Abstract:
A pickup truck and exhaust system combination is designed for a pickup truck having a cab and a bed extending rearwardly therefrom. The bed has a load floor bounded by a front wall adjacent the cab and a pair of side walls. The bed has an opening defined therein. The truck has an engine and an exhaust pipe extending rearwardly under the cab to an outlet end. A flexible exhaust coupler has a first end in fluid communication with the outlet end of the exhaust pipe and a second end in fluid communication with the first end. A hollow elongated collector is disposed on the floor of the truck bed adjacent the front wall. The collector has a first end and an opposed second end with the midportion therebetween. The collector also has an inlet defined in the midportion, with the inlet being connected to the second end of the coupler through the opening in the bed. The collector also has a first outlet defined in the first end and a second outlet defined in the second end, with the outlets being in fluid communication with the inlet. First and second tubular exhaust stacks have lower ends connected to the first and second outlets and extend generally vertically upwardly therefrom to open upper ends.

Description:
REFERENCE TO RELATED APPLICATION 
     This application claims priority from U.S. provisional patent application Serial No. 60/270,807, filed Feb. 23, 2001, the entire contents of which being incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates generally to exhaust systems for vehicles and, more specifically, to a system for a pick-up truck that provides a pair of vertical exhaust stacks. 
     BACKGROUND OF THE INVENTION 
     Generally speaking, an exhaust system of a vehicle routes exhaust gases from the exhaust ports of the vehicle&#39;s engine to a position remote from the engine. The exhaust system typically includes an exhaust manifold connected to the exhaust ports of the engine, a catalytic converter or other pollution control device, a muffler or other sound control device, and tubing interconnecting the manifold, catalytic converter, and muffler. In most passenger vehicles, the exhaust system extends from a front mounted engine underneath the vehicle. The exhaust system has a rear-most portion, often referred to as the tailpipe, that exits near the rear of the vehicle. The exhaust system may consist of a single or dual pipes for a portion of, or the entire length, of the exhaust system. Some commercial vehicles have exhaust systems that extend upwardly from the vehicle along one or both sides of the vehicle and terminate in an upper end near or above the top of the vehicle. These upwardly extending exhaust pipes are sometimes referred to as exhaust stacks. Many owners of pickup trucks like the looks of upwardly extending exhaust stacks. However, providing upwardly extending exhaust stacks on a passenger vehicle is typically costly and complicated. 
     SUMMARY OF THE INVENTION 
     The present invention provides a dual stack exhaust system for a pickup truck that may be provided as a part of a truck or as a conversion system. The system is designed for use with a pickup truck of the type having a cab and a bed extending rearwardly from the cab. The bed has a load floor that is bounded by a front wall adjacent a cab and a pair of side walls. The bed may have an opening defined therein, such as in the load floor. The truck has an engine and an exhaust pipe extending rearwardly under the cab to an outlet end. An exhaust coupler has one end in fluid communication with the outlet end of the exhaust pipe and a second end in fluid communication with the first end. A hollow elongated collector is disposed on the floor of the truck bed adjacent the front wall. The collector has a first end and an opposed end with the midportion therebetween. The collector has an outlet defined in the midportion, with the inlet connected to the second end of the coupler through the opening of the bed such that exhaust flowing from the second end of the coupler flows into the collector. The collector also has a first outlet defined in the first end and a second outlet defined in the second end, with the outlets being in fluid communication with the inlet, such that exhaust flowing into the inlet flows out of the outlets. A first tubular exhaust stack has a lower end connected to the first outlet and extends generally vertically upwardly therefrom to an open upper end such that exhaust introduced into the lower end flows out of the upper end. A second tubular exhaust stack has a lower end connected to the second outlet and extends vertically upwardly therefrom to an open upper end such that exhaust introduced into the lower end flows out of the upper end. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a portion of a pickup truck with a dual stack exhaust system according to the present invention installed in the bed; 
     FIG. 2 is a rear elevational view of the truck and exhaust system of FIG. 1; 
     FIG. 3 is a rear perspective view of a portion of a truck with an exhaust system according to the present invention installed in the bed, further showing a heat shield installed in place over the collector portion of the exhaust system; 
