Abstract:
The invention relates to a connector device for plugingly connecting at least one media conduit. The conduit device ( 1 ) is composed of a housing part ( 2 ) comprising at least one receiving hole ( 4 ) for plugging in the conduit ( 6 ), and a clamping ring ( 8 ) which is arranged in the receiving hole ( 4 ) and cooperates with an inner cone ( 16 ) of the housing part ( 2 ) in order to lock the plugged-in conduit ( 6 ). The inner insertion piece ( 32 ) that is removably connected to the base piece ( 28 ) via a catching connection ( 30 ) and is provided with the inner cone ( 16 ). The insertion piece ( 32 ) is equipped with at least two radially elastic spring arms ( 40 ) so as to be able to remove the conduit ( 6 ), the free ends ( 48 ) of the spring arms ( 40 ) extending from the region of the inner cone ( 16 ) in the direction of the mouth side of the receiving hole ( 4 ). Radially outward-protruding catching extensions ( 42 ) of the spring arms ( 40 ) engage into corresponding catching holes ( 44 ) for detaching purposes. A contamination seal ( 34 ) comprising a sealing area (A) is disposed in the region of free ends ( 48 ) of the spring arms to circumferentially rest upon the media conduit ( 6 ). The catching extensions ( 42 ) of the spring arms ( 40 ) are disconnected, regarding the radial detaching movement thereof, from the sealing area (A) of the contamination seal ( 34 ) via a deformation zone ( 49 ) in such a way that the radial detaching movement of the catching extensions ( 42 ) is performed substantially without being influenced by the contamination seal ( 34 ) radially resting on the media conduit ( 6 ) because the deformation zone ( 49 ) is deformed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to PCT international patent application number PCT/EP2006/065775, filed Aug. 29, 2006 and DE patent application 20 2005 013 691.3, filed Aug. 30, 2005. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a connection device for the plug-type connection of at least one media conduit (pipeline or hose pipe for gases or liquids). 
       BACKGROUND OF THE INVENTION 
       [0003]    Such a connection device is described both in WO 2004/029497 A1 and in WO 2005/028939 A1. In this known embodiment, the insert part is in the form of a sleeve and is inserted into an enlarged portion of the receiving opening of the base part so as to be circumferentially sealing at least with respect to the ingress of dirt or such contaminants. The insert part in the inserted state lying completely within the base part so as to terminate flush on the mouth side. Furthermore, the insert part comprises a first, relatively harder dimensionally stable plastic material, a dirt seal being integrally formed cohesively from a second, relatively softer and elastic plastic material in the free, mouth-side end region of the spring arms. The insert part is therefore in the form of an integral multicomponent molding made from plastic. The spring arms are formed by longitudinal slots of the sleeve-shaped insert part, the longitudinal slots likewise being filled with the injected material of the dirt seal. In the known connection device, it has been shown in practical use that it is sometimes only very difficult to detach the conduit by removing the insert part from the base part. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is based on the object of improving a connection device of the type mentioned in such a way that the detachment process is simplified whilst maintaining secure locking of the inserted media conduit. 
         [0005]    Accordingly the invention provides that the latching shoulders of the spring arms are decoupled from the sealing region of the dirt seal with respect to their radial detachment movement via a deformation zone in such a way that the radial detachment movement of the latching shoulders as a result of the deformation of the deformation zone, with respect to a detaching force to be applied for the detachment movement, takes place substantially uninfluenced by the dirt seal, which rests radially on the media conduit. This achieves an advantageously low detachment force for the detachment movement. 
         [0006]    A first embodiment provides that each spring arm has, as a deformation zone in a region lying between an inner cone and a free spring arm end, a weakening zone with reduced flexural stiffness in such a way that, when the free spring arm end is radially supported on the conduit (preferably indirectly via a dirt seal provided in this region), the latching shoulder is capable of moving radially inward into its detachment position under elastic bending deformation of the weakening zone. For this purpose, a lower radial detachment force is advantageously sufficient because the weakening zone according to the invention makes it possible to achieve a situation in which the free end region, which is preferably supported on the conduit circumference via the dirt seal, of each spring arm does not counteract the radial detachment movement, or only counteracts it to a lesser extent. This means that the latching shoulders of the spring arms with respect to their radial detachment movement are in practice decoupled from the free end region (preferably from the region of the dirt seal). The latching shoulders can therefore move radially with a low radial detachment force, without or with only unsubstantial movement of the spring arms in the end-side region. As a result, overall the detachability is markedly improved. By virtue of the fact that the weakening zone is in each case preferably arranged axially between the latching shoulder and the free spring arm end, in practice, a flexible joint is formed between these regions. 
