Abstract: A cam follower assembly having a plastic guide body and a cam follower having two opposing roller shaft ends is provided. The single piece guide body includes a pair of grooved members. Each of the grooved members include an interior surface defining an elongated guide groove having a recessed surface. The elongated guide grooves are facing and aligned with each other. The cam follower is disposed between the pair of grooved member such that one of the roller shaft ends is received in one guide groove and the opposite roller shaft end is received in the other of the guide groove. The roller shaft ends are slidable in a reciprocal axial direction within the elongated guide grooves and retained between the recessed surfaces. The plastic guide body may be injection molded from a nylon material having glass fibers.

Abstract: A cam follower assembly having a plastic guide body and a cam follower having two opposing roller shaft ends is provided. The single piece guide body includes a pair of grooved members. Each of the grooved members include an interior surface defining an elongated guide groove having a recessed surface. The elongated guide grooves are facing and aligned with each other. The cam follower is disposed between the pair of grooved member such that one of the roller shaft ends is received in one guide groove and the opposite roller shaft end is received in the other of the guide groove. The roller shaft ends are slidable in a reciprocal axial direction within the elongated guide grooves and retained between the recessed surfaces. The plastic guide body may be injection molded from a nylon material having glass fibers.

Abstract: A valve lifter assembly for deactivating a cylinder in an internal combustion engine. The valve lifter assembly is provided with a plunger movably disposed within a bore of a main body member to controllably isolate the cam lift from the rocker arm and valve of the engine. The plunger is normally locked in an extended position to transmit cam lift to reciprocatingly operate the valve. At least one locking pin is moveably disposed within the plunger to engage an inner annular groove of the main body member. Pressurized oil is provided to dislodge the locking pins from the annular groove and allow the plunger to move within the main body member, thereby isolating the cam lift from the rocker arm and valve. The deactivating lifter is preferably disposed within the recess conventionally provided for hydraulic valve lifters.

Abstract: A method for distributing lock pin ejections evenly over all the switchable mechanisms in a plurality of switchable mechanisms: establishing a limiting number of lock pin ejections; designating a primary switchable mechanism for the mode change upon command from an engine control module (ECM); employing the designated primary switchable mechanism until the limit is reached; designating another switchable mechanism a primary; employing the second primary mechanism until the limit is reached again; and designating sequentially each of the remaining switchable mechanisms as primary switchable mechanisms, each until the limit is reached again. The ECM counts the activation commands and switches the primary designation when the limit is reached so that each mechanism has the same exposure to ejections, and the number of ejections per mechanism is evenly distributed.

Abstract: Valve lift variation associated with a deactivation roller hydraulic valve DRVHL (DRHVL) can result in unacceptable valve overlap and idle conditions for an internal combustion engine. Two sources of length variation in a DRHVL are leakdown and residual mechanical lash. Total length variation is the sum of these two factors, and each factor has an associated tolerance. In the prior art, the two factors are independent, resulting in a total population variation that is the sum of the two independent variations. A DRHVL assembly process in accordance with the invention includes the step of associating leakdown test results for individual lash adjusters with residual lash results by adjusting the residual lash characteristics of individual DRHVL assemblies to complement the leakdown characteristics in minimizing total length variation in the population of assembled DRHVLs.

Abstract: A deactivation valve lifter includes a lifter body. The lifter body has a first end configured for engaging a cam of an engine and at least one annular pin chamber. A pin housing includes a pin housing bottom. The pin housing bottom defines at least one pin stop aperture and a radially directed pin bore. A deactivation pin assembly is disposed within the pin bore and includes pin members. The pin housing is concentrically disposed within the lifter body. A portion of each pin member may be disposed within the annular pin chamber to thereby selectively couple and decouple the lifter body to the pin housing. A drain aperture defined by the pin housing bottom extends from the pin bore to an outside surface of the pin housing. A stop pin is disposed in the at least one pin stop aperture for limiting the inward motion of the pin members.

Abstract: A deactivation valve lifter includes a lifter body. The lifter body has a first end configured for engaging a cam of an engine and at least one annular pin chamber. A pin housing includes a pin housing bottom. The pin housing bottom defines at least one pin stop aperture and a radially directed pin bore. A deactivation pin assembly is disposed within the pin bore and includes pin members. The pin housing is concentrically disposed within the lifter body. A portion of each pin member may be disposed within the annular pin chamber to thereby selectively couple and decouple the lifter body to the pin housing. A drain aperture defined by the pin housing bottom extends from the pin bore to an outside surface of the pin housing. A stop pin is disposed in the at least one pin stop aperture for limiting the inward motion of the pin members.

Abstract: A deactivation valve lifter includes a lifter body. The lifter body has a first end configured for engaging a cam of an engine and at least one annular pin chamber. A pin housing includes a pin housing bottom. The pin housing bottom defines at least one pin stop aperture and a radially directed pin bore. A deactivation pin assembly is disposed within the pin bore and includes pin members. The pin housing is concentrically disposed within the lifter body. A portion of each pin member may be disposed within the annular pin chamber to thereby selectively couple and decouple the lifter body to the pin housing. A drain aperture defined by the pin housing bottom extends from the pin bore to an outside surface of the pin housing. A stop pin is disposed in the at least one pin stop aperture for limiting the inward motion of the pin members.