     FIG. 4 is a side elevational schematic of a portion of a pickup truck cab and bed showing the exhaust routing from the existing exhaust system to the collector of the present invention; 
     FIG. 5 is a rear elevational view of the assembled components of an exhaust system according to the present invention; 
     FIG. 6A is a cross-sectional rear view of the collector portion of the exhaust system according to the present invention showing a first preferred embodiment of an exhaust diverter disposed in the collector; 
     FIG. 6B is a cross-sectional view similar to FIG. 6A showing an alternative embodiment of a diverter; 
     FIG. 6C is a cross-sectional view similar to FIGS. 6A and 6B showing a further alternative embodiment of the diverter; 
     FIG. 7 is a perspective view of a heat shield for use with the present invention; and 
     FIG. 8 is a plan view of a secondary heat shield for use with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention provides a dual stack exhaust system for use with a pickup truck. This system is simple and inexpensive, while still providing the desired looks of a dual stack exhaust system. FIGS. 1 and 2 show two views of a pickup truck with a dual stack exhaust system according to the present invention installed therein. As shown, a pair of exhaust stacks extend upwardly out of the bed of the pickup truck, giving the desired look of a dual stack exhaust system. FIG. 4 is a cross-sectional side view showing the exhaust routing. The truck  10  has an engine (not shown) with an exhaust pipe  14  extending from the engine to a catalytic converter  16 . In an unmodified truck, an exhaust system extends rearwardly from the outlet of the catalytic converter  16  and includes a muffler and a tailpipe. The entire system is disposed below the underside of the truck  10 . However, in the present invention, exhaust coupler  18  has one end connected to the outlet of the catalytic converter and extends upwardly through a hole  20  in the load floor  22  of the bed  24  of the truck  10 . 
     Referring now to FIG. 5, the various components of the present invention will be described in more detail. A collector  30  is designed to mount to the floor of the truck bed adjacent the front wall of the truck bed using mounting brackets  32 . The collector is shown mounted in the bed of a truck in FIG.  2 . In one embodiment of the present invention, designed for use with a diesel engine truck, the collector  30  is a five inch by five inch piece of square tubing. However, as will be clear to those of skill in the art, the collector  30  may instead be a round pipe, or may include internal baffles and sound absorbers so as to function as a muffler. In a diesel truck application, connecting the exhaust coupler  18  directly to the outlet of the catalytic converter provides sufficient noise reduction to be used without any additional muffler element. An inlet  34  is provided in the underside of the collector  30 . The exhaust coupler  18  connects to the inlet  34  for routing exhaust gases into the hollow interior of the collector  30 . A single hole has been cut in the floor of the truck bed for allowing the exhaust coupler  18  and inlet  34  to pass therethrough. 
     The collector  30  has openings  44  and  46  at each of its ends and is arranged transversely in the truck bed so that the ends are pointed towards the sides of the truck bed. Each end of the collector  30  preferably has a square-to-round adapter and a 90 degree elbow  36  attached thereto. In one embodiment, the elbows are five-inch elbows. A chrome stack  38  is connected to the outlet end of each of the elbows  36 . The stacks  38  extend upwardly and turn outwardly and rearwardly as may best be seen in FIGS.  1  and  2 . In one embodiment, the stacks  38  are chromed and five inches in diameter. They may also be stainless steel. Mounting brackets  40  are provided on each of the stacks for mounting the stacks to the sides of the truck bed. 
     The exhaust coupler  18  is preferably of flex coupling. This allows for easy installation and also isolates the existing exhaust system of the vehicle from the collector  30 . This allows for relative movement between the two portions. Alternatively or additionally, the collector  30  may be mounted to the bed  22  using flexible mounts to somewhat isolate the collector  30  from the bed  22 . Likewise, the exhaust stack mounting brackets  40  may be flexible mounts to allow some isolation. As shown in FIG. 5, the inlet  34  is preferably a pipe that extends downwardly from one wall of the collector  30 . In some embodiments, the inlet  34  has a three-inch, three and a half inch or four-inch diameter and a length of nine inches, and the exhaust coupler  18  is sized to fit over the inlet  34 . As will be clear to those of skill in the art, the size of the coupler and the inlet are preferably chosen to match the diameter of the existing exhaust system of the truck. 
