(19)
(11)EP 2 405 172 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
05.11.2014 Bulletin 2014/45

(21)Application number: 11183350.5

(22)Date of filing:  18.06.2002
(51)International Patent Classification (IPC): 
F16L 21/00(2006.01)
F16L 21/06(2006.01)

(54)

Pipe Coupling

Rohrkupplung

Couplage de tuyaux


(84)Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

(30)Priority: 21.06.2001 US 886793

(43)Date of publication of application:
11.01.2012 Bulletin 2012/02

(62)Application number of the earlier application in accordance with Art. 76 EPC:
02746583.0 / 1481184

(73)Proprietor: Norma U.S. Holding LLC
Auburn Hills, MI 48326 (US)

(72)Inventors:
  • Amedure, Michael, E.
    Lake Orion, MI Michigan 48360 (US)
  • Ignaczak, Brian, T.
    Rochester, MI Michigan 48307 (US)

(74)Representative: Barker, Rosemary Anne et al
HGF Limited 4th Floor, Merchant Exchange 17-19 Whitworth Street West
Manchester M1 5WG
Manchester M1 5WG (GB)


(56)References cited: : 
DE-B1- 2 230 920
FR-A- 2 794 517
FR-A- 2 689 204
US-A- 2 739 018
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    FIELD OF THE INVENTION



    [0001] This invention relates to pipe couplings; more particularly, it relates to a type of pipe coupling which is especially adapted for joining two pipe ends in a butt joint. This type of pipe coupling is sometimes referred to in the trade as a pipe coupler.

    BACKGROUND OF THE INVENTION



    [0002] There is a need, especially in the automotive industry, for a pipe coupling for connecting two pipes together in a vehicle engine exhaust system. For example, it is becoming common practice in the repair or servicing of an automobile exhaust system to replace the muffler by cutting the pipe between the muffler and the catalytic converter and attaching a new muffler by use of a special coupling which is herein referred to as a coupler. In this example of use, the coupler must be capable of joining two pipes in a butt joint with a good seal against exhaust gas leakage and which has high pull-apart strength. The use of a butt joint has the advantage of avoiding the need for slotted pipe ends as are commonly used in tail pipe-to-muffler lap joints.

    [0003] In the prior art, attempts have been made to provide a pipe coupling which would meet the requirements of mechanical strength, exhaust gas sealing properties and long service life required by the automotive industry. However, the prior art leaves much to be desired with respect to the present day requirements.

    [0004] U.S. Patent No. 2,227,551 granted January 7, 1941 to Morris describes a pipe coupling which comprises a cylindrical metal sleeve and gasket disposed between a clamping shell and the pipes to be coupled together. The metal sleeve is open with confronting ends which have complementary tongues and recesses which come together when the coupling is tightened.

    [0005] U.S. Patent No. 4,056,273 granted November 1, 1977 to Cassel describes a coupling for pipe lap joints which includes a seal ring disposed about the end of the smaller diameter pipe and abutted against the end of the larger diameter pipe. A clamping device has a clamp band which encircles and overlaps the end of the larger diameter pipe and the seal ring. The seal ring includes opposite circumferential ends interengaged with each other, at least one of the seal ring ends having a ramp surface that engages the other seal ring end to move the rings axially relative to each other during clamping of the ring over the inner pipe to thereby provide sealing of the ring between the ring ends.

    [0006] FR-A-2689204 discloses a pipe coupler having the features specified in the pre-characterising portion of claim 1. A relief slot is provided as an opening defined within a closed contour of the tongue.

    [0007] A general object of this invention is to provide an improved coupler which overcomes certain disadvantages of the prior art.

    SUMMARY OF THE INVENTION



    [0008] In accordance with this invention, a coupler is provided for joining a pair of pipes in a butt joint which provides a good seal against fluid leakage and exhibits high pull-apart strength. This is accomplished by providing an improved sealing sleeve in a band clamp which is capable of applying a high clamping load. Further, the invention is especially adapted for use in a coupler for application in vehicle engine exhaust systems.

    [0009] Further, in accordance with this invention, an improved coupler is provided which is adapted for high volume production at low cost, is easy to install and exhibits a good gas seal against leakage with high pull-apart strength and has a long service life.

    [0010] Further, in accordance with this invention, an improved sealing sleeve for a pipe coupler is provided which is constructed of steel with tongue and groove sealing joints which are characterized by an interference fit of side edges with spring members.

    [0011] A complete understanding of this invention will be obtained from the detailed description that follows taken with the accompanying drawings.

