Abstract:
A sealed coupling for connecting two pipe ends include two operating covers for respective connection to respective pipe ends, and elongated bellows having respective ends and a damping element supported by respective rims of said covers, said damping element disposed radially outwardly of said bellows and oriented centrally of said respective bellows ends for dissipating forces on said coupling uniformly across said bellows.

Description:
RELATED APPLICATION 
     Applicant claims the priority of U.S. provisional patent application Ser. No. 61/052,661, filed May 13, 2008 and entitled, “DOUBLE COVER-CENTER CUSHION DECOUPLER”, which application is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to the field of piping and more particularly to flexible couplings for coupling pipe ends one to another compensating for, dissipation of and suppressing transfer of thermal influences, pressure changes, motion such as torsion or bending, noise, vibration and harshness (NVH) and other concerns. 
     BACKGROUND OF THE INVENTION 
     Known flexible couplings for piping systems have an inherent disadvantage in that they place or locate major damping elements in non-uniform locations, usually at the extremities or extreme ends of the coupling device. Where prior coupling joints, which use flexible sealing bellows, have effective pivot points (such as at the damping elements), the result is an off-center or asymmetric stress point or region which is not distributed evenly across the bellows geometry. This results in high, localized stress concentrations. Such higher stress concentrations typically require a longer bellows geometry which undesirably increases the overall length of the joint or coupling. 
     It is thus desired to provide damping apparatus in a piping system for evenly distributing system stress, and diluting stress concentration. 
     Another objective is to provide an elastic bellows coupling of widely dissipated stress concentration and of shorter length than heretofore available. 
     SUMMARY OF THE INVENTION 
     To these ends, one embodiment of the invention contemplates a central damper orientation in a bellows connector or coupler. This provides higher durability, shorter overall length, and a reduced number of components when compared to prior devices. 
     The higher durability advantage is achieved through the distribution of the stress more evenly over all convolutions of the bellows. This is achieved from the reduction in length of the effective moment arm created by the natural pivot of the damping element. 
     The stress reduction allows for fewer convolutions to be required per a given application. This, in turn, reduces the overall length of the joint. Also, orienting the damping element outside of the bellows, instead of at the end extremity, allows shorter overall coupling length. 
     The reduction of components is achieved by covers serving dual structural purposes and damping element retention. Therefore less metal forming and welding, or other assembly processes, are required as compared to prior devices. 
     The integral parts of a coupling according to the invention allow for a gas tight flexible connection that is capable of compensating and performing the benefits of compensating thermal influences, pressure changes, motion such as bending and torsion, noise vibration and harshness (NVH), and other such concerns. 
     These and other objects and advantages will become readily appreciated from the following written description and from the drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of invention shown in an automotive exhaust application; 
         FIG. 2  is an exploded view of the embodiment of the invention illustrating components of one embodiment of the invention in expanded format for clarity of description; and 
         FIG. 3  is a cross-sectional view of the embodiment of  FIG. 1  displaying the position of the damping element in relation to the bellows and other components of the invention including two covers supporting the location of the damping element. The components shown are generally symmetrical about an illustrative center line. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It should be readily understood that the components and steps of the invention, as generally described and illustrated in the Figures herein and accompanying text, can be arranged and designed in a wide variety of different configurations while still utilizing the inventive concept. Thus, the following more detailed description of the preferred embodiments of the system and method for the present invention, as presented in the Figures and accompanying text, is not intended to limit the scope of the invention, but it is merely representative of the presently preferred embodiments thereof. 
     The preferred embodiments of the invention will be best understood by reference to the drawings wherein like parts or steps are designated by like numerals throughout. 
     Turning now to the drawings,  FIG. 1  illustrates one embodiment  10  of the invention in the environment of an internal combustion automotive exhaust system having two exhaust gas pipes  12 ,  14  (shown in phantom) and one of which, for example, may be an exhaust manifold. Coupling  10  may be used in other environments and with other pipes as is apparent. In this description, it will be appreciated that pipes  12 ,  14  are generally oriented co-axially with axis  15  ( FIG. 3 ) of coupling  10 , although coupling  10 , among other things, may compensate for positional misalignment. This particular  FIG. 1  illustrates the coupling  10  installed via press-fit or via welding. An alternative installation method is by fasteners through a flange. Other installation and assembly expedients may be used. 
