Patent Abstract:
An exhaust tip assembly including a cylindrical collar adapted to be secured to the distal end of a vehicular exhaust pipe and to extend beyond the distal end of the exhaust pipe. A rigid support structure is secured inside the collar and a turbine is rotatably coupled on the distal side of the rigid support structure. In a preferred embodiment, the turbine is concentric with the collar and has a fixed axial position adjacent the distal end of the cylindrical collar. It is also preferred for the turbine to form a plurality of vanes facing the distal end of the exhaust pipe such that exhaust gases pass over the vanes and cause the turbine to freely spin in one direction. It is further preferred if the turbine is free to continue spinning independent of exhaust gases continuing to exit the exhaust pipe through the collar.

Full Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to novelty exhaust tips having an exhaust-driven spinning element.  
         [0003]     2. Background of the Related Art  
         [0004]     An exhaust tip is an ornamental assembly for an exhaust pipe. Typically, an exhaust tip is made of metal and/or chrome plated to match other ornamental components of the vehicle. The exhaust tip covers the bare steel exhaust pipe or tail pipe that can become rusty and covered in dirt and grease. Exhaust tips are intended to be readily viewable and generally provide a distinctive appearance to a vehicle.  
         [0005]     The broad general appeal and interest in vehicles has led to a large and growing industry of parts and services to customize vehicles. Some parts and services are directed solely at improving vehicle performance, while other parts and services are directed solely at providing a unique ornamental appearance. Some parts and services may even provide a combination of improved performance and ornamental appearance. Still, the selection of parts and services for a vehicle can be extremely personal and expressive.  
         [0006]     Therefore, there continues to be a demand for further ornamental devices for a vehicle. It is desirable to provide ornamental devices for a vehicle that do not deter the performance of the vehicle and are easy to install and maintain.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides an exhaust tip assembly, comprising a cylindrical collar adapted to be secured to the distal end of a vehicular exhaust pipe and to extend beyond the distal end of the exhaust pipe. A rigid support structure is secured inside the collar and a turbine is rotatably coupled on the distal side of the rigid support structure. In a preferred embodiment, the turbine is concentric with the collar and has a fixed axial position adjacent the distal end of the cylindrical collar. It is also preferred for the turbine to form a plurality of vanes facing the distal end of the exhaust pipe such that exhaust gases pass over the vanes and cause the turbine to freely spin in one direction. It is further preferred if the turbine is free to continue spinning independent of exhaust gases continuing to exit the exhaust pipe through the collar. The most preferred turbine includes a rim that gives the turbine the shape of a wheel with a plurality of spokes. Other aspects of the preferred embodiments are described below with reference to the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     So that the above recited features and advantages of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof that are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.  
         [0009]      FIG. 1  is a perspective view of an exhaust tip assembly mounted to an exhaust pipe.  
         [0010]      FIG. 2  is cross-sectional side view of the exhaust tip assembly mounted to an exhaust pipe.  
         [0011]      FIG. 3  is a back view of the exhaust tip assembly.  
         [0012]      FIG. 4  is a front view of the exhaust tip assembly.  
         [0013]      FIG. 5  is a cross-sectional view of a single vane of a turbine.  
         [0014]     FIGS.  6 A-D are cross-sectional views of alternative vanes.  
         [0015]      FIG. 7  is a plan view of an embodiment of a turbine in the form of a wheel.  
         [0016]      FIG. 8  is a plan view of an embodiment of a turbine without a rim.  
         [0017]     FIGS.  9 A-C are schematic views of alternative embodiments of a structure for supporting a turbine within the collar.  
         [0018]      FIG. 9D  is a schematic side view of the embodiment of  FIG. 9C .  
         [0019]      FIG. 10  is a cross-sectional side view of an exhaust tip assembly mounted to an exhaust pipe and having a support structure with fins that cause the exhaust gases to swirl.  