    DESCRIPTION OF THE DRAWINGS



    [0012] 

    Figure 1 is a perspective view of an embodiment of the present invention;

    Figure 2 is a cross-sectional view of the coupling of Figure 1 installed on the abutted ends of two pipes;

    Figure 3 is a plan view of a split sealing sleeve used in an embodiment of the invention; and

    Figure 4 is a fragmentary view of a split sealing sleeve of the same embodiment of the invention showing the tongue and groove sealing joint in sealing engagement.


    BEST MODE FOR CARRYING OUT THE INVENTION



    [0013] Referring now to the drawings, an illustrative embodiment of the invention is shown in a pipe coupler especially adapted for use in automotive vehicle engine exhaust systems. It will be appreciated, as the description proceeds, that the invention is useful in many different applications and in a wide variety of embodiments.

    [0014] In the embodiment of the invention is shown in Figures 1-2, the coupler 10 is adapted to connect a pair of pipes 12 and 14 in a butt joint which provides a good gas seal and a strong mechanical connection between the pipes. The pipes 12 and 14 have the same nominal diameter, subject to manufacturing tolerances. The ends of the pipes 12 and 14 meet at a juncture 22 in axial alignment with each other. The coupler comprises a clamp 16 which includes a clamp band 18 adapted to encircle the pair of pipes and overlap the ends of the pipes. The clamp band 18 is formed as an open sleeve and terminates in laterally extending, opposed flanges 19 and 21. The clamp 16 also includes a tightening mechanism 24 connected with the clamp band for tightening the clamp to reduce the circumferential length of the clamp band. A split sealing sleeve 26 is disposed inside the clamp band 18 and has first and second circumferential ends with seal structures, respectively, in confronting relationship for contact with each other when the split sealing sleeve is collapsed circumferentially by the clamp band when the clamp is tightened. The sealing sleeve 26 includes a tongue and groove sealing joint provided on the confronting circumferential ends of the sealing sleeve 26. The opening or gap between the confronting ends of the sealing sleeve 26 is located circumferentially with respect to the clamp band 18 so that it does not overlap the gap between the flanges 19 and 21. When the clamp 16 is tightened by the tightening mechanism 24, the sealing sleeve 26 is collapsed circumferentially by the clamp band to cause the tongue and groove sealing joint to close and provide a gas seal against leakage to the atmosphere from the juncture 22 of the pipes.

    [0015] The clamp 16, per se, is of known construction and it is described in U.S. Patent 3,905,623 granted to Cassel granted September 16, 1965. As stated above, the clamp 16 includes a clamp band 18 which is formed as an open sleeve and terminates in laterally extending opposed flanges 19 and 21. The clamp also includes a tightening mechanism 24 connected with the clamp band. The tightening mechanism comprises a spline or reaction member 23 disposed between the flanges 19 and 21 of the clamp band 18. A pair of bolts 25 extend through aligned openings in the flanges and reaction member and a force bar 27 against which threaded nuts 29 are seated for actuating the tightening mechanism. The coupler 10 will be described in greater detail below.

    [0016] The split sealing sleeve 26 is made of sheet metal, suitably stainless steel, and is formed by a stamping operation in flat condition as shown in Figure 3 and is preformed into a circular sleeve for insertion into the clamp band 18.

    [0017] The pipes 12 and 14, as manufactured, have a specified nominal diameter with a specified allowable tolerance range within which the actual pipe diameter may vary. Consequently, pipes 12 and 14 may have the same nominal diameter but have a different actual diameter. The greatest difference in diameter would occur when one pipe has an actual diameter at the minimum value of the tolerance range and the other pipe has an actual diameter at the maximum value of the tolerance range.

    [0018] In use, the coupler 10 in its assembled untightened state is positioned over the abutted ends of pipes 12 and 14 with the juncture of the pipe ends located between the tongue and groove sealing joint. In this position, clamp 16 is ready for tightening by tightening the nuts 27 on the bolts 29. As the tightening of the clamp 16 progresses, the outer end of the tongue enters the groove and the side edges of the tongue engage the side edges of the groove so that there is sliding frictional engagement therebetween. This provides an interference fit between the side edges of the tongue and groove which is effective to maintain a good gas seal.

    [0019] The coupler of the embodiment which is shown in Figures 3 and 4 has only one tongue and groove joint 60. The joint 60 comprises a groove 62 defined by one end of the sleeve 26 and a tongue 64 defined by the other end of the sleeve. The groove 62 has oppositely disposed side edges 66a and 66b. The tongue 64 has oppositely disposed side edges 68a and 68b. The side edges of the groove 62 have an arcuate configuration which extends inwardly of the groove such that the groove is wider at its open end and at its closed end than it is in the region therebetween. A relief slot 72a is disposed adjacent the side edge 66a and extends in the same direction and thereby forms a spring edge member 74a. Similarly, a relief slot 72b is disposed adjacent the side edge 72a and extends in the same direction and thereby forms a spring edge member 74b.

