Abstract:
A fluid line coupling includes a receiving part and a locking part connectable to the receiving part. The locking part includes a plurality of elastically resilient spring tongues engageable behind an annular collar formed on a plug-in part that is insertable into the receiving part. A securing part includes a plurality of elongate securing arms. Guide elements are formed on the securing part and the receiving part that are engagable with one another to displace the securing part in relation to the receiving part. In a securing position of the securing part, each securing arm bears against a respective associated spring tongue and prevents the spring tongue from deflecting outwardly. In this manner, the plug-in part is secured by a very high pull-out force against being pulled out of the receiving part.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a U.S. National Phase Patent Application based on International Application Serial No. PCT/EP2008/003746 filed May 9, 2008, the disclosure of which is hereby explicitly incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to a fluid line coupling. 
     2. Description of the Related Art 
     One known fluid line coupling is disclosed in DE 196 19 026 A1, which has a receiving part and a locking part that is connectable to the receiving part. Formed on the locking part is a number of elastically resilient spring tongues that are adapted to engage behind an annular collar formed on a plug-in part that is to be inserted into the receiving part, so as to hold the plug-in part, in this case, non-releasably in the receiving part. 
     SUMMARY OF THE INVENTION 
     The present invention provides a fluid line coupling which, particularly in the case of a releasable connection between the receiving part and the plug-in part, is distinguished by requiring a very high pull-out force to withdraw the plug-in part from the receiving part when the spring tongues are engaged behind the annular collar. 
     By virtue of the fact that the fluid line coupling according to the invention comprises a securing part which is displaceable in relation to the receiving part, and which, in a securing position involving the cooperation of spring tongues formed on the receiving part and securing arms formed on the securing part, prevents or at least inhibits outward movement of said spring tongues, in the securing position of the securing part the spring tongues cannot move outward without other agency, and remain reliably in the rearwardly engaged position, even under high pull-out forces. 
     In one form thereof, the present invention provides a fluid line coupling including a receiving part and a locking part, which is connectable to the receiving part and on which is formed a number of elastically resilient spring tongues that are adapted to engage behind an annular collar formed on a plug-in part that is to be inserted into the receiving part, characterized in that also provided is a securing part, on which is formed a number, corresponding to the number of the spring tongues, of elongate securing arms, in that formed on the securing part and on the receiving part are guide means that are in engagement with one another for purposes of displacing the securing part in relation to the receiving part, and in that in a securing position of the securing part, each securing arm bears at the outside against a respective associated spring tongue. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is an exploded perspective view of an exemplary embodiment of a fluid line coupling according to the invention, comprising a receiving part and a securing part; 
         FIG. 2  is a perspective view of the exemplary embodiment according to  FIG. 1  with the securing part in a releasing position; 
         FIG. 3  is a longitudinal section of the exemplary embodiment according to  FIG. 1  in the releasing position according to  FIG. 2 ; and 
         FIG. 4  is a longitudinal section of the exemplary embodiment according to  FIG. 1  with the securing part in a securing position. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
     DETAILED DESCRIPTION 
       FIG. 1  is an exploded perspective view of an exemplary embodiment of a fluid line coupling according to the invention, comprising a receiving part  1  made of a hard-elastic synthetic material and having a hollow-cylindrical receiving body  2  and a connecting member  3  adjoined to said receiving body  2 . 
     Formed on receiving body  2  at the end remote from connecting member  3  are two mutually oppositely disposed, shell-shaped end shells  4 , which extend away from connecting member  3  in the longitudinal direction of receiving body  2 , and each of which has a respective latching tongue receiving clearance  5 . Formed between the peripherally confronting edge faces of the end shells  4  in each case is a respective spring tongue receiving space  6 , said spring tongue receiving spaces  6  being disposed diametrically opposite each other. In addition, formed on the receiving body  2  in prolongation of each of the two spring tongue receiving spaces  6  in the longitudinal direction is a respective pair of mutually oppositely disposed, elongate edge rails  7  that extend in the longitudinal direction of receiving part  1  and serve as guide means for the receiving part  1 , and each of which, by an overhanging portion, covers a surface region of the receiving part  1 , and between which is formed a guide bar receiving space  8 . 
     In the exemplary embodiment illustrated in  FIG. 1 , adjoined to the connecting member  3  are two pipe unions  9 , which are mutually aligned and extend in opposite directions, and to which the ends of fluid lines not shown in  FIG. 1  can be connected. It can further be seen from  FIG. 1  that formed on connecting member  3  in the end region remote from receiving body  2 , in prolongation of the spring tongue receiving spaces  6  and of the guide bar receiving spaces  8 , are two diametrically oppositely disposed holding slots  10 , as holding means for the receiving part  1 . 
     The fluid line coupling in the exemplary embodiment according to  FIG. 1  is further provided with a sealing assembly  11 , comprising a first soft-elastic sealing ring  12 , a second soft-elastic sealing ring  13 , and a hard-elastic intermediate ring  14  disposed between sealing rings  12 ,  13 . Sealing rings  12 ,  13  and intermediate ring  14  are insertable into the receiving body  2 . 
     The fluid line coupling according to the exemplary embodiment of  FIG. 1  is further equipped with a locking part  15  made of a hard-elastic synthetic material and having an annular body  16 . Formed on the annular body  16  are, on the one hand, two diametrically oppositely disposed latching tongues  17  that are insertable into the latching tongue receiving clearances  5 , and, on the other hand, between the latching tongues  17 , two also diametrically oppositely disposed spring tongues  18 , which are insertable into the spring tongue receiving clearances  6 , it being the case that in respective idle position, the latching tongues  17  and the spring tongues  18  extend on one side of the annular body  16  and protrude obliquely radially outward beyond said annular body  16 . Formed on the free ends of each spring tongue  18  is a respective radially inwardly projecting locking projection  19 . 