         [0020]      FIG. 11  is a back view of the exhaust tip assembly illustrating the fins and the turbine.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]      FIG. 1  is a perspective view of an exhaust tip assembly  10  of a preferred embodiment mounted on the end of an exhaust pipe  12 . The assembly  10  includes a cylindrical collar  14  that has a diameter greater than the diameter of the exhaust pipe  12 . The collar  14  may be coupled to the exhaust pipe in various manners, including a transitional section  16  that is rigidly coupled to both the collar and the pipe. Preferably, the transitional section  16  forms part of the collar  14  and is rigidly coupled to the exhaust pipe during installation. The preferred method of rigidly coupling the collar and pipe is welding, although it is possible to accomplish the coupling with screws, rivots, or clamps.  
         [0022]     The assembly  10  also includes a turbine in the shape of a wheel  18  that is rotatably coupled to the collar  14  so as to spin as exhaust gases are pushed through the wheel. The collar  14  and wheel  18  are preferably both cylindrical and concentric. The wheel  18  includes a rim  20 , hub  22 , and spokes  24 . The outwardly visible, downstream face of wheel  18  forms a display surface that may be contoured and designed for aesthetic appeal, including, for example, point  26  and grooves  28 . The preferred display face is generally flat or gently curved and may include grooves or other ornamentation. It is desirable for the appearance to be similar to that of a hub-cap. Accordingly, the display surface of individual spokes may be generally symmetrically contoured.  
         [0023]      FIG. 2  is cross-sectional side view of the exhaust tip assembly  10  mounted to an exhaust pipe  12 . As shown, the transitional section  16  of the collar  14  has been coupled to the exhaust pipe  12  by a circumferential weld  30 . At the distal end of the collar  14 , a support structure  32  is secured to the inside surface  34  of the collar  14  and extends into the axial center of the collar  14 . A rotary bearing or bushing  36  is secured to the support structure  32  and rotatably couples a shaft  38  that is part of, or attached to, the turbine wheel  18 . Accordingly, the wheel is rotatably secured to the collar  14  in a fixed axial position, such as immediately inside the distal end of the collar. The present embodiment illustrates the optional feature of the collar  14  having a rolled distal end  40 , which may overlap the rim  20  of the wheel  18 . It is believed that the overlapping may reduce the amount of exhaust gas passing through the generally annular gap  42  formed between the perimeter of the wheel and the collar and allow more of the exhaust gas to be utilized in spinning the wheel.  
         [0024]      FIG. 3  is a back view of the exhaust tip assembly  10 . The support structure  32  of this embodiment extends across the full inside diameter of the collar  14  and is secured to both sides. The preferred support structure  32  includes a central hole  44  for passage of the shaft  38  and holes  46  along the length of the structures  32  to reduce the extent that the structure will block exhaust gas. The wheel  18  rotates about the axial center  48  of the bearing or bushing  36 . Preferably, there is only a small annular gap  42  between the wheel  18  and the collar  14 .  
         [0025]     As shown in  FIG. 3 , it can be appreciated that the support  32 , wheel  18  and rolled end  40  are obstructions that reduce the extent of the cross-sectional area of the collar is open for the passage of exhaust gases. However, the collar may be considered to have an effective cross-sectional area that is the sum of the cross-sectional areas that are not blocked at any given point in the rotation of the wheel  18 . In the embodiment of assembly  10 , the effective cross-sectional area of the collar is substantially the sum of the five openings between the spokes  24 , less some portion of the structural support  32  that may further block these openings. If the collar does not have rolled ends, then the effective cross-sectional area may also include the area of the annular gap  42 . Accordingly, it is preferred that the effective cross-sectional area of the collar is approximately equal to, or greater than, the cross-sectional area of the exhaust pipe so as to avoid forming a restriction that might affect engine performance. This is possible because the collar has a greater diameter than the exhaust pipe.  