    [0020] The tongue 64 is rectangular with straight side edges and has a width somewhat narrower than the width of the entrance mouth of the groove 62 and somewhat greater than the narrowest width between the spring edges members 74a and 74b.

    [0021] In the use of the coupler implemented with the split sealing sleeve 26, the single tongue and groove joint 60 is closed and concurrently with the tightening of the clamp of the coupler in the same manner as described above. As the tightening of the clamp progresses, the outer end of the tongue 64 enters the groove 62 and the side edges of the tongue engage the respective side edges of the groove so that there is a sliding frictional engagement therebetween. The spring edge members 74a and 74b of the side edges of the groove 62 accommodate the variation of actual dimensions of the pipes 12 and 14 within their manufacturing tolerance range. If the two pipes have actual diameters of equal value, the tongue 64 will penetrate an amount corresponding to the actual diameter and develop sealing engagement with the side edges of the groove. If two pipes have different actual diameters, the sleeve will cock accordingly and the side edges of the tongue will maintain contact with the side edges of the groove to provide a seal against leakage through the tongue and groove joint 62. Also, the spring edge members 74a and 74b will provide ehgagement without excessive interference that would prevent closing the clamp with tight sealing engagement and transfer of sufficient clamp loading to prevent relative movement between the pipes.

    [0022] Although the description of this invention has been given with reference to a particular embodiment, it is not to be construed in a limiting sense. Many variations and modifications of the invention are possible with the scope of the appended claims.


    Claims

    1. A pipe coupling for connecting a pair of pipes (12, 14), said coupling being of the type comprising a clamp (16) which includes a clamp band (18) adapted to encircle the pair of pipes, said clamp band being wide enough to overlap respective ends of the pair of pipes, said clamp also including a tightening mechanism (24) connected with said clamp band for tightening said clamp band, and a split sealing sleeve (26') inside said clamp band and having first and second circumferential ends (28, 32) in confronting relationship for contact with each other when the sealing sleeve is collapsed circumferentially by said clamp band, wherein said sealing sleeve includes a tongue-and-groove sealing joint located on said circumferential ends, said sealing joint comprising a groove (62) defined by one circumferential end of the sealing sleeve and a tongue (64) defined by the other circumferential end of the sealing sleeve, said tongue being disposed opposite said groove for mating with said groove when said sealing sleeve is collapsed circumferentially, characterised in that one of said tongue-and-groove have first and second substantially straight and parallel side edges (68a, 68b) and the other of said tongue and groove have first and second convex arcuate side edges (66a, 66b), the first side edge of the tongue and the first side edge of the groove being a first mating pair of side edges, the second side edge of the tongue and the second side edge of the groove being a second mating pair of side edges so that said tongue has an interference fit with said groove, and in that at least one side edge (66a, 66b) of said groove (62) is a spring member (74a, 74b) whereby a seal is provided by the engagement of the mating pairs of side edges when the clamp is tightened.
     
    2. A pipe coupling as defined in claim 1, wherein both side edges (66a, 66b) of said groove (62) are spring members (74a, 74b).
     
    3. A pipe coupling as defined in claim 1 or 2, wherein the or each spring member (74a, 74b) is a unitary strip of arcuate shape extending between opposite ends of a relief slot (72a, 72b) adjacent the side edge of said groove.
     


