Patent ID: 7934476

Claim:
A valve-actuating system for an engine having an engine valve, said valve-actuating system comprising: a camshaft; a pair of first and second cams disposed on the camshaft, and being operatively associated with said engine valve; a rocker arm shaft arranged parallel to the camshaft; and a rocker arm supported on said rocker arm shaft, said rocker arm being swingable around an axis of the rocker arm shaft, and being movable in an axial direction thereof, said rocker arm including left and right rocker arm segments which are independently operable relative to each other; wherein: said system is configured such that during an operation of the engine, in accordance with a rotational movement of the camshaft, the rocker arm abuts on one of the cams so as to be swung, thereby causing the engine valve to perform the opening and closing operations; the rocker arm is moved, in the axial direction, to one of a first operating position, where the rocker arm is allowed to abut on the first cam, and a second operating position where the rocker arm is allowed to abut on the second cam, so that a corresponding one of the cams is selectively used for opening and closing the engine valve; and wherein the rocker arm shaft is supported by an engine frame, said rocker arm shaft being movable in the axial directions thereof; and when the rocker arm is about to be moved to a selected one of the first and second operating positions, the rocker arm shaft is moved in advance to said one of the first and second operating positions, and thereafter the rocker arm is moved to said one of the first and second operating positions.