     The fluid line coupling according to the invention further comprises a securing part  20  made of a hard-elastic synthetic material and, in the exemplary embodiment according to  FIG. 1 , having a flat end plate  21 . Formed on the end plate  21  are diametrically oppositely disposed, elongate securing arms  22  that extend in a direction away from the end plate  21 . In the described exemplary embodiment, the end plate  21  has a central connecting-member clearance  23  and projects radially beyond the securing arms  22 . 
     Each securing arm  22  is configured outwardly, at its end directed away from end plate  21 , with a centrally disposed, raised guide bar  24  and, on each side of each guide bar  24 , a respective edge strip  25  that is thinner than the guide bar  24  and serves as a guide means for the securing part  20 . 
     Each securing arm  22  further comprises, on its side facing the end plate  21 , a respective resilient holding tongue  26 , which extends toward the end plate  21  and each of which has at its free end facing the end plate  21  a respective holding projection  27 , each of which extends radially inward toward the other. 
     Finally, depicted in  FIG. 1  is an elongate, substantially cylindrical plug-in part  28 , which bears a circumferentially raised annular collar  29  and is to be inserted, by an insertion shaft  30  that is tapered at the end, into the receiving body  2  of the receiving part  1 , in order to establish a connection between a fluid line (not shown in  FIG. 1 ) connected to the pipe unions  9  and a fluid line (also not shown in  FIG. 1 ) connected to the plug-in part  28 . 
       FIG. 2  is a perspective view of the exemplary embodiment according to  FIG. 1  in the assembled arrangement of receiving part  1 , sealing assembly  11 , which in the representation according to  FIG. 2  is enclosed by the receiving part  1  and thus cannot be seen, locking part  15  embraced by the end shells  4 , securing part  20  pushed onto the receiving part  1 , and plug-in part  28  pushed into the receiving part  1 , with the securing part in a releasing position in which the securing arms  22  have been pushed so far between the in each case mutually oppositely disposed edge rails  7  that the ends of the securing arms  22  directed away from the end plate  21  are disposed near the spring tongues  18 , but insofar as possible without touching them, or, at the very most, pressing them radially inward far enough so that the annular collar  29  can get past the locking projections  19  substantially unhindered. It is further evident from  FIG. 2  that the edge strips  25  are covered by the overhanging portions of the edge rails  7  and the guide bars  24  are disposed in the guide bar receiving spaces  8 , in order to ensure satisfactory guidance and, in particular, the seating of the securing arms  22  of securing part  20  on the receiving part  1  in a manner that is, in particular, resistant to bending. 
       FIG. 3  is a longitudinal section of the exemplary embodiment according to  FIG. 1  in the releasing position according to  FIG. 2 . It can be seen from  FIG. 3  that the edge rails  7  extend all the way to the locking part  15 , and the securing arms  22 , in the releasing position, preferably run right up against the spring tongues  18 , which are splayed radially obliquely outward in a relaxed, idle position, but without moving them radially inward, such that when the plug-in part  28  is inserted into the receiving part  1 , the annular collar  29  can get past the locking projections  19  without contact or at least substantially unhindered. 
     It can further be appreciated from  FIG. 3  that the holding projections  27  each have a relatively shallowly pitched pushing-on flank  31  that is oriented toward the securing arms  22 , and a relatively steeply pitched pulling-off flank  32  that is oriented away from the securing arms  22 . It is further evident from  FIG. 3  that in this exemplary embodiment the holding projections  27 , in the releasing position, are disposed a given distance from the connecting member  3 , such that the securing part  20  is freely displaceable relative to the receiving part  1  and can be pulled off the receiving part  1  if necessary. 
       FIG. 4  is a longitudinal section of the exemplary embodiment according to  FIG. 1  with the securing part  20  in a securing position that is pushed forward compared to the releasing position of  FIGS. 2 and 3 , and in which, by contrast to the releasing position of  FIGS. 2 and 3 , the securing part  20  has been pushed so far onto the receiving part  1  that the connecting member  3  is disposed in the connecting member clearance  23 , and, to obtain high bending stiffness, the securing arms  22  protrude by only a relatively short segment from the far-advanced edge rails  7 , and bear against the outer faces of the spring tongues  18  and have pressed them radially inward so far that the locking projections  19  engage behind the annular collar  29  and the radially inward-facing end faces bear against the plug-in part  28 . In addition, in the securing position in this exemplary embodiment, the end faces of the ends of the securing arms  22  that are directed away from the end plate  21  bear against terminal bumps  33 , serving as stops, which are formed on the free ends of the spring tongues  18  and protrude radially outward beyond the spring tongues  18 . 
     It can further be appreciated from  FIG. 4  that during the changeover from the releasing position according to  FIGS. 2 and 3  to the securing position according to  FIG. 4 , after the pushing-on flanks  31  have been made to ride up onto the receiving body  3  by a relatively small expenditure of force, the holding projections  27  are disposed in the holding slots  10 , thereby securing the securing part  20  against accidental movement out of the securing position. Only by deliberate action on the end plate  21 , with a relatively high expenditure of force in order to overcome a holding resistance presented by the rigid pull-off faces  32 , can the securing part  20  be withdrawn from the receiving part  1  in order to re-release the plug-in part  28  after canceling the rearward engagement of the locking projections  19  by deflecting the spring tongues  18  radially outward. The plug-in part  28  thus is secured by a very high pull-out force against being pulled out of the receiving part  1 . 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.