     As an alternative to the embodiment illustrated in FIGS. 1,  2  and  5 , the collector  30  may instead be mounted to the front wall  23  of the bed, either adjacent the floor  22  or spaced therefrom. An opening may then be provided in the front wall  23  with the exhaust being routed through this opening. By spacing the collector  30  away from the floor  22 , additional floor space may be freed up. 
     Returning again to FIG. 5, it can be seen that the inlet  34  of the collector  30  is closer to the right-hand end of the collector rather than to the left-hand end. Obviously, the positioning of the inlet depends on the application, positioning of the exhaust system of the vehicle, the location of the hole through the bed, and other factors. However, when the inlet is positioned closer to one end than the other, a diverter  42  is preferable provided to help balance the flows of the two exhaust stacks  38  and/or divert the flow towards the outlets. Preferably, approximately equal amounts of exhaust flow out of each of the stacks to provide an optimal appearance and sound. 
     FIGS. 6A-6C show various designs for an exhaust diverter for use with the present invention. FIG. 6A shows the preferred diverter  42 . As shown, the diverter  42  is a pointed protrusion extending from the wall of the collector  30  opposite the inlet  34 . The protrusion  42  may be formed from a piece of angle iron with straight side walls, or may have sloped sides  43 , such as shown. As exhaust flow comes out of the inlet  34 , it strikes the diverter  42 , causing the flow to split between the two outlets,  44  and  46  of the collector  30 . FIG. 6B shows an alternative diverter  48 . It should be noted that FIGS. 6A and 6B both include small detailed views of the diverters  42  and  48 . As shown, the diverter  48  is a flap extending upwardly from the bottom of the converter  30  inside the square tubing by the inlet  34 . The flap  48  is angled towards the end of the collector further from the inlet  34 . As shown, the diverter  48  may be a flap with fingers and the shape as illustrated. This shape may be easily formed by cutting the flap from the bottom of the collector  30  prior to attaching the inlet  34  and bending the flap upwardly to form the diverter  48 . Obviously, the diverter may be of other sizes, shapes and configurations or may be omitted in certain applications. For example, FIG. 6C shows an alternative configuration of a diverter  50 . In each of FIGS. 6A-6C, exhaust gas flows are shown by arrows A and B. By altering the configuration of the diverters  42 ,  48  or  50 , or other configurations, the exhaust flow through the stacks may be balanced. 
     As will be clear to those of skill in the art, the configuration of the exhaust system shown in FIG. 5 may be altered in various ways. For example, the sizes of the various pipes may be changed to alter the flow resistance, sound characteristics, and look of the system. Also, the pipes may be changed between square, round and other cross-sections. The exhaust coupler  18  is preferable a piece of flexible exhaust pipe to allow some movement between the portions of the exhaust system mounted in the bed of the truck and the existing exhaust system underneath the truck. This may instead be a solid piece of pipe, or other types of flexible joints may be provided. Experimentation has indicated that the configuration illustrated works well with turbo-diesel trucks. In these applications, the combination of the turbocharger and the catalytic converter give some sound reduction such that no muffling element is required in the exhaust system after the catalytic converter. Also, experimentation has indicated that the square tubing gives a pleasing sound. In other applications some muffling may be required. As previously mentioned, the collector  30  may be provided with sound absorption or baffles, such as by providing a pipe within a pipe configuration. Alternatively, or in addition thereto, a muffler may be provided between the catalytic converter and the connector pipe, in the exhaust coupler, in the elbows, or in the stacks. For example, chromed or stainless steel mufflers may be used as a portion of the stacks  38 . Also, it is not necessary that the stacks be chromed or stainless steel. Instead, they may be painted or powder-coated or have other appearances. It is preferred that the collector and elbows be painted or powder-coated or formed out of a stainless steel or chromed material. The stacks  38 , as illustrated, are just one possible configuration. Alternatively, the stack may be shorter, or taller, or be angled at their tops, curved in a different way or include flappers such as used on some commercial vehicles. 
