Abstract:
A connection device for pipe lines includes a connection element that has a receiving opening for a pipe line and a retainer element that stops the pipe line from being pulled out. The retainer element is designed as a spring-elastic toothed ring that has teeth distributed across a circumference and which extend radially inward at an incline and act against the pipe line. The toothed ring is mounted to have limited axial play. At the transition region between an outer circumferential region and the retainer teeth, the toothed ring interacts with a circumferential tilt edge such that the toothed ring can pivot about the tilt edge out of a position in which its outer circumferential region is pressed against a first, lower contact section and a second, upper contact section. The retainer teeth being able to be elastically deformed by bending.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a connection device for pipelines. 
         [0003]    2. Description of Related Art 
         [0004]    One such connection device is described in document EP 0 616 161 B1. The retaining element of this device is configured as a toothed ring that has a plurality of radial, tooth-like, retaining arms which are connected to each other via peripheral connection sections. This known design should provide that the toothed ring is mounted freely movable with its outer circumferential area inside the connecting element, such that the peripheral connection sections can be elastically deformed, so that each tooth as such is not deformed on insertion of the line end but can swivel around each of the two adjacent peripheral connection sections. This design consequently requires a movable mounting of the toothed ring that ensures freedom of movement in its external circumferential area. This free mobility, however, has the disadvantage that the line end to be inserted must be cut off at the end at an exact right angle, so that there is a uniform contact and deformation of the toothed ring all over the circumference on insertion. A diagonally cut pipe could lead to tilting of the toothed ring because of the undefined freedom of movement and thus to problems on insertion of the pipeline end. 
         [0005]    The publication EP 0 160 559 B1 describes a similar pipe connection device in which a toothed or retention ring is likewise mounted so as to be freely movable in its outer circumferential area. 
         [0006]    Another document, EP 1 199 506 A1, likewise describes such a connection device, wherein, in contrast to the above publications, the retaining element is held with its outer circumference area basically without axial clearance relative to the connecting element viewed in the direction of an insertion axis of the pipeline end, so that an elastic deformation only occurs in the area of the retaining teeth on insertion or removal of the line end. This clearance-free mounting of the outer circumferential area of the retaining element is associated in practice with a very high manufacturing cost. 
         [0007]    All known designs explained above also have the disadvantage that they are only suitable for stable pipelines which can stand the radial retaining forces owing to their intrinsic dimensional stability. 
       SUMMARY 
       [0008]    The underlying object of the present invention is to create a pipe connection device which is characterized by a simple embodiment with improved functional properties in terms of construction and manufacture. 
         [0009]    The above object is attained by various alternative solutions and embodiments contained in the description below. 
         [0010]    It should also be pointed out that the individual features respectively defined in the various embodiments can optionally be provided either as alternatives or in combination with each other. 
         [0011]    Hence, according to the present invention, it is provided that a toothed ring is mounted with its outer circumferential area inside the connecting element with an axially limited freedom of movement defined by the axially opposed contact sections existing on both sides inside the connecting element, wherein the toothed ring interacts at the transition between the outer circumferential area and the retaining teeth with a tilting edge corresponding to the circumference provided inside the connecting element, such that on insertion of the line end via its contact with the retaining teeth the toothed ring can be swiveled around the tilting edge in a seesaw manner from a position pressed with its outer circumferential area against the first lower contact section in the direction of insertion until the outer circumferential area moves on the outer side against the direction of insertion with a minor plastic deformation toward a contact supported at the second axially opposed upper contact section, and an elastic bending deformation subsequently occurs in the area of the retaining teeth protruding radially inward in the area of the tilting edge. Thus, a special deformation of the toothed ring during the insertion is achieved by these measures according to the present invention. On insertion of the line end, the toothed ring, which is mounted axially movable with a defined and limited freedom of movement, is first pressed in the direction of insertion with its outer circumferential area against the first lower contact section inside the connecting element. The outer circumferential area of the toothed ring then lies parallel on the contact section formed by a radial, perpendicular surface relative to the insertion axis, which ends radially inward with the tilting edge. By further inserting the line end, an elastic torsional deformation from the outer to approximately central ring area of the toothed ring then virtually occurs in a first phase because of the tipping via the tilting edge according to the present invention, while an elastic deformation only occurs in the area of the retaining teeth protruding radially inward in the area of the tilting edge because the outer circumferential area is, on the one hand, virtually tensioned externally by a double contact at the second contact section, and, on the other hand, at the transition to the retaining teeth at the tilting edge according to the present invention. Therefore, the retaining teeth radially protruding inward over the tilting edge can basically still deform. Overall, an improved insertion behavior, almost insensitive to unavoidable tolerances is achieved by means of the measures according to the present invention. In addition, the toothed ring can also center itself automatically with respect to the line end because of the defined freedom of movement. Finally, the embodiment according to the present invention is also relatively insensitive to diagonally cut pipeline ends. 
