Valve clearance adjustment mechanism

An internal combustion engine, comprising:

• an engine housing including therein at least one rotatable cam lobe, at least one valve, and at least one valve actuator periodically engaging said cam lobe to actuate said valve, wherein a clearance space is defined between said valve actuator and said valve when said lifter is not engaged by said cam lobe;
• and
• a mechanism for adjusting said clearance space, comprising:
• a shaft having a head portion, said shaft adjustably securable to said engine housing between first and second positions;
• and
• an adjustment member mounted to said shaft, said adjustment member having an eccentric portion upon which said valve actuator is pivotally mounted, wherein when said shaft is in said first adjustment position, said adjustment member may be rotated upon said shaft to move said valve actuator and vary said clearance space, and when said shaft is in said second adjustment position, said adjustment member is captured between said shaft head portion and said engine housing to fix the position of said adjustment member.

In combination:

• an internal combustion engine including a cam having a lobe periodically engaging a valve actuator to actuate a valve within a housing of said engine, wherein a clearance space exists between said valve actuator and said valve when said valve actuator is out of engagement with said lobe;
• and
• a valve clearance adjustment mechanism, comprising;
• an eccentric adjustment member upon which said valve actuator is pivotably mounted, said adjustment member adjustable to vary the location of said valve actuator and said clearance space;
• and
• a shaft upon which said adjustment member is rotatably mounted, said shaft engageable with said engine housing to fix the rotational position of said adjustment member and thereby set said clearance space.

An internal combustion engine comprising:

• a cam having a lobe periodically engaging a valve actuator to actuate a valve within a housing of said engine, wherein a clearance space exists between said valve actuator and said valve when said valve actuator is out of engagement with said lobe;
• and
• a valve clearance adjustment mechanism, comprising;
• a shaft supported by said engine housing;
• an eccentric adjustment member rotatably mounted upon said shaft and adjustably supporting said valve actuator, said adjustment member including at least one stop portion engageable with said engine housing to limit the rotation of said adjustment member such that corresponding adjustment of said valve actuator is substantially confined to movement of said valve actuator in a direction parallel to said valve.