Internal-combustion engines – Frame construction – Horizontal cylinder
Reexamination Certificate
1999-10-19
2001-05-01
Kamen, Noah P. (Department: 3747)
Internal-combustion engines
Frame construction
Horizontal cylinder
C440S084000
Reexamination Certificate
active
06223712
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to internal combustion engines and particularly to an internal combustion engine suitable for use in propelling a personal watercraft. Still more particularly, this invention relates to an internal combustion engine and power transmission combination for a personal watercraft that a rider can steer by adjusting his stance and position thereon
Previously available engine/transmission combinations for personal watercraft have height and width that are too large for use in a thin, light weight hull. Excessive height contributes to instability so that the hull has a tendency to roll, which causes difficulty in controlling the watercraft.
SUMMARY OF THE INVENTION
This invention provides a reciprocating piston engine that has a very small height so that the engine is suitable for use in applications having stringent height limitations. An engine/transmission system according to the present invention can include either a two-stroke or four-stroke engine.
The engine according to the present invention may be constructed to have a height of about 6.5 inches. The low height of the engine permits the fully assembled personal watercraft to have a lower center of gravity than was possible using previously available engines transmission combinations. The dimensions of the engine allow it to be mounted under the deck portion where the rider normally stands on a personal watercraft. This mounting location concentrates more weight near the desired axis about which the watercraft turns and allows the center of gravity of the watercraft to be under the rider, which allows the rider to turn the watercraft more easily and safely.
The engine drives a belt and gear that is used to make the engine provide an output that is parallel to the direction of motion of the piston. The engine output is therefore suitable for providing rotational energy to drive a jet pump to propel a personal watercraft.
An internal combustion engine according to the present invention comprises an engine block having a plurality of cylindrical passages therein. A piston is arranged to move reciprocally in a predetermined direction relative to the engine block. A drive shaft is mounted in a first one of the cylindrical passages in the engine block and connected to the piston and arranged to be driven by the piston in rotational motion about a first axis perpendicular to the direction of motion of the piston. The invention further includes means for transferring rotational motion of the drive shaft to a first shaft that is mounted in the engine block parallel to the drive shaft; and means for transferring rotational motion of the first shaft to a second shaft such that the engine produces a rotational output about an output axis that is parallel to the direction of reciprocal motion of the piston.
The means for transferring rotational motion of the drive shaft to the first shaft preferably includes a drive pulley mounted to the drive shaft for driving a belt and an output pulley mounted to the first shaft. The means for transferring rotational motion of the first shaft to the second shaft preferably includes a first gear mounted to the first shaft and a second gear mounted to the second shaft and arranged to mesh with the first gear and be driven in rotational motion thereby such that the engine provides a rotational output about an output axis that is parallel to the direction of reciprocal motion of the piston.
The engine according to the present invention preferably further comprises a rod connected to the piston and a first crankshaft assembly that includes a first crank, the drive shaft extending from the first crank and arranged to rotate concentrically therewith about the first axis, the first crank having a cylindrical cavity therein displaced laterally from the drive shaft. A second crankshaft assembly that includes a second crank and a crank pin is connected to the second crank arranged to extend through a passage in an end of the rod so that reciprocal motion of the piston moves the crank pin in circular motion. The crank pin is further arranged to extend into the cylindrical cavity in the first crank such that circular motion of the crank pin as the second crank rotates causes rotation of the first crank and the drive shaft.
The engine according to the present invention preferably further comprises a starter bendix mounted in a third passage in the engine block and a starter gear mounted to the drive shaft adjacent the starter bendix. A starter motor is mounted to the starter bendix and arranged such that application of electrical power to the starter motor causes rotation of the starter bendix, the starter gear and the drive shaft to start the engine.
An appreciation of the objectives of the present invention and a more complete understanding of its structure and method of operation may be had by studying the following description of the preferred embodiment and by referring to the accompanying drawings.
Kamen Noah P.
Lynn & Lynn
LandOfFree
Personal watercraft engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Personal watercraft engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Personal watercraft engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2443448