         [0012]    With respect to the second aspect according to the independent claim  12 , a support sleeve is arranged coaxially inside the receiving opening of the connecting element is provided, such that the line end can be slid onto the cylindrical outer surface of the support sleeve on insertion, wherein the support sleeve has a support section in the operating area of the retaining element having a wall thickness configured for the radial support of the line end against the radial retaining force, and wherein the support sleeve axially has a section with a reduced wall thickness at least on one side, in particular, however, on both sides of the support section to enlarge an effective inner flow cross-section. This special embodiment of the support sleeve according to the present invention on the one hand guarantees a good radial support of the line end even against higher radial retaining forces of the retaining element. Thus, the connection device according to the present invention is also suitable for such pipelines, or even hose lines, which are configured with less dimensional stability. On the other hand, good flow characteristics are guaranteed despite the support sleeve, whereby it is especially advantageous to configure the inner circumference of the support sleeve over the entire length like a Venturi nozzle 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The invention will be explained in more detail below by means of a preferred exemplary embodiment illustrated in the drawings. They show: 
           [0014]      FIG. 1  is an axial sectional view of a connection device according to the present invention with an inserted pipeline end, 
           [0015]      FIGS. 2   a - 2   d  are each an enlarged detail of area II in  FIG. 1  in various states during the insertion of the line end, 
           [0016]      FIG. 3  is an exploded view of the connection device seen in  FIG. 1 , wherein the individual components are respectively depicted as a half axial sectional view, 
           [0017]      FIG. 4  is a perspective exploded view of several components of the connection device seen in  FIG. 3 , which in part does not have the same scale, and 
           [0018]      FIG. 5  is a depiction, similar to  FIG. 1 , of an alternative embodiment as an angular joint and without line ends. 
       
    
    
       [0019]    It is noted that the same parts are designated with the same reference numerals in the different figures of the drawings. 
       DETAILED DESCRIPTION 
       [0020]    With respect to the description below, it is expressly pointed out that the invention is not restricted to the exemplary embodiments, and thus not to all or several characteristics of described combinations of characteristics, but each individual partial characteristic of the/of each exemplary embodiment can also be fundamental to the present invention independently of all other partial characteristics described above and in association with the claims, as such or also in combination with any characteristics of another exemplary embodiment. 
         [0021]    According to  FIG. 1 , the connection device  1  embodying the principles of the present invention serves for a quick and preferably detachable connection of a pipeline  2  by simply inserting a line end  2   a  into a receiving opening  4  of a connecting element  6 . The direction of insertion is respectively shown with an arrow X in  FIGS. 1 and 2 . Since no connection mandrel is provided for the attachment of the pipeline  2 , it is possible to speak of a “mandrel-free insertion system”. A retaining element, which is configured as a spring-elastic toothed ring  8 —see, in particular, the depictions in FIGS.  3  and  4 —with an outer circumferential area  8   a  and having a plurality of retaining teeth  8   b  distributed over the circumference extending radially inward and at an angle in the direction of the direction of insertion X relative to the long axis Y and as a result acting frictionally and/or positively in a barb-like manner against the outer circumferential area of the line end  2   a , is mounted inside the receiving opening  4  to lock the inserted line end  2   a  against any extraction. At least one circumferential seal  10  is also mounted inside the connecting element  6 , which outwardly seals a radial annular gap relative to the long axis Y between the line end  2   a  and the connecting element  6 , in order to outwardly seal the inserted pipeline  2 . 
         [0022]    The outer circumferential area  8   a  of the toothed ring  8  lies in a non-deformed state in a plane perpendicular to the long axis Y of the connection device  1 , while the retaining teeth  8   b  jointly lie on a cone because of their tilted position. With their inner retaining edges, the retaining teeth  8   b  define a circle relative to the long axis Y whose diameter is smaller in a non-deformed state than the outer diameter of the pipeline  2 . As a result, the retaining edges act against the outer circumference of the inserted pipeline end  2   a  with a radial retaining force, in particular in a positive or at least frictional manner. 
