Patent ID: 7146945

Claim:
An apparatus for an internal combustion engine, the engine having at least one cylinder and associated piston, each cylinder and associated piston having at least one inlet valve and at least one exhaust valve, the apparatus being adapted to control a connection between a combustion chamber in the cylinder and an intake system and an exhaust system respectively, comprising: a rotatable camshaft with a cam curve having at least one cam lobe; a main rocker arm and a secondary rocker arm, the cam curve of the rotatable camshaft having at least one cam lobe, the at least one cam lobe being designed to interact with the main rocker arm and the secondary rocker arm, the two rocker arms serving to transmit movement of the cam lobe to a valve, wherein the cam lobe is arranged to act on both of the rocker arms during each revolution of the camshaft, and the secondary rocker arm interacts with a hydraulic piston which is displaceable in a hydraulic cylinder and which forms part of a hydraulic circuit having a hydraulic fluid source, and which permits switching between at least two different working positions.