Patent Publication Number: US-7913809-B2

Title: Flapper configuration for marine exhaust system

Description:
PRIORITY CLAIM 
     This application claims the benefit of previously filed U.S. Provisional Patent Application entitled “FLAPPER CONFIGURATION FOR MARINE EXHAUST SYSTEM,” assigned U.S. Ser. No. 61/134,901, filed Jul. 15, 2008, and which is incorporated herein by reference for all purposes. 
    
    
     FIELD OF THE INVENTION 
     The present subject matter relates to exhaust systems. More specifically, the present subject matter discloses methods and apparatus for reducing wear and noise generation in a marine exhaust system. 
     BACKGROUND OF THE INVENTION 
     Water cooled marine exhaust systems have been previously employed to generally good effect, but have nevertheless possessed certain operational deficiencies. Prior exhaust tips have included various flapper configurations that are typically positioned downstream of a point at which cooling water flow mixes with exhaust gasses. Under normal operation, such positioning of exhaust flappers works well, but issues often arise upon generation of excessive heat levels within the exhaust systems. 
     In particular, flappers in such systems are often provided with sealing elastomeric, i.e., rubber, material along the edges of the perimeter of the flapper. With continued presence of excessive heat, as for example, from prolonged absence or reduction of cooling fluid, such elastomeric seals may become damaged to the point that direct metal-to-metal contact between the flapper and internal surfaces of the exhaust tips may occur. Such metal-to-metal contact may easily result in significant damage to the flapper as well as the exhaust tip. Additionally, such metal-to-metal contact often results in excessive noise generation during certain operational phases of the marine engine. 
     In light of such deficiencies recognized herewith in the known exhaust tip flapper configurations, it would be desirable to provide a flapper configuration that avoids such heat damage, and provides possibilities for reduced noise generation. 
     Various patents are known concerning marine exhaust related subject matter, including for example Zelinski U.S. Pat. No. 7,104,359 entitled “Muffler having a baffle with angled plates;” Zelinski U.S. Pat. No. 7,013,565 entitled “Removable collector for liquid cooled exhaust;” Zelinski U.S. Pat. No. 6,609,590 entitled “Exhaust system having angled baffle;” and Beson et al. U.S. Pat. No. 6,397,589 entitled “Exhaust pipes and assemblies.” The disclosures of all the patents cited herein are hereby incorporated by reference for all purposes. 
     While various configurations of marine exhaust flapper arrangements have been developed, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the subject technology. 
     SUMMARY OF THE INVENTION 
     In view of the recognized features encountered in the prior art and addressed by the present subject matter, an improved methodology for providing both noise reduction and reduced flapper wear has been developed. It should be understood that the present subject matter equally encompasses both methodologies and corresponding apparatuses. 
     In an exemplary configuration, previously provided exhaust flappers haves been relocated to significantly reduce noise. 
     In one form, the present subject matter provides an exhaust flapper located in a water-cooled exhaust system generally upstream of previously designated locations. 
     In accordance with aspects of certain embodiments of the present subject matter, an exhaust flapper is located proximate a junction point between a metallic exhaust tip and an elastomeric coupling device. 
     In accordance with certain aspects of other embodiments of the present subject matter, methodologies have been developed to reduce noise by positioning a flapper such that a portion thereof will, with normal movement, contact a sound-deadening surface. 
     In accordance with aspects of still further embodiments of the present subject matter, a flapper is positioned to contact an elastomeric coupling component to reduce contact generated noise. 
     One exemplary embodiment of the present subject matter relates to a flapper configuration for a marine exhaust system of the type having cooling water in contact with an exhaust pipe, comprising an exhaust pipe portion located upstream relative to a cooling water contact point of an associated marine exhaust system; an exhaust tip; an elastomeric coupling device coupling such exhaust tip to such exhaust pipe portion; a pivot device situated in such exhaust pipe portion; and a flapper pivotally mounted on such pivot device. 
     In some variations of the foregoing, such exhaust tip may form an opening for exposing a portion of such elastomeric coupling device to such flapper. Further, such flapper may be mounted so as to when pivoting engage such elastomeric coupling device instead of such exhaust pipe portion, in order to reduce noise and wear relative to such flapper. In other alternatives, such exhaust pipe portion and such exhaust tip may comprise metal. 