         [0023]    As is, in particular, apparent from the enlarged depictions in  FIGS. 2   a  to  2   d , according to the present invention, the toothed ring  8  is mounted inside the connecting element  6  with its outer circumferential area  8   a  having a defined limited axial freedom of movement in relation to the long axis Y. This axial freedom of movement is limited inside the connecting element  6  by contact sections  12  and  14  axially opposed on both sides. A first contact section  12  is configured on the “lower” side, ( FIG. 1 ) viewed in the direction of insertion X, by a radial support surface that is perpendicular to the longitudinal axis Y, and a second support section  14  is arranged on the axially opposed “upper” side in the radially outer area of the toothed ring  8 . The contact sections  12  and  14  are axially spaced apart from each other by a clear distance which is greater than the axially measured thickness of the circumferential area  8   a  of the toothed ring. The axial freedom of movement of the toothed ring  8  results from the difference: “distance of the contact sections  12 ,  14  minus the thickness of the circumferential area  8   a  of the toothed ring”. Furthermore, the toothed ring  8  interacts on the angular transition  15  between the outer circumferential area  8   a  and the retaining teeth  8   b  with a circumferential tilting edge  16  provided inside the connecting element  6  on the radial inner circumference of the radial contact area forming the first contact section  12 , such that on insertion of the line end  2   a  via its contact with the retaining teeth  8   b  see  FIG. 2   a  in this respect the toothed ring  8  is swiveled or twisted around the tilting edge  16  in a seesaw manner from an initial position ( FIG. 2   a ) pressed with its outer circumferential edge  8   a  against the first “lower” contact section  12 , until the outer circumferential section  8   a  radially reaches the supported contact with the second axially opposed “upper” contact section  14  on the outer side. The swivel movement of the toothed ring  8  around the tilting edge  16  is illustrated in  FIG. 2   a  by an arrow  18 , and the reached contact position of the outer circumferential area  8   a  thereby attained is depicted in  FIG. 2   b . The outer radial circumference of the circumferential area  8   a  of the toothed ring swiveling in a seesaw manner around the tilting edge  16  consequently protrudes from the first contact section  12  and moves against the second contact section  14 . When, starting from this position, the line end  2   a  is moved further in the direction of insertion X, a bending deformation occurs in the area of the tilting edge  16  of the retaining teeth  8   b  radially protruding inward, see  FIG. 2   c . The insertion procedure is then concluded by retracting the line end  2   a  against the direction of insertion X, see  FIG. 2   d . As a result, the retaining teeth  8   b  positively or at least frictionally intersect the outer circumference of the line end  2   a.    
         [0024]    In addition, or also alternatively, to the embodiment according to the present invention described above, a support sleeve  20  is arranged inside the receiving opening  4  of the connecting element  6  coaxially to the long axis Y, such that the line end  2   a  can be slid onto a cylindrical outer surface  22  of the support sleeve  20  on insertion, also see  FIGS. 3 and 4 . As a result, the inserted line end  2   a  is radially supported by the support sleeve  20 , so that when a radial retaining force generated by the toothed ring  8  is applied, deformations of the pipeline  2  are avoided in the operating area of the toothed ring  8 . In this case, according to the present invention, it is provided that the support sleeve  20  has a support section  24  in the operating area of the toothed ring  8 , wherein this support section  24  has a radially measured wall thickness Dl (see  FIGS. 1 and 3 ) which, taking into consideration the properties of the material of the support sleeve  20 , is designed such that the pipeline  2  is supported without radial deformation against the retaining forces occurring in the practice. The present invention further provides that the support sleeve  20  axially has a section with a reduced wall thickness D1 at least on one side, preferably, however, on both sides, of the support section  24 , a sleeve section  26  and/or  28  with a reduced wall thickness D2 compared to wall thickness D1 to enlarge an effective inner flow cross-section. In the process, the inner circumferential area of the support section  24  and the adjacent sleeve sections  26 ,  28  preferably constantly merge into each other via the transition sections  30  such that the support sleeve  20  has an inner contour of the Venturi nozzle type. In this respect, reference is made to  FIGS. 1 and 3 . Compared to the wall thickness D2, the radially measured wall thickness D1 is greater by at least 0.3 mm to a maximum 0.6 mm. 
