Valve control device and method

A device for controlling an engine valve in response to movement of a camshaft associated with the engine, the valve being contained within a cylinder head of an engine and being movable between open and closed positions, comprising:

• a valve spring for biasing the valve in its closed position, the valve spring being associated with the valve and movable in response to movement of the camshaft;
• and
• a valve engagement assembly, including:
• (a) a reciprocal push rod which is movable upward from a neutral position occupied when the valve is closed in response to actuation by the camshaft and is movable downward in response to actuation by the valve spring,
• (b) a rocker arm occupying a neutral position when the valve is closed and pivotally connected to the engine and associated with the push rod and engageable with the valve so as to open the valve when the push rod moves upward, and
• (c) a push rod spring associated with the push rod, the push rod spring and valve spring acting substantially in unison to actuate the push rod downward and thereby return the valve to its closed position, the push rod spring being adapted to itself substantially actuate the push rod and rocker arm into their respective neutral positions by pulling on the push rod and rocker arm.

A device for controlling an engine valve in response to movement of a camshaft associated with the engine, the valve being contained within a cylinder head of an engine and being movable between open and closed positions and having a stem protruding from the cylinder head, comprising:

• a valve spring for biasing the valve in its closed position, the valve spring being connected to the stem of the valve and movable in response to movement of the camshaft;
• and
• a valve engagement assembly, including:
• (a) a push rod which is reciprocable within a throughbore defined in the cylinder head, the push rod being further movable upward from a neutral position occupied when the valve is closed in response to actuation by the camshaft and movable downward in response to actuation by the valve spring,
• (b) a rocker arm pivotally connected to the cylinder head and associated with the push rod and being engageable with the valve so as to open the valve when the push rod moves upward;
• and
• (c) a push rod spring associated with the push rod, the push rod spring and valve spring acting substantially in unison to actuate the push rod downward and thereby return the valve to its closed position, the push rod spring being adapted to itself substantially actuate the push rod into its neutral position by pulling on the push rod and rocker arm as the valve spring pushes against the rocker arm.

A valve control device for controlling an engine valve in response to movement of a camshaft associated with the engine, the valve being contained within a cylinder head of the engine, and being movable between open and closed positions, comprising:

• first valve closure means, associated with the valve, for resiliently resisting movement of the valve in response to movement of the camshaft;
• and
• a valve engagement assembly, including
• (a) a push rod which is reciprocable in response to the movement of the camshaft, and is movable upward from a neutral position occupied when the valve is closed, and
• (b) a rocker arm pivotally connected to the engine and associated with the push rod and engageable with the valve;
• and
• second valve closure means, associated with the valve engagement assembly, for actuating movement of the valve engagement assembly, the first and second valve closure means cooperating substantially simultaneously together to move the rocker arm and its associated push rod between an engagement position in which the valve is thereby opened and a neutral position in which the valve is thereby closed, the second valve closure means being adapted to itself substantially actuate the push rod into its neutral position.

A method of improving performance characteristics of an engine having an engine valve which is contained within a cylinder head of the engine and is movable between an open and closed position, the engine valve having a predetermined amount of seat pressure acting on it and being regulated by a valve control device that includes (1) first valve closure means, associated with the valve, for resiliently resisting movement of the valve in response to movement of a camshaft associated with the engine, (2) a rocker arm occupying a neutral position when the valve is closed and engageable with the valve and pivotally connected to the cylinder head and to a push rod that is reciprocable in response to movement of the camshaft and movable upward from a neutral position occupied when the valve is closed, the method comprising the steps of:

• (a) replacing the first valve closure means with a substantially weaker first valve closure means;
• and
• (b) replacing the push rod with a push rod having a second valve closure means for actuating movement of the push rod associated with it, the weaker first valve closure means and second valve closure means being adapted to substantially in unison actuate the push rod downward and thereby return the valve to its closed position, the second valve closure means further being adapted to itself substantially actuate the push rod and rocker arm into their respective neutral positions.