Abstract: A valvegear for an engine of reciprocating piston type is disclosed. The valve gear includes a cam, a camshaft and a cam piston, where the cam is mounted to rotate on the camshaft and is in contact with the cam piston. The cam piston is movably arranged within a pressure chamber and is adapted to be moved by the cam away from the camshaft to pressurize a fluid within the pressure chamber. The valvegear further includes an engine valve which is movable between an open position and a closed portion, a restoring spring associated with each engine valve, a valve piston which is movable arranged in an actuating chamber, the engine valve is arranged to be moved into the open position against the force of the restoring spring by the valve piston, where the valve piston is arranged to move in the actuating chamber by the pressure produced in said pressure chamber by movement of said cam piston.

Abstract: An automotive valve rocker arm comprises a valve engagement portion and a cam engagement portion which are mounted for independent rocking movement about a rocker shaft. One of the cam engagement portion and valve engagement portion affords a first bush, which accommodates and is rotatable about the rocker shaft, and the other of which affords a second bush, which accommodates the first bush and is rotatable about the first bush and thus about the rocker shaft also. Selectively actuable locking means are accommodated within the space defined by the outer surface of the second bush and are movable between a first position in which relative movement of the valve engagement portion and the cam engagement portion is permitted and a second position in which they are locked together and such relative movement is prevented.