Abstract: In a twin screw marine vessel that has two engines arranged in tandem along the vessel's centerline, a drive system allows both engines to drive the propellers or, alternatively, either engine to drive both propellers independently (e.g. one in forward, the other in reverse) while the other engine is disengaged and shut down. The output of each engine engages and disengages with one of two chain drives with the use of a clutch. A third clutch is provided between the two chain drives for selectively engaging and disengaging the chain drives with one another. An under/overdrive unit on the output of each chain drive is linked to a respective port or starboard V-drive via a universal drive shaft. Each V-drive has an internal transmission for selective clockwise or counter clockwise rotation of a correspondingly driven one of the port and starboard propellers. The under/overdrive units allow for a change in gear ratio between single engine and twin engine drive for maximum efficiency.

Abstract: A tappet comprising a body portion, a cam follower shoe having an arcuate cam engaging sole, a pivot pin supporting the cam follower shoe for rotation on the body portion of said tappet, and a removable shim for moving said shoe relative to the axis of reciprocation of the body portion of said tappet to vary valve timing.

Abstract: An improved cylindrical tappet for transmitting motion between a camshaft and a valve of an internal combustion engine. The tappet construction affords improved performance by permitting higher lift rates than possible with conventional tappet designs. In addition, cam and tappet face wear and cam walk are minimized due to the construction. The tappet consists of a body portion that is slidably supported in a bore of the engine adjacent to the cam lobe. The body portion has a pocket that is adapted to receive one end of a push rod for actuating the valve upon reciprocation of the tappet body portion. A follower portion is pivotally supported by the body portion about an axis that extends normally to the axis of rotation of the associated cam. The follower portion has a curved cylinder surface which engages the cam lobe and which has a substantially larger radius of curvature than the bore in which the tappet is supported.

Abstract: A valve train for an internal combustion engine that permits adjustment during running of the valve events. This is achieved by a follower having a pair of follower surfaces which may be moved while the engine is running to control both the point of opening and independently the point of closing of each valve.