         [0007]    In a second embodiment of the invention, the spring arms with their free ends are decoupled from the mouth-side end of the sleeve-shaped insert part via axial interspaces, the deformation zone being formed by regions of an elastic plastic material which are arranged in the region of the free spring arm ends and in the interspaces and are integral with the dirt seal, in such a way that during the radial detachment movement of the latching shoulders, the free spring arm ends are correspondingly concomitantly moved radially under the elastic material deformation of the plastic material of the deformation zone. This may also result proportionally in a bending deformation in the region of the free ends of the spring arms. 
         [0008]    In the preferred embodiments, by virtue of the fact that the spring arms are decoupled from the mouth side of the insert part, the latter can be formed at its mouth-side end with a ring section, which is continuous in the circumferential direction, with a planar, front end ring face. This ensures improved support of the dirt seal in particular in the axial direction. 
         [0009]    Despite the improved detachability as a result of the invention, at the same time there is also a high level of protection against undesired detachment. For this purpose, preferred configurations will be explained in the text which follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In the text which follows, the invention will be explained in more detail with reference to preferred exemplary embodiments illustrated in the figures of the drawing, in which: 
           [0011]      FIG. 1  shows an axial section of a first embodiment of a connection device according to the invention in a first section plane (plane I-I shown in  FIG. 2 ), by way of example in an embodiment as an elbow connector with plugged media conduit, 
           [0012]      FIG. 2  shows an axial section in a second plane (II-II according to  FIG. 1 ) which is arranged at right angles with respect to the plane according to  FIG. 1 , 
           [0013]      FIG. 3  shows an enlarged illustration of the region III in  FIG. 2  with the media conduit only illustrated by dashed lines, 
           [0014]      FIG. 4  shows a perspective view of an insert part according to the invention, 
           [0015]      FIG. 5  shows an enlarged plan view of the insert part in the arrow direction V according to  FIG. 4 , 
           [0016]      FIG. 6  shows a partially sectioned side view in the arrow direction VI according to  FIG. 5 , 
           [0017]      FIG. 7  shows an enlarged partial section S-S according to  FIG. 6 , 
           [0018]      FIG. 8  shows a section D-D according to  FIG. 5 , 
           [0019]      FIG. 9  shows an enlarged illustration of the region C in  FIG. 8 , 
           [0020]      FIG. 10  shows an enlarged illustration of the region W in  FIG. 8 , 
           [0021]      FIG. 11  shows a cross section in two axially offset planes corresponding to the profile of the section line F-F in  FIG. 8 , 
           [0022]      FIG. 12  shows an enlarged illustration of the region U in  FIG. 11 , 
           [0023]      FIG. 13  shows an enlarged partial section R-R according to  FIG. 6 , 
           [0024]      FIG. 14  shows a section A-A according to  FIG. 5 , 
           [0025]      FIG. 15  shows a section B-B according to  FIG. 5 , 
           [0026]      FIG. 16  shows an enlarged section L-L according to  FIG. 14 , 
           [0027]      FIG. 17  shows an enlarged section K-K according to  FIG. 14 , 
           [0028]      FIG. 18  shows a section G-G according to  FIG. 5 , 
           [0029]      FIG. 19  shows an enlarged illustration of the region J in  FIG. 18 , 
           [0030]      FIG. 20  shows an enlarged partial section M-M according to  FIG. 19 , 
           [0031]      FIG. 21  shows an enlarged illustration of the region F′ in  FIG. 8 , 
           [0032]      FIG. 22  shows a section in the plane I-I according to  FIGS. 8 and 21 , 
           [0033]      FIG. 23  shows an enlarged illustration of the region Y in  FIG. 15 , 
           [0034]      FIG. 24  shows a second embodiment of the insert part as an alternative to  FIG. 4 , 
           [0035]      FIG. 25  shows an enlarged plan view of the insert part in the arrow direction XXV according to  FIG. 24  (similar to  FIG. 5 ), 
