Abstract:
An exhaust modification system for an all terrain vehicle which reduces the exhaust noise of the vehicle and reduces the possibility of hot particles being discharged with the exhaust gas so as to ignite readily combustible material upon which the particle might land. The exhaust modification system includes a muffler, at least two length of flexible exhaust pipe, exhaust pipe clamps, and mounting brackets for suspending the muffler from the all terrain vehicle.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of prior filed copending provisional application No. 60/218,517, filed Jul. 17, 2000, entitled: ATV Stealth Exhaust System. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the exhaust systems for all terrain vehicles. More particularly it relates to four wheel vehicles of the type used for off-road travel for both recreational and work purposes. 
     BACKGROUND OF THE INVENTION 
     Four wheel all terrain vehicles, typically referred to as ATV&#39;s are currently offered for sale by several manufacturers. ATV&#39;s appeared to have developed as an alternative to off-road motorcycles. As in the case of off-road motorcycles, they are of a rugged design, intended to withstand operation on very rough surfaces, even when traveling at relatively fast speeds. As is true with motorcycles, they are typically provided with a muffler system which is not very effective at reducing the noise caused by the exhaust of the engine. Just as the owners or riders of motorcycles, desired or preferred a greater sound level from the exhaust system then is typically the case with an automobile, so have ATV owners and riders. The more direct flow of exhaust gases through the usual mufflers on motorcycles and ATVs is more likely to permit hot solid particles to be released from the mufflers, which upon landing upon a combustible material could result in a fire. 
     Owners and riders are now finding new uses and therefor have new requirements for their ATVs. For instance, ATV owners and riders having a desire to use their vehicles on public lands, such as state and national parks, are meeting resistance to their use because of the exhaust noise of a stock ATV and because of the possibility of hot particles in the exhaust gases starting fires. Further some ATV owners and riders desire to use their ATVs for quietly approaching wildlife for the purpose of observation or hunting. Others desire to use their ATVs in ranching operations, where the load noise of stock ATV mufflers startles cattle thereby making it more difficult to approach them. 
     Accordingly, it would be advantageous to provide a arrangement whereby ATVs produced by several different manufactures could be readily equipped with an exhaust modification system for reducing the exhaust noise and likelihood of hot particles being emitted to the atmosphere in the exhaust gas. It would be of further advantage to provide an exhaust modification system, comprising a number of components, provided as a kit, which is adaptable for use with the stock exhaust system of ATVs produced by a plurality of different manufactures, and ATVs of the same manufacturer which are provided with different equipment. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide an exhaust modification system adaptable for use with the stock exhaust systems of ATVs to reduce the exhaust noise and the likelihood of hot particles being emitted to the atmosphere in the exhaust gas of the ATVs. It is a further object of this invention to provide an exhaust modification system comprising a number of components, provided as a kit, which is adaptable for use with stock exhaust systems of ATVs produced by a plurality of different manufactures, and ATVs of the same manufacturer which are provided with different accessories, to reduce the exhaust noise and the likelihood of hot particles being emitted to the atmosphere in the exhaust gas of the ATVs. 
     An exhaust modification system for use with the stock exhaust systems of ATVs to reduce the exhaust noise and the likelihood of hot particles being emitted to the atmosphere in the exhaust gas of the ATVs in accordance with this invention comprises a muffler, a plurality of exhaust pipes, connecting adaptors, and mounting and clamping devices. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the rear end of an ATV of a first manufacturer showing the muffler and outlet of the stock exhaust system; 
     FIG. 2 is a perspective view of the rear end of the ATV shown in FIG. 1, provided with the exhaust modification system of this invention; 
     FIG. 3 is an exploded perspective view of the exhaust modification system of this invention as shown installed on an ATV in FIG. 2; 
     FIG. 4 is a perspective view of the exhaust end of the stock muffler of the ATV shown in FIGS. 1 and 2, with an adaptor flange installed on the stock muffler; 
     FIG. 5 is a perspective view of the rear end of an ATV of a second manufacturer showing the muffler and outlet of the stock exhaust system; 
     FIG. 6A is a perspective view of the rear end of the ATV shown in FIG. 5, provided with the exhaust modification system of this invention in a first mounting arrangement; 
     FIG. 6B is a side plan view showing the connection and support between the stock muffler and the exhaust modification system of this invention as shown in FIG. 6; 
     FIG. 7A is a perspective view of the rear end of the ATV shown in FIG. 5, provided with the exhaust modification system of this invention in a second mounting arrangement; 
     FIG. 7B is a side plan view showing the connection and support between the stock muffler and the exhaust modification system of this invention as shown in FIG. 7; 
