Rolling contact rocker arm and pivot

A reciprocating internal combustion engine of the type having an engine block defining a cylinder with a port, a valve reciprocably located in said port and biased to a predetermined position, a valve actuator spaced from the valve and movable in opposite sense to reciprocate the same, and a valve train means including a rocker arm in engagement with the valve and the valve actuator and actuated in rocking movement to reciprocate said valve against said bias to open and close the port for engine operation, the improvement comprising:

• means defining a rocking support intermediate the length of the rocker arm, said means and said rocker arm defining a pair of cooperating inner and outer cylindrical surface contours carrying the reaction forces of rocker arm pivotal movement, the radius of the outer conformation being in the range of substantially two times the radius of the inner conformation;
• restrainer means to anchor the cooperating cylindrical conformations for substantially rolling action in relation to each other, said restrainer means comprising a pin extending radially outward from the inner conformation and into a recess in the outer conformation,
• said recess defining opposed sloping guide surfaces flaring outward in the direction toward the center of the outer conformation and over which the pin engages during rocker arm oscillation, the working surfaces of the pin being of semi-circular profile such that the pin moves in substantially walking motion during such reciprocation in substantial two-point contact with the opposed sloping guide surfaces,
• whereby within the range of rocker arm oscillation the pin establishes substantially rolling contact between the cylindrical surfaces by contact within the recess and itself executes substantially rolling contact with the guide surfaces defined by said recess.

In a valve train for an internal combustion engine of the type having a cylinder block means defining at least one cylinder with a port, a valve reciprocably mounted for controlling flow through the port, a rocker arm having one end thereof operatively associated with the valve, a fulcrum operatively associated with the rocker arm intermediate the ends thereof, a retainer means fixed to said cylinder block means and having a portion thereof extending through both the rocker arm and the fulcrum for holding these elements in operative engagement with each other and, an actuating means operatively associated with the rocker arm to effect rocking motion thereof to reciprocate said valve, the improvement wherein:

• said fulcrum defines a convex, semi-cylindrical fulcrum bearing surface, said fulcrum further including a retainer pin extending radially outward from said fulcrum bearing surface intermediate the ends thereof;
• and wherein, said rocker arm includes means defining a concave, semi-cylindrical bearing surface, said rocker arm further including a guide recess in said bearing surface of a size to operatively receive said retainer pin and defining a pair of opposed sloping guide surfaces for operative engagement by said retainer pin;
• the radius of said bearing surface being in the range of about 1.7 to 3 times the radius of said fulcrum bearing surface, whereby during oscillation of said rocker arm said retainer pin maintains substantially rolling contact between said bearing surfaces by engagement within said guide recess and in turn executes substantially rolling contact with the guide surfaces defined by said guide recess.

In a valve train for an internal combustion engine of the type having a cylinder block means defining at least one cylinder with a port, a valve reciprocably mounted for controlling flow through the port, a rocker arm having one end thereof operatively associated with the valve, a fulcrum operatively associated with the rocker arm intermediate the ends thereof, a retainer means fixed to said cylinder block means and having a portion thereof extending through both the rocker arm and the fulcrum for holding these elements in operative engagement with each other and, an actuating means operatively associated with the rocker arm to effect rocking motion thereof to reciprocate said valve, the improvement wherein:

• said fulcrum defines a convex, semi-cylindrical fulcrum bearing surface of a radius R, said fulcrum further including a retainer pin extending from said fulcrum bearing surface intermediate the ends thereof, said retainer pin having opposed semi-cylindrical working surfaces;
• and, wherein, said rocker arm includes means defining a concave, semi-cylindrical bearing surface of substantially a radius 2R, said rocker arm further including a guide recess in said bearing surface of a size to operatively receive said retainer pin and defining a pair of opposed sloping guide surfaces for operative engagement by said retainer pin, whereby during oscillation of said rocker arm said retainer pin maintains substantially rolling contact between said bearing surface and said fulcrum bearing surface by engagement with said guide surfaces and in turn has the working surfaces thereof in substantially rolling contact with the guide surfaces defined by said guide recess.

In an internal combustion engine of the type having a cylinder block with a valve reciprocably mounted therein and having a rocker arm operatively associated with the valve, a fulcrum means operatively associated with the rocker arm and, a retainer means fixed to the cylinder head and having a portion thereof extending through both the rocker arm and the fulcrum means for holding these elements in operative engagement with each other the improvement wherein:

• said rocker arm includes a pair of spaced apart side flanges extending upward from opposite longitudinal sides of a base having an aperture extending therethrough, said aperture being located intermediate the ends of said base and being sized so as to operatively receive the retainer means and, a pair of fixed opposed rocker members defining semi-cylindrical bearing surfaces extending transversely between said flanges toward said aperture, said bearing surfaces having a retainer pin means extending radially outward therefrom intermediate its ends;
• and, wherein said fulcrum means includes a semi-cylindrical fulcrum surface of a substantially uniform radius engaging said bearing surfaces of said rocker members, said fulcrum means further including a guide slot means defining opposed sloping guide surfaces which extend in a direction parallel to the axis of said fulcrum surface intermediate the ends thereof so as to operatively receive said retainer pin means, the radius of said fulcrum surface being in the range of about 3 to 1.7 times the radius of said bearing surfaces, whereby within the range of rocker arm oscillation said retainer pin means establishes substantially rolling contact between the bearing surfaces and said fulcrum surface by its contact with the guide surfaces with said retainer pin means being in substantially rolling contact with said guide surfaces.