         [0025]    On its free front end penetrating into the line end  2   a  the support sleeve  20  has an outer tilted insertion area  32 , e.g. like a chamfer. In addition, the support sleeve  20  has a stop  34  on its area opposite the free front end held in the connecting element  6  as an insertion limit for the inserted or attached line end  2   a . In an advantageous embodiment, the stop  34  has a conical contact area  36  for the line end  2   a . This conical contact area  36  encompasses a cone angle a (see  FIG. 1 ) with a radial plane perpendicular to the longitudinal axis Y in the range of 5° to 15° and in particular about 10°. This embodiment guarantees an automatic compensation of diagonally cut pipelines  2  which can thus be cut at an angle of up to 15°, which can, in particular, be compensated up to 10° by the preferred embodiment. 
         [0026]    To mount the support sleeve  20  inside the connecting element  6  the support sleeve  20  has a cylindrical insertion section  38  which is inserted fitting into an inner receptacle  40  of the connecting element  6 . In this case the stop  34  also functions as an insertion limit for the support sleeve  20 . 
         [0027]    In another advantageous embodiment of the connection device  1  according to the present invention, it is provided that the connecting element  6  has a housing axially divided in two parts with respect to the longitudinal axis Y, with a first, support-like housing part  42  pointing in the direction of insertion and a second, sleeve-like housing part  44  forming an outlet side of the receiving opening  4 . The housing part  42  can be configured at will, e.g. as a distributor with a different number of outlets, a straight pass-through connector ( FIG. 1 ), as well as an angular connector according to  FIG. 5 , or as an L, T or Y connector. The two housing parts  42 ,  44  are preferably connected to each other via a circumferentially closed snap-on connection  46 , see in particular  FIG. 1 . For this purpose, in the depicted, preferred embodiment, the first housing part  42  engages axially and radially in a positive manner with an insertion section  48  in an inner groove-like locking recess  50  of the second housing part  44 . The housing parts  42 ,  44  also interact in sections with a press-fit in order to guarantee a gap seal, in particular, as a dirt seal. The first housing part  42  can be configured as a screw-in socket with an outer thread attachment  52 . 
         [0028]    The tilting edge  16  for the toothed ring  8  described above can advantageously be configured with an insert ring  54  which preferably also has the first contact section  12  in the form of an end face adjacent radially outward to the tilting edge  16  and perpendicularly to the longitudinal axis Y. The tilting edge  16  is thus configured at the transition between the end face forming the first support section  12  and an inward adjacent conical area  56 , in particular, also see  FIG. 4 . 
         [0029]    The insert ring  54  is, in particular, inserted into the connecting element  6  with the press-fit, that is, preferably into its first housing part  42 . In this case, it is also advantageously provided that the insert ring  54  inside the connecting element  6  delimits a sealing chamber  62  for the circumferential pipe seal  10  with a front face  58  pointing in the direction of insertion together with a flank area  60  of the connecting element  6  that is axially opposite it, or with the first housing part  42 . The circumferential seal  10  preferably is an O-ring which preferentially consists of EPDM (ethylene-propylene-diene-monomer) or NBR (nitrile butadiene rubber=nitrile rubber) used in pressurized air pipelines and used for fuel pipelines made of a fluoroelastomer, which is available, e.g. under the trademark VITON, or silicone. 
         [0030]    The insert ring  54  advantageously decouples the installation space for the retaining element  8  on the one hand, and the sealing element  10  on the other hand. Especially in combination with the support sleeve  20 , eccentricities and ovalities of the pipeline  2  are avoided or compensated in the area between sealing and retaining The insert ring  54  preferably consists of plastic, especially POM without fiberglass reinforcement, PBT or PA6.6, if applicable, with a 30% fiberglass content. Alternatively, the insert ring  54  can consist of metal, especially aluminum. 
         [0031]    The second upper contact section  14  for the outer circumferential area  8   a  of the toothed ring  8  described above is preferably also formed on a ring-shaped insert element  64 , which, according to  FIG. 1 , is supported inside the connecting element  6 , that is, in particular, inside the second housing part  44  in the direction of the pipe detachment, on a retaining annular projection  66  protruding radially inward. In this connection, the second contact section  14  is formed by an end face of an axially protruding annular projection  68  of the support element  64 , wherein this annular projection  68  preferably engages in the first housing part  42  or in its insert section  48 . A press-fit to seal the gap can be provided as a dirt seal in this area between the housing part  42 ,  44  and the insert element  64 . 
