Abstract:
A coupling has respective support elements extending respectively from each coupling end toward the other, but not directly connected to each other. Radially oriented ends of these elements define a pocket capturing a cushion therein. A non-metallic bellows operably covers the coupling. An optional thermal shield is disposed between the bellows and the support element.

Description:
RELATED APPLICATION 
       [0001]    Applicant claims priority of U.S. provisional patent application Ser. No. 61/052,663 filed on May 13, 2008 and entitled “SEALED FLEXIBLE ELEMENT WITH TORSION ACCEPTANCE”, which application is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to couplings for internal combustion engine exhausts and more particularly to such sealed couplings which accommodate bending and torsion of the exhaust components which are coupled. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is known to operatively couple together pipes or conduits which carry combustion exhausts away from an internal combustion engine such as in an automobile environment. Typical would be the use of a coupling to couple an outlet end of an exhaust manifold to an exhaust pipe, for example. 
         [0004]    In the past, such couplings have been designed in an effort to compensate for thermal influences of the system, motion (such as bending or torsion), noise, vibration and harshness (“NVH”) and other parameters. In the past, such couplings have including a metallic bellows applied around the coupled joint. 
         [0005]    The disadvantage of certain prior devices is they require a metal bellows to achieve a gas tight or semi-gas tight performance, and to resist the heat inherent in an exhaust system. The metal bellows has limited motion capabilities and increases the overall length and weight of the product to achieve the necessary motion compensation, in particular, bending and torsion. The metal bellows is not able to accept high torsion environments and must resist the torsion when the torsion would create deformation of the bellows. This adds cost and/or weight to the bellows and transfers the torsion strains downstream into the exhaust system for other portions of the exhaust system to compensate for them. 
         [0006]    Also, the disadvantage of the prior device is that metal bellows are very expensive and must use high nickel alloys in the stainless steel material to achieve the desired performance. 
       SUMMARY OF THE INVENTION 
       [0007]    It is desirable to provide a flexible coupling for an internal combustion or automotive exhaust system which provides increased accommodation of system bending and torsion, which does not deform when subjected to bending and torsion of the system, and which provides semi- or gas tight performance, which is lighter and less costly than prior couplings with metallic bellows, which does not unduly transmit torsion and bending strains downstream into the exhaust system. 
         [0008]    To these ends, a coupling according to the invention contemplates support elements for attachment to exhaust system pipes, a dampener apparatus and a non-metallic bellows disposed over these support elements and dampener apparatus. The use of a non-metallic bellows over the support attachments and dampening mechanism achieves the sealed flexible element with torsion acceptance. 
         [0009]    In higher heat environments, a thermal insulation is added between the support/dampening mechanism and the non-metallic bellows. 
         [0010]    The non-metallic bellows can be fixed to the support elements in a number of ways such as with two metallic rings that fix the bellows (and thermal insulation) to the elements on each end. 
         [0011]    The insulation (fiberglass, composite, etc.) and the non-metallic bellows (rubber, plastic, composites, etc.) can be of a number of different materials. For applications where gas tightness is not required at all, the non-metallic bellows and insulation can be optionally removed. 
         [0012]    The geometry of the bellows can be made in a variety of ways to match the application needs. 
         [0013]    One or more dampening mechanisms can be attached in series within this application 
         [0014]    The non-metallic bellows of the invention are able to accept high bending and torsion requirements of the exhaust system. 
         [0015]    The non-metallic bellows of the invention are far less expensive since they do not contain the steel or metallic bellows of prior system. 
         [0016]    The sealed flexible element with torsion acceptance of the invention allows for a gas tight or semi-gas tight flexible connection that is capable of compensating, and performing the benefits of, compensating thermal influences, motion (such as bending), reducing or suppressing noise vibration and harshness (NVH), and other such concerns. 
         [0017]    According to the invention, the support elements that may in part define the dampening mechanism are internal to a non-metallic diaphragm or bellows. Where high heat conditions exist, the non-metallic bellows is protected by a thermal insulator which is attached between the bellows and the internal support elements. This allows for the NVH dampening properties with a significantly larger range of motions (particularly bending and torsion) and lower cost and size compared to prior devices. The invention can be made with a variety of materials and with any number of plies thickness of the materials. 
         [0018]    This invention thus eliminates the metal bellows of prior devices and replaces this with a non-metallic bellows and (in higher heat conditions) thermal insulation. This allows for a greater range of motion (particularly bending and torsion) in a smaller size and allows for the similar NVH dampening at a lower overall weight and cost. 
         [0019]    These and other benefits and advantages will be readily apparent from the following written description and from the drawings in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is an isometric exterior view of the flexible bellows coupling according to the invention; 
           [0021]      FIG. 1A  is a full cross-sectional view of the bellows of  FIG. 1  displaying the various components and their location in the coupling; and 
           [0022]      FIG. 1B  is an amplified view of a portion of  FIG. 1A  illustrating components thereof in larger scale for clarity. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    It should be readily understood that the components 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, as claimed, but it is merely representative of the presently preferred embodiments of the invention. 
         [0024]    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. 
