Abstract:
A device for engine exhaust extraction improves engine performance and efficiency. The device includes outer and inner tubes sharing a central axis. The inner tube is held in place by supports connected between the inner tube and the outer tube, which supports have a fan-like orientation. Helically oriented vanes reside on an outer surface of the inner tube, which vanes extend outward. An inlet flow separates into an outer flow between the inner tube and the outer tube and an inner flow inside the inner tube. The fanblade-like supports and helically oriented vanes cause the outer flow to rotate about the central axis of the device. The flow recombine near the device outlet.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to improving the efficiency of internal combustion engine, and in particular to an exhaust system which aids in extracting exhaust gases from the combustion chamber. 
   There is a continuing desire to improve the performance, efficiency, and environmental friendliness of internal combustion engines. Cars, motorcycles, and event trucks are raced every weekend in the United States. Even a small increase in power can provide a dramatic advantage in racing. The efficiency of exhaust systems is known to be a critical aspect of engine performance, and attempts to improve exhaust systems to unlock power have been ongoing for many years. 
   Increasing energy costs have also motivated manufactures to continually seeks to improve vehicle mileage, both to gain market share, and to satisfy government mileage requirements. Improvements to exhaust systems in the form of reduced restriction and tuned lengths have become common place, and vehicle mileage has somewhat benefitted from such efforts. However, meeting federally mandated mileage requirements remains a challenge, and further improvements are necessary. 
   Reducing pollution continues to be an important societal objective. Pollution levels in metropolitan areas remain unacceptably high at times, and create an immediate direct health issue for humans, and a longer term issue due to the damage to plant life. Automotive based pollution remains an issue, and auto makers are continually challenged to reduce the emissions from new automobiles. Further, the emissions from older vehicles continues even if new vehicles achieve significant emission reductions. 
   Modern automobiles greatly benefit from Electronic Fuel Injection (EFI) systems and efficient intake manifold and head designs. As a result, new automobiles have greatly improved economy and reduced emissions. But while the intake aspect of engine design has advanced drastically, exhaust systems have not similarly advanced. U.S. Pat. No. 6,213,251 issued Apr. 10, 2001 for “Self Tuning Exhaust Muffler,” describes a muffler having an outer tube and an inner louver tube, wherein a spiral vane extending from the louver tube to the outer tube and forming a helical passage for a flow between the louver tube and the outer tube. A multiplicity of “scoops” on the inside wall of the louvered tube “scoop” an outer portion of the flow through the louvered tube into the helical passage. 
   U.S. Pat. No. 6,679,351 issued Jan. 20, 2004 for “Air Turbine for Combustion Engine,” describes an “air turbine” apparatus creating a rotational flow which creates a muffling effect without restricting flow. The apparatus of the &#39;351 patent includes annular recesses (or convolutions) at the forward end (i.e., before the diameter increases) of the apparatus, which are intended to create a cyclone or vortex effect in the air flow. Following the annular recesses, the air flow enters an expansion chamber, wherein an airfoil is positioned at the front of the expansion chamber to split the air flow into a high velocity lower pressure outer vortex, and a lower velocity higher pressure inner vortex. The air foil is shown in several figures of the &#39;351 patent, and clearly plays the dominant role in the flow characteristics of a muffler according to the &#39;351 patent and is essential to the described invention. Further, in column 4, lines 22-25, the &#39;351 patent states that “the ratio of air passing around the airfoil compared to the air passing through the airfoil for a six inch diameter expansion chamber is approximately 2.7 to 1,” indicating that the air foil plays the dominant role on controlling air flow through the muffler. Additionally, FIG. 10 of the &#39;351 patent shows an embodiment of the invention of the &#39;351 patent which essentially consists of the annular rings and the airfoil, and the inner tube  22  is entirely absent. 