         [0032]    A sleeve-shaped release element  70  is advantageously provided to release the inserted pipeline  2  locked via the toothed ring  8 . This release element  70  engages in an axially displaceable manner in the connecting element  6  such that by inserting the release element  70  in the insertion direction X, the toothed ring  8  can be elastically deformed to release the line end  2   a  in the area of the retaining teeth  8   b . To that end, the release element  70  acts against the retaining teeth  8   b  with the actuation sections  72 . In this regard, reference is, in particular, made to  FIG. 2   d ; when, starting from the locked position shown there, the release element  70  is moved downward in the direction of insertion X, the actuation sections  72  act against the retaining teeth  8   b  so that they are radially deformed outward, i.e. are spread and thus release the line end  2   a  for removal. 
         [0033]    The release element  70  is preferably kept from disassembling inside the connecting element  6  via a lock  74 . On its end pointing in the direction of insertion X, the release element  70  further has latching arms  76  formed by axial slits, which engage with retaining lugs pointing radially outward behind a radial step surface  78  (see  FIG. 1 ) inside the connecting element  6 , wherein this step surface  78  is advantageously formed on the insert element  64  (also see  FIG. 3 ). In another advantageous embodiment, the latching arms  76  are circumferentially connected to the remaining closed ring part of the release element  70  via hinge-like constrictions  80 , as a result of which the radial mobility of the latching arms  76  is favored. 
         [0034]    Furthermore, the release element  70  on the one side has an outer circumferential seal  82  and on the other side an inner circumferential seal  84 . The outer circumferential seal  82  serves to seal an annular gap between the sleeve-shaped release element  70  and the connecting element  6  or its second housing part  44 . The inner circumferential seal  84  seals an annular gap toward the line end  2   a . In a preferred embodiment, the outer circumferential seal  82  also functions as a spring element to produce an axial restoring force for the release element  70 . For that purpose, the circumferential seal  82  acts against an inner, conically narrowing counter-surface  86  inside the connecting element  6  or the second housing part  44 . The force to deform the outer circumferential seal  82  is at least equal or greater than the insertion force of the pipeline  2  through the inner circumferential seal  84 , so that the release element  70  remains in position on the insertion of the pipeline  2 , and thus does not change to the release position. The outer circumferential seal  82  is deformed more than the inner circumferential seal  84  on actuation of the release element  70  by means of a special grooved contour. As a result, the restoring force arises because of the outer circumferential seal  82 . This spring effect can also be achieved by means of the properties of the material of the circumferential seals  82 ,  84 . In this respect, the IRHD (“International Rubber Hardness Degree”) of the outer circumferential seal  82  is at least equal or greater than the IRHD of the inner circumferential seal  84 . 
         [0035]    In the shown preferred embodiment a washer-shaped, cover-like, locking element  88  is provided to close a remaining, ring-shaped, partial opening of the receiving opening  4  encompassing the inserted pipeline  2  on the outlet side. According to  FIG. 1 , this locking element  88  also closes the area of the inner circumferential seal  84 . As a result of this, the inner circumferential seal  84  can be inserted more easily into the release element  70 , since there is no indentation in this area of the release element  70 . Protection against a vapor stream is also attained by means of the locking element  88 . In addition, the locking element  88  can also have at least one projection, which is not shown, protruding axially outward as a handle for the manual actuation of the release element  70 . 
         [0036]    Finally, it should be mentioned with reference to the illustration in  FIG. 4  that the toothed ring  8  preferably configured as a stamped bent part of spring steel sheet is divided in its outer circumferential area  8   a  into a plurality of connection sections  92  connecting the retaining teeth  8   b  via recesses  90  radially opposite the retaining teeth  8   b , i.e. adjacent radially outside to the retaining teeth  8   b . These connection sections  92  are jointly in a plane perpendicular to the Y axis. As is apparent from  FIG. 4 , this preferred embodiment in a top view results in a meander-like zigzag course in the circumferential direction with the respectively alternating retaining teeth  8   b  and the connection sections  92  connecting them. 
         [0037]    The invention has not been limited to the depicted and described exemplary embodiments but also includes all embodiments having the same effect within the meaning of the invention. It is expressly pointed out that the exemplary embodiments have not been limited to all combined characteristics, in fact, each individual partial characteristic can also be fundamental to the present invention independently of all other partial characteristics as such. Furthermore, the invention has not been limited to the combination of characteristics defined in the respective independent claim but can also be defined by any other combination of specific characteristics of all disclosed individual characteristics. This means that basically each individual characteristic of the respective independent claim may virtually be omitted and/or replaced by at least one individual characteristic disclosed at another point of the application. To this extent, the claims are to be merely understood as a first attempt at formulating the invention.