Abstract:
The disclosure relates to a clamping connection for pipes made of polymer material or made of composite materials, containing a connection piece, which has a supporting sleeve for the sliding on of a pipe to be connected and which is bounded at one end by a stop collar, wherein a sealing element is arranged on the supporting sleeve, wherein the clamping connection also comprises a clamping sleeve, which is captively connected to the stop collar of the connection piece before the pipe installation, wherein a pipe inserted onto the supporting sleeve is clamped by sliding the clamping sleeve over the pipe in a direction opposite to the insertion direction of the pipe.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a National Stage of International Application No. PCT/EP2013/061574, filed on Jun. 5, 2013, and published in German as WO 2013/189740 A2 on Dec. 27, 2013. This application claims the benefit and priority of European Application No. 12172685.5, filed on Jun. 20, 2012. The entire disclosures of the above applications are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0003]    1. Technical Field 
         [0004]    The disclosure relates to a clamping joint for pipes made of polymer material or of composite materials, said clamping joint including a connector, which has a support sleeve for fitting onto a pipe to be connected and which is defined at one end by way of a stop collar, wherein a sealing element is arranged on the support sleeve, wherein the clamping joint additionally has a clamping sleeve which is already captively connected to the stop collar of the connector prior to the mounting of the pipe. 
         [0005]    2. Discussion 
         [0006]    Pipes made of polymer material such as, for example, PE-X pipes and multilayer composite pipes which, for example, have an inside and outside layer made of a polymer material such as PE-X and an intermediate layer made of aluminium, are predominantly used in domestic engineering, in the supply of drinking water, for floor heating or heating unit service lines. 
         [0007]    Clamping joints of this type are used in the majority of cases in heating and sanitation installations in order to connect pipes together or to fittings. A clamping joint provides for simple and rapid assembly. In addition, permanent sealing is ensured, which is extremely important in the case of such joints as considerable damage can occur in the event of water leakage. 
         [0008]    DE 42 39 705 C2 makes known a clamping joint which consists of a clamping sleeve and a basic fitting body. The clamping sleeve has an inside contour which is realized, proceeding in each case from the two sleeve ends towards the middle of the clamping sleeve, as a conically narrowing or combined conically/convexly narrowing bore. The effect of said inside contour of the clamping sleeve is that the clamping sleeve can be used regardless of how it is placed in position on the pipe. 
         [0009]    Disadvantages here are the production of the complicated inside contour of the clamping sleeve and the subsequent control of the contour. 
         [0010]    DE 195 14 210 C2 also discloses a clamping joint for pipes and hoses of the same type. The support and clamping sleeves are realized in such a manner that they improve the sealing capacity and also the longitudinal adhesion capacity, which is to be achieved by means of the ribs on the support sleeve and the inside contour of the clamping sleeve. 
         [0011]    The disadvantage of the two clamping joints mentioned previously is that the pipe to be connected has first of all to be widened prior to the connection in order to be able to push it subsequently over the support sleeve. This requires an additional operating step which makes the assembly more expensive. In addition, in the case of the connections mentioned previously the fitting on of the clamping sleeve prior to the attaching of the pipe on the support sleeve can easily be forgotten, which is why the pipe then has to be removed again from the support sleeve and the clamping sleeve has subsequently to be fitted onto the pipe. The pipe can then be pushed onto the support sleeve from the beginning. 
         [0012]    DE 20 2004 000 031 U1 discloses a pipe press coupling which has a support sleeve, a press sleeve and a crimping sleeve. The individual parts are already pre-assembled prior to the mounting of the pipe so that the assembly expenditure can be reduced to a minimum. In addition, the assembly itself is considerably simplified as a result of the pipe coupling not having to be assembled first of all. 
         [0013]    A disadvantage of said coupling, however, is the severe cross-sectional narrowing with regard to the pipe cross section. In addition, the disadvantage of this type of pipe connection, as with the previously mentioned connections, is that where there is strong tensile force on the pipe the clamping/pressing or clamping sleeve/press sleeve becomes detached. 
       SUMMARY OF THE DISCLOSURE 
       [0014]    It is an object of the disclosure to propose a clamping joint which is simple to mount and is able to be produced in a favourable manner. In addition, if there is tensile force on the mounted pipe the joint must not become detached or the clamping joint should become stronger. 
         [0015]    Said object is achieved according to the disclosure in that the clamping of a pipe inserted on the support sleeve is effected by moving the clamping sleeve over the pipe in the direction opposite to the direction in which the pipe is inserted. 
         [0016]    An advantageous development of said clamping joint is that the inside diameter of the connector corresponds approximately to that of the pipe to be inserted or is slightly smaller than the inside diameter of the pipe to be inserted. As a result, cross-sectional narrowings in the line or in the connection to fittings are able to be kept small by means of the clamping joint according to the disclosure, which is positive in terms of flow techniques. 