         [0025]    Turning now to  FIG. 1 , there is shown therein a flexible coupling  15  according to the invention. Coupling  15  preferably includes a non-metallic bellows or diaphragm  16  having an end  17  connectible to a pipe or conduit (not shown in  FIG. 1 ). It will be appreciated that bellows  16  comprises a plurality of convolutions such as at  18 ,  19 , in any suitable number given the overall length of the coupling  15 . 
         [0026]    Coupling  15  includes several elongated support elements generally extending in an axial direction (or in a direction parallel to an axial direction) as the center line or axis CL ( FIG. 1A ). At one end of coupling  15 , two support elements  20 ,  21  extend axially (see  FIG. 1B ). Element  20  includes radially outward extending flange  22  while element  21  includes radially outward extending flange  23 . At the ends of coupling  15 , respective ends  20   a,    21   a  of these elements are co-extensive. 
         [0027]    Another elongated axially extending support element  30  includes an outwardly flared end comprising portions  31  and  32 . Portion  32  includes an inwardly directed flange  33 . 
         [0028]    As best seen in  FIG. 1B , portions  31 ,  32  and flange  33  form, with flanges  22 ,  23 , a pocket  35 . It will be appreciated that, as the coupling elements  20 ,  21  and  30  described are generally cylindrical, pocket  35  is in the form of an annulus about centerline or axis CL ( FIG. 1A ). 
         [0029]    It will further be appreciated that element  30  is longitudinally axially extended at  30   a  to another element end  34  at a far end of coupling  15 , and is not directly connected to elements  20   21  at the other end. 
         [0030]    Preferably a dampener or cushion  38 , also in the form of an annulus, is captured in pocket  35  as shown in  FIGS. 1A ,  1 B. Damper  38  is preferably a yieldable material of rubber or a synthetic, while any suitable damping material can be used. 
         [0031]    Optionally, a thermal insulating elongated and axially extending sleeve  50  is disposed between the opposite ends of coupling  15 . Sleeve  50  has an axially extending flange  51  at one end and a similar flange  52  at the other end for securing sleeve  50  in place at both ends of the coupling. 
         [0032]    Non-metallic bellows  16  also includes an axially extending flange  56  at one end of the bellows and an axially extending flange  57  at another end of the bellows for securing the bellows at the coupling ends. 
         [0033]    Finally, compression rings  25  and  42  are respectively disposed at respective ends of the coupling to secure the components together. Ring  25  has a radially outward extending flange  26  ( FIG. 1B ) and ring  42  has a radially outward extending flange  27 . Rings  25 ,  42  are compressed, drawn or otherwise tightened about the radially inward components shown, to secure them together and, respectively, to ends of exhaust pipes  60 ,  61  (shown for illustration infringement  FIG. 1A ), which coupling  15  operably couples together. 
         [0034]    In particular, ring  25  is secured to capture bellows flange  56 , thermal sleeve flange  52 , support element  21  and support element  20  about pipe  60 . Ring  42  is secured to capture bellows flange  57 , thermal sleeve flange  51  and end  34  of support element  30  about the end of pipe  61  to complete the application of the coupling  15  operable connecting pipes  60 ,  61 . 
         [0035]    It will be appreciated that the bellows  16  optional insulator sleeve  50 , elements  20 ,  21  and  30 , and rings  25 ,  42  are all generally cylindrical in nature, fitting together in appropriate relation as described and shown in the FIGS. and secured via any conventional means. 
         [0036]    Coupling  15  is secured to pipes  60 ,  61  by friction, ring, clamps, compression, welding or any other conventional means. 
         [0037]    It will be appreciated that  FIG. 1B  illustrates, in larger scale, an end of coupling  15  in cross-section and nearest pipe  60  ( FIG. 1A ) at one side of center line CL. 
         [0038]    Accordingly, at least one damping cushion  38  is captured by elements  20 ,  21 ,  30 . The elements and cushion  38  form the support and create the dampening characteristics of the coupling  15 . The coupling  15  can absorb or accept movements (and forces) in the bending, axial, and torsion directions. Without the bellows  16 , the coupling may not be completely gas tight or semi gas tight. To achieve greater gas tightness, the coupling  15  is surrounded by a non-metallic diaphragm or non-metallic bellows  16 . The non-metallic bellows  16  will also protect the mechanism from the harsh outer environment (such as from corrosive materials, from stone or other object impingements, or from other debris that can be absorbed/accepted by the cushion). The non-metallic bellows  16  can be attached to the support elements in many ways. One such means is with two rings  25 ,  42 , that are calibrated to the support elements and thus mechanically fix the bellows to the support elements at either end of coupling  15 . Where higher heat environments exist, a thermal insulator  50  is inserted between the non-metallic bellows and the support elements. The insulator  50  serves the primary function to protect the non-metallic bellows but it can also add to the dampening features of the coupling  15 . It is preferably trapped between the non-metallic bellows and the support elements as shown in the FIGS. 
         [0039]    While pipes  60 ,  61  are preferably coaxial, the flexibility of coupling  15  readily accommodates or compensates off-axial alignment or bending of pipes  60 ,  61  and relative torsion between them without derogation of coupling  15 , while accommodating high heat applications, providing gas tight or semi-gas tight coupling and suppressing NVH of the gas flow system in which it is used at smaller, lighter weight and less costly parameters than prior known systems. 
         [0040]    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.