           [0036]      FIG. 26  shows a side view XXVI according to  FIG. 25  (similar to  FIG. 6 ), 
           [0037]      FIG. 27  shows a section D-D according to  FIG. 25  (similar to  FIG. 8 ), 
           [0038]      FIG. 28  shows an enlargement of the region N in  FIG. 27 , 
           [0039]      FIG. 29  shows a cross section corresponding to the section line F-F in  FIG. 27  (similar to  FIG. 11 ), 
           [0040]      FIG. 30  shows an enlargement of the region U in  FIG. 29  (similar to  FIG. 12 ), 
           [0041]      FIG. 31  shows a section G-G in  FIG. 25  (similar to  FIG. 18 ), 
           [0042]      FIG. 32  shows an enlargement of the region J in  FIG. 31  (similar to  FIG. 19 ), 
           [0043]      FIG. 33  shows an axial section of a second embodiment of a connection device according to the invention, by way of example in the form of a through-connector for two media conduits (not illustrated), 
           [0044]      FIG. 34  shows a section in the plane A-A according to  FIG. 33 , 
           [0045]      FIG. 35  shows an enlargement of the region. B in  FIG. 34 , 
           [0046]      FIG. 36  shows a side view of the insert part in the embodiment according to  FIGS. 33 to 35 , 
           [0047]      FIG. 37  shows a plan view of the mouth side in the arrow direction C according to  FIG. 36 , 
           [0048]      FIG. 38  shows an axial section in the plane D-D according to  FIG. 37 , 
           [0049]      FIG. 39  shows an axial section in the plane G-G according to  FIG. 37  (rotated through 90° in the plane of the drawing), 
           [0050]      FIG. 40  shows a side view (sectioned in regions), of the insert part in the arrow direction E according to  FIG. 37 , 
           [0051]      FIG. 41  shows a section in the radial plane I-I according to  FIG. 40 , 
           [0052]      FIG. 42  shows a detail enlargement of the region b in  FIG. 39 , and 
           [0053]      FIG. 43  shows a very enlarged view of the region N in  FIG. 38 . 
       
    
    
     DETAILED DESCRIPTION 
       [0054]    In the various figures of the drawing, identical parts have always been provided with the same reference symbols, with the result that each description of a part, which may appear only once with reference to a specific drawing figure, also applies analogously with respect to the other figures of the drawing in which the part with the corresponding reference numeral can likewise be seen. 
         [0055]    A connection device  1  according to the invention comprises, according to  FIGS. 1 to 3  and  FIGS. 33 to 35 , a housing part  2  with, at least, one receiving opening  4 , which is open at one end, for axially inserting an end of a media conduit  6  in the form of a pipeline or hose pipe and a clamping ring  8  which is arranged in the housing part  2  or within the receiving opening  4 , for locking the axially, i.e. in the direction of a plug axis  10 , inserted conduit  6 . In this case, the connection device  1  makes it possible for the conduit  6 , which in particular is made from plastic, to be fitted simply and quickly by means of simply being inserted into the housing part  2  without any other fitting steps. The clamping ring  8  rests in an enlarged portion of the receiving opening  4  in such a way that it surrounds the receiving opening  4  and therefore the inserted conduit  6 . At a point on its circumference, the clamping ring  8  has an axially and radially continuous slot, i.e. an interruption in its circumferential profile, as a result of which it can be radially elastically enlarged and/or constricted. In its inner circumferential region, the clamping ring  8  (see in this regard in particular the larger illustrations in  FIGS. 3 and 35 ) has (at least) one radially inwardly protruding, circumferential tooth edge  12 . In addition, the clamping ring  8  has (at least) one outer cone  14 , which interacts with an inner cone  16  of the housing part  2  for the purpose of locking the conduit  6  in such a way that when the conduit  6  is pulled in the detachment direction (arrow direction  18  in  FIGS. 1 to 3 ), i.e. in the event of a movement counter to the insertion direction (arrow  20  in  FIGS. 1 to 3 ), the clamping ring  8  is first carried