Abstract:
A modular muffler that is quickly and easily adapted for use with a wide variety engines is disclosed. The muffler has a dimensionally standardized body member with end portions that may receive any of a number of adaptor end plates provided with various inlet and outlet configurations. The adaptor end plates are inwardly and outwardly adjustable relative to the body member end portions in order to vary the body member internal volume.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to mufflers used to deaden sound in exhaust gas streams generated by internal combustion engines, and more particularly, to a modular muffler that is quickly and easily adapted for use with a wide variety engines. The muffler has a dimensionally standardized body with end portions that may receive any of a number of adaptor end plates provided with various inlet and outlet configurations. 
     BACKGROUND OF THE INVENTION 
     Motor vehicles, whether they be automobiles, light trucks, vans, heavy-duty trucks, buses, etc., are most often powered by various types of internal combustion engines. These types of internal combustion engines, and the many different manufacturers models thereof, vary considerably in terms of their design, operating and performance characteristics, and consequently, they typically result in the production, distribution, storage and use of a widely divergent array of muffler systems that are tailor-made to provide not only a desired amount of exhaust gas noise attenuation, but also a suitable level of exhaust system back pressure for each engine model and type. 
     Attendant with such diversity of systems is increased cost at virtually every commercial stage. Manufacturing expense is boosted by the need to have multiple types of tooling to produce and assemble a multiplicity of perhaps similar yet different sized muffler parts. Storage and inventory cost is inflated by the requirement that a large number of stock keeping units (SKU&#39;s) must be assigned, recorded and maintained, considerable floor space must be set aside for storage, and complex systems must be acquired and maintained to monitor and replenish supplies of the systems. Shipping and handling outlays can also be considerable due to the need to ship order sizes which are less than economic order quantities. 
     In view of the foregoing a need exists to provide a modular muffler construction that not only is highly versatile and thus capable of being used effectively with a variety of engine types and models, but also is more economical to fabricate, acquire, store and install. 
     SUMMARY OF THE INVENTION 
     The present invention is a modular muffler construction that may be quickly and easily adapted for use with a wide variety of internal combustion engine types and manufacturers models thereof. The muffler construction generally comprises a universally-sized, central body member provided with a pair of longitudinally separated open ends. Each open end is capable of receiving an end adaptor plate, a body adaptor, an end cap and/or a vehicle adapter. The body member preferably will be elongated along its central longitudinal axis. It will internally include a pair of diagonally arranged perforated tubes that extend from a first end chamber situated at, and defining one of the open ends to a second end chamber located at and defining the other of the open ends of the body. The body member will further include a plurality of layers of sound deadening material that extend lengthwise along the interior of the body and inwardly toward the perforated tubes so as to wrap the tubes in a noise attenuating blanket. The end adaptor plate may be provided with one or more orifices through which exhaust gas may flow. The orifice(s) may be of any desired diameter and/or may be positioned in any of a number of different locations on the plate. The end adaptor plates, once received within an open body member end, may also be adjusted inwardly and outwardly relative to the end in order to vary the internal volume of the body member. 
     More than one of the muffler body members may be arranged end-to-end, and joined together either by direct contact between their ends or by linking the ends via a body adaptor. The body adaptor may be provided with a deflector plate to facilitate exhaust gas flow between the body members, and it may alternatively be utilized not as a means to join body members, but to install flow restrictors to create turbulence to control flow and sound, and to provide an exhaust gas expansion chamber on one or both ends of a sole body member. 
     The end cap preferably will be a dome-shaped structure, which, when applied to one of the open ends of the body member, will permit exhaust gas that has entered the body member from the opposite end and traveled to the end cap to be diverted by 180 degrees and caused to journey back through the body member and to exit the muffler from the end through which gained entry. Alternatively, the end cap may be partially dome-shaped and additionally include a tubular extension that allows at least some of the exhaust gas to exit from the end cap. 