     Referring to  FIG. 2 , an exploded view displaying various components of the invention is shown. These include an inner cover  30 , inner tube  40 , damping element  50 , bellows  60  and outer cover  70 . These components are preferably nested or are interrelated to each other in the orientation and positions shown in  FIG. 3  which illustrates the assembled components of the invention in cross-section. The damping element or annulus  50 , made of any suitable damping material, is substantially centered in relation to the bellows  60 . Thus, the convolutions  60   a ,  60   b  at each end of the bellows  60  are spaced apart over a distance x as shown. The center or effective center of mass  52  of damping element  50  is disposed a distance x/2 from each of the ends, in a preferred embodiment as shown. 
     One feature of the invention is the use of the inner cover  30  and outer cover  70  to centrally locate and capture the damping element  50  with respect to the bellows  60 . By utilizing the structural/protective inner cover  30  and outer cover  70  to also locate the damping element  50 , the quantity of components is reduced when compared to prior devices. The reduction of components leads to reduced processes in the manufacturing facility. 
     Outer cover  70  includes an outer annular rim  71  extending parallel to axis  15  and inwardly directed damper containing flange  72  extending in an inward direction toward axis  15 . Inner cover  30  includes an inner annular rim  31  parallel to axis  15  and outwardly extending damper containing flange  32  extending in an outward direction away from axis  15 . Inner cover  30  also includes a damper containing annular hump  34 . 
     Inner tube  40  has an enlarged end  41 , a reduced diameter portion  42  and a free distal end  43  as shown. End  41  and portion  42  also extend parallel to axis  15 . Bellows  60  has one flange end  61  captured between enlarged end  41  and inner flange  33  of inner cover  30 . Bellows  60  has another flange end  62  surrounded by inner flange  73  of outer cover  70 . 
     Rims  31 ,  71 , along with respective flanges  32 ,  72 , and hump  34  define a pocket  51  which captures the annular-shaped damping member or cushion  50  in the position shown in the Figures and generally centrally of the opposite end extensions  61 ,  62  of bellows  60  convolutions. This central location is illustrated by the respective dimension X of the bellows  60  and the dimension X/2 between one end of a bellows  60  convolution and the center of damping cushion  50 . 
     It will be noted that tube  40 , in portions  42 ,  43 , extend parallel to axis  15  but end  43  is not connected to end cover  70  or bellows  60 . The end  41  of tube  40  extends along flange  33  of cover  30 , sandwiching therebetween bellows flange  61 . 
     Ultimately in use, end  41  of tube  40  will extend over and is connected to an end of pipe  12 . Bellows flange  62  and flange  73 , both parallel to axis  15 , extend along and are secured to an end of pipe  14 . 
     For example, pipe  12  may have an end abutting end  43  of inner tube  41  if desired. Nevertheless, the bellows  60  effectively seals the coupling across the ends of pipes  12 ,  14  so as to provide a preferably leak-tight coupling between pipes  12 ,  14 . 
     It will be appreciated that the preferably metal bellows  60  is sufficiently flexible to accommodate torsional flex between tubes  12 ,  14 , as well as relative bending motion therebetween. Moreover, damper  50  isolates and damps noise, vibration and harshness in the coupling system. 
     Compression rings (not shown) press or friction fit, or other well-known expedients are used to sealingly secure coupling  10  about ends of pipes  12 ,  14  as will be appreciated. 
     Any pivoting of the components of coupling  10  occurs at pocket  51  capturing damping element  50 . Thus, both torsion and bending stress is centered at the damping element  50  and centrally of bellows  60  as will be appreciated, the respective rims  31 ,  71  and flanges  32 ,  72 , acting oppositely on damping element  50 . 
     The central location of damper  50  as noted with respect to the symmetric center of bellows  60  tends to dissipate concentration of stress and distribute it only uniformly and symmetrically along the bellows  60  during bending and torsional loads. 
     Accordingly, a shorter bellows for a desired stress dissipation parameter can be used as compared to prior bellows systems where the damper is not so oriented. Components and costs are both reduced. 
     Among others, one unique feature of the invention is thus the location of the damping element at the symmetric center of the bellows geometry. This allows for several benefits:
         1) Even stress distribution during bending loads and resulting high durability).   2) Extremely short length for compact packaging requirements.   3) Reduced components and manufacturing processes when compared to other automotive exhaust joints.       

     These and other alternatives, modifications and advantages will become readily apparent to those of ordinary skill in the field to which this invention pertains and applicant intends to be bound only by the claims appended hereto.