Patent Document

FIELD OF THE INVENTION  
         [0001]    The invention relates to a corrugated plastic pipe arrangements and in particular to the connection of corrugated plastic pipes with one another.  
         BACKGROUND ART  
         [0002]    It is known in the art to connect corrugated pipes end to end by way of adapters or the like. Such connection requirements can occur, for example, when corrugated pipes of different materials are to be connected to one another. Furthermore, such needs can arise when corrugated pipes must be connected to one another to bridge large lengths or distances which cannot be achieved with individual corrugated pipe units. It can also be necessary to produce water or liquid tight connections, for instance in liquid conducting systems or in cable protection systems, when the cables are to be protected from humidity.  
           [0003]    It can also occur that long corrugated plastic pipes are to be connected to components, for example switch gear cabinets, machine sections, or the like.  
           [0004]    Conventional technologies, which also included the insertion of unions or the like, leave a lot to be desired with respect to the simplicity of installation, the multitude of parts and, correspondingly, also cost. The sealing of known systems is also relatively unreliable.  
         SUMMARY OF THE INVENTION  
         [0005]    It is therefore an object of the present invention to provide a plastic corrugated pipe arrangement, which enables a reliable sealed connection with simple means. It is furthermore an object in accordance with the invention to provide a more cost efficient connection technology as far as corrugated plastic pipes are concerned. Moreover, the multitude of parts is to be reduced in accordance with the invention.  
           [0006]    The advantages in accordance with the invention are based on the structure of the connecting portion which is in two parts, whereby first and second connecting parts are respectively integrally formed with the first and second pipe body and whereby the first connecting part includes an engagement extent, while the second connecting part includes a holding region which especially reversibly holds the engagement extent.  
           [0007]    This means that a plastic corrugated pipe arrangement is provided which can be continuously produced with a corrugator, whereby at certain, preselected locations, for instance in the region of the mutually adjacent connecting portions produced, the corrugated pipe is cut in order to provide in this manner individual corrugated pipes with an integrated connecting portion, in such a way that without further separate parts an end to end connection of the plastic corrugated pipes is possible. Only in the case where this connection is to provide a special sealing action, it may be required that a sealing element be provided in the connection region, for example an O-ring, a rubber sleeve, or the like in order to perform a sealing function in addition to the holing function, if the connecting parts themselves of the arrangement in accordance with the invention cannot provide a sufficient seal.  
           [0008]    According to the invention, one of the connecting portions can also be provided by way of a fitting. This means that instead of providing both connecting parts at ends of plastic corrugated pipes, one of the connecting parts can be constructed in the form of a fitting, for example one which is manufactured by injection molding technology. This means that, for example, a cylindrical connection fitting can be constructed with features otherwise provided in accordance with the invention at one of the connecting parts of the mutually associated corrugated pipe ends. Such a fitting can be fastened, for example with a screwed connection, to a component, for example a switch gear cabinet, in order to fasten by way of this connecting fitting the corrugated pipe to be connected which includes the complementary connecting portion, to this component, for instance a switch gear cabinet.  
           [0009]    The connecting part with the engagement extent is formed, preferably up to behind the engagement extent, with a cross-section or diameter for allowing the other connecting part to be received in the former or to receive the former. This construction enables an overlapping connection, whereby the components forming the mechanically secured connection can be engaged with one another, which means the engagement extent engages the holding region, whereby at the same time circumferential regions of the connection portion are present which are suited for sealing measures.  
           [0010]    On the other hand, it is also advantageous when the other connecting part with the holding region is provided with a cross-section or diameter in such a way that it can receive the other connecting portion or can be received therein. Advantages are associated herewith which correspond to those already mentioned in the previous paragraph.  
           [0011]    Preferably, the holding region includes a track or slide block guide or the like, whereby the engagement extent can be moved into a holding position along the track, the slide block guide or the like. This means the engagement extent is inserted into the track or slide block guide or the like at the start thereof and then moved along this track or slide block guide into the holding position.  
           [0012]    The holding position is preferably constructed in such a way that it corresponds to a region of the track, the slide block guide or the like, which extends at least in part at more than 90° to the axially longitudinal direction of the associated holding region and/or the associated pipe body. The engagement extent hereby functions as slide block which is rigidly connected with the holding portion and which as soon as it has been guided into the holding position by way of the track, the slide block guide, or the like, securely connects the two pipe ends or the pipe end with the fitting. By providing the respective track or slide block guide or the like with a track or slide block guide portion which extends at 90° from the axially longitudinal direction of the associated holding portion and/or the associated pipe body, it is possible to achieve a fixed connection of the arrangement components to be connected by engagement, latching or twisting, which can only be separated again by an intentional action and in-so-far is reversible.  
           [0013]    The track or slide block guide or the like preferably includes an undercut portion in such a way that the engagement extent can engage behind the undercut so that when the arrangement is to be separated again, the undercut must first be overcome before the engagement extent can again be released from the holding position by way of the track, the slide block guide, or the like.  