along by the force-fitting bearing state of its tooth edge  12  until its outer cone  14  comes to rest in the inner cone  16  of the housing part  2 . If the conduit is pulled further, a radially inwardly directed force is produced via the cones  14 ,  16 , by means of which force the clamping ring  8  is elastically constricted, with the result that the tooth edge  12  interacts in a force-fitting and/or interlocking manner with the substantially smooth, cylindrical conduit outer circumference and, as a result, the conduit  6  is locked so as to prevent it from being withdrawn. In this case, an advantageous configuration, which is not illustrated, however, can provide that the inner cone  16  of the housing part  2  comprises two axially adjacent inner cone sections with different cone angles. A first inner cone section, which is positioned at a distance from the insertion side (mouth side of the housing receiving opening), is designed to have a first, relatively flat cone angle, and a second inner cone section, which is adjoining in the direction toward the insertion or mouth side, has a second, steeper cone angle. In this case, the outer cone  14  of the clamping ring  8  also comprises two axially adjacent outer cone sections with corresponding cone angles so as to match the inner cone sections. As a result of this configuration, shortening of the axial return path for locking purposes is achieved. Details in this regard are included in the earlier application DE 20 2005 009 575.3, to which full reference is therefore made. 
         [0056]    In order to seal off the conduit  6  in a pressure-tight manner, a sealing ring  24  (pressure seal) is arranged within the housing part  2  in the region between the clamping ring  8  and a bore step  22 . In addition, a supporting sleeve  26 , which is coaxial with respect to the plug axis  10 , is preferably arranged within the housing part  2  for engaging in the inserted conduit  6 . The supporting sleeve  26  therefore supports the inserted or plugged-on, conduit  6  on the one hand against the radial force applied via the clamping ring  8  and on the other hand also against the bearing force of the sealing ring  24  from the inside. As a result, the connection device  1  according to the invention is in principle also suitable for relatively flexible hose pipes. 
         [0057]    For, on the one hand, the producibility and fitability of the connection device  1  and, on the other hand, the detachability of the conduit  6 , the housing part  2  is formed in two parts; it comprises a base part  28  and an insert part  32 . The insert part  32  has the inner cone  16  and is connected to the base part  28  via an interlocking latching connection  30  (snap-action interlocking connection with an active face/undercut angle of greater than/equal to 90°). The insert part  32  has, on the mouth side, a dirt seal  34  with a sealing region A for bearing circumferentially on the inserted conduit  6 . The insert part  32  is described in more detail further below with reference to the separate illustrations in  FIGS. 4 to 23  and  36  to  43 . 
         [0058]    The above-described supporting sleeve  26 , in the case of parts which have not been shaped by machining technology, is expediently designed to be integral with the base part  28 , in particular as a molding made from plastic (see  FIGS. 1 and 2 ). According to  FIGS. 33 to 35 , the supporting sleeve  26  can also be in the form of a separate insert part  26   a . As a result, the insert part  26   a  with the supporting sleeve  26  on the one hand and the base part  28  on the other hand can comprise different materials. 
         [0059]    Preferably, the insert part  32  with the dirt seal  34  is formed as an integral multicomponent molding comprising in particular at least two different plastic materials, to be precise the insert part  32  comprises a first, relatively harder and dimensionally stable plastic material, while the dirt seal  34  is integrally formed in one piece directly cohesively from a second, relatively softer and elastic plastic material. Preferably, this material is a thermoplastic elastomer (TPE). In this case, the dirt seal  34  has, on its side pointing radially inward, the seal region A for bearing circumferentially on the conduit  6 . 
