Abstract: A valve drive for activation of gas exchange valves of internal combustion engines, with which valve stroke switching is accomplished with little effort, a low construction height, and at low switching forces. Incorrect switching and damage to the camshaft during valve stroke switching are avoided, even at high engine speeds of rotation. An adjustment shaft that is rotatable by the camshaft and parallel to the camshaft has two adjustment devices rotatably disposed on it, along with two tappets between the adjustment devices. The tappets are connected with a shift gate for valve switching between two different cam profiles of a cam package that is axially displaceable on the camshaft. The tappets each have a contour that contacts the adjustment devices via a guide pin. A gear wheel engages with a gear segment on the camshaft, via a drive on the adjustment shaft, to rotate the adjustment shaft.

Abstract: Valve gears for load-change valves of four-stroke internal combustion engines, in which the load-change valves are closed by spring force, engage a pivot lever moved by a cam for opening a load-change channel. The cam engages an intermediate element that it is additionally moved by the lifting curve of the cam during a different work cycle, and adjusts the pivot lever to open the load-change valve slightly during a different work cycle. The intermediate element is prismatically guided on an element that can pivot in the cylinder head and is adjustable in its position, and engages the cam and the pivot lever, so that the stroke movement of the cam for opening the load-change valve via the pivot lever can be adjusted.

Abstract: A valve gear arrangement for load change valves of internal combustion engines has an intermediate element that is pivoted on a lever in the cylinder head, to activate the load change valves. The intermediate element engages a cam of a camshaft and has fork-shaped parallel guides on guide cylinders, over the center axis of which a guide groove in the shape of a circular ring segment extends. A roller axle of a roller that engages the cam is displaceably guided in the guide groove. There are springs supported on the roller axle that force the roller axle against an adjustable guide element, counter to the acting forces, when it passes through a plateau region of the cam, and lies against the plateau region.

Abstract: A variable valve gear for internal combustion engines, having at least one camshaft and pivot lever disposed in the cylinder head, which lever contacts a valve that closes by means of spring force. An intermediate element of a transfer element is mounted in a supporting and displaceable manner, twice on the supporting body and on the pivot lever. The intermediate element engages a supporting surface disposed on the supporting body, first by way of a supporting cam segment disposed on the intermediate element, and second with the controlling cam segment of the supporting body, and third with the pivot lever, by way of an outer contour surface disposed on the intermediate element. The intermediate element indirectly contacts the cam of the camshaft, by way of a roller disposed on an oscillating crank, which is connected with the intermediate element in articulated manner.