Abstract:
A two-stroke engine utilizing a piston with two sets of intake ports, such that the first set of intake ports of the piston are positioned on the piston such that it is in alignment with the fuel intake when the piston has cycled to the bottom position, permitting the flow of fuel into the crankcase. The second set of intake ports of the piston are positioned such that they are at least partially in alignment with the fuel intake when the piston is cycling from the bottom position to the compression position, permitting the flow of fuel into the crankcase during the alignment.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates two stroke engines, and more specifically but not by way of limitation, to a two-stroke engine utilizing multi-port pistons to increase the amount of fuel directed into the crankcase of the engine by the vacuum created during the upward stroke of the piston.  
       BACKGROUND  
       [0002]     Two-stroke engines are found in devices such as chain saws and personal watercraft because two-stroke engines have some important advantages over four-stroke engines. Two-stroke engines do not have valves, which simplifies their construction and lowers their weight.  
         [0003]     Two-stroke engines fire once every revolution, while four-stroke engines fire once every other revolution. This gives two-stroke engines a significant power boost. Two-stroke engines can work in any orientation, which can be important in something like a chainsaw. A standard four-stroke engine may have problems with oil flow unless it is upright, and solving this problem can add complexity to the engine.  
         [0004]     These advantages make two-stroke engines lighter, simpler and less expensive to manufacture. Two-stroke engines also have the potential to pack about twice the power into the same space as a four-stroke engine because there are twice as many power strokes per revolution.  
         [0005]     The combination of lightweight and twice the power gives two-stroke engines a great power-to-weight ration compared too many four-stroke engine designs.  
         [0006]     In a typical two-stroke reed valve engine, the operation cycle is straightforward. When the fuel and air in the cylinder have been compressed by the piston, the spark plug fires igniting the fuel mixture. The resulting explosion drives the piston downward. When the piston moves downward, it compresses the air/fuel mixture in the crankcase. As the piston approaches the bottom of its stroke, the exhaust port is uncovered. The pressure in the cylinder drives most of the exhaust gases out of cylinder.  
         [0007]     As the piston finally bottoms out, the intake port is uncovered. Because the piston&#39;s movement has pressurized the mixture in the crankcase, the mixture in the crankcase rushes into the cylinder, displacing the remaining exhaust gases and filling the cylinder with a fresh charge of fuel.  
         [0008]     The momentum in the crankshaft starts driving the piston back toward the spark plug for the compression stroke. As the air/fuel mixture in the piston is compressed, a vacuum is created in the crankcase. This vacuum opens the reed valve and sucks air/fuel/oil in from the carburetor.  
         [0009]     Once the piston makes it to the end of the compression stroke, the spark plug fires again to repeat the cycle.  
         [0010]     The piston is doing three different things in a two-stroke engine. On one side of the piston is the combustion chamber, where the piston is compressing the air/fuel mixture and capturing the energy released by the ignition of the fuel. On the other side of the piston is the crankcase, where the piston is creating a vacuum to suck in air/fuel from the carburetor through the reed valve and then pressurizing the crankcase so that air/fuel is forced into the combustion chamber.  
         [0011]     The sides of the piston are acting like valves, covering and uncovering the intake and exhaust ports.  
         [0012]     As can be appreciated with all types of engines there is a desire to improve the amount power generated by an engine, especially with two-stroke engines where the types of use of the engine dictates that the space for the engine is very limited.  
       SUMMARY OF THE INVENTION  
       [0013]     It is the object of the present invention to provide an internal combustion two-stroke engine with improved power output.  
         [0014]     It is another object of the present invention to provide a two-stroke engine utilizing multiple offset intake ports on the pistons to increase the amount of fuel mixture that can enter the engine per stroke, as well as provide additional lubrication.  
         [0015]     To the accomplishment of the above and related objects, the present invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact that the drawings are illustrative only. Variations are contemplated as being a part of the present invention, limited only by the scope of the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     A more complete understanding of the present invention may be had by reference to the following Detailed Description and appended claims when taken in conjunction with the accompanying Drawings wherein:  
         [0017]      FIG. 1  is a top perspective view of a piston in accordance with an embodiment of the present invention; and  
         [0018]      FIG. 2  is a side view of an embodiment of the present invention illustrating a piston within a sectional view of a two-stroke engine. 
     
    
     DETAILED DESCRIPTION  
       [0019]     Referring now to the Figures, wherein the various elements depicted therein are not necessarily drawn to scale, and wherein like elements are designated with identical reference numerals throughout the views and Figures, and in particular to  FIG. 1  there is illustrated a piston  100  constructed according to the principles of the present invention.  
         [0020]     Piston  100  includes a head  110 , piston rings  112  and  114 , and a body  120 . Head  110  is generally solid, while body  120  is hollow and generally cylindrical in shape and extends down from head  110 . Body  120  includes two sets of intake ports  130  and  140 , with intake ports  130  and  140  being offset from each other, with intake ports  130  more proximate head  110  than intake ports  140 . A hole  150  is configured to receive a connecting rod. Intake ports  130  and  140  are holes, which extend from through the wall of body  120 . In the preferred embodiment, intake ports  130  include 3 generally circular holes, and intake ports  140  include 2 generally square holes, however, it is contemplated to be within the scope of this invention that the number, shape, and size of ports for each of intake ports  130  and  140  could be varied based upon a number of factors, including but not limited to the size of the body  120  and a users preference. For example, but not by way of limitation, good results have been achieved with intake ports  130  being three-eighths of an inch holes, located one-eighth of an inch below piston ring  114 .  