           [0014]    The undercut preferably extends in circumferential direction and/or radially. When the undercut extends in circumferential direction, the engagement extent can be brought behind the undercut by way of the track, the slide block guide or the like, since a resilient force must be overcome so that under the action of normal traction on the arrangement in accordance with the invention, the undercut can no longer be overcome by the engagement extent. Correspondingly, it is possible to provide the undercut radially, so that the engagement extent must be radially inwardly or radially outwardly deflected in order to then engage the radial undercut when snapping back into its original radial position. Of course, it is possible to form a combination of a radially and circumferentially extending undercut, for example for special positioning requirements.  
           [0015]    When the arrangement in accordance with the invention is to be specially sealed, for instance liquid tight, it is practical when at least one of the connecting portions is provided with a sealing device, while the other connecting portion should be equipped with a sealing surface in corresponding manner. For example, one connecting portion can be provided with a groove with an O-ring and the other portion with a sealing surface against which the O-ring is pressed in the connecting position for the sealing of the arrangement in accordance with the invention.  
           [0016]    The connecting portions are preferably mutually correspondingly cylindrical or conical in construction, whereby especially a conical construction can provide that in the connecting position surfaces of the connecting cones can be directly and without additional sealing measures fitted into one another in such a way that a sufficient sealing action is achieved without further sealing measures. Of course, the sealingly engaging cones can also be provided with additional sealing measures, for example a rubber sleeve or the like, to guarantee the sealing action also for higher pressures.  
           [0017]    It is especially preferred when the connecting portions together form a type of bayonet connection, whereby the corrugations of a corrugated pipe are especially suited to provide the possibly required restoring force for holding the engagement extent of the bayonet connection in a holding position, as long as the restoring force for the corrugated pipes is applied. In general, corrugated pipes are subject to tension forces, while to overcome such a restoring forces compression forces must be exerted to overcome the required resilient force which is exerted by the corrugations of a corrugated pipe of the arrangement in accordance with the invention.  
           [0018]    If the invention is used, for example, for volatile or diffusive materials, especially fuels for motor vehicles, the plastic wall can be constructed of several layers, especially a diffusion blocking layer.  
           [0019]    It is also preferred in accordance with the invention to provide one of the connecting parts, or also both, as containers which are to be connected in accordance with the invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    The present invention will now be further described by reference to the attached drawings, whereby advantages, features and goals according to the invention are disclosed.  
         [0021]    [0021]FIG. 1 shows a first embodiment in accordance with the invention partially in longitudinal section and partially in side elevation;  
         [0022]    [0022]FIG. 1 a  shows a cross-section through the embodiment according to FIG. 1 in the area of section line A—A;  
         [0023]    [0023]FIG. 2 a  is a side elevational view of a corrugated pipe with a first connecting part for insertion into a second connecting part;  
         [0024]    [0024]FIG. 2 b  illustrates in partial cross-section and partial side elevation a corrugated pipe end with a second connecting part for receiving a first connecting part as shown in FIG. 2 a;    
         [0025]    [0025]FIG. 2 c  is an axial end view of the connecting part according to FIG. 2 b;    
         [0026]    [0026]FIG. 3 a  is a side elevational view of a corrugated pipe with a first connecting portion;  
         [0027]    [0027]FIG. 3 b  is a partially cross-sectional partially side elevational view of a corrugated pipe with a connecting part corresponding to the connecting part shown in FIG. 3 a;  and  
         [0028]    [0028]FIG. 4 is a side elevational view of a connection in accordance with the invention between a container and a corrugated pipe. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    Equal or at least functionally equal components are identified by the same reference numerals in the various figures.  
         [0030]    [0030]FIG. 1 shows a corrugated pipe  40  with a connecting part  11  according to the invention while another corrugated pipe  10  includes a connecting part  15  corresponding thereto.  
         [0031]    As is apparent, the connecting parts  11  and  40  are constructed such that they can be plugged one into the other, whereby in this specific embodiment, the connecting part  40  can be inserted into the connecting part  11 .  
         [0032]    The corrugated pipe  38  has on its connecting part  40  an engagement extent  42  which upon fitting together of the arrangement can be brought into engagement with a radially extending undercut shape  19  by way of a track  16  and a track  18 . The engagement extent  42  and/or the undercut portion  19  can thereby be constructed such that at least one radially evades the other, which is especially clearly apparent from FIG. 1 a.    
         [0033]    The connecting part  11  has a groove  20  into which an O-ring  22  is inserted. The sealing surface of the O-ring  22  rests against the wall of the connecting part  40  opposite thereto in such a way that a good sealing effect can be generated.  
         [0034]    According to FIG. 1 a,  the connecting part  40  has an inwardly extending engagement extent  42  formed with the corrugation, which engages an undercut portion  19  equally formed by corrugation.  