     In other present variations, such coupling device may couple such exhaust tip to such exhaust pipe portion with at least some gap therebetween; and such pivot device and such flapper may be mounted proximate such coupling device so that such flapper engages such coupling device instead of either of such exhaust tip or such exhaust pipe portion upon pivoting of such flapper. Further optionally, such flapper may include a flapper tip covered with elastomeric material about the perimeter thereof, and such elastomeric material and such elastomeric coupling device may comprise rubber. 
     Another present exemplary embodiment relates to a flapper configuration for a marine exhaust system of the type having cooling water in contact with an exhaust pipe, comprising a metallic exhaust pipe portion located upstream relative to a cooling water contact point of an associated marine exhaust system; a metallic exhaust tip; an elastomeric coupling device coupling such exhaust tip to such exhaust pipe portion such as to expose a portion of such elastomeric coupling device to the interior of such exhaust pipe portion; a pivot device situated in such exhaust pipe portion; and a flapper pivotally mounted on such pivot device. Preferably, such flapper when pivoting will engage such elastomeric coupling device instead of such metallic exhaust pipe portion or such metallic exhaust tip, in order to reduce noise and wear relative to such flapper. 
     In an exemplary optional embodiment of the foregoing, such flapper may include a flapper tip covered with elastomeric material about the perimeter thereof. Still further, such elastomeric material and such elastomeric coupling device may comprise rubber. 
     It is to be understood by those of ordinary skill in the art that the present subject matter equally encompasses both apparatus and corresponding methodology. One exemplary present method relates to a method for an improved flapper configuration for a marine exhaust system of the type having cooling water in contact with an exhaust pipe, comprising positioning an exhaust pipe portion relatively upstream of a cooling water contact point of an associated marine exhaust system; and positioning a pivot mounted flapper within such exhaust pipe portion such that a portion of the flapper during its normal pivoting movement will contact a sound-deadening surface, for reducing noise and wear relative to such flapper. 
     Per one present alternative methodology, such exhaust pipe portion may comprise metal and such sound-deadening surface may comprise rubber. In other present alternatives, an exemplary method may further include coupling an exhaust tip to such exhaust pipe portion using an elastomeric coupling device; and wherein positioning such flapper includes mounting such flapper so as to contact such elastomeric coupling device. 
     In other present variations, such exhaust pipe portion may comprise metal and such elastomeric coupling device comprises rubber, and/or an exemplary method may further include providing elastomeric material at least about a portion of the perimeter of the flapper. 
     Additional objects and advantages of the present subject matter are set forth in, or will be apparent to, those of ordinary skill in the art from the detailed description herein. Also, it should be further appreciated that modifications and variations to the specifically illustrated, referred and discussed features, elements, and steps hereof may be practiced in various embodiments and uses of the present subject matter without departing from the spirit and scope of the present subject matter. Variations may include, but are not limited to, substitution of equivalent means, features, or steps for those illustrated, referenced, or discussed, and the functional, operational, or positional reversal of various parts, features, steps, or the like. 
     Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of the present subject matter may include various combinations or configurations of presently disclosed features, steps, or elements, or their equivalents (including combinations of features, parts, or steps or configurations thereof not expressly shown in the figures or stated in the detailed description of such figures). Additional embodiments of the present subject matter, not necessarily expressed in the summarized section, may include and incorporate various combinations of aspects of features, components, or steps referenced in the summarized objects above, and/or other features, components, or steps as otherwise discussed in this application. Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the remainder of the specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  illustrates an exemplary known exhaust and flapper configuration; 
         FIG. 2  illustrates a cross-section of an exemplary exhaust tip and coupling component in accordance with the present subject matter; and 
         FIG. 3  illustrates an oblique view of a cross-section of an exemplary exhaust tip and flapper arrangement in accordance with present disclosure. 
     
