an intermediate element. A first adjustment element rotates the intermediate lever against a spring element around a point located near the crank, the intermediate lever being displaceable along the crank path by a second adjustment element. The first adjustment element is provided with a cam plate whose radius continuously increases or reduces on a circumference with respect to an axis of rotation. The inventive variable stroke valve drive substantially reduces wear in a valve drive.

Abstract: 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.

Abstract: 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 centre of motion forms a constant instantaneous centre 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.