     The vehicle adaptor is a duct-like member that, in addition to having a radially outward extending flange portion for receipt by an open end of the body member, preferably has an outer end portion that is cylindrically shaped and a intermediate portion that is semi-hyperboloid shaped. The vehicle adaptor permits the muffler body member to be used with more than one category of vehicle. By way of example, the vehicle adaptor makes it possible for the one or more of the muffler body members to be applied to larger diameter components (pipes and pipe-like inlets and outlets) of the exhaust systems of heavy duty trucks in addition to smaller diameter components of the exhaust systems of automobiles, light trucks, vans, and the like. 
     The modular muffler construction can further include one or more spark arresters, past which the exhaust gas is caused to flow. Preferably, the spark arrester(s) will be contained within the second end chamber of the body member and be secured to an end adaptor plate and at an exhaust gas exit orifice provided therein. Inclusion of one or more spark arresters in such manner has been found to be particularly useful for off-road vehicle applications. 
     The modular muffler may also be constructed so that elongated, exhaust gas carrying tubes extend from the outboard side of an end adaptor plate, through the plate orifices, into the end chamber of the body member and toward the diagonally arranged tubes within the central portion of the body member. The elongated, exhaust gas carrying tubes can be louvered and/or perforated to obtain desired flow and sound levels. 
     Given the above described modular muffler construction it should be evident that the present invention has as one of its objectives significantly reducing the number and types of different muffler systems and their constituent parts that have to be produced. As previously suggested, achievement of this objective can be expected to yield a number of advantages including, but not limited to, assignment, maintaining and monitoring of fewer SKU&#39;s, lowering production tooling costs and storage space allocations, paring distribution expenses and providing vehicle manufacturing and repair facilities with the ability to quickly and easily assemble muffler systems for a multitude of configurations. These advantages and others will become more readily apparent from a review of the following detailed description of the invention and of the drawings attached hereto. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a top cross sectional view (central portion omitted) of one embodiment of the modular muffler construction of the present invention. 
     FIG. 2 shows an enlarged top cross sectional view of the end portion of the central body member of the muffler construction of the present invention. 
     FIG. 3 shows an end view of the central body member of the muffler construction of the present invention. 
     FIG. 4 shows a cutaway top view of the central body member of the muffler construction of the present invention, including an end portion and a substantial portion of the body member&#39;s midsection. 
     FIGS. 5,  7  and  9  show a front view of adaptor end plates of the muffler construction of the present invention. 
     FIGS. 6,  8  and  10  show a side view of the adaptor end plates shown in FIGS. 5,  7  and  9 , respectively. 
     FIGS. 12 and 13 show a side view of end caps of the muffler construction of the present invention. 
     FIGS. 11 and 14 show a front view of the end caps shown in FIGS. 12 and 13. 
     FIG. 15 shows a side view of a vehicle adaptor of the muffler construction of the present invention. 
     FIG. 16 shows a front view of the vehicle adaptor shown in FIG.  15 . 
     FIG. 17 shows a front view of yet another adaptor end plate of the muffler construction of the present invention. 
     FIG. 18 shows a side view of the adaptor end plate shown in FIG.  17 . 
     FIGS. 19 and 20 show a top, partially cross sectional view of the muffler body member provided at each open end with an adaptor end plate as shown in FIG.  7 . 
     FIG. 21 shows a top, partially cross sectional view of the muffler body member provided at one open end with an adaptor end plate as shown in FIG.  7  and at another open end with an adaptor end plate as shown in FIG.  17 . 
     FIG. 22 shows a top, partially cross sectional view of the muffler body member provided at one open end with an adaptor end plate as shown in FIG.  5  and at another open end with an adaptor end plate as shown in FIG.  7 . 
     FIG. 23 shows a top, partial cross sectional view of the muffler body member provided at one open end with an adaptor end plate as shown in FIG.  7  and at another open end with an adaptor end plate as shown in FIG.  12 . 
     FIG. 24 shows a top, partial cross sectional view of two muffler body members of the present invention arranged in direct end-to-end contact. 