         [0026]      FIG. 4  is a front view of the exhaust tip assembly  10 . Here, the optional rolled end  40  of the collar  14  overlaps with, and hides, most of the rim  20  (see  FIG. 2 ). While the structural support  32  can be seen in the front view of this embodiment, it is preferred to reduce the prominence of the support so that is does not detract from the appearance of the display face of wheel  18 . For example, the wheel  18  preferable has a shiny, metallic surface, such as silver, gold or chrome plate. The support  32  is preferably a dark color, most preferably a matt black. Furthermore, the positioning of the support behind the wheel  18  tends to limit its exposure and puts it in the shadows of the wheel  18  and collar  14 .  
         [0027]      FIG. 5  is a cross-sectional view of a single spoke  24  of a wheel  18  adjacent a rolled end  40  of the collar. The spoke  24  of this embodiment includes a proximal surface  50  that forms a vane. This particular vane has a flat surface  50  that is radially slanted and exposed to a generally axial flow of the exhaust gases in the direction of arrows  52 . While the exhaust gases are deflected around the spoke  24  in the direction of arrow  54 , the spoke is urged radially in the direction of arrow  56  causing the wheel to rotate about the axis  48 . Consequently, it should be recognized that the fixed physical configuration of the vane or vanes determines the direction in which the wheel will spin.  
         [0028]     FIGS.  6 A-D are cross-sectional views of alternative embodiments of spokes  24  having proximal surfaces that form vanes for imparting rotation to the wheel is a similar manner. In  FIG. 6A , the spoke embodiment  24 A has a proximal surface  58  that, while not slanted, preferentially allows exhaust gases to flow around one side more readily than around the other side, thereby imparting rotation. In  FIG. 6B , a triangular block or bar  60  has been attached to the proximal side of the otherwise flat spoke embodiment  24 B. This embodiment simplifies the construction of the spoke  24 B, but requires the attachment of the block  60 . Such attachment may include welding, adhesives or screws. In  FIG. 6C , the spoke  24 C also has an attached block or bar  62  having a different configuration. In  FIG. 6D , the spoke  24 D has a proximal surface with an irregular curvature that generally slants in one direction to similarly impart rotation. These embodiments are exemplary and should not be taken as limiting the scope of the invention. However, it is preferred that the spokes have a generally uniform appearance from the front view (as in  FIG. 4 ).  
         [0029]      FIG. 7  is a plan view of the back side of the wheel-shaped turbine  18 . In this embodiment, the vanes  50  are shown machined into a portion of the back surface of the spokes  24 .  FIG. 7  is consistent with  FIG. 5  and shows the direction of spinning by arrow  56 .  
         [0030]      FIG. 8  is a plan view of another embodiment of a turbine  66  that would function in substantially the same manner as the wheel  18  shown in  FIG. 7 . The primary difference is that the turbine  66  does not have a rim. The use of a rim is presently preferred because of the strength it adds to the spinning member and because of the flywheel effect that the rim provides.  
         [0031]     FIGS.  9 A-C are schematic back views of alternative embodiments of support structures for securing a turbine within the collar  14 . These views are similar to the back view shown in  FIG. 3 . For clarity, the turbine wheel  18  has been left out. Accordingly,  FIG. 9A  shows the support  32  as shown in  FIG. 3  with a central hole  44  for receiving the shaft  38 . It is anticipated that the hole  44  may be omitted by securing the bushing or bearing  36  to the front face of the support  32  and terminating the shaft within the bushing or bearing. In  FIG. 9B , a support  68  includes three legs  70 , preferably at equiangular spacing. A support with any number of legs could be envisioned. However,  FIG. 9C  shows a support  72  having a single leg from the axial center  48  to the side of the collar  14 . This support  72  is advantageous in maintaining more open area for the flow of exhaust gases through the collar. While support  72  might otherwise be less rigid that the other supports  32 ,  70 ,  FIG. 9D  (a schematic side view of the embodiment of  FIG. 9C ) shows a brace  74  that can be used to strengthen the support. Many alternative supports can also be imagined that are within the scope of the present invention.  