   Although attempts have been made to improve performance and efficiency through modifications to exhaust systems, there remains a need to improve overall engine performance, improve mileage, and reduce pollution. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention addresses the above and other needs by providing a device for engine exhaust extraction which improves engine performance and efficiency. The device includes outer and inner tubes sharing a central axis. The inner tube is held in place by supports connected between the inner tube and the outer tube, which supports have a fan-like orientation. Helically oriented vanes reside on an outer surface of the inner tube, which vanes extend outwardly. An inlet flow separates into an outer flow between the inner tube and the outer tube and an inner flow inside the inner tube. The fanblade-like supports and helically oriented vanes cause the outer flow to rotate about the central axis of the device. The flows recombine near the device outlet. 
   In accordance with one aspect of the invention, there is provided an exhaust extracting device comprising an outer tube and an inner tube. The outer tube has an inlet, an inlet adapter portion, an increased diameter center portion, an outlet adapter portion, an outlet, and a central axis. The inlet adapter portion is between approximately four inches long and approximately six inches long and has an inlet adapter entrance and an inlet adapter exit. The outlet adapter portion is between approximately four inches long and approximately six inches long and has an outlet adapter entrance and an outlet adapter exit. The inner tube is substantially co-axial with the outer tube. The inner tube has an outer surface and an inner surface, an inner tube entrance, and an inner tube exit. Helically oriented vanes extend outward from the outer surface of the inner tube between approximately three sixteenths and approximately one fourth inches. The vanes may also extend between approximately three sixteenths and approximately one fourth inches inwardly from the inside surface of the inner tube. 
   Between three and ten inlet supports are proximal to the inner tube entrance and between three and ten outlet supports are proximal to the inner tube exit. The supports extend between the inner tube and the outer tube, and the supports are substantially orthogonal to the outer surface of the inner tube. The supports have a fanblade-like orientation, wherein the vanes and supports cooperate to cause an outer air flow between the inner tube and the outer tube to rotate. The inner tube entrance resides at between approximately twenty five percent and approximately one hundred percent of the distance between the inlet adapter entrance and the inlet adapter exit, and the inner tube exit resides at between approximately zero percent and approximately seventy five percent of the distance between the outlet adapter entrance and the outlet adapter exit. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
       FIG. 1  is an engine powered vehicle utilizing the exhaust extractor of the present invention. 
       FIG. 2  is a cut-away view of the internal structure of the exhaust extractor. 
       FIG. 2A  shows a first cross-sectional view taken along line  2 A— 2 A of  FIG. 2  of the exhaust extractor. 
       FIG. 2B  shows a second cross-sectional view taken along line  2 A— 2 A of  FIG. 2  of the exhaust extractor. 
       FIG. 2C  shows a first cross-sectional view taken along line  2 C— 2 C of  FIG. 2  of the exhaust extractor. 
       FIG. 2D  shows a first cross-sectional view taken along line  2 D— 2 D of  FIG. 2  of the exhaust extractor. 
       FIG. 3  shows an “unwrapped” view of an inner tube with spiral vanes and reliefs according to the present invention. 
       FIG. 4  shows a detailed view of the inlet end of the inner tube and supports according to the present invention. 
       FIG. 5  shows detailed view of the outlet end of the inner tube and supports according to the present invention. 
   