     FIG. 25 shows a front view of a body adaptor of the modular muffler construction of the present invention. 
     FIG. 26 shows an side view of a body adaptor shown in FIG.  25 . 
     FIG. 27 shows a top, partial cross sectional view of two muffler body members joined by the body adaptor shown in FIGS. 25 and 26. 
     FIG. 28 shows a top, partial cross sectional view of the muffler body member provided at one end with the end adaptor shown in FIG.  7  and at the other end with the end cap shown in FIG.  12 . 
     FIG. 29 shows a top, partial cross sectional view the muffler body member provided at one of its ends with body adaptor shown in FIGS. 25 and 26. 
     FIG. 30 shows a top, partial cross sectional view of two muffler body members joined together at their innermost ends by the body adaptor shown in FIGS. 25 and 26 and provided at each of their outermost ends with the vehicle adaptor shown in FIG.  15 . 
     FIG. 31 shows a top, partial cross sectional view of the muffler body member provided with spark arresters within the second end chamber thereof. 
     FIG. 32 shows a top, partial cross sectional view of the muffler body member provided with elongated, exhaust gas carrying tubes extending into the end chamber of the body member and toward the diagonally arranged tubes within the central portion of the body member. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     A modular muffler construction in accordance with the present invention is indicated generally in FIGS. 1 and 2 by the reference numeral  10 . The muffler construction  10  generally includes a central body member  12  that is produced with a pair of longitudinally separated, outwardly flanged open ends  14  and  16 . The central body member  12  has an overall length “L” and an overall width “W”, which in the case of the preferred embodiment are 14 inches and 9 inches, respectively. The central body  12  is provided with a pair of tubes or conduits  13  and  15  which extend diagonally across the central body. Each of the tubes  13  and  15  is fabricated with perforated wall material that permits the passage of exhaust gas from the inside to the outside of the tubes  13  and  15  and toward a plurality of layers of sound deadening material  18  that extend lengthwise along the interior of the body  12  and inwardly therefrom toward the tubes  13  and  15 . The central body  12  is also provided at its opposing end regions with end chambers  17  and  19  which openly communicate with the tubes  13  and  15 . Various known sound deadening materials can be utilized with the present invention. For example, materials such as vermiculate coated fiberglass fabric, including the material sold under the trademark “ZETEX PLUS”, manufactured by New Tex Industries, Inc. 
     As most clearly shown in FIG. 3, the outwardly flanged open end  14  of the central body  12  is provided with a plurality of bores  22  which preferably are threaded internally. The outwardly flanged open end  16  is similarly provided with a plurality of bores  22 . The plurality of bores provided at the ends  14  and  16  facilitate the attachment thereto of end adaptor plates  20  and  21  which may have one or more tubular extensions  23  extending outwardly therefrom. As shown in FIGS. 5 through 18, the adaptor plates  20  and  21  are just two examples of a variety of adaptor plates that may be attached to the muffler central body  12 . FIGS. 5 and 6 show an adaptor plate  24  having a single tubular extension  23  which is situated to the left of the vertical center line of the plate. FIGS. 7 and 8 show the adaptor plate  21  which has a pair of horizontally aligned extensions  23  which are positioned to the left and the right of the plate&#39;s vertical center line. FIGS. 9 and 10 show the adaptor plate  20  which has a singular extension  23  that is centrally located on the plate. FIGS. 17 and 18 show the adaptor plate  26  which resembles the plate  20 ; however, the plate  26  has a larger diameter, centrally located tubular extension  25 . All of the adaptor plates  20 ,  21 ,  24  and  26  are provided with a plurality of bores about their peripheral region. The bores are sized and located so that they may be aligned with the plurality of bores  22  provided in the open ends  14  and  16  of the muffler central body  12  and so that they may receive fasteners  27  to hold them finally against the flanges  14  and  16 . Various fasteners as are known in the art can be utilized to attach adaptor plates  20 ,  21 ,  24  and  26  to open ends  14  and  16 , including, including but not limited to bolts, screws, and clamps. Furthermore, the adaptor plates  20 ,  21 ,  24  and  26  may be attached to open ends  14  and  16  by welding the elements together. The end adaptor plates  20 ,  21 ,  24  and  26  may also be provided with means for allowing them to be adjusted inwardly and outwardly relative the ends  14  and  16  in order to vary the internal volume of the body member  12  and to thus also modify its sound attenuation capabilities. 