    
    
     Repeat use of reference characters throughout the present specification and appended drawings is intended to represent same or analogous features, elements, or steps of the present subject matter. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As discussed in the Summary of the Invention section, the present subject matter is particularly concerned with improved flapper configurations for use with marine exhaust systems. 
     Selected combinations of aspects of the disclosed technology correspond to a plurality of different embodiments of the present subject matter. It should be noted that each of the exemplary embodiments presented and discussed herein should not insinuate limitations of the present subject matter. Features or steps illustrated or described as part of one embodiment may be used in combination with aspects of another embodiment to yield yet further embodiments. Additionally, certain features may be interchanged with similar devices or features not expressly mentioned which perform the same or similar function. 
     Reference will now be made in detail to the presently preferred embodiments of the subject marine exhaust flapper configurations. First with reference to  FIG. 1 , an exemplary known marine exhaust flapper configuration will be described. 
     As shown in  FIG. 1 , a previously known exemplary flapper configuration  100  is illustrated. Exhaust tip  110  has mounted therein a flapper  120  by way of pivot device  130  mounted within exhaust tip  110  at mounting points  132 ,  134 . Elastomeric material  142 ,  144  may be applied respectively on opposite diameter portions of flapper  120 . Generally, elastomeric material  142 ,  144  provides some exhaust sealing properties as well as some noise reduction capabilities. Heat normally generated during operation of an associated marine engine, most especially at reduced cooling water flow levels, will, however, tend to deteriorate elastomeric material  142 ,  144 . 
     Upon deterioration of elastomeric material  142  and  144 , direct contact between flapper  120  and internal portions of exhaust pipe  110  may occur. Such direct contact may produce excessive contact noise as well as potential damage to exhaust pipe  110  and flapper  120 . 
     With reference now to  FIGS. 2 and 3 , a present improved configuration for marine engine exhaust system flappers will be represented and described. As may be seen in  FIGS. 2 and 3 , flapper  220 ,  320  has been repositioned from previously known positions, as, for example, as shown at  120  in  FIG. 1 , to a position upstream of the exhaust system associated with a marine engine (not separately illustrated herewith, and details of which are either well known to those of ordinary skill in the art, or form no part of the present disclosure). 
     More specifically, exhaust tips  210 ,  310  may be coupled to a further exhaust pipe portion  222 ,  322  by way of an elastomeric coupling device  240 ,  340 . Such coupling device  240 ,  340  may be made of rubber or the like and may be configured as a force fit type device. Alternatively, coupling device  240 ,  340  may be fitted with a surrounding pipe clamping device or other appropriate securing device, not presently illustrated, to secure the exhaust pipe sections together, as will be well understood by those of ordinary skill in the art from the complete description and disclosure herewith. Flapper  220 ,  320  may be positioned within exhaust pipe portion  222 / 322  by way of pivot device  230 ,  330  such that a tip portion of flapper  220 ,  320  contacts coupling device  240 ,  340  at an internally exposed area  246 ,  346  of coupling device  240 ,  340 . 
     As illustrated in  FIGS. 2 and 3 , coupling device  240 ,  340  is installed in such a manner as to separate exhaust tip  210 ,  310  at least slightly from an end  242  of exhaust pipe portions  222 ,  322 . In such manner, it is possible to optionally omit or retain such as elastomeric material  142  illustrated in association with flapper  120  of  FIG. 1  while optionally retaining material such as corresponding to elastomeric material  144  of  FIG. 1 . 
     By coupling exhaust tip  210 ,  310  to exhaust pipe portion  222 ,  322  in such a manner, flapper  220 ,  320  may contact an internal surface portion of elastomeric coupling device  240 ,  340 , thereby avoiding potential direct contact between flapper  220 ,  320  and any metallic portion of exhaust tip  210 ,  310 . 
     Those of ordinary skill in the art will appreciate that elastomeric portions similar to portions  142 ,  144  associated with flapper  110  of  FIG. 1  may also be provided in association with flapper  210 ,  310  of  FIGS. 2 and 3 . It should further be appreciated that even under the circumstances that such elastomeric portions should deteriorate due to extreme heat levels within the exhaust system, noise levels will remain relatively low due to avoidance of metal-to-metal contact, as otherwise may occur in the known previous configurations. 
     While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.