     FIG. 8A is a perspective view of the rear end of an ATV of a third manufacturer showing the muffler and outlet of the stock exhaust system; 
     FIG. 8B is a perspective view of the rear end of the ATV shown in FIG. 8A, provided with the exhaust modification system of this invention; 
     FIG. 8C is a side plan view showing the connection and support between the stock muffler and the exhaust modification system of this invention as shown in FIG. 8B; 
     FIG. 8D is a cross-sectional view taken along the line  8 D— 8 D in FIG. 8C; 
     FIG. 9A is a perspective view of the rear end of an ATV of a fourth manufacturer showing the muffler and outlet of the stock exhaust system; 
     FIG. 9B is a perspective view of the rear end of the ATV shown in FIG. 9A, provided with the exhaust modification system of this invention; 
     FIG. 9C is a side plan view showing the connection and support between the stock muffler and the exhaust modification system of this invention as shown in FIG. 9B; 
     FIG. 10A is a perspective view of the rear end of an ATV of a fifth manufacturer showing the muffler and outlet of the stock exhaust system; 
     FIG. 10B is a perspective view of the rear end of the ATV shown in FIG. 10A, provided with the exhaust modification system of this invention; 
     FIG. 10C is a side plan view showing the connection and support between the stock muffler and the exhaust modification system of this invention as shown in FIG.  10 B; 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, the rear end of an ATV  10  of a first manufacturer is shown. The exhaust gas from the stock exhaust system of this ATV is discharged from a rearwardly facing opening  12  in the stock muffler  14 . The stock muffler  14  is suspending beneath the fender  16  positioned over the rear drive wheels  18  and  20 , and inside the left rear drive wheel  18 . A basket  22 , for carrying sundry articles is supported over the fender  16 . The exhaust modification system of this invention is supported from and beneath the basket  22  as shown in FIG.  2 . 
     Referring to FIG. 3, the components of an exhaust modification system in accordance with this invention are shown in an exploded perspective view positioned as they would be for installation on the ATV as shown in FIG.  2 . The exhaust modification system includes an adaptor  24 , a first length of flexible exhaust pipe  26 , a muffler  28 , a second length of flexible exhaust pipe  30 , clamps  32 ,  34 , and  36  for securing the lengths of flexible pipe  26  and  30 , and muffler mounting clamps  38  and  40 . The muffler  28  is an efficient, super quiet, yet high flow muffler. The muffler may reduce exhaust noise by up to 50 percent, while at the same time not having any adverse affects on the engine, such as loss of performance. 
     Since the stock muffler  14  as shown in FIG. 1, is not provided with an outlet pipe, the exhaust modification system of this invention includes the adaptor  24  formed with a cylindrical flange  42 , having mounting holes  44  formed therein, and a cylindrical pipe extension  46  extending from a hole in the center of the flange. The flange  42  is secured to the stock muffler  14  with the cylindrical pipe extension  46  in line with the rearwardly facing opening  12  in the stock muffler  14 . To instal the exhaust modification system of this invention, holes are formed in the stock muffler  14  in line with the mounting holes  44 , to receive fastening devices, such as sheet metal screws  48 , the heads of which are shown in FIG. 4, or rivets, to secure the mounting flange  42  to the stock muffler  14 . However, if welding equipment is available, the mounting flange or a bushing may be welded to the stock muffler. 
     The exhaust modification system muffler  28 , is provided with an inlet  50  on the cylindrical sidewall of the muffler near a first end of the muffler, and an outlet  52  at the center of the second end of the muffler. The inlet and outlet are each formed as cylindrical pipe stubs. A first end of first length of flexible exhaust pipe  26  is secured to cylindrical pipe extension  46  by pipe clamp  32 , while the second end of first length of flexible exhaust pipe  26  is secured to the cylindrical pipe stub of inlet  50  of the exhaust modification system muffler  28  by pipe clamp  34 . A first end of second length of flexible exhaust pipe  30  is secured to the cylindrical pipe stub of outlet  52  of the exhaust modification system muffler  28  by pipe clamp  36 . The second length of flexible exhaust pipe  30  is bend, such that second end  54  faces downward. It has been found that having the open end of the exhaust pipe  30  between 18 and 24 inches from the ground is most desirable from the point of view of further reducing exhaust noise. While having the open end closer to the ground further reduces noise, from an operational viewpoint, it should not be closer than 18 inches. 
     Generally, the use of two lengths of flexible exhaust pipe in the exhaust modification system is preferred, since it can usually be pushed back into the desired shape if it is bend by bumped or hit by some object. 
     The exhaust modification system muffler  28  is secured to the bottom of the basket  22  by muffler mounting clamps  38  and  40 . The muffler clamp  38  includes a u-bolt  56 , a saddle  58  and lock washers  60  and  62  and nuts  64  and  66 . Holes are provided in the bottom of the basket  22  to receive the threaded ends of u-bolt  56 . The muffler clamp  40  is similar to muffler clamp  38 . 