   Corresponding reference characters indicate corresponding components throughout the several views of the drawings. 
   DETAILED DESCRIPTION OF THE INVENTION 
   The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims. 
   A vehicle  10  includes a body  12 , an engine  14 , and wheels  16  and shown in FIG.  1 . The engine consumes fuel and produces exhaust which passes through an exhaust pipe  18  and exits the vehicle through an exhaust extractor  20 . The exhaust extractor  20  may be used independently, or in conjunction with other exhaust devices such as a catalytic converter or a muffler. In vehicles with two or more exhaust pipes  18 , one exhaust extractor  20  may be used with each exhaust pipe. 
   A cut away view of the exhaust extractor  20  is shown in FIG.  2 . The exhaust extractor  20  includes an outer tube  28  comprising an inlet  22   a  and an outlet  22   b , an inlet adapter portion  24   a , a center portion  24   b , and an outlet adapter portion  24   c . The inlet adapter portion  24   a  and the outlet adapter portion  24   c  may be rounded (i.e., shoulder-like) portions as shown in  FIG. 2 , may be conical, and may be a mix of rounded and conical portions. The inlet adapter portion  24   a  has an inlet adapter entrance  38   a  and an inlet adapter exit  38   b , and the outlet adapter portion  24   c  has an outlet adapter entrance  40   a  and an outlet adapter exit  40   b . A central axis  29  runs through the length of the outer tube  28 . The center portion  24   b  of the outer tube  28  is preferably between approximately 2.5 inches in diameter to approximately five inches in diameter, and preferably between approximately fourteen inches long and approximately twenty inches long. 
   Continuing with  FIG. 2 , the exhaust extractor  20  further includes an inner tube  26  which is substantially co-axial with the outer tube  28 . Inlet fan blades  31  are attached to the inner tube  26  and extend outwardly to preferably within approximately 0.01 inches and approximately 0.03 inches of the outer tube  28 . Helically oriented vanes  32  are attached to the inner tube  26  and extend outward from the inner tube  26 . Reliefs  34  are cut into the inner tube  26  in a helical pattern similar to the orientation of the vanes  32 , which reliefs  34  are preferably substantially parallel to the vanes  32 . Front tube supports  30   a  connect the inner tube  26  to the outer tube  28 , and are attached to the inner tube  26  proximal to an inner tube entrance  36   a , and rear tube supports  30   b  connect the inner tube  26  to the outer tube  28 , and are attached to the inner tube  26  proximal to an inner tube exit  36   b . The supports  30   a ,  30   b  have a fanblade-like orientation (i.e., are angled relative to the central axis  29 .) The vanes  32  and supports  30   a ,  30   b  cooperate to cause an outer air flow between the inner tube and the outer tube to rotate. 
   There are preferably between three and ten inlet supports  30   a  proximal to the inner tube entrance  36   a  and between three and ten outlet supports  30   b  proximal to the inner tube exit  36   b , and there are more preferably four inlet supports  30   a  proximal to the inner tube entrance  36   a  and four outlet supports  30   b  proximal to the inner tube exit  36   b . The inlet supports  30   a  are preferably turned at between approximately thirty five degrees and approximately fifty five degrees from the central axis  29 , and the outlet supports  30   b  are turned at approximately sixty degrees from the central axis  29 . The supports  30   a ,  30   b  are more preferably between approximately one half inches long and approximately five eights inches long, and are preferably turned at approximately forty five degrees from the central axis  29 . 
   The inlet adapter portion  24   a  is preferably between approximately four inches long and approximately six inches long, and the outlet adapter portion is preferably between approximately four inches long and approximately six inches long. The inner tube entrance  36   a  preferably resides outwardly with respect to the inlet adapter exit  38   b  toward the inlet adapter entrance  38   a  between zero and seventy five percent of the distance between the inlet adapter exit  38   b  and the inlet adapter entrance  38   a , and more preferably resides at approximately thirty three percent of the distance between the inlet adapter exit  38   b  and the inlet adapter entrance  38   a . The inner tube exit  36   b  preferably resides outwardly with respect to the outlet adapter entrance  40   a  toward the outlet adapter exit  40   b  between zero and seventy five percent of the distance between the outlet adapter entrance  40   a  and the outlet adapter exit  40   b , and more preferably resides at approximately thirty three percent of the distance between the outlet adapter entrance  40   a  and the outlet adapter exit  40   b . As herein described, entrance refers to a point of entrance of exhaust flow into a portion of the exhaust extractor  20 , and exit refers to a point of exit of exhaust flow from a portion of the exhaust extractor  20 . 
   A first cross-sectional view of the exhaust extractor  20  taken along line  2 A— 2 A of  FIG. 2  is shown in FIG.  2 A. The vanes  32  are seen to extend outward from an outer surface  26   a  of the inner tube  26 . The vanes  32  preferably extend between approximately three sixteenths and approximately one fourth inches outwardly from the outside surface  26   a  of the inner tube  26 . The fanblade like supports  30   a  extend from the inner tube  26  to the outer tube  28 , and provide support for the inner tube  26  proximal to the inner tube entrance  26   a.    