     FIGS. 11 through 16 illustrate a variety of additional end structures which may be attached to the open ends  14  and  16  of the central body  12 . FIGS. 11 and 12 show an end cap  30 . The end cap  30  is comprised of an base flange  31  and a dome-shaped central portion  32 . FIGS. 13 and 14 show yet another end cap  40 . The end cap  40  has a base flange  41 , a domed portion  42  and an outwardly protruding tubular member  43  which is off-set from the central portion of the dome portion  42 . FIGS. 15 and 16 show a duct-like vehicle adaptor  50  that is comprised of a base portion  51  and an outwardly projecting portion  52  that resembles a funnel. The funnel-like portion includes a cylindrically shaped outer end portion  53  and a semi-hyperboloid shaped intermediate portion  54 . 
     FIGS. 19,  20 ,  21 ,  22  and  23  illustrate how the various end structures of the muffler construction of the present invention may be combined with the central body portion  12  to provide a variety of exhaust gas flow configurations therethrough. FIG. 19 shows how the adaptor end  21  having dual tubes  23  can be applied to ends  14  and  16  of body member  12  with the result that there is provided an exhaust gas inlet and outlet on each of the ends  14  and  16 . FIG. 20 shows that the same adaptor end  21  having the dual tubes  23  can be utilized so that the end  14  has two exhaust gas outlets and the end  16  has two exhaust gas inlets. FIG. 21 illustrates how the adaptor plate  21  with dual tubes  23  and the adaptor plate  26  with the singular tube  25  may be applied respectively to the ends  14  and  16  with the tubes  23  serving as exhaust gas outlets and the tube  25  serving as an exhaust gas inlet. FIG. 22 shows the central body  12  outfitted with the adaptor plate  24  (single off-set tube  23 ) on the end  14  and the dual-tube adaptor plate  21  on the end  16 . In such arrangement, the tube  23  on the plate  24  functions as an exhaust gas outlet, and one of the tubes  23  on the plate  21  serves as an inlet, while the remaining tube  23  serves as an additional exhaust gas outlet. Lastly, FIG. 23 indicates how the end cap  30  and the dual tube adaptor plate may be included respectively on the ends  14  and  16 . As most clearly shown in FIG. 28, application of the end cap  30  and the adaptor plate  21  as shown FIG. 23 allows the end cap  30  to serve as an exhaust gas deflector that diverts the flow of gas by 180 degrees and permits one of the tubes  23  on the plate  21  to be an exhaust gas inlet and the other tube  23  to be an exhaust gas outlet. 
     FIG. 31 illustrates how the muffler construction may be provided with spark arresters  70 . The spark arresters  70  are enclosed within the end chamber  19  and are secured to the inboard side of the adaptor plate  26  so that they are exposed at their longitudinally outer most sides  70   a  with the innermost open end of the tubular extension  25  and at their longitudinally innermost sides  70   b  to the interior of the chamber  19  and to the end portions the diagonal tubes  13  and  15  that are received by the chamber  19 . While the muffler construction shown in FIG. 31 may be beneficially incorporated into the exhaust system of almost any vehicle, such construction has been found to be particularly useful for off-road vehicle applications. It should also be recognized that while FIG. 31 shows the spark arresters  70  be utilized with the adaptor plate  26  and the tubular extension  25 , the spark arresters may just as easily be used with other adaptor plate/tubular extension combinations, e.g., the plate  20  and the extension  23  as shown in FIG.  10 . 
