Internal-combustion engines – Transmission mechanism from piston – Crankshaft and connecting rod
Reexamination Certificate
1998-10-22
2001-03-20
McMahon, Marguerite (Department: 3747)
Internal-combustion engines
Transmission mechanism from piston
Crankshaft and connecting rod
Reexamination Certificate
active
06202622
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of Invention
The instant invention relates to a crank mechanism designed specifically for internal combustion engines to maximize the transfer of combustion power from the linear motion of the piston to the circular motion of the crankshaft.
2. Description of the Prior Art
Next to the wheel, the crank is the most significant motion-transmitting system-device used as a means of converting linear motion to circular motion, and vice-versa. The device involves a connecting rod acting on a crank pin to rotate a crankshaft. Its origin was traced back to China in 100 BC, and that the first connecting rod appeared in Europe in 830 AD. In other words, this prior and old crank system-device has been a part of public domain since the birth of mechanical science, patented to no one.
The crank is proven to have worked well in various applications, such as in pumps, jig saws, electric motors, and such other tools and equipment needing to convert the linear motion of one component into a circular motion of another component to effect a desired function. However, when applied to an internal combustion engine, this prior crank mechanism does not work well in transmitting combustion power from the linear motion of the piston to the circular motion of the crankshaft. Only a portion of original power is transmitted from the piston to the crankshaft due to certain mechanical limitations imposed by the crank itself in compliance with the engine's fuel-ignition system.
It is the function of the engine crank to convert heat energy into mechanical energy. During the power stroke, the explosion pushes down the piston to act on the crank pin and rotate the crankshaft. It is along the piston's downward axis, otherwise known as the Piston Centerline, that the push-down pressure of the piston is concentrated on. Unfortunately, under the prior art, the piston is not actually pushing the crank pin downwards along the piston centerline, but rather sideways and away from the piston centerline. The Lever Principle dictates that the farther away the crank pin is from the piston's downward axis where the force is concentrated, the lesser “push-down” pressure the piston exerts on the crank pin. Such is the case of the prior art. At the height of the explosion pressure, a substantial portion of the piston's push-down power cannot be transmitted downwards to the crankshaft because of the sideway travel of the crank pin to which the piston is mechanically linked through the connecting rod. It is a fact that only a mere 15%, or so, of the combustion power reaches the wheel to turn it. The downward tendency of most of the combustion pressure to push down the piston is hindered by the sideway travel of the crank pin to the far right, forcing the expanding hot gas to seek other avenues of escape through the cylinder walls, causing the bulk of the engine heat.
Thus, the term “Sideway Power Path” is hereby used to refer and describe the travel path of the crank pin during power stroke, starting from the piston centerline, moving sideways and away from the piston centerline. Such crank mechanism, as characterized in all internal combustion engines, has been the automotive industry's one and only standard for more than a century now. From the time a Belgian-French Etienne Lenoir invented the 2-stroke cycle internal combustion engine in 1857; as well as the 4-stroke cycle engine invented by yet another French engineer Alphonse Beau de Rochas in 1862; until a German engineer Nikolaus Otto successfully built the first 4-stroke cycle engine in 1876 using coal gas as fuel; up to the time Gottlieb Daimler and Carl Benz of Germany introduced their respective Horseless Carriages around 1885 using gasoline as fuel; followed by the introduction of the diesel engine in 1892 by another German Rudolph Diesel; until the time that American industrialist Henry Ford started mass-producing his affordable T-Model motor vehicles in 1908; and up to the time of this patent application (October, 1998), the prior and old crank mechanism used in all the aforesaid internal combustion engines (wherein the piston pushes the crank pin sideways and away from the piston centerline) has remained exactly the same . . . Unchanged.
SUMMARY OF THE INVENTION
Objects and Advantages
Accordingly, it is the object of the instant invention to do away with the shortcomings of the prior crank system (when applied to piston-type internal combustion engines) by providing a means for the piston to have more mechanical leverage in pushing down the crank pin to rotate the crankshaft.
As stated, it is the “Sideway Power Path” of the prior art, wherein the piston pushes the crank pin sideways and away from the piston centerline, that hinders the efficient transfer of combustion power from the piston to the crankshaft. Thus, the new crank system hereby provides for a “Downward Power Path”, to replace the prior art's “Sideway Power Path”, whereby, this time, the piston is able to push the crank pin downwards and close to the piston centerline. Such cranking alternative is in resonance with the Lever Principle that the closer the crank pin is to the piston's downward axis or piston centerline, the more push-down pressure the piston exerts on the crank pin, and thus increasing the twisting force of the crankshaft. In a layman's language, if you want to push down something, push it directly from above, not from the side, to maximize the transfer of power energy from the source to the receiving end.
Operation
Actually, both power paths (Sideway Power Path for the prior art, and Downward Power Path for the invention) are downward in nature because they start from the top (from zero-degree position of the crank pin, moving downwards until 120 degrees thereafter). For purposes of the instant invention, however, what makes a power path either sideways or downwards is its directional travel in relation to the piston centerline where the combustion power is concentrated on. Since the power path under the prior art starts from the piston centerline, moving sideways towards the right and away from the piston centerline, it is regarded as a “Sideway Power Path” in relation to the piston centerline. In the case of the invention, since the power path starts by crossing the piston centerline, moving downwards and close to the piston centerline, then crossing it back at the end of the power stroke, it is regarded as a “Downward Power Path” in relation to the piston centerline. Again, it is hereby emphasized that the “Piston Centerline” is “The” determining factor because it is along this line that the combustion power, through the push-down pressure of the piston, is concentrated on. Considering that the piston does not transmit power directly to the crankshaft but through the crank pin, the output twisting power of the crankshaft therefore depends on “how far” or “how close” the crank pin is to the piston centerline during the power stroke of the combustion cycle.
Following the foregoing line of reasoning, therefore, the only way to bring the power path closer to the piston centerline, is to reposition the crankshaft in relation to the piston centerline. From its prior and usual position along the piston centerline, the crankshaft is moved to the left side of the centerline, thereby also moving the power path of the crank pin to the left, and placing it directly under the piston's downward axis along the piston centerline. The heart of the new system, therefore, lies on an “off-center” position of the crankshaft in relation to the piston centerline which, not only brings the power path closer to or directly along the piston centerline, but also changes the nature of the crank pin's power path, from sideways to downwards. Thus, the term “Off-Center Crankshaft” is hereby used to described the position of the crankshaft away from the piston centerline (to the left side thereof, or right side as the case may be), as against the “Centerline Crankshaft” of the prior art wherein the crankshaft is collinear with t
Benton Jason
McMahon Marguerite
Sulit Florante G.
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