Methods of Valve Actuation

The term actuation in relation to hydraulic valves refers to the various methods of moving the valve mechanism. These methods provide a variable lift for one or more than one engine air valves by a method of variable position hard stop. Valves can be actuated by five basic methods namely, manually, mechanically, electrically, hydraulically, or pneumatically. In machine applications any one of these methods, or a combination can be used to gain optimum control.

Manual methods use hand or foot actuators which include levers, push buttons, knobs, and foot pedals. The electrical methods make the use of A.C. or D.C. solenoids, which can either be of air-gap or oil-immersed type. These solenoids can move the valve mechanism directly, or can provide a hydraulic pilot signal which in turn operates the valve mechanism.

In valves that operate on hydraulically and pneumatically basis, the fluid-pilot signal acts on the piston basis, which in turn moves the valve mechanism to its alternative position.

Many embodiments are revealed, which includes embodiments that control lifts by providing a choice of two or three different fixed stops that continuously vary throughout a range of lifts. The valves that are controlled by a variable position hard stop can be a single engine intake, an exhaust valve, or multiple valves of any number. These use either intake or exhaust valves or both, or of one intake or one exhaust valve for one or more cylinders in engines, having more than one intake or exhaust valve per cylinder.