         [0035]    The start of the lead-in track  16  for the engagement extent  42  is apparent in this cross-sectional illustration. Joined to this track  16  is the track  18 , which is constructed such that its depth decreases in circumferential direction towards the undercut portion  19 . In this matter, the connecting part  11  can be inwardly deformed in the region of the track or the slide block guide  18  and then, when the engagement extent  42  has reached the undercut portion  19 , snapped back into the original position in such a way that the engagement extent safely and fixedly comes to lie in the undercut portion  19 . Of course the connecting part  40  can also be deformable to such an extent that its wall can be flexibly deformed so that the engagement extent  42  in the base of the track  18  evades in order to then again engage the undercut portion by way of the flexible resetting forces.  
         [0036]    Since the components of the arrangement in accordance with the invention are made of plastic, the involved regions of the connecting part  11  as well as the connecting part  40  are in reality probably respectively gradually involved in the evading process.  
         [0037]    It need not be stressed further that of course the undercut portion can conversely also be provided at the outer connecting part  40  and the engagement extent  42  at the inner connecting part  11 .  
         [0038]    The fastening process is hereby carried out in such a way that, as already mentioned above, the engagement extent  42  is inserted into the track  16 , then inserted into the circumventially extending track  18  by rotation of one of the components of the arrangement to finally come to rest in the undercut portion  19 . When tractive forces are then applied to this arrangement, they do then not act in direction of the resilient force which acts between the undercut portion  19  and the engagement extent  42  so that an opening of the connection in accordance with the invention is practically impossible. This equally also applies for thrust forces, since they also do not act radially inwardly.  
         [0039]    A further preferred embodiment with features according to the invention is apparent from FIGS. 2 a  to  2   c.    
         [0040]    A corrugated pipe section  10  with corrugation peaks  14  and corrugation valleys  12  here has an engagement extent  42  on one of the corrugation peaks. The opposing corrugated pipe  40  has a connecting part  11 , which includes an initially axially extending track  19 . This first, axially extending track  19  is joined to a circumferentially extending track portion  18  which then again turns into an essentially axially extending portion  21  as is apparent from FIG. 2 c.  An undercut portion  19  is provided between the two track portions  16  and  21 , extending in axial direction of the pipe arrangement. At the end of the connecting part  11 , a stop region is provided against which the end of the corrugated pipe  10  comes to rest.  
         [0041]    When the two pipes  10 ,  40  are to be connected according to FIGS. 2 a  to  2   c,  the end of the pipe  10  is inserted into the connecting part  11 , whereby the engagement extent  42  slides into the track  16  of the connecting part  11 . The corrugated pipe  10  in this connecting process comes to rest against the stop region  13  and is during the connecting process compressed, which is made possible because of the corrugations. When the engagement extent  42  has reached the end of the track  16 , a twisting force must be exerted on one of the two pipes  10 ,  40  or one of the two connecting parts  11 ,  40  so that the engagement extent  42  is transferred into the circumferentially extending track portion  18 . As soon as the engagement extent  42  has passed through the circumferentially extending track portion  18  and thereby has automatically passed the undercut portion  19 , the compression force which was exerted during the connecting process on the pipes  10 ,  40  involved therein, can be relaxed. The resetting resilient force of the corrugations of the corrugated pipe  10  in the region of the connecting part  40  can drive the engagement extent into the track portion  21  in such a way that a loosening of the arrangement components by tractive forces can no longer be achieved, since the engagement extent  42  is trapped behind the undercut portion  19  in the axially extending track portion  21 . A loosening of this connection is only still possible when again a thrust force is exerted on the arrangement parts and especially on the pipe  10  to compress the corrugations in the region of the connecting part  40 .  
         [0042]    It is apparent from FIGS. 2 a  to  2   c,  FIGS. 1 and 1 a,  as well as FIGS. 3 a  and  3   b  that the corrugated pipes to be connected with one another can have different corrugation shapes. Of course, the corrugated pipes can also have identical corrugation shapes. It has to be noted with respect to all embodiments that in the case where one of the connecting parts  11 ,  40  is part of a connecting fitting, a threaded part or the like, for example, can of course then also adjoin the respective connecting part instead of the illustrated corrugated pipe.  
         [0043]    An arrangement with features according to the invention is illustrated in the FIGS. 3 a  and  3   b,  which is principally constructed exactly as the embodiment according to FIGS. 2 a  to  2   c.  Different therefrom however are the connecting parts  11 ,  40  which are constructed to be mutually conically corresponding so that the conical surfaces coming in contact with one another can simultaneously represent sealing surfaces which provide a sufficient seal without having to take further sealing measures. On the other hand, it is also possible to incorporate, for example, a rubber sleeve into this arrangement so that an especially tightly sealed connection can be produced.  
         [0044]    A container  100  is illustrated in FIG. 4, which is manufactured, for example, by injection molding or the like. The container is provided with a connecting part  11  according to the invention which includes the engagement extent  42 . The corrugated pipe section  10  is provided with the connecting part  40  according to FIG. 3 b.    
         [0045]    Of course, the connecting part  11  of the container  100  can also be constructed according to one of the above mentioned other connecting parts  11 ,  40 , whereby the respectively complementary connecting part is then provided on the corrugated pipe to be connected thereto. Of course, both connecting parts  11 ,  40  can be provided on containers  100 .

Technology Category: f