   A second cross-sectional view of an alternative embodiment of the exhaust extractor  20  taken along line  2 A— 2 A of  FIG. 2  is shown in FIG.  2 B. The second embodiment is shown with internal vanes  32   a  extending inwardly from an internal surface  26   b  of the inner tube. The internal vanes  32   a  are preferably inward extensions of the vanes  32  extending outward from the outer surface  26   a . The vanes  32   a  preferably extend between approximately three sixteenths and approximately one fourth inches inwardly from the inside surface  26   b  of the inner tube  26 . 
   A cross-sectional view of the exhaust extractor  20  taken along line  2 C— 2 C of  FIG. 2  is shown in FIG.  2 C. The fanblade like supports  30   b  extend from the inner tube  26  to the outer tube  28 , and provide support for the inner tube  26  proximal to the inner tube exit  26   b.    
   A cross-sectional view of the exhaust extractor  20  taken along line  2 D— 2 D of  FIG. 2  is shown in FIG.  2 D. The inlet fan blades  31  extend from the inner tube  26  toward the outer tube  28 . There are preferably four to ten inlet fan blades  31 , and more preferably eight inlet fan blades  31 . 
   An unwrapped view of the inner tube  26  is shown in FIG.  3 . The vanes  32  are preferably pairs of vanes  32  residing one hundred and eighty degrees apart on the inner tube  26 . The vanes  32  run continuously between the tube supports  30   a  and  30   b , and are preferably constructed from between approximately two inch and approximately three inch segments, which segments are butted against each other. The reliefs  34  are substantially parallel to the vanes, and preferably are between approximately one eighth inches and approximately three sixteenths inches wide. The vanes  32  and the reliefs  34  are at an angle A1 from the central axis  29 , which angle A1 is preferably between twenty five degrees and forty degrees, and more preferably approximately thirty degrees. 
   A detailed view of the inner tube entrance  36   a  is shown in FIG.  4 . The inlet fan blades  31  and the supports  30   a  are shown extending substantially orthogonal to the inner tube  26 . The inlet fan blades  31  are at an angle A2 to the central axis  29 , which angle A2 is preferably approximately forty five degrees. The supports  30   a  are at an angle A3 to the central axis  29 , and the angle A3 is preferably between approximately thirty five degrees and approximately fifty five degrees from the central axis, and is more preferably thirty degrees from the central axis. 
   A detailed view of the inner tube exit  36   b  is shown in FIG.  5 . The supports  30   b  are shown extending substantially orthogonal to the inner tube  26 . The supports  30   d  are at an angle A4 to the central axis  29 , and the angle A3 is preferably between approximately thirty five degrees and approximately fifty five degrees from the central axis, and is more preferably thirty degrees from the central axis. 
   An exhaust extractor  20  according to the present invention has been constructed and tested on a variety of vehicles. It is believed that the outer flow between the inner tube  26  and the outer tube  28  is accelerated and converted into a vortex like flow by the helically oriented vanes  32  and fanblade like supports  30   a ,  30   b . Thus accelerated, when the flows recombine in the outlet adaptor portion  24   c , the flow through the inner tube is drawn out of the inner tube  26 , thereby extracting the exhaust from the engine  14 , and improving performance. The results of testing before and after installation of one or more exhaust extractors  20  are summarized in Table 1. As can be seen, the performance improvements were substantial. Although it is believed that the performance improvements are obtained as described above, the present invention is not limited to a device functioning as described, and any device functioning in any manner, which device is as described and claimed herein, is intended to come within the scope of the present invention. 
   
     
       
             
             
             
           
         
             
               TABLE 1 
             
             
                 
             
             
               Vehicle 
               Original 
               With Exhaust Extractor 
             
             
                 
             
           
           
             
               1989 Toyota Pickup 
               139 foot pounds torque 
               191 foot pounds torque 
             
             
               (carburetor) 2.2 Ltr 
               HC .53 
               HC .10 
             
             
                 
               CO .23 
               CO .01 
             
             
               1995 Mustang GT 5.0 
               241 foot pounds torque 
               298+ foot pounds torque 
             
             
               1996 Dodge Pickup 
             
             
               2003 Mustang Mach 1 
               168 foot pounds torque 
               180 foot pounds torque 
             
             
                 
             
           
        
       
     
   
   While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.