Valve control apparatus with reset

A valve control apparatus for an internal combustion engine having a valve and a camshaft, the camshaft having an axis of rotation, a first raised portion and a second raised portion, the second raised portion being angularly spaced-apart about the axis from the first raised portion, the apparatus comprising:

• a follower operatively engagable with the camshaft and the valve, the follower having a first operational mode where the first raised portion operatively engages the follower on each revolution of the camshaft to open said valve a first time on each revolution on the camshaft and where the second raised portion operatively clears the follower on each revolution of the camshaft without actuating said valve;
• and
• a mechanism for selectively putting the follower in a second operational mode where the second raised portion operatively engages the follower to open said valve a second time on each revolution of the camshaft, the mechanism putting the follower in the second operational mode on each revolution of the camshaft before the second raised portion rotates completely to alignment with the follower, the mechanism having a device which returns the follower to the first operational mode after the valve is opened by the second raised portion and before the first raised portion fully opens the valve, whereby maximum opening and normal closing of the valve by the first raised portion is unaffected when the mechanism selectively puts the follower in the second operational mode, the device being triggered by the camshaft, the device including a hydraulic piston in a hydraulic cylinder, the piston operatively contacting the valve, a check valve which prevents fluid from exiting the hydraulic cylinder and a member which unseats the check valve when contacted by the first raised portion.

A valve control apparatus for an internal combustion engine having an exhaust stroke and a compression stroke, an exhaust valve and a camshaft, the camshaft having an axis of rotation, a first raised portion and a second raised portion, the first raised portion being positioned on the camshaft to open the exhaust valve on the exhaust stroke of the engine, the second raised portion being angularly spaced-apart about the axis from the first raised portion, and being positioned on the camshaft to open the exhaust valve near top dead center of the compression stroke, the apparatus functioning as a compression release brake and comprising:

• a follower operatively engagable with the camshaft and the valve, the follower having a first operational mode where the first raised portion operatively engages the follower on each revolution of the camshaft to open said valve a first time on each revolution on the camshaft and where the second raised portion operatively clears the follower on each revolution of the camshaft without actuating said valve;
• and
• a mechanism for selectively putting the follower in a second operational mode where the second raised portion operatively engages the follower to open said valve a second time on each revolution of the camshaft, the mechanism putting the follower in the second operational mode on each revolution of the camshaft before the second raised portion rotates completely to alignment with the follower, the mechanism having a device which returns the follower to the first operational mode after the valve is opened by the second raised portion and before the first raised portion fully opens the valve, whereby maximum opening and normal closing of the valve by the first raised portion is unaffected when the mechanism selectively puts the follower in the second operational mode, the device being triggered by the camshaft.

An internal combustion apparatus comprising:

• an engine having a plurality of cylinders, an exhaust stroke and a compression stroke, each said cylinder having an exhaust valve;
• a camshaft, the camshaft having an axis of rotation, a first raised portion and a second raised portion, the first raised portion being positioned on the camshaft to open the exhaust valve on the exhaust stroke of the engine, the second raised portion being angularly spaced-apart about the axis from the first raised portion and being positioned on the camshaft to open the exhaust valve near top dead center of the compression stroke, whereby the apparatus functions as a compression release brake, the first raised portion and the second raised portion being on one cam of the camshaft, the one cam having a lower base circle, the second raised portion being on the lower base circle and the first raised portion being a lobe;
• a follower operatively engagable with the camshaft and with the valve of said each cylinder, the follower having a first operational mode where the first raised portion operatively engages the follower on each revolution of the camshaft to open said valve a first time and where the second raised portion operatively clears the follower on each revolution of the camshaft without actuating said valve;
• and
• a mechanism for selectively putting the follower in a second operational mode where the second raised portion operatively engages the follower to open said valve a second time on each revolution of the camshaft, the mechanism putting the follower in the second operational mode on each revolution of the camshaft before the second raised portion is fully aligned with the follower, the mechanism having a hydraulic device for returning the follower to the first operational mode after the valve is opened by the second raised portion and before the first raised portion fully operatively engages the follower, whereby maximum opening and normal closing of the valve by the first raised portion is unaffected when the mechanism selectively puts the follower in the second operational mode, the device being triggered by the camshaft, said device including a chamber for hydraulic fluid, said chamber being closed and full of hydraulic fluid in one said operational mode and being opened to allow a discharge of said hydraulic fluid in another said operational mode.

A valve control apparatus for an internal combustion engine having an exhaust valve and a camshaft, the camshaft having an axis of rotation, a first raised portion and a second raised portion, the second raised portion being angularly spaced-apart about the axis from the first raised portion, the apparatus comprising:

• a rocker arm assembly operatively engagable with the camshaft and the valve, the assembly having a first operational mode where the first raised portion operatively engages the follower on each revolution of the camshaft to open said valve a first time on each revolution on the camshaft and where the second raised portion operatively clears the assembly on each revolution of the camshaft without actuating said valve, the assembly including a mechanism for selectively putting the assembly in a second operational mode where the second raised portion operatively engages the follower to open said valve a second time on each revolution of the camshaft, the mechanism putting the assembly in the second operational mode on each revolution of the camshaft before the second raised portion rotates completely to alignment with the follower, the mechanism having a device which returns the assembly to the first operational mode after the valve is opened by the second raised portion and before the first raised portion fully opens the valve, whereby maximum opening and normal closing of the valve by the first raised portion is unaffected when the mechanism selectively puts the follower in the second operational mode, the device being triggered by relative movement between a portion of the rocker arm assembly and the valve.

An internal combustion apparatus comprising:

• an engine having a plurality of cylinders, each said cylinder having an exhaust valve;
• a camshaft, the camshaft having an axis of rotation, a first raised portion and a second raised portion, the second raised portion being angularly spaced-apart about the axis from the first raised portion;
• a rocker arm operatively engagable with the camshaft and with the valve of said each cylinder, the rocker arm having a first operational mode where the first raised portion operatively engages the rocker arm on each revolution of the camshaft to open said valve a first time and where the second raised portion operatively clears the follower on each revolution of the camshaft without actuating said valve;
• and
• a mechanism for selectively putting the rocker arm in a second operational mode where the second raised portion operatively engages the rocker arm to open said valve a second time on each revolution of the camshaft, the mechanism putting the rocker arm in the second operational mode on each revolution of the camshaft before the second raised portion is fully aligned with the rocker arm, the mechanism having a device for returning the rocker arm to the first operational mode after the valve is opened by the second raised portion and before the first raised portion fully operatively engages the rocker arm, whereby maximum opening and normal closing of the valve by the first raised portion is unaffected when the mechanism selectively puts the rocker arm in the second operational mode, the device being triggered by the relative movement between a portion of the rocker arm assembly and the valve.