         [0060]    The insert part  32  is formed together with the dirt seal  34  overall substantially in the form of a sleeve and inserted into an enlarged portion  36  of the receiving opening  4  of the base part  28 . In order to seal off the gap between the base part  28  and the insert part  32  against the ingress of dirt and the same contaminants, the insert part  32  has a seal  37  on its outer circumference. In the preferred embodiment illustrated, this seal  37  comprises a relatively soft elastic material and, for this purpose, is integrally formed in particular in one piece and cohesively in a similar manner to the dirt seal  34 . The seal  37  therefore preferably comprises a TPE (thermoplastic elastomer). In this case, it is particularly advantageous if the insert part  32  in the inserted state lies completely within the base part  28  so as to terminate flush on the mouth side. This results in an advantageously compact design of the connection device  1 , which has a planar end face, which is closed via the dirt seal  34  toward the conduit  6 , on the mouth side. 
         [0061]    For the detachability of the conduit  6 , provision is made for the sleeve-shaped insert part  32  (see in this regard in particular the separate, enlarged illustrations in  FIGS. 4 to 23  and  36  to  43 ) to have at least two radially elastic, diametrically opposite spring arms  40 , which are formed by longitudinal slots  38 . Each spring arm  40  engages with a radially outwardly protruding, tab-like latching shoulder  42  in an interlocking manner, i.e. with an undercut ≧90°, in a corresponding latching opening  44  of the base part  28  in a detachable manner. The latching openings  44  are in this case in the form of radial through-openings, with the result that the latching shoulders  42  can be reached from the outside with a suitable tool and moved radially inward for detachment purposes, as a result of which the conduit  6  together with the clamping ring  8  and the insert part  32  can be removed (arrow direction  18  in  FIGS. 1 to 3 ). 
         [0062]    In the preferred configuration described, it is furthermore advantageous if the longitudinal slots  38  of the insert part  32  are completely filled with the material of the dirt seal  34  (see in this regard in particular the section A-A in the region of the longitudinal slots  38  in  FIG. 14  and the cross section in  FIG. 11 ). This configuration means that optimum dirt sealing is ensured since actual gaps are avoided even in the region of the longitudinal slots  38 . Nevertheless, the elasticity of the sealing material filling the longitudinal slots  38  (in particular a TPE) allows for the necessary radial movement of the spring arms  40 . 
         [0063]    Alternatively, the dirt seals  34  and  37  can be embodied by separate elastomeric inserts (for example O rings). In this case, however, it is advantageous to fill the longitudinal slots  38  as described with an elastic material (TPE). 
         [0064]    In the embodiments according to  FIGS. 1 to 32  (see in this regard, for example,  FIGS. 4 ,  6 ,  8 ,  14 ,  15  and  18 ), the longitudinal slots  38  forming the spring arms  40  run from the region of the inner cone  16  continuously as far as the opposite, mouth-side end of the sleeve-shaped insert part  32 . As a result, the spring arms  40  extend starting from a circumferentially closed ring section  46 , which has the inner cone  16 , of the insert part  32  with its free ends  48  as far as the mouth side, where the free ends  48  are connected to the dirt seal  34 . 
         [0065]    According to the invention, it is now provided in all embodiments that the latching shoulders  42  of the spring arms  40  are decoupled from the region of the dirt seal  34  with respect to their radial detachment movement via a deformation zone  49  in such a way that the radial detachment movement of the latching shoulders  42  takes place substantially uninfluenced by the dirt seal  34 , which is supported radially on the media conduit  6 , with the principal deformation of the deformation zone  49  as regards a detachment force to be applied for the detachment movement. As a result, the detachment force is largely independent of an opposing force brought about by the dirt seal  34 , with the result that, overall, an advantageously low detachment force is sufficient for actuating the latching shoulders  42 . 