         [0021]     Referring now to  FIG. 2 , there is illustrated sectional view of a two-stroke-engine  200  utilizing piston  100 . Two-stroke engine  200  includes a cylinder  210  with a portion of cylinder  210  forming a combustion chamber  220 . Combustion chamber  220  is delimited by piston  100 , which is reciprocally moveable in cylinder  210 . Piston  100  drives a crankshaft  230  via a connecting rod  232 . The crankshaft  230  is rotatably positioned within crankcase  250 . Crankcase  250  is connected to combustion chamber  220  via transfer channel  252  and permits the flow of the fuel/mixture from crankcase  250  to combustion chamber  220  when the head  110  of piston  100  is below the upper opening of transfer channel  252 .  
         [0022]     Two-stroke engine  200  includes an intake channel  240 , which opens into cylinder  210 . Intake channel  240  is configured to deliver an air/fuel mixture to two-stroke engine  200  from a carburetor. A reed valve  242  is connected within channel  240  to permit the flow of the air/fuel mixture from the carburetor to cylinder  210  and to inhibit the flow of any exhaust or air/fuel mixture from cylinder  210  back into intake channel  240 .  
         [0023]     Two-stroke engine  200  includes an exhaust  260 , which opens up and leads out from combustion chamber  220 . Exhaust  260  is configured to discharge exhaust materials from combustion chamber  220 .  
         [0024]     Two-stroke engine  200  also includes a spark plug  270 , which is mounted at the top of two-stroke engine  200  and extends into combustion chamber  220 .  
         [0025]     Referring now to  FIGS. 1 and 2  the operation cycle of two-stroke engine  200  will now be described. When piston  100  cycles in the up position, the air/fuel mixture in cylinder  210  is can be compressed by piston  100  because the body  120  of piston  100  blocks off both the exhaust  260  and transfer channel  252 . The spark plug  270  then fires igniting the air/fuel mixture. The resulting explosion drives piston  100  downward. As the piston  100  is driven downward, the air/fuel mixture in crankcase  250  is compressed. The compression of the air/fuel mixture in crankcase  250  closes reed valve  272 . As the exhaust  260  becomes uncovered, the pressure in cylinder  210  drives most of the exhaust gases out of cylinder  210  through exhaust  260 .  
         [0026]     As piston  100  bottoms out, piston  100  clears transfer channel  252  such that transfer channel  252  becomes uncovered. Because of the pressure of air/fuel mixture in crankcase  250  created by piston  100 , the air/fuel mixture traverses through transfer channel  252  into the cylinder  210 , displacing the remaining exhaust gases and filling cylinder  210  with a fresh charge of fuel. While piston  100  is bottomed out, intake ports  130  are in alignment with intake  240 . As the pressure in crankcase  250  decreases as a result of the air/fuel mixture traversing through transfer channel  252  into cylinder  210 , reed valve  242  opens allowing air/fuel mixture from intake  240  to traverse through intake ports  130  and into crankcase  250 .  
         [0027]     The momentum in crankshaft  230  starts to drive piston  100  back toward spark plug  270  for the compression stroke. As piston  100  closes off transfer channel  252 , a vacuum is created in crankcase  250 . The intake ports  140  then come into alignment with intake  240  during the compression stroke. When this occurs, the vacuum in crankcase  250  opens the reed valve and sucks additional air/fuel mixture from intake  240 , through intake ports  130  and into crankcase  250 .  
         [0028]     Once piston  100  makes it to the end of the compression stroke, spark plug  270  fires again to repeat the cycle.  
         [0029]     Having two sets of intake ports  130  and  140  has numerous advantages over a standard ported two-stroke engine of the same size. The air/fuel mixture is utilized more efficiently by engine  200 . The amount of air/fuel mixture that is transferred into crankshaft  250  per cycle is increased, which in turn, increase the amount of air/fuel mixture that is transferred into cylinder  210  per cycle, creating a greater combustion, thereby increasing the horse power. Having two sets of intake ports  130  and  140  also helps to maintain the structural integrity of piston  100 , while maximizing the air/fuel flow and horse power. Maximizing the air/fuel flow into crankshaft  250  also creates better lubrication for engine  200 .  
         [0030]     Although engine  200  is illustrated with only one cylinder  100 , it is understood and contemplated that the present invention is applicable to other types of engines with any number of cylinders.  
         [0031]     In the preceding detailed description, reference has been made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments, and certain variants thereof, have been described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other suitable embodiments may be utilized and that logical changes may be made without departing from the spirit or scope of the invention. The description may omit certain information known to those skilled in the art. The preceding detailed description is, therefore, not intended to be limited to the specific forms set forth herein, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents, as can be reasonably included within the spirit and scope of the appended claims.