         [0032]      FIG. 10  is a cross-sectional side view of another embodiment of an exhaust tip assembly  80  mounted to an exhaust pipe  12  and having a support structure  82  with fins  84  that cause the exhaust gases  88  to deflect and swirl before reaching the turbine, such as wheel  18 . The swirling exhaust gas then drives the wheel  18 . While this embodiment may function without regard to the profile of the spoke  24  or vane surface  50 , the swirling exhaust gases may be most effective in driving a vane of the type shown in  FIGS. 6A  or  6 B if the swirling gases are directed by the fins  84  against the projecting walls  86 . Many alternative fin and vane designs can also be imagined that are within the scope of the present invention.  
         [0033]      FIG. 11  is a back view of the exhaust tip assembly  80  shown in  FIG. 10 , illustrating the fins and the rotational direction of the wheel  18 . The exhaust gases flow down the exhaust pipe  12  and down the collar  14  (into the page as shown as a dot connected to arrow  88  in FIG.  11 ) before being deflect by the fins  84 . The exhaust gases flow in direction  88  and push against the side of the wall  86  or even the spoke  24  itself.  
         [0034]     In operation, the embodiments described above perform in a similar manner. Upon ignition of the vehicle engine, exhaust gases begin to flow through the exhaust pipe and the collar. Depending on the amount of friction in the bearing or bushing that rotatably supports the shaft of the wheel and the size, number and pitch of the vanes, the wheel may begin spinning either under engine idling conditions or begin only upon the engine reaching higher rotations per minute or other engine conditions producing a higher exhaust gas flow rate. In one embodiment, the friction is as low as possible to encourage spinning even at low exhaust gas flow rates and to maximize the spinning rate at higher flow rate. A low friction bearing or bushing will also increase the extent of continued spinning after the exhaust gas flow has declined or stopped. Having the wheel continue to spin after the engine is shut off or vehicle movement has stopped is highly desirable. Still, in another embodiment, the friction in the bearing or bushing may be slightly greater in order to keep the spinning rate in a range that increases viewability. It is anticipated that the wheel may reach such high spin rates that any detail or light reflective surface features of the wheel may become blurred to the point that the visual effect is diminished. Consequently, friction may be used to regulate the spin rate to a desirable range over the intended driving conditions. Still further, the spin rate will effect the sound of the exhaust. In some applications, the dynamic exhaust tip delivers a “whirring” sound characteristic of a turbocharger. It is believed that the spinning turbine or “wheel” could potentially improve the exhaust flow, resulting in lower exhaust backpressure and thereby increasing performance and/or fuel economy.  
         [0035]     The term “shaft” means a supporting member that carries a wheel and either rotates with the wheel or allows the wheel to rotate freely on it. The term “vane” means a flat or curved surface exposed to a flow of fluid so as to be forced to move or to rotate about an axis. The term “turbine” means a bladed or vaned device that rotates on a shaft and is actuated by the reaction to a current of fluid. The term “fin” means a fixed structure having a flat or curved surface exposed to a flow of fluid so as to impart a swirling direction to the fluid. References to a turbine in the shape of a “wheel” mean a turbine, as defined above, that includes a circular frame with a hub at the center for attachment to a shaft, about which it may revolve.  
         [0036]     This description is intended for purposes of illustration only and should not be construed in a limiting sense. The scope of this invention should be determined only by the language of the claims that follow. The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The term “consisting essentially of,” as used in the claims and specification herein, shall be considered as indicating a partially open group that may include other elements not specified, so long as those other elements do not materially alter the basic and novel characteristics of the claimed invention. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. For example, the phrase “An assembly comprising a wheel” should be read to describe an assembly having one or more wheels. The term “one” or “single” shall be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” are used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is not a required feature of the invention in its broadest form.

Technology Classification (CPC): 5