Abstract: A two-step roller finger follower having a high-lift follower portion that rotates relative to a low-lift follower portion about a pivot shaft, including a lost-motion compression spring disposed in a linear bore formed in the high-lift portion to exert force against an curved pad on the back side of the valve pallet of the low-lift portion. The spring is retained and guided in its bore by a spring retainer having a planar bottom for engaging the curved pad. Preferably the retainer is a cup positioned in the spring bore such that the stroke of the cup is limited, to prevent leak-down of the associated hydraulic lash adjuster. Driving the spring by a linear-acting retainer in a linear bore causes the spring to be compressed linearly, resulting in a highly stable and predictable spring rate.

Abstract: An improved dual feed hydraulic lash adjuster (HLA), for use in an internal combustion engine, comprising a hollow body and a plunger assembly disposed in a bore of the engine. A one-piece plunger body includes a first chamber for forming a low-pressure oil reservoir and receiving a lash adjustment mechanism, and a second chamber open at one end and partially closed hemispherically for supporting a rocker arm and providing valve deactivating oil thereto for an auxiliary valve actuation system. The first and second chambers are separated by a transverse web, optionally having a small-diameter passage therethrough for air evacuation. The one-piece plunger body provides a high degree of resistance to side loads which may be imposed on the HLA in use.

Abstract: A roller finger follower rocker arm assembly for deactivating an engine valve. A follower body pivots on a hydraulic lash adjuster, and engages a valve stem or lifter. The body receives a reciprocating member having a first and second rollers outboard of the body for following eccentrics of a cam lobe that straddles the body, the body having elongate openings on either side of the reciprocating member. A locking pin selectively locks and unlocks the body to the reciprocating member. The reciprocating member does not make contact with the cam lobe and functions only as a link between the latching mechanism and the rollers. The pin engages the reciprocating member by a latching spring and is disengaged by pressurized oil supplied through the hydraulic lash adjuster. Means is provided for limiting axial growth of the HLA during deactivation mode of the rocker arm assembly.

Abstract: A valve deactivation lifter including means for restricting relative rotation between the pin housing and the lifter body. When used in a V-style or slant engine, a prior art deactivation lifter can be subject to oil drainage during engine shutdown if the oil supply port in the pin housing rests in the “down” position. In an improved lifter, relative rotation between the pin housing and the lifter body is limited and the pin housing is oriented such that the oil supply port is never on the underside of the pin housing. Rotation may be limited by any of several means, for example, a ball disposed in a dimple in the pin housing and extending into a longitudinal groove in the lifter body, and a flat on the pin housing and locking means installed in the lifter body to engage the flat and thus prevent rotation of the pin housing.

Abstract: A valve deactivation lifter including means for restricting relative rotation between the pin housing and the lifter body. When used in a V-style or slant engine, a prior art deactivation lifter can be subject to oil drainage during engine shutdown if the oil supply port in the pin housing rests in the “down” position. In an improved lifter, relative rotation between the pin housing and the lifter body is limited and the pin housing is oriented such that the oil supply port is never on the underside of the pin housing. Rotation may be limited by any of several means, for example, a ball disposed in a dimple in the pin housing and extending into a longitudinal groove in the lifter body, and a flat on the pin housing and locking means installed in the lifter body to engage the flat and thus prevent rotation of the pin housing.

Abstract: A deactivation valve lifter includes a lifter body. The lifter body has a first end configured for engaging a cam of an engine and at least one annular pin chamber. A pin housing includes a pin housing bottom. The pin housing bottom defines at least one pin stop aperture and a radially directed pin bore. A deactivation pin assembly is disposed within the pin bore and includes pin members. The pin housing is concentrically disposed within the lifter body. A portion of each pin member may be disposed within the annular pin chamber to thereby selectively couple and decouple the lifter body to the pin housing. A drain aperture defined by the pin housing bottom extends from the pin bore to an outside surface of the pin housing. A stop pin is disposed in the at least one pin stop aperture for limiting the inward motion of the pin members.

Abstract: A valve deactivation system includes a deactivation rocker arm assembly and a free motion spring assembly. The deactivation rocker arm assembly includes an elongate rocker arm defining an aperture. A center post is slidingly disposed within the aperture. The center post is configured for engaging a valve stem of a valve of an internal combustion engine. Coupling means selectively couple together and decouple the center post and the rocker arm. The free motion spring assembly includes an inner spring retainer surrounding a portion of the valve stem. An outer spring retainer surrounds a portion of the valve stem. An inner spring surrounds a portion of the valve stem between the inner spring retainer and a disk cap associated with the valve stem. An outer spring surrounds the inner spring.