         [0017]    The attaching of the clamping joint according to the disclosure on the pipeline or the inserting of the pipe into the clamping joint does not require any prior widening of the pipe by means of an additional operating process in order to fit it onto the connector afterwards, as is known from clamping joints from the prior art. The lead-in cone on the connector or on the support sleeve enables the pipe to be inserted without having to widen it first of all. The lead-in cone serves, among other things, for widening the pipe. 
         [0018]    The stop collar of the connector additionally serves for the purpose of preventing the clamping sleeve from moving on one side in the mounted state of the clamping joint, or serves as a one-sided stop for the clamping sleeve. As a result of this such a joint is also not removable again. 
         [0019]    An additional achievement provided by the clamping joint according to the disclosure is that the connection or clamping is strengthened in the event of tensile force being exerted onto the pipe. As the displacement of the clamping sleeve in the direction of the sealing element, through the tensile force on the pipe, strengthens the clamping between the sealing element or the support sleeve and the tapered inside diameter of the clamping sleeve even more. 
         [0020]    The clamping sleeve preferably has two regions. One of these is elastic and serves for the pre-assembly as well as the assembly of the clamping joint. The second region is rigid and serves for the clamping as well as the guiding of the pipe. The clamping sleeve can obviously have even more regions. 
         [0021]    The clamping of the pipe interacting with the sealing element or with the cross-sectional widening of the support sleeve is achieved by the tapering of the inside diameter. The tapering is effected in the rigid region of the clamping sleeve in the direction of the elastic region, the dimension of the inside diameter of the elastic region being independent of the development of the inside diameter or of the inside contour of the rigid region. The inside diameter in the elastic region is preferably greater than the outside diameter of the inserted pipe and is not tangent to the pipe even in the mounted state of the clamping joint. 
         [0022]    The elastic region is formed by the at least two segments which are preferably distributed in a regular manner over the circumference. The elastic region preferably has eight to  16  segments which ensure the radial elasticity. 
         [0023]    A channel along the inside diameter of the segments serves for the axial positioning as well as fixing of the clamping sleeve. As a result, the clamping sleeve is fixed and positioned or pre-positioned on the stop collar. The channel corresponds to the width of the stop collar. An advantageous design consists in that the clamping sleeve in the channel as well as the stop collar have a corresponding phase or inclination which simplifies the assembly or the pushing down of the clamping sleeve from the stop collar. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0025]    An exemplary embodiment of the disclosure is described by way of the Figures, the disclosure not being restricted to only the exemplary embodiment, in which: 
           [0026]      FIG. 1  shows a longitudinal section through a pre-assembled clamping joint according to the disclosure at the beginning of the mounting of the pipe, 
           [0027]      FIG. 2  shows a longitudinal section through a pre-assembled clamping joint according to the disclosure with the mounting of the pipe having progressed only a little, 
           [0028]      FIG. 3  shows a longitudinal section through a pre-assembled clamping joint according to the disclosure with the pipe inserted completely, 
           [0029]      FIG. 4  shows a longitudinal section through a pre-assembled clamping joint according to the disclosure in the finished assembled state, 
           [0030]      FIG. 5  shows a longitudinal section through a pre-assembled pipe coupling which has a clamping joint according to the disclosure on both sides, 
           [0031]      FIG. 6  shows a view of a distributor which has clamping joints according to the disclosure for connecting the pipes and 
           [0032]      FIG. 7  shows a longitudinal section and a view of the clamping sleeve of the clamping joint according to the disclosure. 
       
    
    
       [0033]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0035]      FIG. 1  shows a clamping joint  1  according to the disclosure where the pipe  14  to be connected has already been pushed lightly onto the conical region of the support sleeve  3  or the lead-in cone  11 . The connector  2  has a lead-in cone  11  which makes it possible for the pipe  14  to be connected to be inserted. The lead-in cone  11  makes it possible to dispense with a previous widening of the pipe  14 , which saves on one operating step during assembly and, as a result, makes the assembly simpler and quicker. The pipe  14 , which is produced from a polymer material or from a composite material, is widened as it is being inserted over the lead-in cone  11 , as a result of which the insertion of the connector  2  or of the support sleeve  3  is made possible. The clamping sleeve  6 , which is already pre-assembled on the connector  2 , serves, among other things, for guiding the pipe  14  during the insertion, which can be seen from  FIG. 2 . When reaching the clamping sleeve  6 , the pipe  14  is directed along the inside contour or the inside diameter of the clamping sleeve  6  and along the support sleeve  3 . The sealing element  5 , which is preferably formed by an O-ring seal, serves for the optimum tightness of the clamping joint  1 . The sealing element  5  is arranged on the support sleeve  3  and is situated in a groove  12  which is provided for this purpose and which prevents the displacement of the sealing element  5 . The pipe  14  is pushed into the clamping joint  1  as far as up to the radius  13  and is then fastened to the clamping sleeve  6 , which is already pre-assembled on the connector  2 . The clamping sleeve  6 , as already mentioned, is