         [0066]    In order to improve or facilitate the detachability of the latching connection  34 , the embodiments according to  FIGS. 1 to 32  provide that each spring arm  40  has, as a deformation zone  49 , a weakening zone  50  with reduced flexural strength in such a way that, when the free spring arm end  48  is radially supported via the dirt seal  34  on the conduit  6 , the latching shoulder  42  is capable of moving radially inward into its detachment position under elastic bending deformation of the weakening zone  50 . In this regard, reference is made to the illustrations in  FIGS. 2 and 3 . If, for detachment purposes by means of a suitable tool (not illustrated) through the latching openings  44 , in each case a radial detachment force F L  is applied to the latching shoulders  42 , as a result first the spring arms  40  are moved (pivoted) overall elastically radially inward. Since, however, the free ends  48  of the spring arms  40  are supported, indirectly via the dirt seal  34 , on the circumference of the media conduit  6 , given a continued radial movement of the latching shoulders  42  in each case a bending deformation in the region of the weakening zone  50  occurs after a specific radial compression of the dirt seal  34 , with the result that the weakening zone  50  acts as a flexible joint. As a result, in practice the free spring arm ends  48  are “decoupled” from the detachment force, i.e. the free ends  48  at most cause only a slight force which counteracts the detachment force F L , as a result of which the detachment force F L  is overall advantageously low. 
         [0067]    In a preferred embodiment, the weakening zone  50  of each spring arm  40  is arranged in the region lying axially between the latching shoulder  42  and the dirt seal  34 . In this case, advantageously the weakening zone  50  of each spring arm  40  can be formed by a cross-section reduction, to be precise by a cross-section reduction of at least 25% to at most approximately 75%, preferably of from 50% to 75% to from approximately 50% to 25%, of the original spring arm cross section which is provided in the adjoining regions of the spring arm  40 . In this case, the cross-section reduction can be formed by an outer radial cutout and/or by an inner radial enlargement of the inner cross section. 
         [0068]    In the preferred exemplary embodiment illustrated according to  FIGS. 1 to 32 , on the one hand each spring arm  40  has, in the weakening zone  50  on its radially outwardly pointing side, a radial cutout  52 , which preferably runs in the manner of a groove in the circumferential direction. On the other hand, the insert part  32  has, in the region of the spring arms  40  on its inner side pointing radially inward toward the conduit  6  and in the region of the deformation zones  49 , an enlarged inner diameter. In this case, it is provided that the inner diameter adjoining the smallest diameter of the inner cone  16  is enlarged in the direction of the deformation zones  49  via cone sections  54  running at an angle. In this regard, particular reference is made to  FIG. 3  and also to  FIGS. 8 and 15 . Accordingly, an edge  56  with an inner diameter which is greater than the outer diameter of the media conduit  6  ( FIG. 3 ) is formed between the inner cone  16  and the cone sections  54  in the region of each spring arm  40 . As a result of the inner contour described of the spring arms  40 , a radial movement play which is sufficient for the detachment movement is provided. During the detachment movement, in each case the edge  56  of each spring arm  40  can come to bear on the conduit  6  beyond a certain radial excursion, as a result of which a further radial movement of each spring arm  40  then only still takes place in the region between the edge  56  and the free end  48  or the deformation zone  49  (as a result of the free ends  48  of the spring arms  40  being supported on the conduit  6  via the dirt seal  34 ). 
         [0069]    An advantageous configuration of the invention will now be explained with reference to  FIGS. 2 ,  3  and  5  and  FIGS. 34 ,  35  and  37 . Accordingly, the latching shoulder  42  of each spring arm  40  has a latching edge face  58  with an outer radius of curvature R a , which is at least approximately equal to the inner radius R i  of the base part  28 . According to  FIGS. 5 and 37 , in the unstressed rest position of the spring arms  40  the latching edge faces  58  protrude radially outward beyond the inner circumference, which substantially corresponds to the outer circumference of the insert part  32 , of the base part  28 , in order that the latching edge faces  58  can engage in the latching openings  44 . In this case, the radii mid-points of the radii of curvature R a  of the latching edge faces  58  are radially offset with respect to the radii mid-point of the radius R i . As a result of the detachment movement of the latching shoulders  42  radially inward, the mid-points of the radii R a  then move toward the mid-point of the radius R i , with the result that the latching edge faces  58  then also precisely correspond to the inner curvature of the base part  28 . As a result, an improvement of the release of the latching during detachment is achieved by virtue of the latching shoulder  42  of each spring arm  40  with the latching edge face  58  coming completely free from the region of the latching opening  44  given the smallest possible radial excursion. If, in contrast to this, the radius of curvature R a  were to be greater by the offset of the mid-points of the radii R a  and R i  according to  FIGS. 5 and 37 , each latching shoulder  42  would have to be moved further radially inward in order that the lateral end regions, which point in the circumferential direction, of the latching edge face  58  also come free from the latching opening  44 . The detachment is likewise facilitated by this advantageous configuration. 