In an internal combustion engine of the type having a cylinder block with a valve reciprocably mounted therein and having a rocker arm operatively associated with the valve, a fulcrum means operatively associated with the rocker arm and, a retainer means fixed to the cylinder head and having a portion thereof extending through both the rocker arm and the fulcrum means for holding these elements in operative engagement with each other the improvement wherein:

• said rocker arm includes a pair of spaced apart side flanges extending upward from opposite longitudinal sides of a base having an aperture extending therethrough located intermediate its ends and sized so as to operatively receive the retainer means and a pair of fixed opposed rocker members defining semi-cylindrical bearing surfaces extending transversely between said flanges toward said aperture, said bearing surfaces having a retainer pin means extending upward therefrom intermediate its ends, and wherein said fulcrum means includes a semi-cylindrical fulcrum surface of a substantially uniform radius engaging said bearing surfaces of said rocker members, said fulcrum means further including a guide slot means defining opposed sloping guide surfaces which extend in a direction parallel to the axis of said fulcrum surface intermediate the ends thereof so as to operatively receive said retainer pin means, the radius of said fulcrum surface means being substantially two times the radius of said bearing surfaces and the opposed working surfaces of said retainer pin means being of semi-cylindrical profile, whereby within the range of rocker arm oscillation said retainer pin means establishes substantially rolling contact between the bearing surfaces and said fulcrum surface by its contact with the guide surfaces with said retainer pin means being in substantially rolling contact with the guide surfaces defined by said guide slot means.

A reciprocating internal combustion engine of the type having an engine block defining a cylinder with a port, a valve reciprocably located in said port and biased to a predetermined position, a valve actuator spaced from the valve and movable in opposite sense to reciprocate the same, and a valve train means including a rocker arm in engagement with the valve and the valve actuator and actuated in rocking movement to reciprocate said valve against said bias to open and close the port for engine operation, the improvement comprising:

• means defining a rocking support intermediate the length of the rocker arm, said means and said rocker arm defining a pair of cooperating inner and outer bearing surfaces of semi-cylindrical configuration carrying the reaction forces of rocker arm pivotal movement, the radius of the outer bearing surface being in the range of about 3 to 1.7 times the radius of the inner bearing surface;
• restrainer means to anchor the cooperating cylindrical bearing surfaces for substantially rolling action in relation to each other, said restrainer means comprising a pin extending radially outward from the inner bearing surface and a recess in the outer bearing surface of a size to receive said pin,
• said recess defining opposed sloping guide surfaces of such degree of flare as to define substantially the envelope of the laterally most extended points of rolling contact between said bearing surfaces during rocker arm oscillation, the pin having opposed convex working surfaces of a profile so that said pin remains in said recess with the working surfaces thereof in substantially rolling engagement with said guide surfaces during said oscillation.

A reciprocating internal combustion engine of the type having an engine block defining a cylinder with a port, a valve reciprocably located in said port and biased to a predetermined position, a valve actuator spaced from the valve and movable in opposite sense to reciprocate the same, and a valve train means including a rocker arm in engagement with the valve and the valve actuator and actuated in rocking movement to reciprocate said valve against said bias to open and close the port for engine operation, the improvement comprising:

• means defining a rocking support intermediate the length of the rocker arm, said means and said rocker arm defining a pair of cooperating inner and outer bearing surfaces of semi-cylindrical configuration carrying the reaction forces of rocker arm pivotal movement, the radius of the outer bearing surface being in the range of about 3 to 1.7 times the radius of the inner bearing surface;
• restrainer means to anchor the cooperating cylindrical bearing surfaces for substantially rolling action in relation to each other, said restrainer means comprising a pin extending radially outward from the inner bearing surface and a recess in the outer bearing surface of a size to receive said pin,
• said recess defining opposed sloping guide surfaces of such degree of flare as to define substantially the envelope of the laterally most extended points of rolling contact between said bearing surfaces during rocker arm oscillation, the pin having opposed working surfaces located symmetrical about a line of symmetry passing through the center of curvature of said inner bearing surface and each working surface consisting of circular arcs whose centers of curvature lie on the contact points of said inner bearing surface with said outer bearing surface on the opposite side of said line of symmetry during rolling engagement between said bearing surfaces.

A reciprocating internal combustion engine of the type having an engine block defining a cylinder with a port, a valve reciprocably located in said port and biased to a predetermined position, a valve actuator spaced from the valve and movable in opposite sense to reciprocate the same, and a valve train means including a rocker arm in engagement with the valve and the valve actuator and actuated in rocking movement to reciprocate said valve against said bias to open and close the port for engine operation, the improvement comprising:

• means defining a rocking support intermediate the length of the rocker arm, said means and said rocker arm defining a pair of cooperating inner and outer cylindrical bearing surface contours carrying the reaction forces of rocker arm pivotal movement, the radius of the outer conformation being in the range of about 3 to 1.7 times the radius of the inner conformation;
• restrainer means to anchor the cooperating cylindrical conformations for substantially rolling action in relation to each other, said restrainer means comprising a pin extending radially outward from the inner conformation and a recess in the outer conformation of a size to receive said pin,
• said recess defining opposed sloping guide surfaces flaring outward in the direction toward the center of the outer conformation and of such degree of flare as to define substantially the envelope of the laterally most extended contact points on the pin as its translation and rotation is traced so that the pin substantially walks over the guide surfaces during rocker arm oscillation, the conformation of the pin being such that each successive point of contact thereof on an associate guide surface falls on an imaginary line that extends for the point of contact between said bearing surface through said point which line is substantially perpendicular to that guide surface so that the pin moves in substantially walking motion during such reciprocation,
• whereby within the range of rocker arm oscillation the pin establishes substantially rolling contact between the cylindrical surfaces by contact with the guide surfaces of the recess and itself executes substantially rolling contact with the guide surfaces defined by the recess.