     FIG. 32 shows how the muffler construction of the present invention may include a pair of exhaust gas carrying tubes  23  that extend from the outboard side of an end adaptor plate  21 , through the plate orifices, into the end chamber  17  of the body member  12  and to open ends of the diagonally arranged tubes  13  and  15  situated within the central portion of the body member  12 . The extension portions  23 ′ of the tubes  23  that extend through the chamber  17  can be louvered and/or perforated in order to obtain desired flow and sound levels. 
     FIGS. 24 and 27 show two of the ways in which two (or more, if desired) of the muffler central bodies  12  may be linearly arranged in order to provide a multiple muffler exhaust system tailored to a specific type of vehicle and engine used therewith. FIG. 24 shows the instance in which two of the muffler central bodies  12  are joined in direct end-to-end contact with the end  14  of one of the bodies  12  abutted against the end  16  of the other of the bodies  12  with such abutment is effected by bringing the plurality of bores  22  provided in the flanged portion of the respective ends  14  and  16  and securing them together by inserting and tightening a fastener  27  (not shown) in the aligned pairs of bores  22 . FIG. 27 shows the case where two of the muffler central bodies  12  are joined by way of a body adaptor  60 . As shown in FIGS. 25 and 26, the body adaptor  60  is comprised of an oval-shaped central duct section  62  that is open at both of its longitudinally separated ends  64  and  66  which serve as either an inlet or an outlet for exhaust gas. Each of the ends  64  and  66  is provided with an outwardly extending flange  61  and  63 . Like the flange  14  of the muffler central body  12 , the flanges  61  and  63  are provided with a plurality of bores  22  that are alignable with the bores  22  provided in the flange  14  and that with insertion and tightening fastener  27  effect a secure adjoinment of the central muffler bodies  12 . As further shown in FIGS. 25 and 26, the body adaptor  60  may be provided internally with a deflector plate  68 . The deflector plate preferably will extend laterally across the oval duct section  62  and will have a generally wedge-shaped cross section. 
     FIG. 29 suggests ways in which the body adaptor  60  may alternatively be utilized either singly with only one of the muffler central bodies  12  or in cooperation with one of the other end structures of the muffler construction of the present invention, such as the end adaptor plates  20  or  21 . 
     FIG. 30 is exemplary of a manner in which more than one of the muffler central bodies  12  may be configured for use not only with the vehicle adaptor  50 , but also with the body adaptor  60 . As specifically shown in FIG. 30, two muffler central bodies  12  have been joined at the innermost of their ends  14  and  16  by the body adaptor  60 . Additionally, the bodies  12  are each provided at the outermost of their ends  14  and  16  with one of the vehicle adaptors  50 . The vehicle adaptors are joined to the ends  14  and  16  of the bodies  12  via the same method as is used to join the other end structures of the construction of the present invention, i.e., via the fasteners  27 . The assembly of muffler bodies  12  with the vehicle adaptors  50  depicted in FIG. 30 is envisioned to be suitable to adapt the muffler/body adaptor combination, which might otherwise be useable with the exhaust system of an automobile engine, for use with the exhaust system of a much larger heavy duty truck engine. By suitably varying the dimensions of the vehicle adaptor in response to the dimensions of the exhaust system hardware of yet other types and models of vehicles the muffler/body adaptor combination shown in FIG. 30 as well as a multitude of other combinations may be applied to a variety of other vehicle types and models. 
     In use the various embodiments of the present invention create a system of interchangeable parts that are selectively connected in order to create a muffler with the proper characteristics for various vehicles. Accordingly, a service center or muffler shop utilizing the system, will no longer need to stock numerous different mufflers for different vehicles. The facility will utilize a body member with the proper characteristics for the selected vehicle, and will match the necessary end plate adapters with the selected body member to provide a suitable muffler for the selected vehicle. It should be noted that the system may include body members having characteristics suitable for a number of different vehicles. 
     While the preferred embodiments of the invention has been described above, it will be recognized and understood that various modifications may be made therein.