         [0070]    In a preferred configuration, it is also provided according to  FIG. 23  that holding edges are formed within the insert part  32  adjacent to the inner cone  16  as an axial end stop opposing a movement of the clamping ring  8  directed in the withdrawal direction of the conduit  6 , to be precise first holding edges  60  are formed in the region of the spring arms  40  and second holding edges  62  are formed in the regions lying between the spring arms  40  and in each case between the slots  38 . As a result of the holding edges  60 ,  62 , high withdrawal forces are made possible, which ensures a high level of protection against undesired detachment of the conduit  6 . In this case it is provided according to  FIG. 23  that the first holding edges  60  are offset with respect to the second holding edges  62  by an axial offset X in the direction of the inner cone  16  in such a way that the clamping ring  8  (not illustrated here), when subjected to a force F Z  acting in the withdrawal direction of the conduit  6 , first comes to bear only on the first holding edges  60 , as a result of which the spring arms  40  are subjected to a radially outwardly acting holding force component F H . In this case, the axial offset X is designed to be small, however, so that, after a deformation in the elastic region, the clamping ring  8  additionally comes to bear against the second holding edges  62 , which further improves the protection against detachment. When the clamping ring  8  is bearing against the first holding edges  60 , forces are therefore resolved, the radial component F H  ensuring that the holding force of the elastic spring arms  40  is increased. As a result, very high withdrawal forces are achieved. 
         [0071]    In particular in connection with the above-described configuration; it is furthermore advantageous if the latching shoulder  42  of each spring arm  40  has, in the region of its latching edge face  58 , a stop element  64  in such a way that, in a state in which the conduit  6  is subjected to the force F Z  in the withdrawal direction, the latching shoulder  42 , in a position in which it engages in a defined manner in the latching opening  44  of the base part  28 , is supported against a further radially outwardly directed movement, which in particular results from the above-described holding force component F H . For this purpose, the stop element  64  is supported on the inner circumference of the base part  28  in the region adjoining the latching opening  44  (see in this regard  FIGS. 2 and 3 ). As illustrated, the stop element  64  can be in the form of a shoulder on the latching edge face  58  (see in this regard, for example,  FIGS. 6 ,  8  and  10 ). The stop element  64  therefore delimits the spring excursion radially outward whilst loading the connection device  1 . This avoids a situation in which, in particular as a result of the radial holding force component F H , the spring arms  40  could be pushed too far radially outward. As a result of such an excessive deformation of the insert part  32 , the latter could possibly jam during the detachment process and/or the clamping ring  8  could be ripped out despite the axial stop at the holding edges  60 ,  62 . These problems are advantageously avoided by the stop elements  64 ; the detachability is improved whilst ensuring high withdrawal forces. 
         [0072]    As can furthermore best be seen in the enlarged illustrations in  FIGS. 3 and 35 , each latching shoulder  42  advantageously has, on its side protruding radially outward, when viewed in the axial direction, a rounded-off flank face  66 . As a result of the fact that the contour of the outer region is rounded off in this way, undesired compressions in the region between the latching edge face  58  and the base region, which adjoins the ring section  56 , of the spring arms  40  are avoided which can result owing to the bending during unlocking of the spring arms  40 . In addition, the frictional forces when withdrawing the unlocked insert part  32  are reduced. 
         [0073]    Finally, in an advantageous configuration the dirt seal  34  is chambered axially on both sides on the free mouth side at least in subregions of its circumference. On the mouth side, this is achieved by injection-molded web sections  68  comprising the relatively hard first plastic material (see, for example,  FIGS. 3 ,  8  and  21 ). These web sections  68  also act as a supporting ring for the dirt seal  34 , with the result that good dimensional stability is achieved. 