     Referring again to FIG. 2, various options are available with the exhaust system. For example, an antenna mount  45  is shown connected to the top side of the collector  30  with an antenna  48  mounted to the top of the mount  45 . This is also shown in FIG.  1 . The collector  30  may be provided with mounting holes for an antenna mount, or provided with the mount itself. Also, as best shown in FIG. 2, the collector  30  and the elbows  36  are positioned in the bed of the truck in a position such that they may be contacted by materials in the bed. In turbo-diesel applications, it has been found that the collector  30  generally remains cool enough that no additional protection is necessary. However, it may be desirable to provide a heat shield to cover some or all of the collector  30  and/or elbows  36 . Alternatively, the pipes may be wrapped in insulation or otherwise insulated. FIGS. 3 and 7 show various views of a guard for use with the exhaust system according to the present invention. FIG. 7 is an isometric view of the guard  60 . As will be clear to those with skill in the art, the guard  60  may be mounted around the collector  30 , either by mounting it directly to the collector or connecting it to the bed or a bracket adjacent to the collector. Vent holes may also be provided. A space between the guard  60  and the collector  30  keeps the guard  60  cooler thereby preventing damage to objects which contact the guard. As shown, the guard  60  preferably is an angled piece of metal designed to fit around the collector, as shown in FIG.  3 . The guard  60  has a rear portion  62  and a top portion  64  that are preferably positioned at approximately 90 degree to one another. The top portion  64  fits above the top of the collector, while the rear portion  62  fits over the rear of the collector. As shown, the top portion  64  is preferably sized such that it extends most of the distance between the elbows  36 , thereby covering a portion of the elbows  36  and the top of the collector. The rear portion  62  is longer than the top portion  64  and extends almost to the side walls of the truck bed. The rear face  62  preferably has a lower edge  66  that bends outwardly to help prevent materials from falling onto the collector. Likewise, the top portion  64  preferably has an upturned rear edge  68  to help prevent materials from getting behind the collector. As shown, the guard  60  preferably has a plurality of holes  70  therethrough. Fasteners, not shown, pass through these openings  70  and engage the collector for positioning the guard  60  in a spaced-apart relationship with the collector. As shown in FIG. 3, the guard  60  may include cut out portions  72  which acts as vents for further cooling. The cut out  72  may be shaped so as to form words or logos. FIG. 8 shows an alternative front heat guard  72 . This heat guard  72  is designed to connect to the front face of the collector so if material falls between the front wall  23  of the bed and the collector, the guard keeps it away from the collector. FIG. 7 shows an example position of the guard  72 . As with the guard  60 , the guard  72  preferably has vents  74  and openings  76  for receiving fasteners. 
     To install an exhaust system according to the present invention, the installer preferably removes the existing exhaust system rearwardly of the catalytic converter of the vehicle. A hole is then cut in the floor of the truck bed in a position appropriate for lining up with the inlet of the collector. The collector is then mounted with the inlet extending downwardly either into or through the hole in the floor of the bed. The exhaust coupler is interconnected between the rear of the catalytic converter and the inlet on the collector. The elbows and stacks are then mounted to the collector and the side brackets are used to mount the stacks to the side of the bed. As another alternative, braces may be provided such that the stacks are braced to the collector or to other portions of the system or the truck bed, to avoid the necessity of holding the stacks to the sides of the bed. As another alternative, the existing exhaust system may be left mostly intact underneath the vehicle so as to allow the vehicle to be converted back to its original configuration. As yet another alternative, the collector and stack portion of the exhaust system according to the present invention may be mounted in the bed of the truck without connecting the system to the exhaust system of the vehicle. In this way, the cosmetic appearance of stacks is provided, though the system remains non-functional. 
     While the present invention has been illustrated as having a single inlet to the collector  30 , other alternatives are also possible. For example, two inlets may be provided for connection to two exhaust pipe underneath the truck. This would be especially suitable to dual exhaust systems. In this case, both inlets may feed into the same common collector, or the collector may be divided into two sections with a complete divider, or may be entirely separately formed and not interconnected. Alternatively, a partial connection may be provided. Additional inlets may be further provided, as needed. 
     Those with skill in the art will appreciate that the preferred embodiment of the present invention may be altered in various ways without departing from the scope or teaching of the present invention.