Abstract: In an electromagnetic operating arrangement for actuating the intake and exhaust valves of an internal combustion engine wherein a valve operating member is movably supported in axial alignment with a valve stem and engaged by an operating member spring which biases the valve operating member into engagement with the valve stem, the valve operating member has an armature disc movably supported thereon but held in engagement with a stop on the valve operating member by a spring arrangement which exerts a spring force smaller than the spring force exerted by the valve operating member spring but greater than the resultant of the valve closing and the valve operating springs such that the valve operating member is always in force-transmitting contact with the valve.

Abstract: In a hydraulic-mechanical operating mechanism for a breathing valve of an internal combustion engine in which the valve is engaged by two compression springs, one biasing the valve in opening direction and the other biasing the valve in a closing direction, the valve has a stem with first and second cam areas for engagement by the pistons of first and second cylinder and piston structures for retaining the valve in its closed and open end positions wherein the first cylinder and piston structure includes spring means biasing its piston into engagement with the associated cam area and the second cylinder and piston structures includes spring means biasing the associated piston away from the associated cam area and the respective cylinders can be hydraulically actuated to release the valve when it is in the closed end position and to engage the valve when it is in its open end position.