         [0074]      FIGS. 24 to 32  illustrate a second embodiment of the insert part  32 , in which in particular the region of the dirt seal  34  is modified with respect to the first embodiment shown in  FIGS. 1 to 23 . In order to ensure a good sealing effect toward the inserted media conduit  6  for providing safe dirt sealing as a result of relatively high radial compression, but at the same time to keep the plugging force to be applied for inserting the conduit  6  and also the radial detachment force F L  (cf.  FIG. 3 ) low, this embodiment according to  FIGS. 29 to 32  provides that tangential or secant-like recesses  70  are formed in the region of the longitudinal slots  38  between the relatively soft plastic material and the relatively hard plastic material radially outside and axially beneath the region of the dirt seal  34  (see also  FIGS. 39 and 42 ). This can be achieved in terms of molding technology by corresponding cross-slides. In this case, according to  FIGS. 31 and 32  the dirt seal  34  is supported in the region of the recesses  70  axially in the insertion direction  20  (cf.  FIGS. 1 to 3 ) via webs  72  comprising the elastic material. Furthermore, according to  FIGS. 27 and 28  the region of the largest inner cross section of the weakening zone  50  according to the invention of each spring arm  40  directly adjoins a radial face  74 , which points in the insertion direction  20 , of the dirt seal  34 . As a result of these described measures, a certain flexibility is achieved in the region of the dirt seal  34  given a good radial sealing effect in such a way that the radial compression of the dirt seal  34  has at most very little influence on the detachment force F L  and on the plugging force. 
         [0075]    The embodiment according to  FIGS. 33 to 43  differs from the embodiments according to  FIGS. 1 to 32  by a particular configuration of the deformation zone  49  according to the invention. In this case, the spring arms  40  are designed to be axially shortened in such a way that they, with their free ends  48 , are decoupled from the mouth-side end of the sleeve-shaped insert part  32  via axial interspaces  80 . In this case, the deformation zone  49  is formed by regions of the elastic plastic material, which are arranged in the region of the free spring arm ends  48  and in the interspaces  80  and are integral with the dirt seal  34  in such a way that, during the radial detachment movement of the latching shoulders  42 , the free spring arm ends  48  are concomitantly moved radially under elastic material deformation of the plastic material. In this regard, particular reference is made to the enlarged illustration in  FIG. 43 . Preferably, the free end  48  of each spring arm  40  is formed by an axial radially inner web section  82 , whose radially measured thickness is reduced in comparison with the spring arm  40 . In this case, the elastic plastic material forming the deformation zone  49  engages over the web sections  82  radially and axially in the direction toward the latching shoulders  42 . As a result of this advantageous configuration, a ring section  84 , which is continuous in the circumferential direction and comprises the first, dimensionally stable plastic material, can be formed at the mouth-side end of the insert part  32 . This ring section  84  has a planar, front end ring face  86 . This configuration results in improved, in particular axial support and covering (chambering) of the dirt seal  34  for the purpose of protection, for example, against a water jet (see in this regard in particular  FIGS. 35 ,  38  and  43 ). 
         [0076]    In a further advantageous configuration, preferably two mutually diametrically opposite, radially outwardly protruding shoulders  88  are arranged at the mouth-side end of the sleeve-shaped insert part  32  (see, for example,  FIGS. 37 and 40 ). These shoulders  88  engage in corresponding cutouts of the base part  28  in such a way that they are used firstly for radially positioning the insert part  32  in the base part  28  and secondly as an end stop for the axial insertion limitation (see in particular  FIG. 33 ). 
         [0077]    The invention is not restricted to the exemplary embodiments described and illustrated, but also includes all embodiments with a similar effect within the context of the invention. In addition, the invention is also not restricted to the combination of features defined in claim  1 , but can also be defined by any desired other combination of specific features of all individual features disclosed as a whole. This means that, in principle, in practice any individual feature of claim  1  can be omitted or can be replaced by at least one individual feature disclosed at another point in the application. To this extent, claim  1  is merely to be understood as a first attempt at a formulation for an invention. 
         [0078]    As a person skilled in the art will appreciate, the above description is meant as an illustration of implementation of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation, and change, without departing from the spirit of this invention, as defined in the following claims.