pre-assembled on the connector  2 . The connector  2  has a stop  4  on the opposite end of the lead-in cone  11  of the support sleeve  3 . Said stop serves, among other things, for the pre-assembly of the clamping sleeve  6 . The clamping sleeve  6  is fastened on the stop collar  4 . The pre-assembly and the removal of the clamping sleeve  6  from the stop collar  4  are ensured by means of the radially elastic region  9  of the clamping sleeve  6 . A radially elastic region  9  on the clamping sleeve  6  is formed by the arrangement of segments  7  on the clamping sleeve  6 , which can be seen in  FIG. 7 . For the pre-assembly, the segments  7  can be widened slightly in the radial direction in order to insert the stop collar  4  of the connector  2 . Through their elasticity they are then clamped on the stop collar  4  in a fixed manner, the inside contour of the segments  7  having a channel  8 , which corresponds to the width of the stop collar  4 , as a result of which the clamping sleeve  6  is fixed or positioned in an axial manner on the stop collar  4 . The elastic region  9  consists of at least two segments  7 . It is advantageous when both the clamping sleeve  6  and also the stop collar  4  have a phase  15  which simplifies the pushing down of the clamping sleeve  6  from the stop collar  4  onto the inserted pipe  14 .  FIG. 3  illustrates this operation. The elastic region  9 , which is formed by the segments  7 , is deformed in a manner such that the clamping sleeve  6  is pushed in the direction opposite to the insertion of the pipe  14 , as a result of which the phase  15  of the clamping sleeve  6  can be pushed over the phase  15  of the stop collar  4  and, as a result, the clamping sleeve  6  can be pushed onto the inserted pipe  14 . By the inside contour or the inside diameter of the clamping sleeve  6  having a tapering in the rigid region  10  of the clamping sleeve  6 , the inside diameter in the rigid region  10  reducing in the direction of the elastic region  9 , during the assembly or the clamping operation, the tapered part of the clamping sleeve  6  or the clamping sleeve  6  is moved in the direction of the sealing element  5 . By means of the sealing element  5  and the groove  12  provided for said sealing element, the support sleeve  3  has an enlarged cross section at this position, which brings about a clamping action when the clamping sleeve  6  is displaced in the direction of the sealing element  5 . 
         [0036]      FIG. 4  shows the finished assembled clamping joint  1 . It can also be seen from  FIG. 4  that the clamping would be strengthened by tensile force on the pipe  14  as the clamping sleeve  6  would also move in said same direction and thus would appear at the sealing element  5  on account of the tapered diameter of the clamping sleeve  6  or the pipe  14  situated in between would be crimped accordingly. The stop collar  4  serves after the assembly for the purpose of also defining the clamping sleeve  6  in the other direction and ensuring that it cannot be removed. 
         [0037]    No such clamping joint, where the fitting on of the clamping sleeve is effected against the direction in which the pipe is inserted, is known from the prior art, as such an operation up to now has been perceived as not logical since, as a result, the pipe in the case of the known clamping joints would be pushed down again by the support sleeve. In addition, in the case of conventional clamping joints which are pre-assembled, the clamping sleeve is also attached on the support sleeve, however not on the side of the stop collar but on the side of the pipe to be inserted. 
         [0038]    An assembly in said direction of the pipe  14  is possible by means of the development of the inside contour or of the tapering of the inside diameter of the clamping sleeve  6  of the present disclosure and the cross-sectional widening of the support sleeve  3  by the sealing element  5 , a mere cross-sectional widening on the support sleeve  3  without a sealing element  5  being equally conceivable in order to achieve said clamping effect where the clamping is strengthened instead of removed when there is tensile force on the pipe. It can also be seen from  FIG. 4  that the inside diameter of the connector  2  has approximately the same cross section or diameter as the pipe to be inserted. As a result, a narrowing of the line in the case of pipe couplings or fitting connections is able to be reduced with the clamping joint according to the disclosure. In addition, an optimum transition is formed by the lead-in cone  11  such that no flow-impairing obstructions are created by the inserted connector  2 . 
         [0039]      FIG. 5  shows a pipe coupling  16  which is suitable for connecting pipes  14 . The coupling  16  has a clamping joint  1  according to the disclosure on both sides. The pipe coupling  16  is shown in the pre-assembled state. Such clamping joints  1  are also suitable, for example, for connections on fittings. 
         [0040]      FIG. 6  shows a clamping joint  1  according to the disclosure which is arranged on a distributor. 
         [0041]    The clamping sleeve  6  of the clamping joint  1  according to the disclosure, which is shown separately in  FIG. 7 , has an elastic region  9 . The radially elastic region  9  is composed of segments  7  which are arranged along the circumference. The number and size of the segments  7  are to be adapted to the requirements of the clamping joint  1  and to its dimension. In addition, the clamping sleeve  6  has a rigid region  10  which makes it possible for the inserted pipe  14  to be clamped. The inside contour or the inside diameter in the rigid region  10  is tapered in the direction of the elastic region  9 , as a result of which, as described previously, the clamping action is achieved in dependence on the support sleeve  3 . The clamping sleeve  6  preferably has a web  17  on the outer circumference, which web serves for the assembly. The clamping joint  1  can be mounted with the aid of a corresponding assembly tool by means of the web  17  on the clamping sleeve  6 . 
         [0042]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.