Dual control valve

The control apparatus wherein 1 the boost piston has a stroke that is limited to a certain stroke length such that when the engine valve is opened the certain stroke length the engine valve is free of mechanical interference with a reciprocating engine piston in a cylinder served by the engine valve.

A control apparatus for an engine valve, the engine valve being an intake/exhaust valve, the engine valve for admitting and exhausting a fluid mixture to and from a combustion chamber of an internal combustion engine, comprising:

• a selectively actuatable controller being in fluid communication with a source of pressurized actuating fluid and being in fluid communication with a substantially ambient actuating fluid reservoir, the controller having a first control valve for selectively independently porting actuating fluid to and venting actuating fluid from a drive piston, the drive piston being operably coupled to the engine valve, and a second control valve for selectively independently porting actuating fluid to and venting actuating fluid from a boost piston, the boost piston being selectively operably coupled to the engine valve, the two control valves are being independently electrically actuatable.

A control apparatus for an engine valve, the engine valve being an intake/exhaust valve, the engine valve for admitting and exhausting a fluid mixture to and from a combustion chamber of an internal combustion engine, comprising:

• a selectively actuatable controller being in fluid communication with a source of pressurized actuating fluid and being in fluid communication with a substantially ambient actuating fluid reservoir, the controller having a first control valve for selectively independently porting actuating fluid to and venting actuating fluid from a drive piston, the drive piston being operably coupled to the engine valve, and a second control valve for selectively independently porting actuating fluid to and venting actuating fluid from a boost piston, the boost piston being selectively operably coupled to the engine valve, a return piston being operably coupled to the engine valve, the return piston being continually exposed to actuating fluid, the force generated on the return piston by the pressurized actuating fluid effecting an engine valve closing pressure.

A valve actuator for actuating an engine valve, the engine valve being an intake/exhaust valve, the engine valve admitting and exhausting a fluid mixture into a combustion chamber of an internal combustion engine, comprising;

• a drive piston being operably coupled to the engine valve, the drive piston being selectively fluidly couplable to a controller, the controller having a first control valve for selectively independently porting actuating fluid to and venting actuating fluid from the drive piston;
• and
• a boost piston being selectively operably coupled to the engine valve, the boost piston being selectively fluidly couplable to a controller, the controller having a second control valve for selectively independently porting actuating fluid to and venting actuating fluid from the boost piston.