    Ansprüche

    1. Rohrkupplung zum Verbinden eines Paars von Rohren (12, 14), wobei die Kupplung dem Typ angehört, der eine Klemme (16) umfasst, die ein Klemmenband (18) enthält, das dazu ausgelegt ist, das Paar von Rohren zu umschließen, wobei das Klemmenband breit genug ist, um jeweilige Enden des Paars von Rohren zu überlappen, wobei die Klemme auch einen Spannmechanismus (24), der mit dem Klemmenband verbunden ist, zum Spannen des Klemmenbandes und eine geteilte Dichthülse (26') innerhalb des Klemmenbandes und mit einem ersten und einem zweiten Umfangsende (28, 32) in einer gegenüberliegenden Beziehung für einen Kontakt miteinander umfasst, wenn die Dichthülse durch das Klemmenband umfangsmäßig zusammengedrückt wird, wobei die Dichthülse eine Zunge- und-Nut-Dichtverbindung umfasst, die an den Umfangsenden angeordnet ist, wobei die Dichtverbindung eine Nut (62), die durch ein Umfangsende der Dichthülse definiert ist, und eine Zunge (64), die durch das andere Umfangsende der Dichthülse definiert ist, umfasst, wobei die Zunge gegenüber der Nut zum Paaren mit der Nut, wenn die Dichthülse umfangsmäßig zusammengedrückt wird, angeordnet ist, dadurch gekennzeichnet, dass eine der Zunge und der Nut erste und zweite im Wesentlichen gerade und parallele Seitenkanten (68a, 68b) aufweist und die andere der Zunge und der Nut erste und zweite konvexe bogenförmige Seitenkanten (66a, 66b) aufweist, wobei die erste Seitenkante der Zunge und die erste Seitenkante der Nut ein erstes zusammenpassendes Paar der Seitenkanten sind, die zweite Seitenkante der Zunge und die zweite Seitenkante der Nut ein zweites zusammenpassendes Paar der Seitenkanten sind, so dass die Zunge einen Presssitz mit der Nut aufweist, und dass mindestens eine Seitenkante (66a, 66b) der Nut (62) ein Federelement (74a, 74b) ist, wodurch eine Dichtung durch den Eingriff der zusammenpassenden Paare der Seitenkanten bereitgestellt wird, wenn die Klemme gespannt wird.
     
    2. Rohrkupplung nach Anspruch 1, wobei beide Seitenkanten (66a, 66b) der Nut (62) Federelemente (74a, 74b) sind.
     
    3. Rohrkupplung nach Anspruch 1 oder 2, wobei das oder jedes Federelement (74a, 74b) ein einheitlicher Streifen mit einer bogenförmigen Gestalt ist, der sich zwischen entgegengesetzten Enden eines Entlastungsschlitzes (72a, 72b) benachbart zur Seitenkante der Nut erstreckt.
     


    Revendications

    1. Couplage de tuyaux pour raccorder une paire de tuyaux (12, 14), ledit couplage étant du type comprenant un dispositif de serrage (16) qui comprend une bande de serrage (18) adaptée pour encercler la paire de tuyaux, ladite bande de serrage étant assez large pour recouvrir des extrémités respectives de la paire de tuyaux, ledit dispositif de serrage comprenant également un mécanisme de serrage (24) raccordé avec ladite bande de serrage, pour serrer ladite bande de serrage, et un manchon d'étanchéité fendu (26') à l'intérieur de ladite bande de serrage et ayant des première et seconde extrémités circonférentielles (28, 32) en relation de face pour être en contact entre elles lorsque le manchon d'étanchéité est plié circonférentiellement par ladite bande de serrage, dans lequel ledit manchon d'étanchéité comprend un joint d'étanchéité de type à languette et rainure positionné sur lesdites extrémités circonférentielles, ledit joint d'étanchéité comprenant une rainure (62) définie par une extrémité circonférentielle du manchon d'étanchéité et une languette (64) définie par l'autre extrémité circonférentielle du manchon d'étanchéité, ladite languette étant disposée à l'opposé de ladite rainure pour se coupler avec ladite rainure lorsque ledit manchon d'étanchéité est plié de manière circonférentielle, caractérisé en ce que l'une parmi ladite languette et rainure a des premier et second bords latéraux (68a, 68b) sensiblement droits et parallèles et l'autre parmi ladite languette et rainure a des premier et second bords latéraux (66a, 66b) arqués convexes, le premier bord latéral de la languette et le premier bord latéral de la rainure étant une première paire de couplage de bords latéraux, le second bord latéral de languette et le second bord latéral de la rainure étant une seconde paire de couplage de bords latéraux de sorte que ladite languette a un ajustement avec serrage avec ladite rainure, et en ce qu'au moins un bord latéral (66a, 66b) de ladite rainure (62) est un élément formant ressort (74a, 74b), moyennant quoi un joint d'étanchéité est fourni par la mise en prise des paires de couplage de bords latéraux lorsque le dispositif de serrage est serré.
     
    2. Couplage de tuyaux selon la revendication 1, dans lequel les deux bords latéraux (66a, 66b) de ladite rainure (62) sont des éléments formant ressorts (74a, 74b).
     
    3. Couplage de tuyaux selon la revendication 1 ou 2, dans lequel le ou chaque élément formant ressort (74a, 74b) est une bande unitaire de forme arquée s'étendant entre des extrémités opposées d'une fente en relief (72a, 72b) adjacente au bord latéral de ladite rainure.
     




    Drawing











    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description