     Referring to FIG. 5, the rear end of an ATV  68  of a second manufacturer is shown. The exhaust gas from the stock exhaust system of this ATV is discharged from a rearwardly facing opening  70  in the stock muffler  72 . The stock muffler  72  is suspending beneath the fender  74  positioned over the rear drive wheels  76  and  78 , and inside the left rear drive wheel  76 . A framework  80 , is supported over the fender  74 . The exhaust modification system of this invention may be supported from framework  80  in either of two positions, a low position as shown in FIG. 6A, and a high position as shown in FIG.  7 A. 
     As in the embodiment shown in FIGS. 1-4, the exhaust modification system shown installed in FIGS. 6A and 7A on the ATV  68  shown in FIG. 5, includes the same components as the exhaust modification system shown in FIG. 3, and installed on an ATV as shown in FIG.  2 . As shown in FIGS. 6B and 7B an adaptor  82  is installed over the outlet of the stock muffler  72 . For the low position shown in FIGS. 6A and 6B, a short coupling pipe  86  is connected between the adaptor  82  and the inlet  88  of exhaust modification system muffler  90 , and is secured by clamps  92  and  94 . For the high position, the adaptor  82  is connected to the inlet of the exhaust modification system muffler  90  by an elbow pipe  95  and a length of flexible exhaust pipe  97 . The connections between the adaptor  82  and elbow pipe  95 , between the elbow pipe  95  and the flexible exhaust pipe  97 , and between the flexible exhaust pipe  97  and the inlet of the exhaust modification system muffler  90 , are secured by clamps,  99 ,  101 , and  103 . The exhaust modification system muffler  90  is secured to the framework  80  by one or a pair of muffler clamps  96  and  98 , each of which includes a u-bolt  100 , a saddle  102  and nuts  104 , and L-shaped brackets  106 . One leg of each L-shaped bracket is secured to one of the muffler clamps, and the other is secured to the framework. As shown in FIGS. 6A and 7A, a first end of length of flexible exhaust pipe  108  is secured to the cylindrical pipe stub of outlet  110  of the exhaust modification system muffler  90  by a pipe clamp  112 . The flexible exhaust pipe  108  is bend, such that second end  112  faces downward. 
     Referring to FIG. 8A, the rear end of an ATV  114  of a third manufacturer is shown. The exhaust gas from the stock exhaust system of this ATV is discharged from a downwardly facing pipe  116  of the stock muffler  118 . As in the previously described embodiments, the stock muffler  118  is suspending beneath the fender positioned over the rear drive wheels, and is positioned inwardly from the right rear drive wheel. A trapezoidal shaped frame  120  extends downwardly at the rear of the vehicle from a deck  122  positioned over the fenders of the ATV. As shown in FIG. 8B, the exhaust modification system muffler  124  is secured to two legs of the trapezoidal shaped frame  120  by a pair of muffler clamps  126  and  128 . Referring to FIG. 8C, the connection between the stock muffler and the exhaust modification muffler is similar to that shown in FIG. 7B, in that it includes an elbow and a length of flexible exhaust pipe. FIG. 8D shows one of the bracket  130  which is secured to the muffler clamp and the leg of the trapezoidal shaped frame  120 . As shown in FIG. 8B, a first end of length of flexible exhaust pipe  131  is secured to the cylindrical pipe stub of the outlet of the exhaust modification system muffler  124  by a pipe clamp  133 . The flexible exhaust pipe  131  is bend, such that second end  135  faces downward. 
     Another ATV is shown in FIG. 9A without the exhaust modification system of this invention, and with the exhaust modification system of this invention in FIG.  9 B. In this embodiment, as shown in FIG. 9C, only a short straight piece of pipe  132  is required between the outlet of the stock muffler and the inlet of the exhaust modification muffler. A bracket  134  includes a circular portion  136  clamped around the exhaust modification muffler  138 , and an L-shaped portion  134 , one leg of which is secured to a deck  140  positioned over the fender of the ATV. 
     Still another ATV is shown in FIG. 10A without the exhaust modification system of this invention, and with the exhaust modification system of this invention in FIG.  10 B. In this embodiment, a preformed piece of pipe  142 , as shown in FIG. 10C, is connected between the outlet of the stock muffler and the inlet of the exhaust modification muffler. A pair of brackets  144  support the exhaust modification muffler  146  from a tubular frame member  148  located above the rear fender of the ATV. 
     While several applications of the exhaust modification system of this invention have been shown, it should be apparent to those skilled in the art that what have been described are considered at present to be preferred application of the exhaust modification system of this invention. In accordance with the Patent Statute, changes and modifications may be made in the exhaust modification system and its application to ATVs without actually departing from the true spirit and scope of this invention. The appended claims are intended to cover all such changes and modification which fall in the true spirit and scope of this invention.